Recycling of crushed stone powder as a partial replacement for silica powder in extruded cement panels

The continuously increasing amount of crushed stone powder normally coming from the production of crushed aggregates or sawing stone has led to an increase in the waste disposal costs or instances of improper disposal. In this study, the effective methodology to increase the utilization of crushed stone powder was studied by considering CaO/SiO2 mole ratio in mix design. The hydrothermal reaction to synthesis tobermorite related to strength development was also considered to improve rigidity in hardened cement. The results showed the optimized C/S mole ratio is 0.87 and a valid method for curing conditions relating to hardened cement was desired to be acquired by 2 h of pre-curing, 4 h of atmosphere steam curing (65 °C) and 4 h of autoclave curing (180 °C, 10 atm). The extruded panels satisfied all performance requirements relating to fire resistance as well as sound insulation and can have a possible application to building materials. The main findings of this investigation revealed that the stable crystal formation of tobermorite by the hydrothermal synthesis reaction affects the most important mechanism in hardened cement and mix design by considering C/S mole rate in addition to the analysis of microstructures promotes the recycling of crushed stone powder for building materials.