Numerical simulation of internal stress in pavement concrete under rolling fatigue load

This study explores the development law of concrete internal stress and strain under rolling wheel loads. To do this, strain gauges are embedded in different positions inside concrete, and the stress and strain values at different positions inside the concrete are measured using the rolling fatigue test. A numerical model is established using COMSOL Multiphysics software, and the concrete internal stress and strain values are simulated. A comparison between the calculated and measured values shows that the numerical model can simulate the actual stress state inside the concrete. The numerical model can predict the internal stress and strain variation of concrete specimens under more complicated load conditions. The prediction results show that under the same fatigue load conditions, the concrete stress peak is hardly affected by the fatigue loading times, but there is a marked increase in the strain value inside the specimen. When the stress peak of concrete does not reach its design strength, an excessive increase of the internal strain will cause hidden damage to the concrete. By investigating the internal stress and strain of the concrete, a theoretical basis can be determined for the deterioration mechanism of concrete microstructure and the durability design of concrete.