Simulation of Porosity Effect on Mechanical and Creep Properties of Cement Paste at Microscale

Due to the complex microstructure and properties of cement-based materials, the influences of pores on concrete mechanical and creep properties are still in debate. This study conducts research both experimentally and numerically at the microscale to take a further look at the mechanism of porosity effects. In addition to adopting the analytical homogenization schemes based on continuum micromechanics, a finite element model is developed to simulate the porosity effect by considering the pore volume and pore size distribution. The simulated results show that the elastic modulus decreases with increasing volume fraction of pore, while the relationship between the creep property and the volume fraction of pore exhibits an opposite trend. The pore size distribution also affects the mechanical and creep properties to some extent. The simulated results are then compared to the results measured by microindentation. It is found that the simulated results agree well with the experimental measurement, validating the feasibility of the numerical simulation for porosity effect.