Lime activation of fly ash in mortar in the presence of metakaolin

Abstract

The effect fly ash activated with lime in the presence of metakaolin on selected properties of mortars is investigated. This work is aimed at producing mortar without the use of cement as a binder in order to reduce the environmental impact of traditional mortar or concrete applications. Two mortar mixes were prepared to conduct this study. The first mix was the control mix with proportion 1 (cement): 3 (sand) and the water to cement ratio was 0.6. In the second mix, the binder consisted of 80% fly ash, 5% lime and 15% metakaolin (by weight). Specimens were cured for different time at 20°C and no elevated temperatures were used. The result shows that the mortar containing fly ash had its highest compressive strength of 0.46MPa and it is much lower than the control. Also the density of the predominantly fly ash mix had a lower density at all ages when compared with the control mix.