Experimental Study on the Effect of Freeze‐Thaw Cycles on Axial Tension and Compression Performance of Concrete after Complete Carbonization

Abstract

The effect of freeze-thaw cycles on the axial tension and axial compression properties of completely carbonized concrete are investigated in this study. Three grade concrete specimens (C30, C40, and C45) were fabricated. The freeze-thaw cycle test was carried out on the completely carbonized specimens, followed by axial tension and axial compression tests. The results show that completed carbonization increases the axial tensile peak stress of C30, C40, and C45 concrete specimens by 8.7%, 9.7%, and, 12.1%, respectively. The peak axial tension strain increased by 1.9%, 7.2%, and 9.6%, respectively. The peak axial compressive stress increased by 10.5%, 19.1%, and 24.1%, respectively. The peak axial compressive strain decreased by 13.7%, 14.1%, and 14.3%, respectively. With the increase of freeze-thaw cycles, the peak stress of tensile stress, peak strain, and compressive stress of concrete decrease continuously. The peak strain of compressive strain increases. The lower the strength grade of concrete, the faster the decline rate of stress and strain. According to the data changes of peak stress and peak strain at different times of freeze thaw after carbonization, the stress-strain curve fitting formula for concrete under freeze-thaw cycles after complete carbonization is put forward, which has a good coincidence with the experimental result.

Analysis of Carbonation Behavior of Cracked Concrete

“…It mainly focuses on the causes of cracks, crack control and numerical simulation, characteristics of cracks, and so on [10][11][12][13]. However, there are relatively few experimental studies on the carbonation law of concrete at the crack [14][15][16][17]. Miao et al [18] found that micro cracks and micropores in concrete were important factors affecting the The goal of this research is to decipher the carbonation law of cracked cement paste and to investigate the carbonation mechanism.…”

Study on the Dynamic Properties of Concrete under Freeze-Thaw Cycles and CT Fine View Damage

“…However, in the road construction in the seasonal freezing area of northwest China, the concrete structures not only have to withstand the deterioration caused by freezing and thawing, but also inevitably sufer the isodynamic load caused by construction blasting disturbance [1][2][3]. In this complex environment, the internal cracks in concrete are intensifed and expanded, and the degree of damage is aggravated, which is macroscopically manifested as a decrease in the mechanical properties of concrete [4,5], seriously afecting the durability of the use of the structure and posing a potential threat to the development of the subsequent performance of the concrete structure and its service life [6,7]. Terefore, it is of great signifcance to investigate the dynamic mechanical properties and damage change characteristics of concrete under freeze-thaw cycle conditions to predict the performance deterioration law of concrete under freeze-thaw and dynamic load disturbance.…”