Effects of early-age temperature and salt ion corrosion on the macroproperty deterioration of concrete and corresponding micromechanism

This paper experimentally examines variations in the macroscopic properties of concrete under the interaction of early-age temperature and salt ion corrosion and investigates the microscopic mechanism of these variations from the perspective of pore structure and microcracks. The results show a prominent initial defect compaction stage of the compressive stress-strain curves of the specimens under the interaction of two factors, an increase in the number of pores and a high degree of crack development. Accordingly, the peak strength, secant elastic modulus and porosity of the specimens are greatly affected by the interaction between early-age temperature and salt ion corrosion, as reflected by the obvious deterioration trend. Based on a theoretical analysis, the concept of the initial defect strain ratio is proposed, the relationship between the total deformation and two indicators (initial defect deformation and matrix deformation) is clarified, and a constitutive model that reflects the initial defect compaction characteristics is established.

Automated summary

This paper experimentally investigates the variations in macroscopic properties of concrete under the interaction of early-age temperature and salt ion corrosion, focusing on the perspective of pore structure and microcracks. The results indicate a prominent initial defect compaction stage in the compressive stress-strain curves of specimens, with an increase in the number of pores and a high degree of crack development. Peak strength, secant elastic modulus, and porosity of the specimens are significantly affected by the interaction between early-age temperature and salt ion corrosion, showing a clear deterioration trend.