Freeze-thaw Damage Mechanism and Cracking Behaviour of PerforatedPlateau Concrete Structure

Abstract

The harsh environment and poor quality of building materials used in plateau concrete projects adversely affect the ability of such structures to withstand the damaging impact of freeze-thaw. A fast-freezing test with a single variable control was carried out and the process of microstructural changes in the plateau concrete was traced. The results also showed that the plateau curing environment led to an increase in width and porosity of the interface transition zone (ITZ), and that clay content in building materials significantly impacted the microstructure of paste. The frost resistance of plateau concrete was found to be far lower than that of plain concrete. Perforated concrete structures are common in engineering, and concrete members can easily experience frost cracking in cold regions. This study conducts frost heave tests on perforated concrete, aiming at the problem of the frost heave cracking risk of perforated concrete structures in cold regions. The cracking characteristics of concrete with holes under freeze-thaw cycles are mastered by performing rapid freeze-thaw tests on concrete with holes and observing the cracked section. Finally, hydrophobic filling materials were adopted to alleviate the frost heave stress on concrete.

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