循环荷载作用下冻融劣化混凝土能量耗散规律及破坏形态分析

发布时间：2018-04-03 08:12

本文选题：混凝土　切入点：冻融　出处：《水电能源科学》2017年09期

【摘要】：为研究冻融劣化混凝土在循环荷载作用下的能量耗散规律及其破坏形态,对强度等级为C30的混凝土立方体(300mm×300mm×300mm)试件进行压缩试验。结果表明,当冻融循环次数不超过10次时,混凝土应力—应变曲线的外包络线呈两段式。当冻融循环次数超过10次时,包络曲线的应力与应变呈现出非线性增长,且这种非线性增长关系随冻融循环次数的增加而趋于明显;当冻融循环次数由10次逐渐增加至35次时,冻融劣化混凝土的破坏形态由剪压破坏逐渐向轴压破坏转变;冻融劣化混凝土试件在循环加卸载过程中耗散能、弹性应变能、塑性应变能的释放规律一致,都经历了前期能量释放缓慢,中期能量释放迅速,后期能量释放趋于平缓的变化阶段。研究成果可为严寒地区的混凝土构件设计及工程实践提供指导。
[Abstract]:In order to study the rule of energy dissipation and failure pattern of freeze-thaw degraded concrete under cyclic load, compression tests were carried out on concrete cube specimens with strength grade C30 脳 300mm 脳 300mm 脳 300mm.The results show that when the number of freeze-thaw cycles is less than 10 times, the outer envelope of the stress-strain curve of concrete is two-segment.When the number of freeze-thaw cycles exceeds 10 times, the stress and strain of the envelope curve show a nonlinear increase, and the nonlinear growth relationship tends to be obvious with the increase of freeze-thaw cycles, and when the number of freeze-thaw cycles increases gradually from 10 times to 35 times,The failure form of freeze-thaw degraded concrete gradually changed from shear compression failure to axial compression failure, and the releasing law of the dissipation energy, elastic strain energy and plastic strain energy of the frozen and thawed deteriorated concrete specimens during cyclic loading and unloading were consistent.Both of them experienced slow energy release, rapid energy release and gentle energy release.The research results can provide guidance for the design and engineering practice of concrete members in cold areas.
【作者单位】：湖北工业职业技术学院建筑工程系;三峡地区地质灾害与生态环境湖北省协同创新中心;十堰市建筑设计研究院;
【分类号】：TU528

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