Effects of Aggregate Properties and Concrete Rheology on Stability Robustness of Self-Consolidating Concrete

Abstract

Compared with ordinary concrete, the segregation resistance of self-consolidating concrete (SCC) are more sensitive to small variations of mix proportions such as dosage of superplasticizer, and the size, volume, and gradation, as well as moisture content of the fine and coarse aggregates. To design a SCC mixture, which is robust against small variations in raw materials, it is critical to understand the mechanism of how mix proportions affect robustness. In this paper, modified segregation probe was used to study the effects of various mixture properties on static stability robustness of SCC. It was found that a static segregation rate equation is helpful to explain how paste rheology and aggregate properties affect robustness. Mixture properties, such as higher paste volume, lower superplasticizer % by weight of cement, lower slump flow, smaller aggregate size, better gradation, and higher aggregate packing density may improve robustness. Among the aggregate properties, smaller aggregate size and better gradation seem to have more significant effects than higher aggregate packing density. As expected, no obvious relationship was observed between concrete rheology and robustness in this study.