Numerical Simulations of Nonlinear Creep of Concrete at Mesoscale

In order to predict the nonlinear creep of concrete, it is necessary to establish a reasonable meso-finite element model of concrete. Base on the computational methods and principles of nonlinear creep in concrete, a mesoscale three-phase numerical model of concrete, which considering aggregates, cement paste, and the interfacial transition zone, was developed by using ABAQUS finite element analysis software through secondary development. The “aggregate scaling method” was proposed to generate a uniform interface transition zone in the two-phase finite element model, which was subsequently used to establish a three-phase model. By introducing strain increments caused by damage based on linear creep, the nonlinear creep effect was effectively simulated. The mesoscale three-phase numerical model of concrete successfully simulated the complex mesoscale structure of concrete and computed creep behavior by using recursive formulas, demonstrating good performance in simulating strain changes in concrete under sustained loads. Finally, the accuracy of the model was validated through existing creep test data from concrete cylindrical and prismatic specimens.