Micromechanics analysis of thermal expansion and thermal pressurization of a hardened cement paste

TL;DR

This paper presents a multi-scale micromechanics model to analyze thermal expansion and pressurization in fluid-saturated cement paste, revealing anomalously high pore fluid expansion and enabling parameter extrapolation.

Contribution

It introduces a micromechanics-based model calibrated with experimental data to predict thermal behaviors of cement paste with various water-to-cement ratios.

Findings

Pore fluid thermal expansion coefficient is higher than pure water.

Model accurately predicts thermal pressurization effects.

Allows estimation of pore volume thermal expansion coefficient.

Abstract

The results of a macro-scale experimental study of the effect of heating on a fluid-saturated hardened cement paste are analysed using a multi-scale homogenization model. The analysis of the experimental results revealed that the thermal expansion coefficient of the cement paste pore fluid is anomalously higher than the one of pure bulk water. The micromechanics model is calibrated using the results of drained and undrained heating tests and permits the extrapolation of the experimentally evaluated thermal expansion and thermal pressurization parameters to cement pastes with different water-to-cement ratios. It permits also to calculate the pore volume thermal expansion coefficient f a which is difficult to evaluate experimentally. The anomalous pore fluid thermal expansion is also analysed using the micromechanics model.