Experimental Analysis and Micromechanics-Based Prediction of the Elastic and Creep Properties of Polymer-Modified Concrete at Early Ages

Polymer-modified concrete (PCC) has been used since the 1980s mainly for repair and restoration. Nowadays, it is also increasingly applied in construction. The desirable future integration of PCC into guidelines and standards requires a reliable mathematical description of the mechanical behavior of PCC. Notably, PCC exhibits less elastic stiffness and a more pronounced creep activity compared to conventional concrete. This contribution presents a combined experimental-computational study concerning early-age mechanical properties of PCC. Experimental characterization comprised 3 min-long creep tests which were performed every hour, spanning material ages from 1 day after production up to 8 days. This allowed for a quasi-continuous quantification of the early-age evolutions of the elastic stiffness and of the non-aging creep properties. As for computational modeling, an existing multiscale model for the elastic stiffness of concrete is extended toward the consideration of polymers. It is shown that the extended model can reliably describe the elastic stiffness of PCC, provided that entrapped air is adequately considered.