Analisis Kuat Tekan dan Lentur Beton dengan Substitusi Sebagian Agregat Halus Menggunakan Pasir Pantai

Abstract

This study aims to analyze the effect of adding beach sand  from the Matano area in Bungku Tengah District, Morowali Regency on the mechanical properties of concrete, particularly its compressive strength and flexural strength. In addition, the research is intended to determine the optimal percentage of beach sand that can be used as a partial substitute for fine aggregate, thereby effectively improving the mechanical performance of concrete.This study employs an experimental quantitative approach with analysis of variance (ANOVA). The research variables include the percentage of fine aggregate substitution (25%, 50%, 75%, 100%) and the treatment of beach sand washing (washed and unwashed). The test specimens consist of cylinders measuring 150 mm × 300 mm and reinforced beams measuring 1500 mm × 100 mm × 150 mm, all of which were cured by immersion for 28 days before being tested for compressive strength and flexural strength.The results show that the use of fully washed beach sand as a complete replacement for fine aggregate does not significantly reduce the quality of concrete. The best performance was achieved at 100% substitution, with a compressive strength of 26.65 MPa, a flexural strength of 19.82 MPa, a maximum deflection of 1.61 mm, and normal cracking. This indicates that properly washed beach sand is suitable for full use as fine aggregate in concrete