Tajunnisa, Y. ., Husin, N. A. ., Kusbiantoro, A. ., Azmi, A. D. ., Ashara, K. F. ., & Shigeishi, M. . (2025). Performance Changes in Mass and Compressive Strength of High-Calcium Fly Ash Based Geopolymer Concrete Due to Sodium Sulphate Exposure. IPTEK The Journal of Engineering, 10(1), 1–10. https://doi.org/10.12962/j23378557.v10i1.a16232