ARTICLE | doi:10.20944/preprints202012.0294.v1
Subject: Engineering, Automotive Engineering Keywords: construction and demolition waste; renovation; demolition; waste disposal; pre-renovation audit; waste audit; construction; comparison; costs
Online: 11 December 2020 (16:20:49 CET)
The issue of sustainability has long been the subject of interest of the architecture engineering and construction sector. All three aspects of sustainability - economic, environmental and social - can be affected through appropriate construction waste management. Construction and demolition waste (CDW) is one of the largest worldwide waste streams, therefore it is given great attention by all stakeholders (investors, contractors, authorities, etc.). Researches have shown that one of the main barriers to insufficiency CDW recovery is inadequate policies and legal frameworks to manage CDW. It is also one of the EU's environmental priorities. Aim of the article is to confirm the economic potential of construction and demolition waste audit processing through case study. A pre-demolition waste audit has been processed for unused building of shopping center in the town Snina in Slovakia. Subsequently, a comparison of economic parameters (waste disposal costs and transport costs) of recommended CDW management was performed. This comparison confirmed the economic benefits of environmentally friendly construction waste management methods according to the waste audit results, which will also increase the sustainability of construction projects. In addition, the cost parameters of selected waste disposal methods could be another dimension of building information modelling.
CONCEPT PAPER | doi:10.20944/preprints202105.0740.v1
Online: 31 May 2021 (11:01:15 CEST)
Highlights: A new material with a bending strength higher than that of concrete was developed using vegetable or fruit waste. The new material maintains the color, taste, and flavor of the original vegetable or fruit. Without water resistant treatment, the material is edible and can be conditioned with seasonings
Subject: Engineering, Civil Engineering Keywords: waste management; civil construction waste; sustainability
Online: 27 October 2019 (10:26:32 CET)
Given the importance of the development of urban infrastructure and environmental impacts produced by the civil construction waste (CCW), it is important to correct the handling of CCW with objective solutions that are more environmentally friendly. In that sense the present study aimed to determine indicators that make it possible to estimate the amount of CCW generated from construction sites in the city of Londrina, Parana State, Brazil. The generation of CCW was estimated in a general way, regarding the composition of its mixture, correlated to the gross areas of the buildings studied and their generated volumes of RCC. This generating rate was evaluated in a general way and specifies two types of sites: the new residential and new non-residential constructions. The data required for the development of these indicators was obtained through extensive survey and interviews carried out at the environment secretariat of the City Hall. The generating rate of CCW obtained for non-residential buildings was 0.2052m3/m2 or 170.44kg/m2, for new residential sites was 0.2054m3/m2 or 170.60kg/m2 and for new commercial or non-residential construction sites, it was 0.20453 m3/m2 or 169.85kg/m2. It was also possible to estimate the amount generated annually per inhabitant in the municipality, which is 0.60m3/inhabit.year or 498.55kg/inhabit.year.
ARTICLE | doi:10.20944/preprints202107.0409.v1
Subject: Engineering, Automotive Engineering Keywords: Effective Construction; Waste Reduction; achieving Sustainable Development Goals; partial least square structural equation modeling (PLS-SEM)
Online: 19 July 2021 (12:11:42 CEST)
As a result of rapid population growth, an exponentially growing human population, and industrial expansion, it has become increasingly difficult to manage municipal solid wastes throughout the world. Decentralized waste management systems have created difficult situations in developing countries such as Malaysia. Wastes generated in the country, due to various cultural, social, and religious activities, organic and contributing to environmental pollution (air, water, and soil) and human health troubles. A questionnaire survey was participated by 220 construction professionals in Malaysia using structured and semi-structured methods. The framework was assessed using A partial least square structural equation modeling (PLS-SEM) to target sustainable development goals (SDG). Statistical analysis results indicate a significant effect between SCW management, since(r(270)=.687, P<0.001). Improving factors has strong relationship with SCW management, since(r(270)=.723, P<0.001). The mediation results also suggested a significant indirect positive effect of improving factors drivers on SCW management through policy-related factors sinceβ=0.688, t=8.254, P<0.001, 95% CI for β=0.536,0.866. Finally, policy-related factors construct has a strong relationship with SCWM) management, since(r(270)=.811, P<0.001) With the R Square of 0.787 and 0.785. The developed framework can improve construction waste management in the construction industry and enhance construction waste management to achieve global sustainable development goals. The findings show that one of the most critical issues of enhancing profitability is using preventive policies to reduce construction waste. This study could guide construction industry stakeholders in identifying the different waste management features during a building project's construction and design stage
ARTICLE | doi:10.20944/preprints202004.0451.v1
Subject: Engineering, Civil Engineering Keywords: Construction and Demolition Waste; recycled aggregate; structural concrete; absorption coefficient; graded aggregate; soil, base layer
Online: 24 April 2020 (14:20:23 CEST)
Construction and demolition waste (CDW) represents 1/3 of the weight of all-waste produced. Increasing their recycling and reutilization with recycled aggregates (RA) means closing the life cycle of construction materials. Research has been carried out on artificial aggregates from the exclusive crushing of structural concrete waste in selective demolitions (CDWRConc). This study analyses the use of recycled concrete as graded aggregate (GARConc) and in cement soil (CSRConc). The material complies with the requirements as a road base, although due to the low values of resistance to fragmentation these materials are adequate for use in sensitive road systems and other places such as urban roads and car parks. The sensitive road systems are infrastructures in places of great natural wealth and low traffic intensity, with an annual average of heavy vehicle traffic (AADTh) below 50 vhp/d. As soluble salt contents have been detected, additional waterproofing or drainage measures must be adopted to prevent water infiltration into the layers made up of CDWRHorm. Finally, the high initial values of UCS allow the temporary passage of light vehicles over CSRConc after 3 days.
REVIEW | doi:10.20944/preprints202205.0009.v1
Subject: Engineering, Other Keywords: mineral waste; bio-base waste; natural fiber; biomass; sulfur waste; copper flotation; fly ash; biochar; sustainable construction
Online: 4 May 2022 (13:12:11 CEST)
The new climate law introduces a policy of sustainable construction, the assumption of which is the reduction of CO2 by the construction industry and the use of environmentally friendly materials, such as agricultural, mineral, and recycled waste, while limiting the consumption of natural resources. The article is a literature review that analyzes selected waste materials from various sectors of the economy that can be used as additives or partial substitutes for natural resources in the production of cement and in and cement building materials, the production of which reduces CO2 emissions, producing materials with high mechanical strength and environmentally friendly.
ARTICLE | doi:10.20944/preprints202103.0286.v1
Subject: Engineering, Civil Engineering Keywords: Frame Construction; Multiple Buildings; Construction Period; Uncertainty Factors; Queue Model
Online: 10 March 2021 (13:24:10 CET)
The frame construction of an apartment complex that consists of multiple buildings encounters various uncertainties, owing to the complex relationships among units of work. Currently, the period of such a construction is calculated based on the number of floors of the highest building in the complex. This study quantitatively analyzes an apartment frame construction period using a queue model and evaluates the validity of the estimated period. In this regard, a methodology is proposed for analyzing the construction period by applying the concept of a customer and a server. A case study on the duration of an apartment frame construction is conducted with Korea Land and Housing Corporation, which has supplied the largest number of apartments in South Korea. It was found that the stable state of a queue system was observed when the rate of server utilization was applied to the basement and aboveground floors. However, a stable state was not reached on the ground floor. This study includes non-working days in its calculation and quantitatively analyzes uncertainty factors during construction. Therefore, the findings can be practically utilized to quantitatively plan the durations of work units in an apartment frame construction.
ARTICLE | doi:10.20944/preprints201804.0371.v1
Subject: Engineering, Civil Engineering Keywords: economic regions; regional classification; classification methodology; construction industry; cluster analysis; accidents in construction
Online: 28 April 2018 (12:14:29 CEST)
The article presents the methodology for classifying economic regions with regards to selected factors that characterize a region, such as: the economic structure of the region, and thus the share of individual sectors in the economy; employment; the dynamics of the development of individual sectors expressed as an increase or decrease in production value; the population density in the region and also the level of occupational safety. Cluster analysis, which is a method of multidimensional statistical analysis available in Statistica software, was used to solve the task. The proposed methodology was used to group Polish voivodships with regards to the speed of economic development and occupational safety in the construction industry. Data published by the Central Statistical Office was used for this purpose, such as the value of construction and assembly production, the number of people employed in the construction industry, the population of an individual region and the number of people injured in occupational accidents.
ARTICLE | doi:10.20944/preprints202003.0162.v1
Online: 10 March 2020 (10:26:12 CET)
This publicly available simulation analysis compares baseline construction options versus sustainable options and evaluates both break-even costs as well as environmental effects. The simulation (https://rminator.shinyapps.io/sustain4/) provides users with comparative estimates based upon existing research on costs. This is the first simulation of its type that quantifies multiple sustainable construction options, associated break-even points, and environmental considerations for public use. Results estimate that a 100% solar solution for the baseline 3,000 square foot / 279 square meter house with 2 occupants results in a break-even of 9 years. The simulation includes options for rainwater harvesting or wells, Icynene foam, engineered lumber, Energy Star windows and doors, low flow water fixtures, aerobic / non-aerobic waste treatment or municipal services, and many other options. This is the first simulation of its type to provide publicly available sustainable construction analysis based on research, and it illustrates that sustainable construction might be both green for the environment and green for the pocketbook.
ARTICLE | doi:10.20944/preprints202111.0053.v1
Subject: Engineering, Civil Engineering Keywords: Building Information Modelling; Construction safety; Planning; Safety Elements; Construction Site Management; Falls from height.
Online: 2 November 2021 (22:23:31 CET)
As is known, the construction industry has one of the highest occupational accidents incidence rates among all economic sectors. Currently, Building Information Modeling (BIM) appears as a tool that addresses occupational safety issues throughout the construction life cycle projects, avoiding hazards and risks and, consequently, increasing safety. This work investigates BIM methodology and related technologies application for building safety planning in construction and demonstrates the potential of this technology for the integrated implementation of safety measures during the design phase and the construction site management. The first step consisted of a literature review on the application of BIM in safety in the design and planning phases. Following, to show the potentialities of construction simulation, a case study based on BIM 4D to prevent falls from height was developed. With BIM 4D, it is possible to follow the construction process over time, giving the construction safety technicians’, designers, supervisors and managers the capability to analyse, in each phase, the potential risks and which safety measures should be implemented. BIM can effectively integrate safety measures from the design phase to the construction and use phase and do integrated safety planning within construction planning, leading to reliable safety management throughout the construction process.
REVIEW | doi:10.20944/preprints202112.0168.v1
Subject: Engineering, Construction Keywords: offsite construction; housing associations; strategic management
Online: 10 December 2021 (09:02:12 CET)
Offsite construction is increasingly being presented as a way to increase housing delivery and reduce the housing crisis. Housing Associations play a pivotal role in the delivery of affordable homes and therefore offsite construction could be beneficial in alleviating the crisis. For offsite construction uptake to increase, the conceptual and pragmatic advantages and challenges surrounding offsite housing in relation to evolving social domestic needs to be explored and understood. The purpose of this paper is to discuss the viability of offsite construction as not only a full-service solution to social housing provision, but an integral strategic partner for meeting the range of specialised fabrication needs for these new properties. A literature review is carried out to explore the conceptual and pragmatic advantages and challenges encountered by HAs adopting offsite construction methods. The paper also investigates which the housing tenures are most suited to offsite construction technology. The paper highlighted that whilst individual case studies and example homes offer one mode of justification for Housing Associations to move forward, it is the cumulative effect of cost savings, sustainability, specialised skill sets, labour reduction, structural innovation, and rate of construction that should be weighed and incorporated into this consideration-making process.
ARTICLE | doi:10.20944/preprints201703.0189.v1
Subject: Engineering, Civil Engineering Keywords: construction industrialization; dimensions; index system; evaluation
Online: 24 March 2017 (11:21:31 CET)
In recent years, there have been concerns raised about construction industrialization in China, which have initiated a wave of policy change in both governmental and industrial organizations in order to change the mode of conventional construction. However, the current development level of regional construction industrialization (RCI) in China has not been well-characterized. This study screened preliminary index systems in five dimensions: technical, economic, sustainable, enterprise development and development environment. Based on the data gathered from the questionnaire surveys and subsequently analyzed, twenty-two critical evaluation indicators were identified. Analytic Hierarchy Process (AHP) was then employed to determine the weighting of each indicator. The evaluation method of the development level was formulated on the basis of the evaluation criteria. Jiangsu Province was used as an example in this study, with the development level of this province being comprehensively examined using a combination of the index system and evaluation method. The results show that Jiangsu has a relatively high RCI development level. The data from analysis scores of five dimensions and twenty-two indicators show that the index system is feasible, with evaluation results being consistent with actual practice. These findings provide a good practical reference for making decisions about how best to guide the development of RCI.
ARTICLE | doi:10.20944/preprints202207.0313.v1
Subject: Engineering, Construction Keywords: engineering procurement and construction project (EPC); project management; design changes; infrastructure development projects; construction management; New Zealand
Online: 21 July 2022 (08:06:44 CEST)
Design changes seem inevitable in engineering, procurement and construction EPC projects. Such changes create a need for a proactive approach to adjusting project scope, cost and time (the triple constraints) for efficiency and effectiveness in overall delivery. This study investigates the causes and implications of design changes in order to improve design change management practices. Data for the study was obtained through online interviews with New Zealand industry practitioners. Thematic analysis was used to collate the results into meaningful data. The study found that design changes were predominantly caused by clients' inadequate strategic planning, insufficient attention to design, EPC contractors' inadequate design ability, and on-site variations. There were three categories of such design changes: direct impact on the project, the reciprocal and complementary effect on stakeholders, and the far-reaching impact on the community. The study concludes by suggesting improvements, such as strengthening the integration of project teams to enhance design quality, strategic alignment of stakeholders at the planning stage, early contractor involvement (ECI) between the planning and design phases, and improving collaboration between design and construction teams. Further, a combination of high technical skills (e.g. design ability) and soft skills (can-do attitude, interpersonal skills, problem-solving skills, documentation skills, etc.) are needed to effect the desired improvement in design change management.
ARTICLE | doi:10.20944/preprints202105.0737.v1
Subject: Engineering, Automotive Engineering Keywords: double-skin facade perforation; environmental design; robotics in construction; VR/AR for monitoring; digital twin in construction
Online: 31 May 2021 (10:42:05 CEST)
In contemporary design practices, there is a disconnect between the design techniques used for early-stage design experimentation and performance analysis, and those used for the manufacture and construction. This study addresses the problems in developing an integrated digital design workflow and provides a research framework for integrating environmental performance requirements with robotic manufacturing processes on a construction site. The proposed method enables the user to import a design surface, identify design parameters, set several environmental performance goals, and thereafter simulate and select a robotic building strategy. Based on these inputs, design alternatives are developed and evaluated, considering their robotically simulated constructibility, in terms of their performance criteria. To validate the proposed method, the design is evaluated in an experiment wherein a double-skin facade perforation is generated using the proposed methodology. The results suggest a heuristic feature to improve the simulated robotic constructibility. Moreover, the functionality of the prototype is demonstrated.
