Load-Induced Strains in Hardened Cement Paste

As an initial stage in a more fundamental and flexible approach to the prediction of load-induced dimensional changes in concrete the elasticity and creep of hardened cement paste were examined. Experimental data were presented to illustrate the relationships between elastic and creep strains and the variables, stress, porosity, age at loading, moisture loss, and period under load. Equations are developed in which elastic and creep strains of hardened cement paste can be computed with reasonable accuracy from the product of a series of predictive functions, each function being dependent upon one variable only. The equations reflect the close relationship between elastic and creep strains and their increase with the loss of moisture for specimens conditioned at relative water vapor pressures equal to or greater than 0.4. Under more severe drying creep strains diminish with further loss of moisture, while elastic strains remain relatively unaffected.