Utilization of Recycled Concrete Sand in Soil Stabilization

Abstract

In this research, the efficacy of recycled concrete sand (RCS), a by-product of demolished concrete structures, as an alternative to traditional lime for soil stabilization was investigated. The study examined RCS from four different categories of parent concrete, sorted based on their original compressive strengths (30–39 MPa, 40–49 MPa, 50–59 MPa, and 60–69 MPa), applied to lean clay soil. Hydrated lime and natural sand were used as comparative references. Key assessments were performed using Unconfined Compressive Strength (UCS) test to investigate the mechanical property of the stabilized soils after 28 days of curing. The study observed an increase in pH values due to calcium hydroxide leaching from RCS, resulting in improved soil strength. A direct correlation was found between the parent concrete strength and the 7th-day strength of the stabilized soil, revealing higher strength in the soil stabilized with RCS derived from stronger parent concrete. Additionally, the physical shape of the RCS, due to the impact crushing method, facilitated better interlocking and binding mechanisms. The research concludes that RCS has potential for soil stabilization, enhancing its mechanical properties. However, further investigations on durability are needed to fully comprehend the potentiality of RCS in this application. This study contributes to the expanding body of knowledge regarding sustainable and cost-effective alternatives in the construction industry.