ARTICLE | doi:10.20944/preprints202105.0086.v1
Subject: Keywords: double-skin facade perforation, environmental design, robotics in construction, VR/AR for monitoring, digital twin in construction.
Online: 6 May 2021 (13:11:51 CEST)
In contemporary design practices, there is a disconnect between the design techniques used for early-stage design experimentation and performance analysis, and those used for the manufacture and construction. This study addresses the problems in developing an integrated digital design workflow and provides a research framework for integrating environmental performance requirements with robotic manufacturing processes on a construction site. The proposed method enables the user to import a design surface, identify design parameters, set several environmental performance goals, and thereafter simulate and select a robotic building strategy. Based on these inputs, design alternatives are developed and evaluated, considering their robotically simulated constructibility, in terms of their performance criteria. To validate the proposed method, the design is evaluated in an experiment wherein a double-skin facade perforation is generated using the proposed methodology. Initial results suggest a heuristic feature to improve the simulated robotic constructibility. Moreover, the functionality of the prototype is demonstrated.
REVIEW | doi:10.20944/preprints202207.0010.v3
Subject: Engineering, Other Keywords: beneficiation; slag; flotation; construction material; soil remediation
Online: 12 August 2022 (06:20:08 CEST)
Mining is an important industry, accounting for 6.9% of global GDP. However, global development promotes accelerated demand, resulting in the accumulation of hazardous waste in land, sea, and air environments. It reached 7 billion tonnes of mine tailings generated yearly worldwide, and 19 billion solid tailings will be accumulated by 2025. Adding to this, the legacy of environmental damage from abandoned mines is worrying; in Canada there are around 10,000 abandoned mines, 50,000 in Australia, 6,000 in South Africa, and 9,500 coal mines in China, reaching 15,000 by 2050. In this scenario, restoration techniques from mining tailing have become increasingly discussed among scholars due to their potential to offer benefits towards reducing tailings levels, thereby reducing environmental pressure for the correct management and adding value to previously discarded waste. This review paper explores available literature on the main techniques of mining tailing recycling and reuse and discusses leading technologies, including the benefits and limitations, as well as emerging prospects. The findings of this review serve as a supporting reference for decision-makers concerning the related sustainability issues associated with mining, mineral processing, and solid waste management.
ARTICLE | doi:10.20944/preprints202207.0228.v1
Subject: Engineering, Construction Keywords: smart primary healthcare; building; Construction; South Africa
Online: 15 July 2022 (06:32:30 CEST)
Smart primary healthcare building facility services capture a new level of process and operational data through advanced monitoring, enabling experts to use the building facilities to produce significant and efficient healthcare service delivery within the individual spheres of influence. This study assessed the impact of IoT services on achieving smart primary healthcare building facilities in the rural area of South Africa to enhance primary healthcare delivery. The study identified three (3) basic constructs of IoT services that comprised the application of IoT location recognition and tracking services, the application of the IoT high-speed communication network-based services, and the application of IoT-based services. The study is quantitative, and a questionnaire was used to collect data from the project managers and healthcare practitioners working with the primary healthcare agency in South Africa. The study found a variable degree of impact between the three (3) IoT constructs and the achievement of primary healthcare building facility services in South Africa. The study recommends adopting IoT essential services for achieving smart primary healthcare building facility services in the rural areas of South Africa and other developing countries facing similar primary healthcare delivery challenges.
Online: 30 October 2020 (15:35:00 CET)
In the information age today, data are getting more and more important. While other industries achieve tangible improvement by applying cutting edge information technology, the construction industry is still far from being enough. Cost, schedule, and performance control are three major functions in the project execution phase. Along with their individual importance, cost-schedule integration has been a significant challenge over the past five decades in the construction industry. Although a lot of efforts have been put into this development, there is no method used in construction practice. The purpose of this study is to propose a new method to integrate cost and schedule data using big data technology. The proposed algorithm is designed to provide data integrity and flexibility in the integration process, considerable time reduction on building and changing database, and practical use in a construction site. It is expected that the proposed method can transform the current way that field engineers regard information management as one of the troublesome tasks in a data-friendly way.
ARTICLE | doi:10.20944/preprints201809.0232.v1
Subject: Arts & Humanities, Architecture And Design Keywords: concrete; construction history; Iceland; Reykjavík; Guðmundur Hannesson
Online: 13 September 2018 (10:11:59 CEST)
The quick modernisation of Iceland, that rapidly took place from the first decades of the 20th century onwards, did not only bring fishing trawlers and cars into the country. Among all the techniques of modernity, concrete [steinsteypa] was to become the key material that changed the built landscape of the island and was soon adopted by the first Icelandic architects, such as Rögnvaldur Ólafsson (1874–1914) and Guðjón Samúelsson (1887–1950). Interestingly, the main supporter of this material was Guðmundur Hannesson (1866–1946), a medical doctor and town planner who wrote several articles and even a guidebook published in 1921 and titled Steinsteypa. Leiðarvísir fyrir alþýðu og viðvaninga [Concrete. Guidebook for Common People and Beginners]. In a country that was seeking an architectural self-representation, he understood the technical and formal possibilities that concrete could offer: he claimed, “people [...] were trying to change, to build out of a new material with a new form” (Guðmundur Hannesson 1926, 14). This essay aims thus to retrace the rhetoric of Guðmundur Hannesson and his role in writing an Icelandic chapter of the history of concrete, from its early stage of unmodern trial-and-error to the definition of a modern Icelandic architecture.
ARTICLE | doi:10.20944/preprints201808.0541.v1
Subject: Engineering, Other Keywords: anaerobic process; biogas; coffee wastewater; digester construction
Online: 31 August 2018 (05:47:42 CEST)
Wet coffee processing methods will produce wastewater containing organic matter. The high content of organic matter can be utilized as biogas through the anaerobic process. Anaerobic digesters construction can affect removal process of wastewater pollution and biogas quantity. The purpose of this study is to determine the effect of digester construction between conventional digester, CSTR and UASB producing biogas from coffee wastewater. The conventional digester worked without temperature control system as control, a UASB digester, and CSTR digester worked with temperature control system. Biomass volume was about 5 L with 35 days incubation time. Temperature and pH for UASB and CSTR were set within the range 30 – 35oC and pH 6.0 – 8.0. Based on the feeding variations, UASB has a stable performance with 83.57 ml/day of average biogas production. It has also highest remediation efficiency of COD, BOD and C/N with 85.00±0.34 %, 84.40%± 5.66 and 97.78± 0.57.
ARTICLE | doi:10.20944/preprints201710.0172.v1
Subject: Engineering, Civil Engineering Keywords: laser; construction monitoring; measurements; uncertainty; bridge inspection
Online: 27 October 2017 (16:17:23 CEST)
Recent researches proved that the underbridge geometry can be reconstructed by mounting a 3D laser scanner on a motorized cart travelling on a walkway located under the bridge. The walkway is moved by a truck and the accuracy of the bridge model depends on the accuracy of the trajectory of the scanning head with respect to a fixed reference system. In this paper, we describe the metrological characterization of a method that uses non-contact systems to identify the relative motion of the cart with respect to the walkway; the orientation of the walkway with respect to the bridge is determined using inclinometers and optical rails, while the position of the truck with respect to the bridge is measured using a conventional odometer. The measurement uncertainty of the proposed system was initially evaluated by numerical simulations and successively verified by experiments in laboratory conditions. The complete system has then been tested in operative conditions; the validity of the proposed approach has been demonstrated by comparing the geometry of buildings reconstructed with the proposed system with the geometry obtained with a static scan. Results evidenced that the errors are approximately 6 mm.
ARTICLE | doi:10.20944/preprints202012.0291.v1
Subject: Engineering, Civil Engineering Keywords: information technology; construction project management; cost management; impact factor model; progressive technology; construction industry, life cycle cost management.
Online: 11 December 2020 (16:12:55 CET)
Construction project management and cost management is a difficult process that affects the overall success of construction projects. The success of a construction project can be assessed according to key performance indicators (KPIs). Cost savings and cost optimization over the life of a construction project is one of these KPIs. Cost management is largely performed through intelligent information technology in the construction industry. Information systems and information technologies have seen an increase in use in the management of construction projects. The same goes for cost management. Several studies mentioned in the paper point to this increase in use in recent years also in the management of costs at various stages. Many studies point to the use of information technology and software applications in the field of cost management. Still, to a large extent, there are no surveys focused on the analysis of the impact and impact factor of information technology on cost savings or cost optimization in various phases of construction projects. The research discusses the issue of the impact of information technology on cost management in various phases of a construction project. The main goal of the research is to analyze the influence of information technology factors on cost savings and optimization in individual phases of a construction project. Several statistical methods were used in the research. The resulting model of information technology impact factor was created based on data processing and the use of the AHP method.
ARTICLE | doi:10.20944/preprints202201.0030.v1
Subject: Engineering, Civil Engineering Keywords: New-age (Nano) Modified Emulsion (NME) stabilisation; identifying construction problems; preventing construction related problems; material related problems; constructability using nanotechnology applications; nano-silane stabilisation of granular materials; construction quality control problems; construction equipment problems; practical implementation of nano-silane stabilisation.
Online: 11 January 2022 (10:37:34 CET)
The use of New-age (Nano) Modified Emulsions (NME) for the stabilisation of marginal materials for use in the upper-pavement layers of roads have been proven in laboratories, through Accelerated Pavement Tests (APT) and in practice. In addition, material design methods have been developed based on the scientific analysis of granular material mineralogy and the chemical interaction with the binder to design a material compatible NME stabilising agent for naturally available (often marginal) materials. However, the introduction of any new disruptive technology in a traditionally well-established industry, such as the road construction industry, is usually associated with considerable resistance. This is especially relevant when the new technology enables the use of granular materials traditionally considered to be of an unacceptable quality in combination with relatively new concepts such as New-age (Nano) Modified Emulsions (NME). In practice, few road construction projects are without any problems. The introduction of new-technologies obviously makes it an easy target to blame for any non-related problem that may arise during construction. This article aims to assist in pre-empting, recognising, preventing and resolving material or non-material related construction problems through the correct identification of the cause of the problem and recommending the best, most cost-effective way to correct any deficiencies on site.
ARTICLE | doi:10.20944/preprints202207.0227.v1
Subject: Engineering, Construction Keywords: earth buildings; residential construction; awareness; education; New Zealand
Online: 15 July 2022 (05:48:48 CEST)
The construction of earth buildings, both throughout history and in the current day, is well-established worldwide. Despite New Zealand's pre- and post-colonial history of earth construction, earth buildings as residential homes have not been well-received or popularised throughout present-day New Zealand. This research aims to identify the reasons for this lack of awareness and to determine methods that promote earth buildings in New Zealand. This research is based on data collected from semi-structured interviews conducted with subject matter experts and via an online questionnaire completed by members of the Earth Building Association New Zealand (EBANZ). The data collected revealed the experiences and perceptions of all participants regarding the advantages, challenges and promotion of earth buildings specific to New Zealand. Upon analysing these responses, key reoccurring themes were identified and compared. Regarding New Zealand's lack of awareness of earth buildings, interview and questionnaire participants responded that this shortcoming was due to earth construction being a very niche market and lacking commercial marketing. Education was the most frequently reoccurring theme raised by all participants as the top promotional tool for raising awareness of earth buildings. The results of this research can be applied to future work regarding obstacles that limit the growth of New Zealand's earth building industry, as well as research on the role of New Zealand's education system in exposing the next generation of builders, designers, and consumers to earth construction.
ARTICLE | doi:10.20944/preprints202012.0737.v1
Subject: Engineering, Automotive Engineering Keywords: adaptive design; sustainability of construction; BIM environment; formwork
Online: 29 December 2020 (16:44:42 CET)
Progressive technologies and practices are shifting the possibilities of building design and improving work efficiency. Constantly changing site conditions require different procedures and designs that take into account these changing conditions, whether it is a design solution, a change in environmental conditions, or just sustainability factors. Adaptive building design offers opportunities to cope with changing factors to achieve the highest possible level of building quality. This case study deals with the topic of adaptive formwork design for building renovation, taking into account sustainability. Aim of the article is an investigation and demonstration of the building information modelling (BIM) environment used for the adaptive design of formwork elements for the building renovation in the context of sustainability. The object of the case study is a building in the center of Kosice, Slovakia. BIM environment allows prompt and correct adaptation of the formwork design to changing conditions of lighting, ventilation, heating and temperature during the design of the building.
ARTICLE | doi:10.20944/preprints202010.0034.v1
Subject: Engineering, Automotive Engineering Keywords: Sustainability; MIVES method; tunnels; construction materials; M-30
Online: 2 October 2020 (09:27:51 CEST)
In 2007, the excavation of the M-30 ring road located in Madrid and the creation of a green corridor either side of the Manzanares river brought significant change to the metropolitan area. The corridor and linear park which it provided were designed to contribute to the regeneration of the fluvial ecosystem, establish links among residents on each side of the river and promote cultural and leisure activities. This paper provides a sustainability analysis of the excavation of the M-30 (involving the socio-economic and environmental impact) 14 years after its construction. In order to show such an impact, an analysis of the area both prior to the project and after completion, as well as a hypothetical solution that uses improved materials, has been performed. This entails use of the multi-criteria decision-making model named MIVES (initials in Spanish, modelo integrado de valor para una evaluación sostenible). The MIVES method is based on the application of value functions of sustainability indicators selected by socio-economic and environmental criteria, chosen by experts. Results from analysis showed that the excavation of the M-30 considerably improved the sustainability of the area (sustainable index 3.43 and 6.26 both before and after the excavation works). However, use of improved materials in contrast with the application of conventional materials slightly improved the sustainability of the work (Sustainability Index 6.26 and 6.74, respectively, of the conventional materials).
Subject: Social Sciences, Accounting Keywords: construction engineering; lean supply chain; target cost management
Online: 13 November 2019 (08:57:42 CET)
The lean supply chain of construction engineering projects is to achieve the maximum satisfaction of the owners' needs in order to effectively achieve the goal of supply chain management. This paper explores an effective method of lean supply chain cost management for construction engineering projects with target cost management, so that each participating unit on the supply chain node can fully utilizes its core competencies to minimize internal consumption and waste, and achieve the optimal overall efficiency of the supply chain. According to the requirements of the goal planning theory of the construction project company, establish a lean supply chain cost planning system for the construction project, realize the basic model of the lean supply chain cost management of the construction project, and set the target cost from the lean project of the construction project. The technical decomposition is established by the process of cost decomposition and cost pressure transmission and sub-target cost planning.
ARTICLE | doi:10.20944/preprints201811.0230.v1
Subject: Engineering, Civil Engineering Keywords: accident; construction project; causes; Bangladesh; RII based rank
Online: 9 November 2018 (03:29:17 CET)
Bangladeshi construction industry suffers a lot of safety and accidental issues than other developing countries in the world. Among many of these, accident of construction project goes far beyond and shape a horrific figure of death for every year. The aims of this study is that analysis and discussion of causes of accident at construction project in Bangladesh. A widespread statistical data collection and data analysis take place to identify the causes and design the questionnaire. The questionnaire-based survey was used to elicit the attitude of four stakeholders as workers, owners, consultants, and contractors towards passive causes of fatal accident at construction site. These study also identify 77 passive causes under 14 major groups and ranked them based on Relative Importance Index (RII). The top 5 major group of causes are (1) Management related, (2) Consultant related, (3) Technology related, (4) Labour related and (5) Contractor related. The top 5 passive causes are: (1) Unaware of safety-related issue, (2) Lack of personal protective equipment, (3) Lack of safety eliminating/ avoiding design, (4) Unfit equipment, (5) Lack of knowledge and training on equipment.
