Effect of Surface Protection on the Strength Properties and Frost Resistance of Hydraulic Concrete

The effect of the surface protection with insulating materials of the two types on the bending and compressive strengths, internal temperature, mass loss, and relative dynamic elastic modulus of hydraulic concrete was studied. In comparison with unprotected concretes, the surface protection can delay the temperature drop of the concrete bulk and increase its final temperature. Polyurethane and polystyrene were compared as to their efficiency in the surface protection of hydraulic concrete during the freeze-thaw cycle test. Those materials can increase a maximum number of freeze-thaw cycles. As compared to unprotected concrete, the number of cycles increased by 100 and 75%, respectively. After 100 freeze-thaw cycles, the relative compressive and bending strengths of polyurethane-protected concrete are 75 and 64%, while these characteristics for unprotected concretes make up 61 and 57%. Such an approach effectively withstand the deterioration of mechanical properties of concrete during freeze-thaw cycles.