Performance evaluation of steam and membrane curing on geopolymer mortar with fly ash and carbide waste

This study evaluates the performance of steam and membrane curing methods on the compressive strength of geopolymer mortar incorporating fly ash and carbide waste. Cube specimens measuring 5×5×5 cm were prepared with fly ash proportions of 100%, 80%, 60%, and 40%, combined with carbide waste at 0%, 20%, 40%, and 60%. After casting, the specimens were cured using two methods: (1) membrane curing by wrapping in impermeable plastic, and (2) steam curing at ±70 °C for approximately 2 hours, followed by cooling and wrapping. Compressive strength tests were conducted at 7, 14, and 28 in accordance with SNI 6882:2014. The results show that steam curing consistently produced higher compressive strength compared to membrane curing across all mixture variations. At 28 days, the highest compressive strength under steam curing reached 52.66 MPa for the 100% fly ash mixture. For the 40% fly ash and 60% carbide waste mixture, steam curing achieved 25.76 MPa. These findings confirm that steam curing accelerates geopolymerization, resulting in a denser matrix and higher strength development. This study highlights steam curing as an effective approach to enhance the performance of geopolymer mortar incorporating industrial waste materials.