ARTICLE | doi:10.20944/preprints201810.0272.v1
Subject: Arts & Humanities, Linguistics Keywords: past participle construction, auxiliaries, resultatives, exaptation, refunctionalisation, capitalisation
Online: 12 October 2018 (14:40:04 CEST)
The chapter presents the current state of research concerning the development of the BE + past participle constructions from Latin to Spanish. Starting from the description in Rosemeyer (2014) and the theoretical background collated in Kailuweit & Rosemeyer (2015), it will be shown that the functional change does not follow traditional grammaticalisation paths. Several concepts that deal with cases contradicting traditional grammaticalisation theory will be discussed. ‘Exaption’ (Lass 1990, 1997) focussing on total defunctionalisation does not account for the fact that the resultative value of the BE + past participle construction, marginal in Latin, becomes central in Mediaeval Spanish. ‘Refunctionalisation’ Smith (2008) captures this aspect in a more appropriate way. However, the development of the construction could be also conceived as the opposite of what Pountain (2000) describes as ‘capitalisation’: a process of ‘decapitalisation’ by which a feature is exploited not for wider, but for more restricted purposes.
ARTICLE | doi:10.20944/preprints201808.0441.v1
Subject: Engineering, Civil Engineering Keywords: digital construction; 3D-concrete-printing; buildabiltiy; additive manufacturing
Online: 27 August 2018 (06:37:13 CEST)
Buildability, i.e. the ability of a deposited material bulk to retain its dimmensions under increasing load, is an inherent prerequisite for formwork-free digital construction (DC). Since DC processes are relatively new, no standard methods of characterization are available yet. The paper at hand presents practice-oriented buildabilty criteria by taking various process parameters and construction costs into consideration. In doing so, direct links between laboratory buildability tests and target applications are established. A systematic basis for calculating the time interval (TI) to be followed during laboratory testing is proposed for the full-width printing (FWP) and filament printing (FP) processes. The proposed approach is validated by applying it to a high-strength, printable, fine-grained concrete. Comparative analyses of FWP and FP revealed that to test the buildability of a material for FP processes, higher velocities of the printhead should be established for laboratory tests in comparison to those needed for FWP process, providing for equal construction rates.
ARTICLE | doi:10.20944/preprints201705.0107.v1
Subject: Engineering, Civil Engineering Keywords: Cement; Multicriteria analysis; Life Cycle Analysis; Construction industry
Online: 12 May 2017 (17:45:58 CEST)
The attention to sustainable-related issues has grown fast in recent decades. The experience gained with these themes reveals the importance of considering this topic in the construction industry, which represents an important sector in the world. This work consists on conducting a multicriteria analysis of four cement powders, with the objective of calculating and analysing the environmental, human health and socio-economic effects of their production processes. The economic, technical, environmental and safety performances of the examined powders result from official, both internal and public, documents prepared by the producers. The Analytic Hierarchy Process permitted to consider several indicators (i.e. environmental, human health related and socio-economic parameters) and to conduct comprehensive and unbiased analyses which gave the best, most sustainable cement powder. As assumed in this study, the contribution of each considered parameter to the overall sustainability has a different incidence, therefore the procedure could be used to support on-going sustainability efforts under different conditions. The results also prove that it is incorrect to consider only one parameter to select the ‘best’ cement powder, but several impact categories should be considered and analysed if there is an interest for pursuing different, often conflicting interests.
ARTICLE | doi:10.20944/preprints201703.0165.v1
Subject: Social Sciences, Geography Keywords: Regulation Effectiveness; Land Use Plan; Construction Land; China
Online: 20 March 2017 (18:42:46 CET)
Nowadays the relationship between planning land use and actual land use is not so clear in general. A lot of efforts have been put in the failures of regulation for the expansion of construction land. However, it still lacks an integrated approach to study the effectiveness of land use regulation in terms of different land use types. Furthermore, the existing evaluation of land use plan mainly focuses on a general level, a detailed research on the regulation effectiveness of each construction land use type is absent. Therefore, this research tries to evaluate regulation effectiveness of land use plan, which takes Cangwu country, Guangxi Province as an example. The finding by analysis is that the total area of construction land expansion was about 3494.73 ha, nearly 1.1 times of the plan quota. Moreover, the effectiveness differs greatly in various construction land use types. Town, industrial/mining sites can be well regulated through the quota of land use plan. While, the quota regulation system is not as effective for other type of construction land. Thus, we suggest to improve the regulation effectiveness of construction land through different plan instruments.
ARTICLE | doi:10.20944/preprints202008.0450.v1
Subject: Medicine & Pharmacology, Nursing & Health Studies Keywords: workplace; health promotion; public health; health checks; education; construction
Online: 20 August 2020 (09:42:29 CEST)
Interprofessional learning (IPL) is essential to prepare healthcare trainees as the future public health workforce. WHIRL was an innovative IPL intervention that engaged multi-professional teams of volunteer healthcare trainees (n=20) to deliver health checks (n=464), including tailored advice and signposting, to employees in the UK construction industry (across 21 events, 16 sites, 10 organisations) as part of an ongoing research programme called Test@Work. Volunteers undertook a four-part training and support package of trainer-led education, observations of practice, self-directed learning and clinical supervision, together with peer mentoring. In a one-group post-test only design, IPL outcomes were measured using the Inventory of Reflective Vignette - Interprofessional Learning (IRV-IPL), and the psychometric properties of the IRV-IPL tool were tested. WHIRL demonstrably improved healthcare trainees’ interprofessional skills in all five areas of collaboration, coordination, cooperation, communication, and commendation. The IRV-IPL tool was found to be a valid and reliable measure of interprofessional competencies across three scenarios; before and after health promotion activities, and as a predictor of future health promotion competence. This industry-based workplace IPL programme resulted in attainment of health check competencies, and bridged the gap between research, education and clinical practice.
ARTICLE | doi:10.20944/preprints202002.0002.v1
Subject: Engineering, Construction Keywords: construction; rainwater harvesting; solar; spray foam; finger-jointed studs
Online: 3 February 2020 (03:04:44 CET)
The question of building sustainable in a geographical locality is inexorably linked to cost. In 2011, one of the authors built a sustainable house that was (at the time) the highest certified sustainable home based on the National Association of Home Builder’s standards for sustainable construction. This Texas house has been used for residential and research purposes for the past decade. In this case study, the authors evaluate components of the construction and their effectiveness as well as unseen secondary and tertiary effects. Some of the specific components discussed are home site placement; rainwater harvesting (100% of residential requirements); aerobic septic system; grid-tied solar array power; electric car charging; geothermal heating and cooling; reclaimed wood framing; spray foam installation; selection of windows, fixtures, and appliances; on-demand electric water heaters for guest areas; generator backups; and use of local items. Electric bills and water system improvements are discussed in detail, as improvements were made as part of residential and research requirements. This case study suggests that the financial outlay is worth the extra up-front costs if residents in this geographical area and climate will occupy the residence 7 years.
Subject: Engineering, Civil Engineering Keywords: risk assessment; BIM; supply chain management; prefabricated construction products
Online: 19 March 2019 (13:07:57 CET)
Improving the efficiency of the supply process in prefabricated components is challenging and requires accounting for a variety of risks involved in the management of the suppliers. The purpose of this study is to present a method to account for the systematic trade-offs between several supplier alternatives. A novel framework is presented for the whole assessment of supplier alternatives by taking advantage of the information extracted from customized building information modeling (BIM) and a database required for assessment of impacts. A data library related to assessment criteria for supply alternatives is built to facilitate the storage and sharing of information. Analytic hierarchy process (AHP) is used to select the optimal supplier that is able to provide the most satisfaction for the determined criteria. The proposed framework was also illustrated by the implementation in a mega project. The study implication is that BIM-enabled supplier selection can indeed lead to more benefits and higher values for all stakeholders.
ARTICLE | doi:10.20944/preprints201902.0255.v1
Subject: Engineering, Civil Engineering Keywords: Construction project cost; influencing factors; Bayesian SEM; New Zealand
Online: 27 February 2019 (12:01:41 CET)
Construction projects are usually operating in a complex and dynamic environment in which the accumulation of many interrelated factors causes high uncertainty. Construction projects are complex and frequently involve substantial uncertainties including process complicatedness, intricate organization structure, dynamic environment, and financial strain. The study aims to categorize the influencing factors into three groups, namely construction project system, economic-market climate, and external environment. It attempts to adopt a novel analysis tool to examine the relationship between the project cost and multiple influencing factors by using Bayesian SEM. While the Bayesian SEM method has been receiving increasing attention in exploring the relationship between latent variables, construction studies still heavily rely on the covariance-based SEM approach. This study introduces several advantages of Bayesian SEM that make it more flexible and powerful than covariance-based SEM and provides the foundation of Bayesian SEM estimation and inference by illustrating this method in a project cost application.
ARTICLE | doi:10.20944/preprints201902.0217.v1
Subject: Engineering, Construction Keywords: Construction project cost; influencing factors; Bayesian SEM; New Zealand
Online: 25 February 2019 (08:41:01 CET)
Construction projects are usually operating in a complex and dynamic environment in which the accumulation of many interrelated factors causes high uncertainty. Construction projects are complex and frequently involve substantial uncertainties including process complicatedness, intricate organization structure, dynamic environment, and financial strain. The study aims to categorize the influencing factors into three groups, namely construction project system, economic-market climate, and external environment. It attempts to adopt a novel analysis tool to examine the relationship between the project cost and multiple influencing factors by using Bayesian SEM. While the Bayesian SEM method has been receiving increasing attention in exploring the relationship between latent variables, construction studies still heavily rely on the covariance-based SEM approach. This study introduces several advantages of Bayesian SEM that make it more flexible and powerful than covariance-based SEM and provides the foundation of Bayesian SEM estimation and inference by illustrating this method in a project cost application.
ARTICLE | doi:10.20944/preprints201705.0162.v1
Subject: Keywords: machine learning; Counterparty Credit Risk; CDS Proxy construction; classification
Online: 22 May 2017 (08:21:59 CEST)
Regulators require financial institutions to estimate counterparty default risks from liquid CDS quotes for the valuation and risk management of OTC derivatives. However, the vast majority of counterparties do not have liquid CDS quotes and need proxy CDS rates. Existing methods cannot account for counterparty-specific default risks; we propose to construct proxy CDS rates by associating to illiquid counterparty liquid CDS Proxy based on Machine Learning Techniques. After testing 156 classifiers from 8 most popular classifier families, we found that some classifiers achieve highly satisfactory accuracy rates. Furthermore, we have rank-ordered the performances and investigated performance variations amongst and within the 8 classifier families. This paper is, to the best of our knowledge, the first systematic study of CDS Proxy construction by Machine Learning techniques, and the first systematic classifier comparison study based entirely on financial market data. Its findings both confirm and contrast existing classifier performance literature. Given the typically highly correlated nature of financial data, we investigated the impact of correlation on classifier performance. The techniques used in this paper should be of interest for financial institutions seeking a CDS Proxy method, and can serve for proxy construction for other financial variables. Some directions for future research are indicated.
ARTICLE | doi:10.20944/preprints202110.0181.v3
Subject: Engineering, Civil Engineering Keywords: Construction practices using nanotechnology applications; nano-modified emulsion stabilisation of granular materials; nano-modified emulsion stabilised layers in highway construction; central plant
Online: 23 December 2021 (10:52:06 CET)
The introduction of any new disruptive technology in a traditionally well-established industry, such as the road construction industry, is usually associated with considerable resistance. This is especially relevant when the new technology is based on the use of granular materials traditionally considered to be of an unacceptable quality in combination with relatively new concepts such as New-age (Nano) Modified Emulsions (NME). In such cases, the fact that the material design methods are based on fundamental scientific principles and have been proven in laboratories and through Accelerated Pavement Testing (APT), may be of little influence. However, the general acceptance of new disruptive technologies, e.g. telecommunications and Information Technologies (IT), have been based on the considerable advantages it presented. The same principles are applicable to the general acceptance and use of NME stabilisation/enhancement of materials in the road construction industry. This article is aimed at the practical cost-effective demonstration of the general application of the use of nanos-silane modified emulsions in the construction of the highest order roads, i.e. inter-city multi-lane highways, lower order roads (including Low-Volume-Roads (LVR)) and even local accesses to farms and in villages/townships. The implementation of NME technologies is directly associated with ease of use, time and cost savings and the addressing and reduction of risks applicable to the use thereof.
ARTICLE | doi:10.20944/preprints201805.0281.v1
Subject: Keywords: construction technology adoption process; construction; mining; digital technology; diffusion; implementation; mix methods; grounded theory; thematic analysis; data and methodological triangulation techniques; AHP; NVivo
Online: 22 May 2018 (04:52:39 CEST)
Due to the complexity, high-risk, and conservative character of construction companies, advanced digital technologies do not become widely adopted in the short term, while vendors make determined efforts to overcome this and disseminate their technologies. This paper presents the methods of an investigation addressing the extremely complex issues related to the current practices of digital technology adoption in construction. It discusses how construction companies follow a specific logical process linked to need, project objectives, characteristics of the adopting organization, and the characteristics of the new technology to be adopted. The study aims to demonstrate a novel method of data collection and analysis including data and methodological triangulation techniques including the use of NVivo and AHP to explore how companies make the decision to uptake a new technology (e.g. advanced crane, tunnel boring machine or drones) by focusing on customer and vendor activities, their interactions, contributing factors, and people involved in the process. The major original contribution of this paper is to develop an innovative methodological Cube for investigating the Construction Technology Adoption Process (CTAP) covering technology adoption, acceptance, diffusion and implementation concepts. CTAP is a framework that delineates the phases of the process that customer organizations use when deciding to adopt a new digital technology and the parallel vendor activities. The significance of these contributions is that they enable vendors to understand how to match their strategies with customer expectations in each phase of the CTAP. It also provides a benchmark for new construction companies to use the current best practice of decision making. Future research is warranted to more clearly delineate any differences with developing nations or related industries such as mining and property management.
