Multiscale Estimation of Elastic Constants of Hydrated Cement

Abstract

Hydrated cement produces the strength and stiffness of concrete, a widely utilized infrastructural material. Estimation of elastic constants of hydrated cement, a heterogeneous material consisting of numerous constituents, is a complex problem. This paper presents a comprehensive multiscale micromechanical estimation methodology. X-ray diffraction (XRD) investigations along with Rietveld refinements were done to estimate the constituents of hydrated cement. Molecular dynamics investigations were carried out for each individual constituent to determine individual elastic constants. Micro computed tomography (microCT) investigations determined the porosity of the sample at different cross sections and also estimated the pore-size distributions. The Mori–Tanaka homogenization principle was used on the constituent elastic constants to estimate the final elastic constants of the hydrated cement, which were compared with values obtained from experimental investigations in the literature. The methodology demonstrated that consideration of tobermorite (all three phases) and jennite along with the estimated macroporosity can predict the overall stiffness of the cement paste with an error of about 8%.