Effects of the physicochemical properties of fly ash on the compressive strength of high-volume fly ash mortar.

This study investigated the effect of the physicochemical properties of fly ash, including the particle sizes and chemical composition of the amorphous phase, on the compressive strength of high-volume fly ash mortars in which 50 vol.% of ordinary Portland cement was replaced with fly ash. The enhancement in the compressive strength of the high-volume fly ash mortars was observed due to the pozzolanic reaction after 7 days of hydration. This was found to depend on a combination of factors, including the content of amorphous SiO 2 and Al 2 O 3 , amorphous alkalinity, and surface area per volume of fly ash. [ABSTRACT FROM AUTHOR]