ARTICLE | doi:10.20944/preprints201902.0077.v1
Subject: Engineering, Civil Engineering Keywords: inter-personal relationships; construction innovation; knowledge sharing; inter-organizational relationships
Online: 8 February 2019 (09:20:06 CET)
Abstract: Guanxi, a Chinese term that defines social networks of power and benefits, can be divided into inter-personal and inter-organizational relationships, and guanxi significantly influences construction innovation in China. Many studies have examined the relationship between guanxi and construction innovation at the project or organizational level. However, few of these studies explained how guanxi could affect an individual’s innovative behaviour from a double-level perspective. This paper builds on social capital theory and social exchange theory to examine guanxi’s role in motivating innovative behaviour in a China-specific construction context. It investigates the main effects of inter-personal relationships on innovative behaviour, the mediating effects of knowledge sharing, and the cross-level moderating effects of inter-organizational relationships. These elements were tested using a survey that received 178 responses from 35 different organizations. The results were analysed using Hierarchical Linear Modelling (HLM) and revealed that inter-personal relationships have positive influences on innovative behaviour, thus highlighting the partial mediating effects of knowledge sharing. In addition, the analyses showed that inter-organizational relationships augment inter-personal relationships and knowledge sharing on innovative behaviour by cross-level interaction. The research findings enhance an understanding of guanxi and innovative behaviour in China-specific construction project settings, as well as verifying the significance of guanxi in stimulating innovative behaviour.
ARTICLE | doi:10.20944/preprints201804.0272.v1
Subject: Medicine & Pharmacology, Nursing & Health Studies Keywords: construction industry; heart health; lifestyle behaviors; healthy eating; physical activity
Online: 20 April 2018 (14:59:45 CEST)
Objectives: 1) To describe the cardiovascular health of the construction workers in Hong Kong, 2) to examine the demographic differences in cardiovascular health, and 3) to examine the association between modifiable lifestyle behaviors and cardiovascular conditions. Methods: 626 registered construction workers were included in the analysis. Blood chemistry, blood pressure, weight and height were measured. Face-to-face questionnaire interview was conducted. T-tests and One-way ANOVAs were used to compare the cardiovascular health score, cardiovascular outcomes, and lifestyle behaviors by demographic characteristics. Logistic regressions were performed to assess the cardiovascular outcomes by lifestyle behaviors. Results: Two-thirds of the construction workers failed to achieve three out of the seven “ideal” cardiovascular health indicators. The younger, more educated, and female subjects had better cardiovascular health scores than their counterparts. The ideal fish and seafood consumption was associated with 1) ideal weight status and 2) ideal cholesterol level, whereas less soft drink consumption was associated with ideal cholesterol level. Conclusions: The findings highlighted the importance of promoting cardiovascular health in the construction industry. This study provided insights for future interventions, which should include increasing fish and seafood intake, decreasing soft drink consumption, and enhancing the health literacy amongst older, less educated, and male construction workers.
ARTICLE | doi:10.20944/preprints201704.0054.v1
Subject: Earth Sciences, Environmental Sciences Keywords: construction industry; energy rebound effect; sustainability; solow remainder; ridge regression
Online: 10 April 2017 (07:35:45 CEST)
As the largest energy consumer and carbon emitter, China has made substantial efforts to improve energy efficiency for decrease energy consumption, while the energy rebound effect determines its effectiveness. The embodied energy consumption of construction projects accounted for nearly one-sixth of the total economy's energy consumption in China. This paper is based on the logical relationship among capital input, technological progress, economic growth, and energy consumption, adapting an alternative estimation model to estimate the energy rebound effect for the construction industry in China for the first time. Empirical results in our paper reveal that the energy rebound effect for the construction industry in China is about 59.5% for the period of 1990–2014. The results indicate that the energy rebound effect does exist in China’s construction industry and it presented a fluctuating declining trend. This implies that half of the energy savings by technological progress is achieved. In addition, China’s government should implement proper energy pricing reforms and energy taxes to promote the sustainable development of China’s construction industry.
ARTICLE | doi:10.20944/preprints202108.0131.v1
Subject: Engineering, Automotive Engineering Keywords: recycled concrete aggregate; construction waste; shear strength; shear provision; design equation
Online: 5 August 2021 (09:41:27 CEST)
The brittle shear failure of reinforced concrete beams is complexed and unfavorable. For decades, research on the mechanical properties and durability of recycled coarse aggregate (RCA) to make recycled aggregate concrete (RAC) has been widely investigated. However, test results on the shear strength of reinforced recycled aggregate concrete beams are still limited and contradictory. This paper reports the shear strength of reinforced recycled aggregate concrete beams without stirrups. Eight RAC beams and two controlled beams with natural coarse aggregate (NCA) were tested under the four-point flexural test with the shear span-to-effective depth ratio (a/d) of 3.10. Parameters in this study were the replacement percentage of RCA (0%, 25%, 50%, 75%, and 100%) and longitudinal reinforcement ratio (w) of 1.16% and 1.80%. It was found that the normalized shear stresses of RAC beams with w = 1.80% at all levels of replacement percentage were quite similar to that of the NAC counterparts. Normalized shear stress of the beam with 100% RCA and w = 1.16% was lower than that of the NAC beam by 5%. Database of 128 RAC beams without shear reinforcement from literature was analyzed to evaluate the ability of the most recent ACI 318-19 shear provisions in shear strength prediction. A reduction factor of 0.75 is proposed to the current ACI code provision to account for the physical variations of RCA such as replacement percentage, RCA source and quality, density, amount of residual mortar, and physical irregularity.
ARTICLE | doi:10.20944/preprints202102.0433.v1
Subject: Engineering, Automotive Engineering Keywords: sustainable concrete; wastewater; industrial waste management; sustainable development; sustainable construction materials
Online: 19 February 2021 (10:04:58 CET)
Concrete, as one of the essential construction materials is responsible for a vast amount of emissions. Using recycled materials and gray water can considerably contribute to the sustainability aspect of concrete production. Thus, finding a proper replacement for fresh water, in the production of concrete, is significant. The usage of industrial wastewater, instead of water in the concrete can is considered in this paper. In this study, 450 concrete samples are produced with different amounts of wastewater. The mechanical parameters such as slump, compressive strength, water absorption, tensile strength, electrical resistivity, rapid freezing, half-cell potential, and appearance are investigated. The results showed that the usage of industrial wastewater does not significantly change the main characteristics of concrete. Although, increasing the concentration of the wastewater can decrease durability and strength features nonlinearly.
ARTICLE | doi:10.20944/preprints202011.0703.v1
Subject: Physical Sciences, Acoustics Keywords: quark matter; NJL model; RMF theory; deconfinement phase transition; Maxwell construction
Online: 27 November 2020 (20:18:36 CET)
We study the hadron-quark hybrid equation of state (EOS) of compact-star matter. The Nambu—Jona-Lasinio (NJL) local SU(3) model with vector-type interaction is used to describe the quark matter phase, while the relativistic mean field (RMF) theory with scalar-isovector $\delta$-meson effective field adopted to describe the hadronic matter phase. It is shown that the larger the vector coupling constant, the lower the threshold density for the appearance of strange quarks. For a sufficiently small value of the vector coupling constant, the functions of the mass dependence on the baryonic chemical potential have regions of ambiguity which leads to a phase transition in non-strange quark matter with an abrupt change in the baryon number density. We show that within the framework of the NJL model, the hypothesis on the absolute stability of strange quark matter is not realized. In order to describe the phase transition from hadronic matter to quark matter, the Maxwell's construction is applied. It is shown that the greater the vector coupling, the greater the stiffness of the EOS for quark matter and the phase transition pressure. Our results indicate that the infinitesimal core of the quark phase, formed in the center of the neutron star, is stable.
ARTICLE | doi:10.20944/preprints202008.0238.v1
Subject: Engineering, Construction Keywords: autonomous rammed earth construction; red clay; epoxy emulsion; mechanical properties; microstructure
Online: 10 August 2020 (06:21:39 CEST)
Existing rammed earth construction methods have disadvantages such as increased initial costs for manufacturing the large formwork and increased labor costs owing to the labor-intensive construction techniques involved. To address the limitations of existing rammed earth construction methods, an autonomous rammed earth construction method is introduced herein. As this autonomous rammed earth construction method uses a modular formwork, alternative materials must be used in the construction to satisfy the requirements for the early-age binder performance. Accordingly, this study evaluates the use of an epoxy emulsion composed of epoxy and a hardener to enhance the performance of the binder. Preliminary experiments were conducted to determine the optimal formulation of the epoxy emulsion, following which the compressive strength, water loosening, shrinkage, rate of mass change, and microstructure of several red clay binder specimens with and without epoxy emulsion were analyzed at early ages. The results confirmed that the epoxy emulsion can be applied to satisfy the performance requirements for autonomous rammed earth construction by improving the durability and strength of the binder at early ages.
ARTICLE | doi:10.20944/preprints202001.0022.v1
Subject: Engineering, Civil Engineering Keywords: Leadership in Energy and Environmental Design; LEED; sustainable construction cost; Iran
Online: 3 January 2020 (04:42:10 CET)
Buildings use 30-40 % of all energy resources and are thus their main consumers in modern society. Moreover, buildings require a vast amount of different raw materials. During the last two decades, several green building certifications have been created in order to consider social, economic and environmental aspects of sustainability of buildings. One of the most famous and widely used of these certifications is Leadership in Energy and Environmental Design (LEED). So far, the use of LEED has concentrated in the US and other developed countries. One reason that restricts the use of this point-based system certification in developing countries is the limited data about its costs. In this study, the extra cost of the certification process will be evaluated besides the changes needed in the design of the building to reach the points required by LEED. At the first stage, the number of points the case study earns in its current format (Scenario 1) were found out, then the cost difference of getting either the Certified (Scenario 2) or Silver (Scenario 3) level LEED certification for the building was studied. It was found that besides some technical considerations, filling the criteria of the Certified and Silver level increases the total costs of construction by 3.4% and 5.9%. Further improvement of the building’s energy efficiency would enable the attainment of a higher-level certification. The results of the study could help to promote the use of green building certifications in Western Asia.
ARTICLE | doi:10.20944/preprints201811.0216.v1
Subject: Engineering, Construction Keywords: Construction, worker safety, safety helmet, three-axis accelerometer sensor, data mining
Online: 8 November 2018 (14:03:21 CET)
In the Korean construction industry, legal and institutional safety management improvements are continually being pursued. However, there was a 4.5% increase in the number of workers’ deaths at construction sites in 2017 compared to the previous year. Failure to wear safety helmets seems to be one of the major causes of the increase in accidents, and so it is necessary to develop technology to monitor whether or not safety helmets are being used. However, the approaches employed in existing technical studies on this issue have mainly involved the use of chinstrap sensors and have been limited to the problem of whether or not safety helmets are being worn. Meanwhile, improper wearing, such as when the chinstrap and harness fixing of the safety helmet are not properly tightened, has not been monitored. To remedy this shortcoming, a sensing safety helmet with a three-axis accelerometer sensor attached was developed in this study. Experiments were performed in which the sensing data were classified whether the safety helmet was being worn properly, not worn, or worn improperly during construction workers’ activities. The results verified that it is possible to differentiate among wearing status of the proposed safety helmet with a high accuracy of 97.0%
ARTICLE | doi:10.20944/preprints201809.0571.v1
Subject: Engineering, Civil Engineering Keywords: Suspension bridge; Girder construction; RCS process; Form-finding analysis; Model test
Online: 28 September 2018 (15:06:34 CEST)
The determination of the non-loading condition of the rail cable shifting (RCS) system, which consists of main cables, hangers and rail cables, is the premise of the girder erection for the long-span suspension bridges. An analytical form-finding analysis model of shifting system is established according to the basic assumptions of flexible cable structures. Herein, the rail cable is discretized into segmental linear cable elements and the main cable is discretized into segmental catenary elements. Moreover, the calculation and analysis equation of each member and their iterative solutions are derived by taking the elastic elongation of the sling into account. In addition, by taking the girder construction of Aizhai suspension bridge as engineering background, a global scale model of the RCS system is designed and manufactured; also the test system and working conditions are established. The comparison between the test results and analytical results shows the presented analytical method is correct and effective. The process is simplified in the analytical method, and the computational results and precision can satisfy the practical engineering requirements. In addition, the proposed method is suitable to apply to the computation analysis of similar structures.
ARTICLE | doi:10.20944/preprints201806.0339.v1
Subject: Engineering, Construction Keywords: post disaster housing; rapid assembly systems; foam filled sandwiches; modular construction;
Online: 21 June 2018 (12:52:55 CEST)
In this paper the development process of a deployable modular sandwich panelized system for rapid assembly building construction is presented, and its structural performance under some different action effects is investigated. This system, which includes an innovative sandwich panel and its integrated connections, can be used as structural walls and floors in quickly assembled post-disaster housing, as well as load bearing panels for pre-fabricated modular construction and semi-permanent buildings. Panels and connections are composed of a pneumatic fabric formwork, and two 3-D high-density polyethylene (HDPE) sheets as the skins, filled with high-density rigid Polyurethane (PU) foam as the core. HDPE sheets manufactured with a studded surface considerably enhance the stress distribution, buckling performance and delamination strength of the sandwich panel under various loading conditions. The load-carrying behaviour of the system in accordance with some ASTM standards is presented here. The results show the system satisfies the codes criteria regarding semi-permanent housing.
ARTICLE | doi:10.20944/preprints201805.0024.v1
Subject: Engineering, Construction Keywords: virtual information modeling; project management knowledge areas; construction projects; communication management.
Online: 2 May 2018 (11:40:14 CEST)
In the contemporary construction management, poor project performance, cost overrun, and low-quality construction have become a central point of attention for improving project performance including information, interaction and communication management. virtual design and construction and building information modelling play indispensable role in improving the project performance. The aim of this study is to propose a Virtual Information Modeling as a novel information and communication technology method with potential to overcome problems in the construction industry. Using one-sample t test with Kolmogorov-Smirnov approach, we analysed data collected from structured questionnaire survey involving project managers working at architecture, engineering and construction industries in Tehran, Iran. The results suggest that the most important benefits and challenges of using Virtual Information Modeling are related to the area of integration, and implementation of Virtual Information Modeling has the greatest impact on this area of project management knowledge. Thus, integration should be considered a top priority for construction companies implementing Virtual Information Modeling in their projects. Policymakers should understand that careful management of virtual information is essential for improving the performance of projects and enhancing the process efficiency.
ARTICLE | doi:10.20944/preprints202207.0197.v1
Subject: Engineering, Construction Keywords: construction; safety; risk; hazard; critical control risk management; critical control; fatality prevention
Online: 13 July 2022 (09:18:21 CEST)
Across the global construction industry, fatalities continue to occur from high-risk activities where the risk controls have been defined, however were unreliable. In the mining industry, Critical Control Risk Management has provided positive results in reducing major accidents, which raises the question, could the Critical Control approach reduce the fatality rate in the construction industry? This study analysed 10 years of serious and fatal incident investigation reports from four international construction companies to i) assess the reliability of their Critical Controls (CCs) and ii) assess the factors which affect the reliability of CCs. The results show the reliability of CCs, measured by implementation and effectiveness, averaged just 42%. Human performance factors including risk identification, decision-making and competency together with supervision, job planning, communication organisational factors were identified as affecting the reliability of CCs. The study used bow-tie diagrams with real event data to find the actual CC effectiveness. This gave actionable findings directly related to individual CCs enabling the participating organization to focus resources on improving specific verification processes. The results confirm the applicability of CCs for the Major Accident Event hazards analyzed and highlights further review is required of the factors which need to be considered when implementing a CC program. This paper details our methodology and results, to assist others apply CCs as a risk management tool.
