冻融循环对完全碳化混凝土轴拉性能的影响

The Effect of Freeze-thaw Cycles on Axial Tensile Property of Full Carbonated Concrete

为研究冻融作用对完全碳化混凝土轴拉性能的影响,制作了C30、C40、C45三个强度等级的混凝土试件,经完全碳化后进行冻融循环试验和轴心受拉试验。结果表明:完全碳化使C30、C40和C45混凝土的峰值应力分别上升8.7%、9.7%和12.1%,峰值应变分别上升1.9%、7.2%和9.6%;随冻融循环次数的增加,混凝土受拉峰值应力和峰值应变不断下降,且混凝土强度等级越低,下降速度越快。根据碳化后不同冻融循环次数时混凝土的峰值应力和峰值应变数据变化情况,提出了相应的拟合公式。根据试验结果拟合了受拉应力-应变上升段曲线,结果表明:拟合效果良好。

In order to study the influence of freeze-thaw on the axial tensile property of concrete after full carbonation,the specimens of C30,C40 and C45 were prepared.After full carbonation,freeze-thaw cycles and axial tensile tests were carried out.The results show that full carbonation increases the peak stress of C30,C40 and C45 concrete by 8.7%,9.7%and 12.1%,and the peak strain by 1.9%,7.2%and 9.6%respectively.With the increase of freeze-thaw cycles,the peak tensile stress and strain of concrete decrease.The lower the concrete grade,the faster the changing rate.According to the data changes of peak stress and peak strain at different freeze-thaw times after carbonation,a fitting formula was proposed.The tensile stress-strain rising curves were fitted,and the results show that the fitting effect is good.