Properties of binary and ternary blended cement mortars containing palm oil fuel ash and metakaolin

Abstract

This paper has investigated the properties of mortars made from binary and ternary blends of metakaolin (MK), palm oil fuel ash (POFA), and ordinary Portland cement (OPC). A total of 17 different mortar mixtures were produced. The OPC in the mixtures was partially replaced by MK, POFA, or a combination of MK and POFA at different replacement levels of (0–30%) by weight of the binder. At the fresh state, the flow (workability) of mortar mixtures was determined, while at the hardened state, the compressive strength and porosity at the ages of 7, 28, and 90 days were evaluated. The results showed that the flow of mortar is boosted with the combined use of MK and POFA compared to when MK is separately used. Besides, improvement in low early compressive strength development and reduction in high porosity from use of POFA occurred with the addition of up to 10% MK content. Therefore, the combination of POFA and MK could be used as a supplementary cementitious material to produce cement-based material of higher quality than OPC.