ARTICLE | doi:10.20944/preprints202203.0228.v1
Subject: Engineering, Civil Engineering Keywords: concrete frames; modules; gridshell structures; 3D concrete printing; digital construction; SHCC; ECC
Online: 16 March 2022 (09:33:46 CET)
Despite all their advantages, load-bearing concrete shell structures with double curvatures are not frequently in use. The main reason is the complexity of their construction. In such a context, this article starts with a brief, critical review of existing technologies while their pros and cons are highlighted. Against that background the authors then propose a new approach for the highly automated fabrication of gridshell structures from variable modules. To demonstrate the feasibility of such a new technology, a demonstrator called ConDIT 1.0, a sphere-like shell structure composed of several frames was designed and built. The frame modules were fabricated automatically using extrusion-based 3D printing and a printable, strain-hardening cement-based composite (SHCC). This article presents the design of ConDIT 1.0, the mechanical material characterization of printed SHCC, the technology of module production, the results of geometry verification for print modules using 3D scanning, and the procedure for the demonstrator’s assembly.
Subject: Engineering, Civil Engineering Keywords: physical modelling; numerical modelling; construction works; growing risks; safety requirements; hybrid modelling
Online: 26 August 2020 (08:54:55 CEST)
We are witnessing a progressive divestment of some institutions with strong traditions and skills in physical modelling and their consequent impoverishment, to the detriment of numerical modelling. For many reasons, the economic imperatives and the exponential growth of computational means and numerical methods should certainly not be excluded. In this work, we aimed to highlight the new requirements of the recent sophisticated developments in physical modelling, precisely due to the new needs imposed on them by mathematical and numerical modelling and the growing risks in civil construction works. In this context, reflections are reported, justified by scientific and real-world examples, on the need for maintenance and reinforcement of investments in physical modelling, both to support the scientific community and to design buildings of significant economic, social and environmental impact.
ARTICLE | doi:10.20944/preprints201908.0276.v1
Subject: Earth Sciences, Environmental Sciences Keywords: risk perception; safety; construction; workers; working at height; manual handling; workload; Malawi
Online: 27 August 2019 (03:54:38 CEST)
This study employed a deductive research approach and a survey strategy to assess risk perception and its influencing factors among construction workers in Malawi. Three specific construction hazards and their associated risks were selected. The hazards were ‘working at height (WAH) ‘manual handling of loads (MHL)’ and ‘heavy workload or intense pressure to be more productive (HWP)’. The study engaged multistage sampling of 376 subjects. Univariate analysis, factor analysis and multiple linear regressions were performed in order to determine the main influencing factors among the independent variables. The study established that workers were aware of risks posed by their work. They perceived the risk associated with WAH, MHL and HWP as very high (62.7%, = 8.80 ± 1.95); (48.5%, = 8.10 ± 2.38); (57.9%, = 8.49 ± 2.22) respectively. The study identified six factors as variables that showed significant effect on workers’ perception of risk (p < 0.05). These factors were “dreaded factor”, “avoidability and controllability”, “expert knowledge”, “personal knowledge”, education level and age. It is concluded that contractors in the Malawian construction industry should integrate analysis of behaviors and risk perception of the workers and other players to guide the identification of better health and safety interventions at their worksites.
ARTICLE | doi:10.20944/preprints201901.0004.v2
Subject: Engineering, Civil Engineering Keywords: civil engineering; construction contract; court strategy; conflict modelling; decision analysis; game theory
Online: 28 January 2019 (10:51:40 CET)
Recently there has been growing interest in the application of game theory (GT) to solve many diverse problems in the field of construction, including i.a.: tender preparation, selection of a contractor for construction works, negotiating terms and conditions of cooperation of the parties to the contract, analysis and modeling of investment risk. In the authors opinion, the use of GT by general contractor (GC) of construction works to indicate the best strategy leading to winning court proceedings in a situation of conflict with investor (IN), so far has not been the subject of research. Taking into account the above, the aim of the presented paper is to indicate the optimal strategy from the GC point of view in the conflict situation with IN. The article presents a list of the most common causes of conflicts between parties of the construction works' contract, defines the background of the problem and the cause of the dispute, and on its basis, the authors generate the theoretical model of the game. Based on the analyzed game model, expected payoffs for players were calculated and the probability border value at which GC should apply the indicated strategy determined. The results of the study show that in the case when the probability of issuing a judgment favorable for GC is at least equal to 69.23%, it is justified to use an aggressive strategy. The analysis also confirms that from the financial perspective, litigation in most cases of conflicts in the area of construction should be the last choice.
ARTICLE | doi:10.20944/preprints201901.0180.v1
Subject: Keywords: Cognitive Presence, Reflective Writing, E-Portfolio, Community of Inquiry, Construction of Knowledge
Online: 17 January 2019 (12:12:27 CET)
Traditionally understood in reference to distance education, cognitive presence may be defined as "the extent to which the participants in any particular configuration of a community of inquiry can construct meaning through sustained communication. The purpose of this paper was to create a blueprint for the reflective ePortfolio as the capstone project for my graduate degree. The blueprint was accomplished by adapting for use cognitive presence as a tool for both analysis and framing, which has never been done to the best of my knowledge. I considered myself to be a participant in a “community of inquiry” model and substituted the result of my interaction with each of the required instructor-course content pairings I took to serve as fellow participants in this community model. The result of my participation was understood to be the knowledge and experience that I have gained, which was reflected in eight of my academic research papers. These selected papers were the artifacts around which my ePortfolio was ultimately developed and demonstrated my participation as an active member in this community of inquiry constructing meaning through sustained communication.
ARTICLE | doi:10.20944/preprints201811.0199.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: electrocardiogram (ECG); LASSO; overcomplete multi-scale dictionary construction; signal representation; sparse inference
Online: 8 November 2018 (10:12:45 CET)
The electrocardiogram (ECG) was the first biomedical signal where digital signal processing techniques were extensively applied. By its own nature, the ECG is typically a sparse signal, composed of regular activations (the QRS complexes and other waveforms, like the P and T waves) and periods of inactivity (corresponding to isoelectric intervals, like the PQ or ST segments), plus noise and interferences. In this work, we describe an efficient method to construct an overcomplete and multi-scale dictionary for sparse ECG representation using waveforms recorded from real-world patients. Unlike most existing methods (which require multiple alternative iterations of the dictionary learning and sparse representation stages), the proposed approach learns the dictionary first, and then applies an efficient sparse inference algorithm to model the signal using the learnt dictionary. As a result, our method is much more efficient from a computational point of view than other existing methods, thus becoming amenable to deal with long recordings from multiple patients. Regarding the dictionary construction, we locate first all the QRS complexes in the training database, then we compute a single average waveform per patient, and finally we select the most representative waveforms (using a correlation-based approach) as the basic atoms that will be resampled to construct the multi-scale dictionary. Simulations on real-world records from Physionet's PTB database show the good performance of the proposed approach.
ARTICLE | doi:10.20944/preprints201712.0141.v1
Subject: Physical Sciences, Applied Physics Keywords: metamaterial absorber; metallic resonator; three-dimensional construction; broadband absorption; lower-frequency absorption
Online: 20 December 2017 (09:20:54 CET)
Resistive patch array incorporating with metallic backplane provided an effective way to the achievement of broadband metamaterial absorbers(MAs). When loading metallic metamaterial to resistive MA, the outstanding construction helps realize more flexible and diversified forms of broadband absorption. In this paper, we attempted to load metallic resonators(MRs) to resistive MA in the three-dimensional construction, which benefits further enhancement of lower-frequency absorption. Simulation showed that the partial absorption band was separated to lower frequency, while the rest of broadband absorption was unaffected. Meanwhile, after combining multi-unit of the proposed MAs, the stair-stepping broadband absorption was also achieved. At last, three samples were fabricated. The agreements between simulations and experimental results demonstrated that resistive MA loaded with MRs provided an effective way for further enhancement of lower-frequency absorption with almost no change of the absorbing structure and areal density. Thus, it is worthy to expect a wide range of applications to emerge inspired from the proposed attempt.
ARTICLE | doi:10.20944/preprints201610.0062.v1
Subject: Earth Sciences, Geophysics Keywords: Qinghai-Tibet Plateau; geoid anomaly inversion; crustal and upper mantle density construction
Online: 15 October 2016 (08:25:13 CEST)
As the most active plateau on the Earth, the Qinghai-Tibet Plateau has a complex crust-mantle structure. Knowledge of the distribution of such a structure provides information for understanding the underlying geodynamic processes. We obtains a three-dimensional density model of crustal and upper mantle beneath Qinghai-Tibet plateau and its surrounding areas from the residual geoid anomalies using the Earth Gravitational Model (EGM) 2008. We estimate a refined density model by iterations, using an initial density contrast model. We confirm that the EGM2008 mission products can be used to constrain the crust-mantle density structures. Our major findings are: (1). At 300-400 km depth, high-D anomalies terminate around Jinsha River Suture (JRS) in the central TP, suggesting that the Indian plate has been reached over the Bangong Nujiang Suture (BNS) and almost reach to the JRS. (2). On the eastern TP, low-D anomalies at the depth of 0-300 km together with high-D anomalies at 400-670 km further verified the current eastward subduction of Indian plate. The ongoing subduction provides forces to the occurrences of frequent earthquakes and volcano. (3). At 600 km depth, low-D anomalies inside the TP illustrate the existence of hot weak material beneath there, contributing to the external material inward-thrusting.
ARTICLE | doi:10.20944/preprints202206.0314.v1
Subject: Social Sciences, Economics Keywords: two-way FDI; structural distortion; ecological civilization construction; spatial econometrics; carbon emission intensity
Online: 22 June 2022 (10:10:13 CEST)
In this paper, industrial structure distortion, two-way FDI and carbon emission intensity are brought into a unified research framework, and based on China's panel data from 2011 to 2020, empirical tests are conducted employing Exploratory Spatial Data Analysis (ESDA), spatial econometric model and intermediary effect test. The results show the following. Firstly, China's industrial structure distortion index shows a downward trend. The industrial structure distortion index is the highest in the west, followed by the middle, and the lowest in the East. Secondly, the relationship between carbon emission intensity and economic development shows a "decoupling" effect and keeps decreasing year by year. The spatial disparity is remarkable, showing the pattern of "the east leading, the middle catching up and the west lagging ". At the provincial level, except in Xinjiang province, the carbon emission intensity of other provinces showed different degrees of decline. In terms of spatial distribution, the polarization characteristics of carbon emission intensity are significant, and the traditional spatial distribution pattern has been broken. Thirdly, there is a positive spatial correlation between China's industrial structure distortion, two-way FDI and carbon emission intensity. The distortion of industrial structure will not only lead to the increase of local carbon emission intensity but also produce reverse spillover to adjacent areas. IFDI and OFDI provide a strong driving force for the decline of carbon emission intensity. IFDI promotes the decline of carbon emission intensity in adjacent areas, while OFDI will increase the carbon emission intensity in surrounding areas. The interaction of IFDI and OFDI can significantly reduce the carbon emission intensity of local and adjacent areas. Fourthly, the results of intermediary effect analysis show that two-way FDI is the two channels of industrial structure distortion affecting carbon emission intensity. Industrial structure distortion can affect the transmission mechanism of carbon emission intensity by affecting two-way FDI.
ARTICLE | doi:10.20944/preprints202201.0132.v1
Subject: Engineering, Other Keywords: carbon emission intensity; gravity model; social network; driving effect; sustainable development; Construction industry
Online: 11 January 2022 (08:46:34 CET)
To explore the spatial network structure characteristics and driving effects of carbon emission intensity in China's construction industry, the investigation combined the modified gravity model and social network analysis method to deeply analyze the spatially associated network structure characteristics and driving effects of carbon emission intensity in China's construction industry, based on the measurement of carbon emission data of China's construction industry from 2006 to 2017. The results show that the regional differences of carbon emission of construction industry are significant, and the carbon emission intensity of construction industry show a fluctuation trend. The overall network of carbon emission intensity shows an obvious “core-edge” state, the hierarchical network structure is gradually broken. Economically developed provinces generally play a leading role in the network, and play an intermediary role to guide other provinces to develop together with them. Among the network blocks, most of the blocks play the role of “brokers”. The block with the leading economic development has a strong influence on the other blocks. The increase of network density, the decrease of network hierarchy and network efficiency will reduce the construction carbon emission intensity.
REVIEW | doi:10.20944/preprints202104.0383.v1
Subject: Engineering, Automotive Engineering Keywords: COVID-19; pandemic; construction project; risk management; use of technology; recovery and resilience
Online: 14 April 2021 (14:12:17 CEST)
The global coronavirus (COVID-19) pandemic has created a whole new set of risks in construction industries generating unprecedented delays, disruptions, and uncertainty on construction projects, and has forced the industries in adopting more sophisticated technologies while combating the reduced workforce on job sites. Further, the post-pandemic era of construction is expected to be a lot different as the industries will embrace the technology as the augmentation and collaboration strategy. Thus, it will be extremely hard to sustain for construction industries in the absence of effective risk management. The existing risk plans need to be inspected for their capability of handling new risks arising from COVID-19 and the project managers will need to make the necessary revisions as needed. This paper discusses on past (NORM), present (NEW NORM), and future (Post COVID-19 NORM) of the construction industry and highlights key strategies for managing projects and construction risks during and post COVID-19 pandemic.
ARTICLE | doi:10.20944/preprints202103.0455.v1
Subject: Engineering, Automotive Engineering Keywords: Total Quality Management; construction projects; Saudi Arabia; Harris-hawks optimization; support vector regression
Online: 17 March 2021 (17:01:02 CET)
This research is aimed at evaluating two different scenarios, firstly, appraising the impacts of employing the concepts of Total Quality Management (TQM) to the construction projects in Saudi Arabia. The results of the study were obtained through utilization of a descriptive analytical approach, where 300 questionnaires were distributed to engineering firms and companies with a response rate of 200 questionnaires, hence achieving the study sample for this research. The data gathered was analyzed by applying the Statistical Package for Social Science (SPSS) program and calculating the Relative importance index (RII) and the mean values. From the research conducted, the outcomes showed that the management’s ability to commit using TQM while applying BIM obtained a relative importance of (0.717), while the relative importance for the management’s ability to commit using TQM without the application of BIM is (0.552). The results showed that construction projects in Saudi Arabia still sustain setbacks from applying TQM concepts and suffer from the lack of administrative, scientific and technical applications. In a second scenario, a hybridized support vector regression (SVR) Harris-hawks optimization (HHO) (i.e., SVR-HHO) were used to predict the TQM. The performance accuracy of the models was checked through three different evaluation metrics namely; mean square error (MSE), correlation co-efficient (CC) and Nash-Sutcliffe efficiency (NSE). the hybridized emerging SVR-HHO outperformed the other two data driven approaches in both the training and testing stages based on the employed evaluation metrics. Overall, the obtained results showed that both the machine learning and metaheuristic approaches were capable of predicting TQM.
