Effect of Perlite Composition on Compressive and Split Tensile Strength of Fly Ash-Based Geopolymer Concrete

Geopolymer concrete is an environmentally friendly alternative to cement as it can reduce carbon dioxide gas emissions during the production process. This study uses fly ash, a waste from the combustion of steam power plants, and perlite, a silicate glass rock with high alumina content, as cement replacement materials. Variations of perlite were used in geopolymer concrete mixtures to replace fly ash with percentages of 0%, 10%, 20%, and 30%, with a concentration of 12 M, and a Na 2 SiO 3 /NaOH ratio of 2.5 and AA/PM of 0.5. For the treatment of geopolymer concrete using oven curing method at 80°C for 16 hours. The results showed that variation 4 (fly ash 70% + perlite 30%) had an optimum compressive strength value of 27.145 MPa at the age of 28 days. The optimum split tensile strength value at the age of 28 days also occurred in variation 4 with a value of 3.130 MPa. In addition, variation 1 (100% fly ash + 0% perlite) had the highest slump value of 9.15 cm, while variation 4 (70% fly ash + 30% perlite) had the lowest density value of 2047.014 kg/m 3 .