Mesoscopic damage model of concrete subjected to freeze-thaw cycles using mercury intrusion porosimetry and differential scanning calorimetry (MIP-DSC)

Frost deterioration of concrete is one of the most significant durability problems in low temperature regions. Macro-damage parameter studies have been performed to investigate the variations of the mechanical characteristics in concrete materials. However, the macro-damage parameter often underestimates the pores and overestimates the macroscopic properties of concrete because of its intrinsic limitations. In this paper, an innovative mesoscopic damage parameter is developed by following a unique calculation procedure in which the damage parameter is cumulatively computed from the minimum to the maximum by iterative cycles instead of using a direct calculation method. This research was based on the mercury intrusion porosimetry (MIP) and differential scanning calorimetry (DSC) testing sequence, for determining the volumes and diameters of the pores and the corresponding feature pore size subjected to each rapid freeze-thaw testing. Additionally, the determination of mechanical properties of concrete was tested by conventional mechanical experimental instrument. Finally, a new freeze-thaw damage constitutive relationship is proposed based on the mesoscopic damage parameter. (C) 2017 Elsevier Ltd. All rights reserved.