Mortar with fly ash as a partial cement replacement: Analysing the compressive strength and heat of hydration

¹ Department of Architecture, Universitas Atma Jaya Yogyakarta, Babarsari 44-Yogyakarta, Indonesia
² Institute for Clean Growth and Future Mobility, Coventry University, Priory Street CV1 5FB, Coventry, United Kingdom

^* Corresponding author: andi.prasetiyo@uajy.ac.id

Abstract

Identifying sustainable alternatives and addressing the environmental impacts of cement production are becoming increasingly vital. Alternative materials, such as fly ash, can be used as a partial replacement for cement in concrete and mortar. This study will examine the impact of early-age heat of hydration on compressive strength of mortar when cement is partially replaced by fly ash. The mix proportion used in this study was 1:3 (cement: fine aggregate) with a w/b ratio of 0.4. Furthermore, the replacement of cement with fly ash was calculated based on weight percentage proportions, ranging from 10, 30, and 50% of the cement weight. Fly ash can be effectively used as a substitute for cement to reduce thermal hydration and maintain acceptable levels of compressive strength. As the fly ash substitution rate increased, the thermal hydration of the samples decreased. Nevertheless, the increased strength level may serve as a counterbalance for the initially reduced strength of the mortar that contains fly ash.