Mesoscale simulation method for preplaced aggregate concrete based on physics engine

Preplaced aggregate concrete (PAC) has up to 60% aggregate volume content, making mesoscale modelling difficult. A novel mesoscale simulation method based on physics engine was proposed in this study to accurately simulate the coarse aggregate skeleton of PAC. Unlike in conventional mesoscale simulations, point-to-point contacts between aggregates were formed due to virtual gravity in the physics engine. To verify this novel method, mechanical property and shrinkage behavior tests of PAC were conducted under different aggregate gradings and with different expansive agents. For the mechanical property test, the simulation results were compared with the test results in terms of the aggregate stacking state, failure mode, stress–strain curve, and mechanical property parameters. Repeatability and aggregate shape analyses were performed using finite element (FE) model. A similar comparison between the simulation and test results was also performed for the shrinkage behavior. A shrinkage coefficient reflecting the relationship between grout and PAC shrinkage was proposed. This novel mesoscale simulation method based on physics engine is particularly suitable for PAC. However, it is not limited to PAC and can be applied to the simulation of conventional concrete, thus solving the problem of traditional simulation methods that struggle to achieve a high aggregate fraction.