Impact of coarse aggregate morphology andseparation distance on concrete properties based on visual learning

The morphology of coarse aggregates plays a significant role in concrete performances. This study conducted a quantitative analysis on the morphology of coarse aggregates using visual learning technology, aiming to explore their effects on fluidity, rheology and mechanical properties of fresh concrete. The parameters of flatness, angularity, roughness, roundness, sphericity and coarse aggregate separation distance (CSD) on concrete properties are discussed. The results showed that CSD, flatness and sphericity had the most significant effect on slump, with its weighting of 0.99, 0.96 and 0.94, respectively. Higher value of CSD, flatness and sphericity help to produce concrete with better flowability. The yield stress of concrete was mainly affected by roughness, roundness and CSD with weighting of 0.98, 0.87 and 0.76, respectively. Plastic viscosity was also affected by these factors with weighting of 0.96, 0.85 and 0.80, respectively. Aggregate roughness (weight 0.96) and roundness (weight 0.87) are the two significant factors influencing the compressive strength. Through numerical analysis, mathematical models correlating the morphological parameters coarse aggregates with the performance of concrete are established, which can provide some indications for the smart design of concrete mixture.