自密实橡胶混凝土循环受压应力-应变关系

Stress-strain relations of self-compacting rubber concrete under cyclic compression

为研究自密实橡胶混凝土循环受压力学性能,以橡胶类型(橡胶粉、橡胶颗粒)和橡胶掺量(15%、20%、30%)为变化参数,设计7组(每组9个,共计63个)试件进行单调压缩和循环受压试验。试验结果表明:与单调压缩曲线相比,循环受压全曲线包络线的上升段略微下凹,表现出压实效应;橡胶掺量越大,试件延性破坏特征越明显,强度和刚度的降幅越大,峰值应变越延后;相比其他类型试件,掺入橡胶粉的试件循环受压力学性能更优,延性和耗能能力更强;橡胶掺量不超过20%时,掺入橡胶粉的试件塑性应变相对较大,但峰值前应力退化较快。在试验基础上,提出了自密实橡胶混凝土循环受压应力-应变关系模型,本文研究结果可为结构分析与设计提供参考。

In order to study the mechanical properties of self-compacting rubber concrete under cyclic compression,seven groups(9 specimens in each group,totalling 63)of specimens were designed for monotonic compression and cyclic compression tests with rubber type(rubber powder,rubber granules)and rubber admixture(15%,20%,30%)as the variation parameters.The results show that compared with the monotonic compression curve,the rising section of the envelope curve of the cyclic compression stress-strain curve was slightly concave,showing the compaction effect.With the increase in rubber content,the ductile failure characteristics of the specimens were more obvious,the strength and stiffness decreased more,and the peak strain was gradually delayed.Compared with other types of specimens,the cyclic compressive mechanical properties of the specimens mixed with rubber powder were better,and the ductility and energy dissipation capacity were enhanced;When the rubber content was not more than 20%,the plastic strain of the specimen mixed with rubber powder was relatively large,but the stress degradation before the peak was faster.The stress-strain relationship model of self-compacting rubber concrete under cyclic compression was proposed on the basis of experiments,and the research results of this paper can provide reference for the design and analysis of self-compacting rubber concrete structures.