Experimental Investigation on Concrete Strength and Mechanical Properties Using Crushed Sandstone Dust as a Partial Replacement of Fine Aggregate

Abstract

- In recent years, the problem of natural river sand scarcity and its environmental impact has triggered the need for sustainable alternative materials. Crushed Sand Stone Dust (CSSD) is a by-product of the stone industry, which is presented as a possible substitute for natural sands. In this paper, CSSD was used as a partial replacement for fine aggregate in concrete mixtures without any chemical admixtures. A constant water-cement (W/C) ratio of 0.45 was determined, and series of concrete cubes were prepared by replacing fine aggregate with CSSD in percentages of 0%, 10%, 20%, 30%, 40%, 50%. The fresh concrete workability was assessed using slump tests, while the hardened concrete properties were evaluated in terms of compressive, flexural strengths, and water absorption values at the ages of 7 and 28 days. The obtained results indicate the possibility of using CSSD as a partial replacement for fine aggregate in concrete production. The most efficient percentage of substitution was found to be 30%, where the compressive and flexural strengths of concrete reached their maximum. Specifically, at the age of 28 days, the compressive and flexural strengths were 47.03 MPa and 4.11 MPa, which is 8.2% and 23.4% higher than those of the ordinary concrete sample, respectively. In addition, the water absorption was minimum at 30% substitution, reaching 1.03%. On the other hand, the concrete’s mechanical properties decreased by 15.4% and 26.8% on average for compressive and flexural strengths, respectively, when exceeding the 30% CSSD replacement due to low