Analytical Study on the Change of Fluidity of Fresh Concrete Containing Mineral Admixture with Rest time

Abstract

Supplementary cementitious materials, such as fly ash (FA) and ground granulated blast furnace slag (BFS), are usually used to replace cement for improving the properties of concrete and achieving environment-friendly concrete. In this paper, the time-dependent fluidity of fresh concrete with mineral admixture was discussed by the time-dependent Discrete Element Method (td-DEM). The effects of FA and BFS on the time-dependence were taken up. A gravity-induced funnel flow test of fresh mortar, in which FA or BFS replaced part of Portland cement, and the numerical funnel flow simulation using the td-DEM, were conducted respectively. The agreement of the numerical and experimental results indicates that the td-DEM is applied to the prediction of the change of fluidity of fresh concrete containing FA or BFS. The numerical and experimental results also show that the use of mineral admixture would decrease the rest time-dependence of fresh concrete.