Optimization of Eco-Friendly Cement Composition Based on Fly Ash in Geopolymer Concrete Mortar Production

Arwanto Arwanto (Universitas Bina Darma Palembang)
Firdaus Firdaus (Universitas Bina Darma Palembang)

Formosa Journal of Science and Technology (FJST)
Vol. 4 No. 9 (2025): September 2025

This study develops geopolymer cement using a dry mix method, replacing Portland cement with fly ash and utilizing solid Na₂SiO₃ derived from rice husk ash. Paste and mortar samples with three mix variations were tested for setting time and compressive strength. The initial setting time ranged from 75 minutes, while the final setting time reached up to 360 minutes. The highest compressive strength was 26 MPa for paste at 14 days and 20 MPa for mortar at 56 days. The results confirm the feasibility of producing environmentally friendly geopolymer cement with this method, though further research is needed to improve compressive strength and apply it in concrete production.