To study the failure mechanism of high ductile coagulation (HDC) under sulfate attack in cold saline soil area, cement-based cementing material (cement: fly ash: sand: water reducing agent: water = 1:1:0.72:0.03:0.58) and 2 % polyvinyl alcohol fiber (PVA) were used to prepare HDC sample, to increase the density and ductility of concrete. a 540-day sulfate-long-term immersion test was performed on HDC specimens under two low-temperature curing environments and different sulfate solution concentrations (5 %, 10 %). Using a combination of macro and microscopic methods, according to the principle of energy dissipation, To study the relationship between the evolution of energy (total damage energy U, dissipated energy Uds, elastic strain energy Ues) and the deterioration of strength and the change of pore structure during the compression process of HDC. According to the characteristics of stress-strain curves during HDC compression, the damage evolution characteristics of characteristic stress points during HDC compression are summarized, establish energy storage indicators Kel to evaluate the degree of internal damage of HDC. The results show that during the compression damage process of HDC after long-term soaking in sulfate solution under low temperature environment, Uds and Ues of HDC at characteristic stress points both increase first and then decrease, Kel are reduced first and then increased. The development trend of elastic strain energy and dissipative energy of HDC in 10 % sulfate solution is more drastic than that in 5 % sulfate solution. Compared with the other three groups, the D group energy storage level rises and falls more violently, and the HDC has a smaller ability to resist damage under this condition. Through the study of the correlation between macro and micro changes of HDC in cold saline soil areas and energy evolution, to provide a reference for the stable operation of highly ductile concrete in cold saline soil areas.

来源平台：JOURNAL OF BUILDING ENGINEERING