Properties of Cementitious Composites Containing Active/Inter Mineral Admixtures

摘要

Fly ash and ground iron ore tailings with fineness similar to cement were used as active and inert mineral admixtures in this study. This paper examines the compressive strength development of plain mortar and blend mortar containing fly ash and ground iron ore tailing. The mortar was cured at the same curing regime and a different water to cementitious material ratio was used. The autogenous shrinkage is also detected in the first seven days. At the early stage of hydration, fly ash and ground iron ore tailings played a role as physical filler during the hydration of the cementitious composites. As age increases, the pozzolanic reaction of fly ash became dramatic. Concrete with fly ash and ground iron ore tailings has a similar trend of autogenous shrinkage. As the amount of fly ash and ground iron ore tailings increases, autogenous shrinkage linearly decreases and their autogenous shrinkage is similar to each other. The autogenous shrinkage of concrete in one day is more than the total shrinkage of 80% in seven days.