Utilizing Recycled Sand from Excavation Wastes for Sustainable Cement Mortar Production

Abstract

This research investigates the feasibility of using recycled sand produced from excavation waste as natural sand alternative for sustainable cement mortar production. Two different types of recycled sand, namely limestone powder (RS1) and scalping powder (RS2), were collected and characterized. Thorough characterization encompassed particle size distribution, morphology, specific gravity, water absorption, and chemical composition. The recycled sands are then utilized to replace natural sand in mortar compositions, with varying proportions reaching up to 20%. The properties of the produced mortars were examined using the following tests: compressive strength, workability, density, water absorption, and thermal stability via thermogravimetric analysis (TGA). The results revealed that the inclusion of RS in cement mortar led to a decrease in compressive strength and workability, coupled with an increase in water absorption for both types of recycled sand. The decline in strength became more pronounced with higher RS proportions, with RS1 demonstrating superior compressive strength compared to RS2. Despite these effects, the thermal stability of cement mortar was only marginally impacted by the presence of RS. This research underscored the promise of recycled sand from excavation waste in cement mortar production, highlighting performance characteristics and suggesting further investigation, especially regarding thermal behavior under elevated temperatures.