In this paper, the effect of the coarse aggregate (CA) shape and content on the flow performance index of fresh concrete in the L-box test (B m ) was investigated based on Discrete Element Method (DEM). The Hertz-Mindlin-JKR (Johnson-Kendall-Roberts) contact model was used to characterize the constitutive relationships of fresh concrete. The parameters of contact model were calibrated by the experiment and simulation of the slump test, L-box flow test and V-funnel test. The shape of CA was quantitatively characterized, and a functional relationship between the specific surface area of concrete...