Strength Development and Microstructural Characterization of Ternary Blended Alkaline Activated Mortars under Different Curing Conditions

Abstract

This article reports the contribution of diverse oxides existent inraw materials such as ultrafine palm oil fuel ash (UPOFA), ground granulated blast furnace slag (GGBFS), and metakaolin (MK) on the performance of alkaline activated mortars (AAMs). The strength and microstructure development of ternary-blended alkali-activated mortar (AATMs) under various curing conditions, namely temperature, ambient, water, and steam were investigated. Themixturewas prepared with the same content of binder, aggregate and alkaline activator (AA) and cured at 75 ⁰C for 24 hours. The mixture was characterized in terms of compressive strength (CS) as a main property, and confirmed by XRD, and FTIR analyses. The findings indicated that ternary blended AAMs cured at steam temperatures exhibited higher strengths, accompanied by better compacted and homogeneous microstructure, compared to other curing conditions applied. The results showed that due to the high geopolymerization reactivity of ternary blended alkali-activated mortars which is sensitive to the curing conditions and curing at steam temperature was beneficial to the development of geopolymer CS. The XRD and FTIR analyses showed that the total content of Al2O3 and SiO2 plays an important role in CS development