DEM simulation of SCC flow in L-Box set-up: Influence of coarse aggregate shape on SCC flowability

Coarse aggregate are one of the main components of self-compacting concrete (SCC) and the size, shape, and grading of coarse aggregate can lead to different characteristics of SCC. In this paper, the effect of needle-shaped coarse aggregate on SCC flowability is systematically investigated and presented. A new method is proposed to randomly generate SCC with arbitrary aggregate shape and grading. Aggregate shapes are determined and classified by calculating the shape descriptors of aggregate, and thereby, SCC meeting the calculation requirements is generated. Based on this new method of aggregate generation, the discrete element method (DEM) is used to simulate the SCC flow process in L-box test. By continuously adjusting the content of needle-shaped coarse aggregate, the impact of coarse aggregate shape on the SCC flowability is evaluated, and the acceptable range of needle-shaped coarse aggregate content is obtained, which has guiding significance for the actual selection of concrete coarse aggregate.