ARTICLE | doi:10.20944/preprints202005.0213.v1
Subject: Engineering, Construction Keywords: BIM; construction; critical infrastructure; cybersecurity; cyber-physical systems; digital twin; EPCIP; Industry 4.0
Online: 12 May 2020 (12:44:01 CEST)
The umbrella concept for the current efforts to digitize construction is known as Construction 4.0. One of its key concepts is cyber-physical systems. The construction industry is not only creating increasingly valuable digital assets (in addition to physical ones) but also the buildings and built infrastructures are increasingly monitored and controlled using digital technology. Both make construction a vulnerable target of cyber-attacks. While the damage to digital assets, such as designs and cost calculations, may result in economic damage, attacks on digitally-controlled physical assets may damage the well-being of occupants and, in worst-case scenarios, even damage (or death) to the users. The problem is amplified by the emerging cyber-physical nature of the systems, where the human checks may be left out. We propose that construction learns from the work done in the context of critical infrastructures (CI). First, a lot of CI is construction-related, and the process of designing and building it must be secured accordingly. Second, while most assets may not be critical in the CI sense, they are critical to the operations of a business and the lives of citizens. In the end, we recommend some steps so that well-established processes of critical infrastructure protection trickle down to make Construction 4.0 and the built environment more cyber-secure. With that in mind, we describe the possible inclusion of Construction 4.0 considerations into existing critical infrastructure protection (CIP) frameworks with minimum frictions. We also propose some suggestions regarding possible future courses of action to improve the increasingly vulnerable cyber-security environment of the built environment across all life cycle phases - design, construction, operation, maintenance, and end of life.
ARTICLE | doi:10.20944/preprints201608.0210.v1
Subject: Engineering, Civil Engineering Keywords: smart city; smart city construction; urban sustainability; driving factors; grounded theory; empirical research
Online: 26 August 2016 (11:18:30 CEST)
Driving factors of smart city construction are exploratively studied by grounded theory method based on text sources from journal papers in SCI and CSSCI databases. Initial scale of driving factors about smart city construction is obtained on the basis of above analyses. This paper modifies measuring items of the initial scale with a small sample pretest and reliability test, then forms final items by exploratory factor analysis. According to the above scale, questionnaires are designed to obtain empirical data, and confirmatory factor analysis is used to verify further validity and reliability of the scale. The results show that driving factors of smart city construction include three main dimensions: problem-oriented factors, business- or technology-driven factors and endogenous development requirements.
ARTICLE | doi:10.20944/preprints202110.0315.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Code construction; minimum code distance; noise immunity; coding efficiency; theoretically achievable boundary; correction codes
Online: 21 October 2021 (15:08:02 CEST)
The digital representation of various signals allows, at the subsequent stages of their transmission, to apply correction codes that provide protection against possible errors arising from the action of interference in the communication channel. At the same time, it is important that, with the required correcting ability, these codes have the maximum possible speed. The article presents the results of calculations for linear codes, showing their really achievable limiting capabilities.
ARTICLE | doi:10.20944/preprints202008.0331.v1
Subject: Engineering, Construction Keywords: small particle size; porous ultra-thin overlay; scattering resistance; construction scheme; energy equivalence principle
Online: 15 August 2020 (05:48:32 CEST)
To address the severe distresses of asphalt pavement, a new type of pavement maintenance treatment, porous ultra-thin overlay (PUTO) with small particle size was proposed. The PUTO has a thickness of 1.5~2.5 cm and a large void ratio of 18~25%. As a newly asphalt mixture, the structure characteristics differ from traditional pavement. Therefore, it is necessary to investigated the fabrication schemes in laboratory and on-site, respectively. In this study, the optimal fabrication schemes, including compaction temperature and number of blows of PUTO were determined based on Cantabro test and volumetric parameters. Then, the corresponding relationship between laboratory and on-site compaction work was then established based on the energy equivalent principle. On this basis, the numbers of on-site rolling passes and the combination method were calculated. The results show that increased compaction temperature and number of blows reduce the height and enhance the compactness of the Marshall sample. With the same temperature and number of blows, the scattering resistance of coarse gradation (PAC-1) is better than that of fine gradation (PAC-2), and the increased asphalt viscosity significantly improves the scattering resistance of the asphalt mixture. To ensure the scattering resistance and volumetric characteristic, the initial compaction temperature of the PAC-1 and PAC-2 should not be lower than 150 °C and 165 °C, respectively. Then, the laboratory compaction work and on-site compaction work were calculated and converted based on the principle of energy equivalence. Consequently, the on-site compaction combination of rolling machines for four asphalt mixtures was determined. According to the volumetric parameters, the paving test section proved that the construction temperature and the on-site rolling combination determined by laboratory tests are reasonable, and ultra-thin overlay has good structural stability, drainage and skid resistance.
CONCEPT PAPER | doi:10.20944/preprints201811.0622.v1
Subject: Engineering, Construction Keywords: prevention through design; safety climate; lean construction; transformation-flow-value; lean project delivery system
Online: 30 November 2018 (07:57:22 CET)
The construction industry is one of the most fatal industries, so it is important to pay more attention to safety solutions. Even though work-related accidents are known as major waste in construction projects, little attention has been paid so far to incorporating safety into the lean construction framework. In this research, lean construction theory is reviewed through the lens of safety. That being so, the identified challenges in previous research on improving safety in construction projects are categorized and those related to the concept of lean project delivery are introduced. Then, the principles of the lean construction framework are explained and the relevant changes for incorporating safety into the framework are introduced and discussed. It is expected that this hybrid model would further enrich the lean construction framework. The careful attention of project executives to this model may improve the safety situation in construction projects.
ARTICLE | doi:10.20944/preprints201807.0441.v1
Subject: Engineering, Construction Keywords: prefabricated footing system; residential structures; reactive soils; modular construction; design for manufacture and assembly
Online: 24 July 2018 (05:45:06 CEST)
The consistently positive Australian economic environment and stable population increase have led to a higher demand for new houses in recent years. Prefabrication is a promising method to help alleviate the issues related to housing shortage and affordability due to reduced material wastage, construction delays due to weather conditions, unexpected costs, shortage in labour and onsite risks. With the advancements in automation and manufacturing methods such as Design for Manufacturing and Assembly (DfMA), the quality and precision of prefabricated materials is tightly controlled, and the fabrication and assembly period are reduced. However, the full potential of prefabricated construction is yet to be realised in part due to most of developments being focused on its superstructure. A review of the current available options suitable for houses is necessary to understand the present state of the residential footing industry, which will help evaluate the necessary innovations for the growth of the Australian construction industry considering the local reactive soil conditions. This paper presents a summary of existing footing systems and potential prefabricated footing solutions for low-rise residential structures with one storey to two storeys. This paper also reviews the benefits and challenges of designing, manufacturing, transporting, handling and installing of prefabricated footings on site, which have great influence on the acceptance of these innovative footing systems.
ARTICLE | doi:10.20944/preprints201709.0115.v1
Subject: Social Sciences, Econometrics & Statistics Keywords: Bivariate Kumaraswamy distribution; copula based construction; Kendall'stau; dependence structures; application in insurance risk modeling
Online: 25 September 2017 (06:55:52 CEST)
A copula is a useful tool for constructing bivariate and/or multivariate distributions. In this article, we consider a new modified class of (Farlie-Gumbel-Morgenstern) FGM bivariate copula for constructing several dierent bivariate Kumaraswamy type copulas and discuss their structural properties, including dependence structures. It is established that construction of bivariate distributions by this method allows for greater flexibility in the values of Spearman's correlation coefficient rho, and Kendall's tau . For illustrative purposes, one representative data set is utilized to exhibit the applicability of these proposed bivariate copula models.
ARTICLE | doi:10.20944/preprints201608.0143.v1
Subject: Engineering, Civil Engineering Keywords: participatory modelling; causal loop diagram development; structural analysis; systems modelling; construction innovation; Russian Federation
Online: 15 August 2016 (08:56:30 CEST)
This research integrates systemic and participatory techniques to model the Russian Federation construction innovation system. Understanding this complex construction innovation system, and determining the best levers for enhancing it, requires the dynamic modelling of a number of factors such as flows of resources and activities, policies, uncertainty and time. To build the foundations for such a dynamic model, the employed study method utilised an integrated stakeholder-based participatory approach coupled with structural analysis (MICMAC - Matrice d'Impacts Croisés Multiplication Appliquée à un Classement Cross-Impact Matrix). This method identified the key factors of the Russian Federation construction innovation system, their causal relationship (i.e. influence/dependence map) and ultimately a causal loop diagram. The generated model reveals pathways to improving construction innovation in the Russian Federation, and underpins the future development of an operationalised systems dynamic model.
ARTICLE | doi:10.20944/preprints202109.0445.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: Many-sorted partial algebra; free completion; category of completions; weakly initial object; comma category of objects over a completion; Schmidt construction; Schmidt homomorphism; twisted morphism category; Schmidt endofunctor; functoriality of the Schmidt construction
Online: 27 September 2021 (11:45:35 CEST)
After proving, in a purely categorial way, that the inclusion functor InAlg(Σ) from Alg(Σ), the category of many-sorted Σ-algebras, to PAlg(Σ), the category of many-sorted partial Σ-algebras, has a left adjoint FΣ, the (absolutely) free completion functor, we recall, in connection with the functor FΣ, the generalized recursion theorem of Schmidt, which we will also call the Schmidt construction. Next we define a category Cmpl(Σ), of Σ-completions, and prove that FΣ, labeled with its domain category and the unit of the adjunction of which it is a part, is a weakly initial object in it. Following this we associate to an ordered pair (α,f), where α=(K,γ,α) is a morphism of Σ-completions from F=(C,F,η) to G=(D,G,ρ) and f a homomorphism in D from the partial Σ-algebra A to the partial Σ-algebra B, a homomorphism ΥαG,0(f):Schα(f)B. We then prove that there exists an endofunctor, ΥαG,0, of Mortw(D), the twisted morphism category of D, thus showing the naturalness of the previous construction. Afterwards we prove that, for every Σ-completion G=(D,G,ρ), there exists a functor ΥG from the comma category (Cmpl(Σ)↓G) to End(Mortw(D)), the category of endofunctors of Mortw(D), such that ΥG,0, the object mapping of ΥG, sends a morphism of Σ-completion in Cmpl(Σ) with codomain G, to the endofunctor ΥαG,0.
ARTICLE | doi:10.20944/preprints202111.0254.v1
Subject: Engineering, Construction Keywords: Korean Heritage; Asian Architecture; Tadao Ando; Hypogeal Chambers; Architectural Proportions; Ashlar Construction; Innovative Architectural Projects.
Online: 15 November 2021 (11:23:12 CET)
The purpose of this article is to disclose the architectural proportions and nature of the Korean national treasure in Seokguram Grotto, Gyeongju. The authors compare its features with those of other ancient hypogeal or ashlar constructions and intend to rediscover its relevant hidden configuration and latent structural properties to show its uniqueness. The methods employed in the research belong initially to architectural design and composition to advance at a later stage, into the nuances of stone masonry, lighting effects or cohesive construction. In this discussion and thorough analysis, different philosophical and scientific subtleties come afloat. The results demonstrate a significant potential capable to be applied in part to recent architectural developments like Tadao Ando’s Buddha Hill in Hokkaido (2017) and the authors’ own project for a Buddhist monument.
ARTICLE | doi:10.20944/preprints202106.0208.v1
Subject: Arts & Humanities, Linguistics Keywords: insubordinated constructions; the expressive function of language; language and emotion; ni que construction in Spanish
Online: 8 June 2021 (10:34:07 CEST)
Authors such as Schnoebelen (2012: 12) suggest that in some languages (cf. Navajo) certain dependent clauses are frequently used independently to “mark emotional evaluation and background information”. Evans (2007) uses the term insubordination to refer to this phenomenon. Our study focuses on a particular insubordinate construction introduced by the sequence ni que in Spanish, as in the example [¡Una carta cada día!] Ni que yo fuese Umbral. (CORPES 100), used as an independent clause with a sociopragmatic meaning which is different from that of its subordinate counterpart (cf. No escribiría una carta cada día ni que yo fuese Umbral). Our research questions ask about the potential for ni que to be used as a discourse marker fulfilling an expressive function when it introduces this type of construction, and the derived hypothesis is then oriented to test whether Schnoebelen's (2012) observation about insubordinate constructions applies also to this Spanish construction. In order to test this hypothesis, we performed a functional-discourse analysis of more than 2000 concordances (and their extended contexts) in Mark Davies' Corpus del Español and the Real Academia CORPES XXI. Our findings show that the insubordinate construction differs in function and meaning from its subordinate counterpart, the former fulfilling a stronger emotive function, often combined with other discourse-pragmatic functions, such as evaluation or the organization of discourse.
ARTICLE | doi:10.20944/preprints202010.0168.v2
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: Genetic Programming; Evolutionary Computation; Machine Learning; Classification; Multiclass Classification; Feature Construction; Hyper-features; Spectral Indices
Online: 24 December 2020 (08:59:19 CET)
Genetic Programming (GP) is a powerful Machine Learning (ML) algorithm that can produce readable white-box models. Although successfully used for solving an array of problems in different scientific areas, GP is still not well known in Remote Sensing. The M3GP algorithm, a variant of the standard GP algorithm, performs Feature Construction by evolving hyper-features from the original ones. In this work, we use the M3GP algorithm on several sets of satellite images over different countries to create hyper-feature from satellite bands to improve the classification of land cover types. We add the evolved hyper-features to the reference datasets and observe a significant improvement of the performance of three state-of-the-art ML algorithms (Decision Trees, Random Forests and XGBoost) on multiclass classifications and no significant effect on the binary classifications. We show that adding the M3GP hyper-features to the reference datasets brings better results than adding the well-known spectral indices NDVI, NDWI and NBR. We also compare the performance of the M3GP hyper-features in the binary classification problems with those created by other Feature Construction methods like FFX and EFS.
ARTICLE | doi:10.20944/preprints202009.0657.v1
Subject: Medicine & Pharmacology, Allergology Keywords: HIV; workplace intervention; SMS; HIV testing; construction; mobile phone; Covid-19; health promotion; text messaging
Online: 27 September 2020 (03:02:41 CEST)
Background: HIV poses a threat to global health. With effective treatment options available, education and testing strategies are essential in preventing transmission. Text messaging is an effective tool for health promotion and can be used to target higher risk populations. This study reports on the design, delivery and testing of a mobile text messaging SMS intervention for HIV prevention and awareness, aimed at adults in the construction industry and delivered during the COVID-19 pandemic. Method: Participants were recruited at Test@Work workplace health promotion events (21 sites, n=464 employees), including health checks with HIV testing. Message development was based on a participatory design and included a focus group (n=9) and message fidelity testing (n=291) with assessment of intervention uptake, reach, acceptability, and engagement. Barriers to HIV testing were identified and mapped to the COM-B behavioural model. 23 one-way push SMS messages (19 included short web links) were generated and fidelity tested, then sent via automated SMS to two employee cohorts over a 10-week period during the COVID-19 pandemic. Engagement metrics measured were; opt-outs, SMS delivered/read, number of clicks per web link, and four two-way pull messages exploring repeat HIV testing, learning new information, perceived usefulness and behaviour change. Results: 291 people participated (68.3% of eligible attendees). A total of 7,726 messages were sent between March and June 2020, with 91.6% successfully delivered (100% read). 12.4% of participants opted out over 10 weeks. Of delivered messages, links were clicked an average of 14.4%, max 24.1% for HIV related links. The number of clicks on web links declined over time (r= -6.24, p=0.01). Response rate for two-way pull messages was 13.7% of participants. Since the workplace HIV test offer at recruitment, 21.6% reported having taken a further HIV test. Qualitative replies indicated behavioural influence of messaging on exercise, lifestyle behaviours and intention to HIV test. Conclusion: SMS messaging for HIV prevention and awareness is acceptable to adults in the construction industry, has high uptake, low attrition and good engagement with message content, when delivered during a global pandemic. Data collection methods may need refinement for audience and effect of COVID-19 on results is yet to be understood.
