Damage Characteristics And Microstructures Of Low-Exothermic Polymer Grouting Materials Under F-T Cycles

Low-exothermic polymer grouting materials are used for repairing buildings, and the damage experienced under freeze-thaw (F-T) cycling directly affects their repair effectiveness and service life. In this study, F-T cycling, indoor uniaxial compression, and scanning electron microscope tests were performed to study the damage characteristics of polymer samples during F-T cycles. The damage mechanism of the compressive strength of the sample was revealed, and the evolution form of F-T damage for the polymer sample was discussed. From the results, the peak stress of the polymer samples gradually decreased as the number of F-T cycles increased. Additionally, the failure mode of the samples under uniaxial stress gradually changed from plastic failure to brittle failure. Under the F-T cycles, the cell structure of the sample gradually exhibited damage from the surface to the inside, eventually experiencing cell rupture. This was an important factor reducing the compressive strength of the sample. The mass loss and compressive-strength loss of the polymer samples gradually increased with an increase in the number of F-T cycles. Moreover, the loss was inversely proportional to the density, indicating that higher density polymer samples have better frost resistance. According to the theory of damage mechanics, the mass loss rate and compressive-strength loss rate were used as damage parameters, and damage variable D was introduced to establish the F-T damage evolution equation of polymer samples. The research results provide a practical reference for road restoration in cold areas. (c) 2021 Elsevier Ltd. All rights reserved.