Pengaruh Pemanfaatan Pre-Treatment Spent Bleaching Earth (SBE) dengan Fly Ash sebagai Subtitusi Parsial Semen terhadap Kuat Tekan Beton

This study aims to analyze the effect of utilizing pre-treated Spent Bleaching Earth (SBE) combined with fly ash as a partial cement replacement on the compressive strength and shrinkage of concrete with a target strength of f’c 20 MPa, as well as modeling its prediction using the Decision Tree Regression algorithm in RapidMiner Studio. This laboratory experimental study utilized cylindrical specimens measuring 150 mm x 300 mm. The tested mixture variations included: 5% SBE + 25% fly ash, 10% SBE + 20% fly ash, 15% SBE + 10% fly ash, and 20% SBE + 10% fly ash of the total binder weight. Compressive strength tests were conducted at 7 and 28 days, while shrinkage was observed up to 72 hours. The results indicated that the combination of SBE and fly ash significantly affected the physical and mechanical properties of the concrete. The 20% SBE + 10% fly ash + 70% cement mixture exhibited the optimum performance, achieving the highest compressive strength of 19.20 MPa at 7 days and 20.23 MPa at 28 days, thereby meeting the target strength of f’c 20 MPa. The lowest shrinkage value of 0.65% was obtained from the 10% SBE + 20% fly ash and 15% SBE + 10% fly ash variations. Integrating experimental data with RapidMiner computational modeling yielded high precision in predicting compressive strength. Thus, the utilization of pre-treated SBE and fly ash shows great potential as an eco-friendly alternative concrete material (green concrete).