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: ilicosis; silicon powder; crystalline silica (SiO2); construction workers; occupational exposure; occupational exposure limit; occupational hygiene
Online: 8 April 2020 (04:22:26 CEST)
Chronic exposure of workers to powder containing crystalline silica (SiO2) can lead to chronic lung diseases (lung cancer, silicosis, etc.). The aim of the study was to evaluate the exposure of Greek construction workers to SiO2 and describe their pulmonary function. The study involved 86 outdoor and underground workers. Medical and professional history was obtained, and breath samples were collected at morning hours through a mask for the determination of SiO2 levels. Pulmonary function tests, radiological examination and evaluation of radiographs were, also performed. During the examination of the pulmonary function, the majority of the workers were within normal range (61.4%) while the rest were diagnosed with mild (26.5%) and more severe impairment (7.2%). Working conditions (underground-outdoor) were statistically significantly related to the categorization of pulmonary function (p = 0.038). During radiological examination, the type of working conditions (underground-outdoor) were statistically significantly related to the categorization of these findings (p = 0.044). Of the 69 employees, 52 did not present findings (75.4%) and five (5) were diagnosed with findings specific to occupational diseases (7.2%). The environmental exposure to RCS (Respirable crystalline silica) was detected at 0,0125 mg/ m3 in the workplace, which is not beyond the legal limits. Underground workers with more than 15 years of exposure to SiO2 are more likely to present chronic silicosis compared to the workers of outdoor activities.
ARTICLE | doi:10.20944/preprints201912.0411.v1
Subject: Engineering, Construction Keywords: safety; electrical contractors; construction accidents; nature and outcome of injuries; Chi-square test of independence
Online: 31 December 2019 (11:19:50 CET)
Electrical contractors have experienced a rise in occupational fatalities in recent years. In 2017, electrical contractors also had the second highest number of non-fatal injuries among specialty trade contractors. Identifying statistically significant dependencies between these catastrophic outcomes and a handful of well-defined contributing factors in construction accidents offers a first step in mitigating the risks of construction accidents in this trade. Therefore, this study used methodologies of descriptive and quantitative statistics to identify the contributing factors most affecting occupational accident outcomes among electrical contracting enterprises, given an accident occurred. Accident reports were collected from the Occupational Safety and Health Administration’s fatality and catastrophe database. To ensure the reliability of the data, the team manually codified more than 600 incidents through a comprehensive content analysis using injury-classification standards. Inclusive of both fatal and non-fatal injuries, the results showed that most accidents happened in nonresidential buildings, new construction, and small projects (i.e., $50,000 or less). The main source of injuries manifested in parts and materials (46%), followed by tools, instruments, and equipment (19%), and structure and surfaces (16%). The most frequent types of injuries were fractures (31%), electrocutions (27%), and electrical burns (14%); the main injured body parts were upper extremities (25%), head (23%), and body system (18%). Among non-fatal cases, falls (37%), exposure to electricity (36%), and contact with objects (19%) caused most injuries; among fatal cases, exposure to electricity was the leading cause of death (50%), followed by falls (28%) and contact with objects (19%). The analysis also investigated the impact of several accident factors on the degree of injuries and found significant effects from such factors such as project type, source of injury, cause of injuries, injured part of body, nature of injury, and event type. In other words, the statistical probability of a fatal accident—given an accident occurrence—changes significantly based on the degree of these factors. Beyond these outcomes, the described content-analysis methodology contributes to the accident-analysis body of knowledge by providing a framework for codifying data from accident reports to facilitate future analysis and modeling attempts (e.g., developing logistic regression models) to subsequently mitigate more injuries in other fields.
ARTICLE | doi:10.20944/preprints201811.0059.v1
Subject: Keywords: History of Modern Architecture; 20th Century; Walter Gropius; Rationalization; Construction Kit; Assembly Line; Weimar Republic; Bauhaus
Online: 2 November 2018 (13:23:10 CET)
With the breakthrough of modernism, various efforts are undertaken to rationalize architecture and building processes using industrial principles. Few architects explore these as intensively as Walter Gropius, the founder of the Bauhaus. Even before World War One, and increasingly in the interwar years, Gropius and a number of colleagues undertake various experiments which manifest in a series of projects, essays, model houses and Siedlungen. These aim at conceptually different goals, i.e. they follow two different categories of industrial logic: first, a flexible construction kit and, second, an assembly line serial production. This article traces the genesis of these two concepts and analyses their characteristics using these early manifestations. Compared to existing literature, this article takes into account hitherto neglected primary sources as well as technological and construction history aspects—allowing for a distinction based not only on theoretical, but also technological and structural characteristics. This article shows that Gropius succeeds in formulating and exploring the two principles in theory and practice as well as drawing conclusions by the end of the 1920s. With them, he contributed significantly to the rationalization of architecture, and his principles have been picked up and developed further by numerous architects since then.
ARTICLE | doi:10.20944/preprints201810.0067.v1
Subject: Engineering, Civil Engineering Keywords: Digital construction, concrete, 3D-printing, extrusion-based deposition, layer interfaces, bond strength, cold joints, concrete testing
Online: 3 October 2018 (17:44:13 CEST)
Interfaces between layers in 3D-printed elements produced by extrusion-based material deposition were investigated on both macro- and micro-scales. On the macro-scale, compression and bend tests were performed on two 3D-printable cement-based compositions (3PCs), namely C1 and C2. The influences of binder composition and time interval between layers on layer-interface strength were critically analyzed. In the context of additive manufacturing, the optimized composition C2, containing pozzolanic additives, exhibited mechanical performance superior to that of the mixture with Portland cement as the sole binder. In particular, Mixture C2 showed a less pronounced decrease in interface tensile strength. Even for time intervals between depositions of two layers as long as 1 day the loss in corresponding flexural strength was below 25%, as compared with C2 specimens tested in the perpendicular direction. In contrast, the decrease in flexural strength measured for C1 specimens amounted to over 90% for the same set of parameters. Higher porosity at the interfaces of the printed concrete layers was identified as the cause for the lower interface strengths of C1. Microscopic observations supported the findings of the macroscopic investigations. While a pronounced recovery (“self-healing”) of the porous, discontinuous interlayers was observed with increasing age for Mixture C2, in case of C1 the filling products grown in the porous interlayer were found to be non-strengthening.
ARTICLE | doi:10.20944/preprints201810.0019.v1
Subject: Engineering, Construction Keywords: Building Information Modeling (BIM); Benefit-Cost Analysis (BCA); Railway construction; Liquidated damage; Infrastructure; Planning and design
Online: 1 October 2018 (16:54:20 CEST)
Recent technological improvements have made abundant changes in construction industry. In specific, some technical applications, such as Building Information Modeling (BIM) opens up many possibilities. Some studies have articulated the use of BIM and its advantages in construction, but most of them are theoretical, not practical. This study is to provide an insight to such obstacles in BIM research. By investigating a real project that could utilize BIM in planning and construction phases, the authors try to investigate a possible outline of advantages in BIM implementation. The study area was set to a railway construction site in South Korea. The site covers a multiple railway tracks, stations, telecommunication facilities, infrastructure facilities, railway structures, and so numerous. In the site, the authors have identified 12 errors in 7 projects that could be prevented if BIM was utilized before the construction. The total upfront costs required to provide a BIM for 7 projects were $116,348. On the other hand, the total costs required to fix the errors in 7 projects were $166,486. This can be regarded as the benefits of using BIM because if BIM was implemented then the associated errors are easily replaced. Therefore, the benefit-cost ratio can be estimated as 1.32 for one-month delay and 1.36 for a three-month delay.
ARTICLE | doi:10.20944/preprints201806.0387.v1
Subject: Engineering, Civil Engineering Keywords: alkali activated materials; construction and demolition waste; brick powder; acid resistance; extruded polystyrene aggregates lightweight materials
Online: 25 June 2018 (12:26:06 CEST)
The annual construction and demolition waste (CDW) generated from EU construction sector was 850 million tons, which represented 31% of the total waste generation and about 28% of CDW was ceramics (bricks and tiles). In this study, the feasibility of using CDW brick powder as the precursor of alkali activated mortar (AAM) and extruded polystyrene (XPS) as the lightweight aggregates to form lightweight brick powder AAM (LW-BP-AAM) for non-structural applications was investigated. The thermal conductivity of LP-BPAAM was 0.112 W/m·K with density of about 1,135 kg/m3 which was lower than the counterparts with similar density in literature. The acid resistance of LW-BP-AAM is comparable to conventional fly ash based AAM and superior than ordinary Portland cement. From the scanning electron microscopy with energy dispersive X-ray spectroscopy, there was no severe damage on the surface of LW-BP-AAM but aluminate was removed from the matrix which was further verified in Fourier transform infrared spectroscopy. The mass and strength loss of LP-BP-AAM was 1.5% and 33%, respectively. Although the compressive strength of the LP-BP-AAM was low (about 1.8 MPa), it can be improved by optimising the particle size of the XPS aggregates.
ARTICLE | doi:10.20944/preprints202010.0361.v1
Subject: Engineering, Automotive Engineering Keywords: Accident; Accident connotation; Accident science; New definition of safety; Conceptual model of accident science; Discipline basic construction
Online: 19 October 2020 (09:25:37 CEST)
In order to establish a new discipline specializing in accident science from the perspective of safety science. Under the guidance of the current research theories and methods of safety science, combined with the research paradigm of humanities and social medicine, this paper puts forward new viewpoints, new theories and new models about accident research. First of all, through literature retrieval, this paper analyzes the relevant research results of accidents at home and abroad, and expounds the existing problems and the basic trend of accident science research. Secondly, it puts forward eight kinds of attribute relations of the accident, and makes clear the characteristics and connotation of the accident. In the study of accident types, a hierarchical classification model based on accident cognition is created for the first time. It also points out the logical relevance of five levels of accident science research and the realistic relevance of three levels. At the same time, according to the thought of science of science, this paper puts forward a new definition of safety under the thinking of accident science and other basic concepts related to safety science, and explains the connotation. In addition, it creates and constructs the basic concept of accident science, establishes the conceptual model of accident science, and points out the “3-4-5” model of accident science research and its connotation. Thirdly, draw lessons from the interdisciplinary paradigm to study the relevant theoretical basis and discipline classification relationship of accident science, and construct the tree of accident science. Finally, the research contents of three main aspects of accident science are summarized. The results show that the research results in this paper not only play a fundamental role in the basic construction of accident science, but also further enrich and perfect the discipline system of safety science, which has a certain theoretical significance.
ARTICLE | doi:10.20944/preprints201809.0056.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: mmWave; 5G heterogeneous network; meshed backhaul; outdoor dynamic crowd; SDN; dynamic construction; testbed; numerical analysis; experimental validation
Online: 4 September 2018 (05:51:50 CEST)
5G heterogeneous network overlaid by millimeter-wave (mmWave) access employs mmWave meshed backhauling as a promising cost-efficient backhaul architecture. Due to the nature of mobile traffic distribution in practice which is both time-variant and spatially non-uniform, dynamic construction of mmWave meshed backhaul is prerequisite to support the varying traffic distribution. Focusing on such scenario of outdoor dynamic crowd (ODC), this paper proposes a novel method to control mmWave meshed backhaul for efficient operation of mmWave overlay 5G HetNet through Software-Defined Network (SDN) technology. Our algorithm is featured by two functionalities, i.e., backhauling route multiplexing for overloaded mmWave small cell base stations (SC-BSs) and mmWave SC-BSs’ ON/OFF status switching for underloaded spot. In this paper, the effectiveness of the proposed meshed network is confirmed by both numerical analyses and experimental results. Simulations are conducted over a practical user distribution modeled from measured data in realistic environments. Numerical results show that the proposed algorithm can cope with the locally intensive traffic and reduce energy consumption. Furthermore, a WiGig (Wireless Gigabit Alliance certified) device based testbed is developed for Proof-of-Concept (PoC) and preliminary measurement results confirm the proposed dynamic formation of the meshed network’s efficiency.
DATA DESCRIPTOR | doi:10.20944/preprints202108.0295.v3
Subject: Engineering, Other Keywords: sustainability; sustainable building criteria; sustainable building planning and design; sustainable site selection; sustainable construction; performance and renovation criteria.
Online: 28 December 2021 (10:52:46 CET)
Published data or available literature on sustainable building plan-design, construction, performance, and renovation criteria have covered some stages or some parts of each stage. These data usually have been published partially in many different papers―there have not been any papers that published these data together. Hence, this paper aims to collectively review these data and publish them together. The collection and review of these data were carried out by our twenty-five team members who specialized in sustainable urban, architectural, and civil engineering and construction management. The gathered and reviewed outputs were combined and validated based on a general group consensus. This consensus decision-making proceeded through two major group meetings with several follow-up meetings. The first major meeting was to combine and improve the gathered reviewed sustainable building criteria for Cambodia. The second major meeting was to validate the improved reviewed sustainable building criteria for Cambodia. The several follow-up meetings were to discuss the relevance and importance of the validated data “criteria and their classifications and descriptions” in all stages and more focused on their importance and applicability to Cambodia. The collective reviewed data in this paper would be useful to researchers in the fields. They could also be useful collective knowledge and information for policymakers from governmental agencies and development partners, particularly for sustainable building and construction companies.
ARTICLE | doi:10.20944/preprints202012.0800.v1
Subject: Social Sciences, Accounting Keywords: organizational learning; circular economy; small and medium enterprises (SMEs); business model; supply chain; construction; Italy; Barrier and enabler
Online: 31 December 2020 (12:40:30 CET)
To contribute to small and medium enterprises (SMEs) sustainable transition into the circular economy, the study proposes the activation of organizational learning (OL) processes – denoted here as multi-level knowledge creation, transfer, and retention processes – as a key phase in introducing circular business models (CBMs) at SME and supply chain (SC) level. The research employs a mixed-method approach, using the focus group methodology to identify contextual elements impacting on CBM-related OL processes, and a survey-based evaluation to single out the most frequently used OL processes inside Italian construction SMEs. As main result, a CBM-oriented OL multi-level model offers a fine-grained understanding of contextual elements acting mutually as barriers and drivers for OL processes, as possible OL dynamics among them. The multi-level culture construct – composed of external stakeholders’, SC stakeholders’, and organizational culture – identify the key element to activate CBM-oriented OL processes. Main implications are related to the identification of cultural, structural, regulatory, and process contextual elements across the external, SC, and organizational levels, and their interrelation with applicable intraorganizational and interorganizational learning processes. The proposed model would contribute to an improved implementation of transitioning into the circular economy utilizing sustainable business models in the construction SMEs.
