Multi-scale analysis framework for predicting tensile strength of cement paste by combining experiments and simulations

The experimental method that accurately assesses the responses of cementitious materials with complex microstructures requires significant time and effort. To address this issue, a multi-scale analysis approach that synergistically combines experiments and simulations can be adopted. In this study, a framework was designed to evaluate the macroscale (upper-scale) tensile strength of cement paste using microscale (lower-scale) characteristics and properties. The upper- and lower-scale microstructures of the cement paste are obtained through this approach using high-resolution synchrotron X-ray micro-CT. Solid-phase properties at the lower-scale are determined using a nanoindentation experiment and lower-scale micro-CT characteristics. The upper-scale solid phase properties are correlated by comparing the distributions of the linear attenuation coefficients or the grayscale values of the micro-CT images from the two scales. To evaluate the proposed method, splitting tensile test simulations of the cement pastes were conducted with upper-scale solid-phase input material parameters. The simulated results were comparable to the experimental ones. It was concluded that the proposed multi-scale approach combining experiments and simulations can reduce the time and effort required to evaluate the mechanical responses of cement paste. It thus contributes to advancing material innovations.