Stress-Strain Model for Concrete Under Compressive Stress that Has Undergone Freeze-Thaw Deterioration

This study aims to develop a stress-strain model for concrete under compressive stress that has undergone freeze-thaw deterioration. A stress-strain equation is proposed based on an examination of the results of compression tests on cylindrical specimens. First, cylindrical specimens with various degrees of deterioration were created, and these underwent compression testing to determine the stress-strain relationship. Based on the test results, it was thought that the behavior of the tested concrete that had undergone freeze-thaw deterioration was influenced by the tiny voids (micro cracks) in the concrete, which were created as the result of freeze-thaw deterioration and which close when compressive force is applied. Based on the above finding, a simple model was assumed in which the strain caused by closing of the voids created by freeze-thaw action was factored into the stress-strain relationship of concrete under compressive stress, as described in the JSCE Standard Specifications for Concrete Structures. The relative dynamic modulus of elasticity was used as a parameter for the model, since it is widely used as a deterioration index for concrete that has undergone freeze-thaw deterioration. The stress-strain relationship proposed in this study was verified as roughly agreeing with the results of the experiment on concrete freeze-thaw deterioration.