Strain-temperature hysteresis in concrete under cyclic freeze-thaw conditions

Submerged concrete specimens with 0.55 and 0.65 water-cement ratio were studied under cyclic freeze-thaw conditions at two different rates of temperature change. The strain variation at the centres of each of the specimens was measured using embedded strain-gauges. The strain at the centres of the specimens due to thermal gradients were modelled based only on the temperatures at the surface and the centres of the specimens. It was found that the hysteresis observed in the strain-temperature variations could be attributed to the thermal gradients with significant accuracy even at low rates of temperature change. Thermal gradients were found to be an essential requirement of any comprehensive modelling dealing with cyclic freeze-thaw tests in the laboratory. (C) 2008 Elsevier Ltd. All rights reserved.