Mesoscale simulation of cracking and shrinking during drying under coupled effect of environmental factors using 3D RBSM

Accurately predicting and evaluating durability issues in reinforced concrete (RC) structures presents a significant challenge, particularly in the case of cracking induced by drying shrinkage. Experimental investigations of drying-related cracking problems are characterized by lengthy experimental cycles, the need to consider multiple influences, and a high degree of randomness, rendering the challenge inadequately addressed in the form of comprehensive experimental analyses. This kind of cracking arises from the uneven distribution of moisture within concrete, where water evaporation and loss through voids and cracks result in volume shrinkage and crack formation. The entire process has a prolonged duration and is significantly influenced by stochastic environmental factors, making the prediction and evaluation of shrinkage strains and of structural performance after cracking challenging. In this study, a 3D Rigid Body Spring Model (RBSM) is employed to simulate the process of concrete drying. An input strain model that takes account of various environmental factors is established and validated against previously reported experiments. Totally, four kinds of environmental factors are considered. The validation results indicate that, at the material level, the model effectively simulates the shrinkage behavior of concrete under the coupled effect of multiple environmental factors. The influence of individual environmental factors on the drying process is clearly distinguished. Additionally, the effects of multiple environmental factors on the drying process are discussed.