STUDI PERILAKU PASTA GEOPOLYMER-ORDINARY PORTLAND CEMENT HYBRID

Heat treatment on the geopolymer paste can result in high early compressive strength because the geopolymer reaction is endothermic. This condition is one of the obstacles to its application. This article describes the characteristics of geopolymer-Portland cement hybrid pastes without heat treatment. The hybrid geopolymer-Portland cement paste was obtained by varying the percentage substitution of Portland cement to fly ash, namely 0%, 5%, 10%, and 15%. Parameters observed are consistency, setting time, and compressive strength. The results show the characteristics of the hybrid geopolymer-Portland cement paste Its consistency is smaller than standard Portland cement. The higher the percentage of substitution, the initial and the final setting time are shorter, less than one hour, but the compressive strength increases. This shows that hybrid geopolymer-Portland cement can be used for the works that require a short initial setting time, such as paving blocks or road pavement layers.