Stresses and strains in the hardened cement paste — Water system

The length change theory proposed by Flood and Heyding for microporous solids is applied to cement paste in considering the effect of porosity and compressibility on the solid phase. The theory is also used to estimate the dependence of modulus of elasticity on humidity and is in general agreement with experiment. Some insight into microstructural change and its effect on length change is provided by estimates of a structure factor, κ. For humidities up to 56%, values of κ are approximately constant, but major changes in structure occur at higher humidities.