Quarry waste fines and eggshells are unavoidable wastes which relentlessly contribute to environmental load and pollution. Although a number of studies have suggested various methods for recycling, these wastes remain underutilized due to some technical constraints. In addition, no study has yet been explored on the possibility of combining quarry waste fines (QWF) and eggshell powder (ESP) for tobermorite synthesis. Tobermorite is the main component which primarily provides strength to the autoclaved aerated concrete products. For this purpose, this study seeks to evaluate the potential of QWF- ESP mix at 10%, 15% and 20% amounts of cement, respectively. The XRF, XRD, and TGA–DTA techniques were used to characterize the waste materials while physical and mechanical property tests and XRD analysis were performed on the autoclaved samples. It was found that QWF contains 53.77% SiO2, while ESP contains 97.8% CaO which are key components for tobermorite synthesis. This study also revealed that the mixture with only 10% cement has the highest compressive strength among the QWF-ESP samples. Furthermore, the formation of tobermorite in the samples was confirmed through XRD analysis. Hence, the hydrothermal curing of QWF –ESP can be further developed to produce functional tobermorite – bearing materials.

Background: Work experience is a key factor that influences safety awareness among workers. This study investigated the influence of work experience on the level of awareness on adverse health effects of silica dust exposure among stone quarry workers in Ghana while controlling for theoretically relevant compositional and contextual factors, evaluated the magnitude and order of association between the predictors and the predicted variable. Method: A cross-sectional survey data of 524 randomly selected stone quarry workers were subjected to multivariate statistical analyses. Results: Stone quarry workers who had 6 to10 years and more than 10 years of work experience were 48% (OR = 1.475, P = 0.021) and 82% (OR = 1.816, P = 0.003) respectively more likely to be aware of the adverse health effects of silica dust exposure compared to their counterparts who had 1 to 5 years work experience. Workers who had secondary or higher education were 32% (OR = 1.320, P = 0.036) more likely to be aware of the adverse health effects of silica dust exposure compared to their counterparts who had no education. Conclusion: These findings provide relevant information for managers and policymakers to plan and maximize awareness on silica dust health hazards among silica exposed workers.

Chert rock is a by-product of sand quarrying (about 40% in the geological section). All attempts to use ordinary technologies for aggregate production from chert have been economically unsuccessful, resulting in significant chert "waste" accumulation covering vast quarry areas. This paper presents the study results of the effect of microwave irradiation on the mechanical properties of chert gravel, which is mineralogically relatively homogenous and consists of fine quartz grains. The results show that an increase in irradiation time decreases the strength of chert gravel (by a factor of 4-6 for the 2.5 min of irradiation), while the quenching changes the fractional content of the samples after the crushing test, decreasing the Gravel-to-Sand ratio.