Pemanfaatan Limbah Beton Mini Pile Sebagai Subsitusi Parsial Agregat Kasar Dengan Variasi 10%-50% Terhadap Kuat Tekan Beton Mutu Fc’ 20 Mpa

This study aims to analyze the effect of utilizing mini-pile concrete waste (K-500) as a partial substitution for natural coarse aggregate from Tanjung Balai with variations of 10%, 20%, 30%, 40%, and 50% on fresh concrete performance and compressive strength for a target strength of f'c = 20 MPa (K-250). Material characterization showed that the recycled aggregate has a specific gravity of 2.61, moisture content of 1.69%, and water absorption of 0.92%. The test results indicated that increasing waste content reduced the slump value of fresh concrete, while the hardened unit weight at 7–14 days ranged between 2,310–2,410 kg/m³. Cylinder compressive strength tests at 7 days yielded 15.20 MPa, 16.85 MPa, 17.40 MPa, 16.10 MPa, 14.80 MPa, and 13.20 MPa across 10% to 50% variations. At 14 days, values reached 19.10 MPa, 21.30 MPa, 21.95 MPa, 20.25 MPa, 18.60 MPa, and 16.80 MPa, respectively. Mini-pile waste substitutions from 10% to 30% successfully met the target strength of f'c = 20 MPa, with the optimum proportion achieved at 20%.