Water absorption and sorptivity of alkali-activated ternary blended composite binder

This study examined the crucial durability properties of cementitious materials named water absorption and sorpitivity of two alkali-activated binders (AAB) namely AAB-1 and AAB-2, which incorporated a different composition of pozzolans including rice husk ash, fly ash, palm oil fuel ash, and slag. NaOH with a concentration of 2.5 M was used to activate these binders. While the water absorption was measured at 28, 90, 180, and 270 days the sorptivity test was performed at 90, 180, and 270 days on mortar specimens. The test result indicates the AABs absorbed more water than OPC, especially at the initial period, which reduced over the curing period. Porous microstructure and consequential lower compressive strength of AABs has been considered responsible for this. Similarly, the sorptivity value was higher for both AAB than OPC. The higher water absorption and lower strength of AABs lead to a higher sorptivity. The water transport properties can be improved through increasing the strength and making a dense microstructure by optimizing the properties of pozzolans and the mixture composition of AAB.