Feasibility of recycling marble waste powder as fine aggregate in self-compacting sand concrete

Building materials generate about half of solid waste worldwide, with an environmental impact at every step of its production process, i.e., extraction of raw materials, processing, manufacturing, transportation, construction, and disposal at the end of a building’s useful life. Among these materials, we distinguish the marble powder waste (MW). This work aims to study the possibility of recycling MW, especially those from the cutting and polishing process of marble stone discharged in nature. After collecting, these wastes were crushed, extruded in the form of grains, and used in the mass of self-compacting sand concrete (SCSC) as a partial replacement of natural sand volume with different percentages (10, 20, 30, 40, and 50%). The obtained results show a decrease in the fluidity and an increase in the density and occluded air of SCSC with increasing MW content. However, the compressive and flexural strengths of SCSC are improved by about 24% and 28% for a 10% substitution ratio of natural sand with MW and maintained comparable to CSCSC for up to 50% MW. The capillary water absorption, shrinkage, and thermal conductivity of all MW-based SCSCs are greater than those of the control SCSC. However, up to 40% of MW content, all SCSC mixes are classified as acceptable for structural application with water absorption and shrinkage less than 10% and 1000 m/m, respectively. This study also ensures that reusing marble wastes in SCSC gives a positive approach to reduce the cost of materials and solve some environmental problems.