Subject: Arts & Humanities, Anthropology & Ethnography Keywords: spiritual intelligence; leadership; Bible; project management; supply chain; workplace spirituality; theology of work; construction; neuroscience; cognitive psychology; psychoanalysis; neurology
Online: 3 August 2021 (09:36:11 CEST)
Spiritual intelligence had an impact on different biblical leaders, and in this text, we see some cases to serve as a sample (Joseph, Bezalel, and Daniel). In the Bible, this impact is demonstrated in innovations introduced by Joseph in Egypt, Bezalel the manager of the macro project of building in crisis time, Daniel the politician. It is the supreme intelligence and leaders are invited to make a shift from rationality to spirituality. The more leaders of organizations will use spiritual intelligence, the more leaders and followers will experience satisfaction, joy, accomplishment.
ARTICLE | doi:10.20944/preprints201807.0581.v1
Subject: Engineering, Civil Engineering Keywords: panelised construction; lightweight frames; hybrid systems; cold formed steel; hot rolled steel; design for earthquake, lateral force resisting system
Online: 30 July 2018 (10:24:10 CEST)
A new lateral force-resisting wall panel is presented for applications in mid-rise prefabricated lightweight steel construction in seismic prone regions. This panelised system is composed of a hot-rolled frame and cold-formed studs and tracks, which works as a lateral force resisting system in lightweight steel framing. The proposed hybrid panel system exhibits proper ductility and energy dissipation behaviour. The hysteretic responses of full-scale panel experiments demonstrate that the system can safely resist high cyclic loads. The hot-rolled steel part, on the other hand, can significantly improve the initial lateral stiffness of the total system that will control the maximum allowable drift of multi-story buildings. Finally, in a case study, by applying the proposed system to the design of a mid-rise building in a high seismic area, the performance of the hybrid panels, are compared with those of fully hot-rolled systems (moment resisting frames) and fully cold formed systems. The findings indicate that applying hybrid panels will result in lower weights and better performance in seismic prone regions.
ARTICLE | doi:10.20944/preprints201706.0038.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Public bus transportation; Battery-swapping e-bus; Battery charging; Construction costs; Particle swarm optimization (PSO); PSO-genetic algorithm (GA)
Online: 6 June 2017 (17:52:24 CEST)
The greenhouse gases and air pollution generated by extensive energy use have exacerbated climate change. An electric-bus (e-bus) transportation system favors reducing pollution and carbon emissions. This study analyzed the minimization of construction costs for an all battery-swapping public e-bus transportation system. A simulation was conducted according to existing timetables and routes. Daytime charging was incorporated during the hours of operation; the two parameters of the daytime charging scheme were the residual battery capacity and battery-charging energy during various intervals of daytime peak electricity hours. The parameters were optimized using three algorithms: particle swarm optimization (PSO), a genetic algorithm (GA), and a PSO–GA. This study observed the effects of optimization on cost changes (e.g., number of e-buses, on-board battery capacity, number of extra batteries, charging facilities, and energy consumption) and compared the plug-in and battery-swapping e-bus systems. The results revealed that daytime charging can reduce the construction costs of both systems. In contrast to the other two algorithms, the PSO–GA yielded the most favorable optimization results for the charging scheme. Finally, according to the cases investigated and the parameters of this study, the construction cost of the plug-in e-bus system was lower than that of the battery-swapping e-bus system.
ARTICLE | doi:10.20944/preprints201808.0040.v1
Subject: Physical Sciences, Mathematical Physics Keywords: British Columbia; environmental assessment; marine construction; circulation; numerical model; sediment model; tidal current; wind-driven current; stratification; initial dilution zone
Online: 2 August 2018 (08:36:50 CEST)
Major marine construction projects, resulting in the release of sediments, are subject to environmental assessment and other regulatory approval processes. An important tool used for this is the development of specialized numerical methods for these marine activities. An integrated set of numerical methods addresses four distinct topics: the near-field release and mixing of suspended sediments into the water column (i.e. the initial dilution zone); the transport of the suspended sediments under the influence of complex ocean currents in the far-field; the settling of the transported suspended sediments onto the seabed; and the potential for resuspension of the deposited sediments due to sporadic occurrences of unusually large near-bottom currents. A review of projects subjected to environmental assessment in the coastal waters of British Columbia from the year 2006 to 2017, is presented to illustrate the numerical models being used and their ongoing development. Improvements include higher resolution model grids to better represent the near-field, the depiction of particle size dependent vertical settling rates and the computation of resuspension of initially deposited sediments, especially in relation to temporary subsea piles of sediments arising from trenching for marine pipelines. The ongoing challenges for this numerical modeling application area are also identified.
ARTICLE | doi:10.20944/preprints202108.0557.v1
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: Conoid; Ellipse; Ramanujan; Calculus of surface areas; number Psi; number Pi; 3D-construction of complex Geometries; Engineering Design Objects; Architectural Forms.
Online: 31 August 2021 (11:04:18 CEST)
Unlike the volume, the expression for the lateral area of a regular conoid has not yet been obtained by means of direct integration or a differential geometry procedure. As this form is relatively used in engineering, the inability to determine its surface, represents a serious hindrance for several problems which arise in radiative transfer, lighting and construction, to cite just a few. Since this particular shape can be conceived as a set of linearly dwindling ellipses which remain parallel to a circular directrix, a typical problem appears when looking for the length of such ellipses. We conceived a new procedure which, in principle, consists in dividing the surface into infinitesimal elliptic strips to which we have subsequently applied Ramanujan’s second approximation. In this fashion, we can obtain the perimeter of any ellipse pertaining to the said form as a function of the radius of the directrix and the position of the ellipse’s center on the X-axis. Integrating the so-found perimeters of the differential strips for the whole span of the conoid, an unexpected solution emerges through the newly found number psi (ψ). As the strips are slanted in the symmetry axis, their width is not uniform and we need to perform some adjustments in order to complete the problem with sufficient precision. Relevant implications for technology, building science, radiation and structure are derived in the ensuing discussion.
TECHNICAL NOTE | doi:10.20944/preprints202102.0304.v1
Subject: Engineering, Automotive Engineering Keywords: Field Information Modeling (FIM)™; point cloud to BIM; point cloud vs. BIM; n-D information modeling; digital engineering and construction
Online: 12 February 2021 (13:19:06 CET)
This study presents established methods, along with new algorithmic developments, to automate the point cloud processing within the Field Information Modeling (FIM)™ framework. More specifically, given an n-D designed information model, and the point cloud’s spatial uncertainty, the problem of automatic assignment of the point clouds to their corresponding elements within the designed model is considered. The methods addressed two classes of field conditions, namely, (i) negligible construction errors; and (ii) existence of construction errors. The emphasis was given to describing and defining the assumptions in each method and shed light on some of their potentials and limitations in practical settings. Considering the shortcomings of current point cloud processing frameworks, three new and generic algorithms were developed to help solve the point cloud to model assignment in field conditions with both negligible, and existence (or speculation) of construction errors. The effectiveness of the new methods was demonstrated in real-world point clouds, acquired from construction projects, with promising results.
ARTICLE | doi:10.20944/preprints201807.0623.v1
Subject: Engineering, Civil Engineering Keywords: Panelised and Modular Prefabricated construction, Weatherproofing and Waterproofing, Sealing joints of façade components and walls, Finite Element Analysis, Implementation and Evaluation
Online: 31 July 2018 (12:38:00 CEST)
Prefabricated forms of construction have led to the rapid onsite assembly of buildings however there are still on-site tasks and processes which can be reevaluated and redone specifically in keeping with the principles of prefabrication instead being adapted to fit its purpose. One such process is that of waterproofing between prefabricated panels and modules which come from the factory fully complete façade and all. Conventional means of waterproofing can be used however it results in more work done on site, potential delays and generally requires access from the external face of the building. This paper presents the Modelling, Implementation and Evaluation of purpose developed weatherproof seals specific for Prefabricated Construction. An overview is provided of the entire development process and specific focus is given to the modeling using FEA computer simulations, manufacturing and testing which then resulted in the implementation in a prefabricated panelised building which is used as a case study and the means of further evaluation. These strategies have enabled an efficient and robust prefabricated waterproofing solution specific for this form of construction to be understood and implemented. The resulting case study has successfully verified the time and cost savings when compared to conventional techniques whilst still providing a durable and effective weatherproof seal for prefabricated panelised and modular systems.
ARTICLE | doi:10.20944/preprints202011.0048.v1
Subject: Engineering, Automotive Engineering Keywords: Construction safety; worker safety; Doppler radar tracking; Doppler Bearing tracking; Localization; Amplitude of returned signal; Kalman Filters; Unscented Kalman Filter; Filter initialization
Online: 2 November 2020 (14:22:18 CET)
Accidents and mishaps in industrial environments like construction, mining, and transport are rampant - mainly due to human negligence and improper monitoring of the workplace. In this paper, we address the safety of workers operating in dangerous environments by improving their situational awareness. According to Occupational health and safety rules, everyone must wear hard hats while on site. Our main idea is to make the hard hats smart by incorporating miniature-sized Doppler radars sensing the users’ surroundings. These Doppler radars are lightweight, rugged, and consume low-power compared to vision-based solutions. This paper discusses the observability of range from Doppler frequency measurements and the magnitude of estimation errors introduced by the human head, walking, and working motions. We present the framework to estimate the position of walls and targets surrounding the worker. For testing, we simulated an indoor environment with randomly moving workers. Experiments showed that once observability conditions are met, human head and walking movements can be handled through added noise in the system. We also present an innovative idea of using two Doppler radars to obtain the estimators’ initial estimates, reducing the estimation error to less than 5cm and convergence time by more than 80
Subject: Engineering, Control & Systems Engineering Keywords: energy efficiency; building automatic control; energy use under field conditions; two-stage construction process; cost-benefit evaluation; deep retrofit of residential buildings
Online: 5 July 2020 (04:55:24 CEST)
Only now, four decades after passive houses were designed in the US and built in Canada, the authors are able to discuss the next generation of new and retrofitted buildings in the same way. This paper presents a universal system for different types of buildings and climates that includes construction experience and is reinforcing multi-disciplinary synergies. A next generation of technology uses adaptable indoor climate, integrates HVAC and building structure; applies field monitoring of energy and indoor environment and develops a performance model that is based on artificial neutral network. This approach, includes: 1. The self-learning ANN as a part of the building management system, 2. This management system guides energy optimization in a post-construction stage 3. A two-stage construction process for new and retrofits. The first stage prescribes investment level and optimizes performance; opposite in the second stage. This paper highlights that some elements of the proposed methodology have already been applied in the practice. It also underlines that this integrated multi-disciplinary system can be applied with a different combination of technological elements.
ARTICLE | doi:10.20944/preprints201711.0163.v1
Subject: Engineering, Civil Engineering Keywords: D number, Analytical Network Process (ANP), MABAC, Multi-criteria decision making (MCDM), Consistent fuzzy preference relation (CFPR), Construction project risk, Risk Management
Online: 24 November 2017 (16:46:59 CET)
Multi-stakeholder based construction projects are subject to various risk factors due to dynamic business environments. These risks affect project activities which indirectly impact construction costs, resulting in delays and poor building quality. So, managing these project risks requires suitable risk mitigation strategies to evaluate and analyse their severity. Hence, risk evaluation and assessment of construction projects is a multi-criteria decision making (MCDM) problem. In present real-life problems, evaluation of project risks is often uncertain and even incomplete, and the prevailing methodologies fail to handle such situations. To address the problem, this paper extends the analytical network process (ANP) methodology in the D number domain to handle three types of ambiguous evaluations, viz. complete, uncertain, and incomplete, and assesses the weight of risk criteria. The D number based approach overcomes the deficiencies of the exclusiveness hypothesis and completeness constraint of Dempster-Shafer (D-S) theory. Here, preference ratings of the decision matrix for each decision-maker are determined using a D number extended consistent fuzzy preference relation (D-CFPR). An extended multi-attributive border approximation area comparison (MABAC) method in D number is then developed to rank and select the best alternative risk response strategy. Finally, an illustrative example from construction sector is presented to check the feasibility of the proposed approach. For checking the reliability of alternative ranking, a comparative analysis is performed with different MCDM approaches (D-COPRAS, D-ARAS, D-MABAC, and D-TOPSIS). Based on different criteria weights, a sensitivity analysis of obtained ranking of the hybrid D-ANP-MABAC model is performed for verify the robustness of the proposed method.
ARTICLE | doi:10.20944/preprints201807.0621.v1
Subject: Engineering, Civil Engineering Keywords: Panelised and Modular Prefabricated construction, Weatherproofing and Waterproofing, Sealing joints of façade components and walls, Design for Manufacturing and Assembly (DfMA), Design and Development
Online: 31 July 2018 (12:27:23 CEST)
Satisfactory weatherproofing of buildings is vital to maximise their design life and performance which requires the careful design of external sealing technologies. Systems commonly available have served well in conventional construction however with many prefabricated systems emerging in the building industry new and novel means of weatherproofing between panels and modules need to be developed purpose specific to this application. This paper presents a holistic and fundamental methodological approach to Design and Development of waterproof seals and has been applied specific for prefabricated panelised and modular systems. Two purpose specific weatherproof seals are finally presented. Flow charts of the overview of the suggested methodological approach and the processes within which include DfMA that have been incorporated into understanding and developing seals for this practical application. These strategies have enabled a resourceful and holistic set of processes that can be adapted and used for similar forms of product research in new and developing areas of construction such as prefabrication. The design and development process is thoroughly explored and has resulted in an exploration of the technical challenges and potential solutions which take into consideration factors from installation limitations to building tolerances.
ARTICLE | doi:10.20944/preprints201811.0335.v1
Subject: Engineering, Construction Keywords: 3D printing (3DP), Construction processes, Architectural design, Concrete Engineering, Numerical Modelling, Arch-Roof, High-density polyethylene (HDPE), Additive manufacturing (AM), Computer-aided design (CAD), Manufacture, Design, Sustainability
Online: 14 November 2018 (10:39:43 CET)
Three-dimensional (3D) printing technologies are transforming the design and manufacture of components and products across a variety of disciplines, however their application in the construction industry is still limited. Material deposition processes can achieve infinite geometries and have advanced from rapid prototyping and model-scale markets to their application in fabricating functional products, large objects and the construction of full-scale buildings. Many international projects have recently been realized and the construction industry is beginning to utilise these dynamic technologies. The potential advantages for integrating 3D printing into house construction are significant, these include the capacity for mass customization of designs and parameters for functional and aesthetic purposes, reduction in construction waste from highly precise material placement, and the use of recycled waste products in layer deposition materials. With the ultimate goal of improving construction efficiency and decreasing building costs, applying Strand7 Finite Element Analysis software, a numerical model was designed specifically for 3D printing in a cement mix incorporated with recycled waste product High Density Polyethylene (HDPE) and found that construction of an arched truss-like roof was structurally feasible without the need for steel reinforcements. The lab sizes prototypes were manufactured based on the destined numerical model by using a 3D printing technology. Currently available 3D printing technologies can be adopted for building construction and this paper discusses the applications, advantages, limitations and future directions of 3D printing as an innovative and viable solution for affordable house construction.