Evaluating tensile strength of cement paste using multiscale modeling and in-situ splitting tests with micro-CT

Abstract

This study investigated a strategy to simulate splitting tests to evaluate the tensile strength of cement paste within a multiscale framework, and validated the approach with in-situ micro-CT measurements. Phase-field fracture model was used to simulate the splitting test using virtual microstructures reconstructed from the macroscale micro-CT measurements. Among the modeling parameters, the range of the diffusive crack width, which is an internal parameter for phase-field fracture model, was further investigated. The cracks propagated through the weaker solid phase, and the predicted strengths and standard deviations were comparable to those obtained from the experiments. It was found that the diffusive crack width should be smaller than the characteristic length of the weaker phase to predict the crack pattern accurately. These findings confirm the effectiveness of the proposed multiscale modeling approach in predicting the tensile strength of cement paste.