为研究碳化对混凝土反复受压力学性能的影响,对两种强度等级混凝土棱柱体试件进行了快速碳化与反复加卸载试验.结果表明:随着混凝土碳化深度增大,试件破坏脆性越明显,混凝土初始弹性模量、割线模量以及峰值应力均有不同程度增长,而其峰值应变却明显降低,共同点轨迹线越发偏离包络线,包络线下降段明显变陡,卸载曲线越发凹曲,再加载曲线更为平缓,变形恢复滞后现象越来越明显.在试验研究基础上,提出反复荷载作用下碳化混凝土应力-应变关系数学函数模型.%The accelerated carbonation tests and repeated loading tests on C20 and C30 concrete specimens were carried out to investigate the effect of carbonation on the mechanical properties of concrete under repeated loading. Test results show that with the increase of carbonation depth, the brittle failure of concrete became more significant, the elastic modulus and the compressive strength increased, the strain at peak compressive stress decreased, respectively. The common point curve deviated farther from the envelop curve, the shape of the descending branch of envelop curve became much steeper, the concave shape of the unload curve became more and more obviously, the shape of reload curve became more and more gentle, the hysteresis of strain recovery for carbonated concrete became more obviously. Based on regression analysis of test result, the analytical stress-strain response of carbonated concrete subjected to repeated loading were established.
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