Structure–Property Relationships of Polymer-Modified Cement Concrete (PCC) Under Service Temperature Conditions

Polymer modification is a widely employed technique for optimizing specific properties of mortars and concretes. This process entails the precise tailoring of the binder phase to the requirements of the given application. The polymer addition exerts a significant influence on both the fresh and hardened states of mortar or concrete. In this study, a systematic, stepwise experimental campaign was carried out to investigate the effects of three different polymer dispersions on the time-dependent properties of cement pastes, mortars, and concretes at different temperatures in the service temperature range. The experimental findings demonstrate that polymer modifications significantly influence the behavior of hardened cement-based materials. In general, the strength and deformation resistance decreased with increasing temperature, with this effect being more pronounced in polymer-modified materials. This is indicative of the intrinsic temperature-dependent behavior of the polymers. Temperatures of -20 °C induced specific alterations in the mechanical behavior, particularly evident in the flexural strength and in the early age stiffness development of the pastes, mortars, and concretes. This phenomenon is attributed to the freezing of pore water, which results in the stiffening of the binder structure. In summary, the findings offer significant insights into the structure-property relationships of polymer-modified cement-based materials in relation to temperature.