Kinetics of Pozzolanic Reaction and Strength Build-Up in the Mortar of Biomass/Coal Fly Ash with Calcium Hydroxide

This paper addresses kinetics and strength build-up of pozzolanic reactions in 2-inch-cubes of biomass, coal fly ash and sand mortar. A comprehensive experimental design of six biomasses/coal fly ashes, three temperatures, three mass ratios of fly ash/CH and six test dates of up to 1 year was set up. The results show that the compressive strength of biomass fly ash samples exceeds that of coal ash samples by factors of 2-3 and rivals that of pure cement ones. Further investigations indicate that except CH reaction extent, other factors such as fly ash type, mixing ratio of fly ash with CH and curing temperature, all have significant effects of compressive strength build up of fly ash samples.