Study on degradation of macro performances and micro structure of concrete attacked by sulfate under artificial simulated environment

Based on the similarity principle, the similarity criterion of concrete attacked by sulfate corrosion was deduced, and the change laws of concrete sulfate attack under natural condition and artificial simulated environment were revealed. The variations of micro structure, morphology and compositions of concrete before and after sulfate attack were investigated by Environmental Scanning Electron Microscope (ESEM), Mercury Intrusion Porosimetry (MIP), Fourier Infrared Spectrometer (FTIR), Differential Scanning Calorimetry and Thermogravimetric (DTA-TG). The results showed that the artificial simulated environment test method could be used to simulate the real deterioration of concrete under sulfate environment. Moreover, the concrete root rot phenomenon could also be reappeared by artificial simulated environment. The ultimate bearing capacity of concrete specimens attacked by sulfate decreased with erosion age. The transverse and longitudinal dynamic modulus of elasticity of concrete first increased and then decreased with erosion age. The changes of the micro structure, compositions and morphology of concrete were caused by the generation of expansive substances and decomposition of hydration products. The numerical simulation indicated that the optimal accelerated ratio of concrete sulfate attack between natural condition and artificial simulated environment was about 50. (C) 2020 Elsevier Ltd. All rights reserved.