循环荷载作用下聚丙烯纤维再生混凝土受压性能试验研究  

Experimental study on the compressive performance of recycled polypropylene fiber concrete under cyclic loading

作　　者：吴辉琴[1] 朱真 陈宇良[1] 梁海区 WU Huiqin;ZHU Zhen;CHEN Yuliang;LIANG Haiqu(School of Civil Engineering and Architecture,Guangxi University of Science and Technology,Liuzhou 545006,Guangxi,China;Guangxi Yufeng Concrete Co.,Ltd.,Liuzhou 545006,Guangxi,China)

机构地区：[1]广西科技大学土木建筑工程学院,广西柳州545006 [2]广西鱼峰混凝土有限公司,广西柳州545006

出　　处：《实验力学》2023年第5期645-654,共10页Journal of Experimental Mechanics

基　　金：中国博士后科学基金项目(2021M693854);柳州欧维姆机械股份有限公司博士后科研工作站科研项目(202123);广西科技大学博士基金项目(校科博18Z09)。

摘　　要：为研究循环荷载作用下聚丙烯纤维再生混凝土(PFRAC)的力学性能,以粗骨料取代率、纤维掺量、加载速率为变化参数,设计了78个圆柱体试件进行单轴循环受压试验。通过试验观察PFRAC的破坏形态,获取了应力-应变曲线、峰值应力、峰值应变、刚度退化等重要指标,研究了不同变化参数对其力学性能指标的影响规律,得到了循环荷载作用下聚丙烯纤维对再生混凝土的阻裂机理。结果表明:循环荷载作用下PFRAC主要发生斜向劈裂破坏;随着聚丙烯纤维掺量的增加,试件表面主裂缝宽度减小;循环荷载下PFRAC试件受压应力-应变曲线包络线与单调受压应力-应变曲线相似;聚丙烯纤维的加入可显著改善PFRAC循环荷载下的力学性能,随着纤维掺量的增加,峰值应力、弹性刚度比先增大后减小;纤维掺量为0.9%时的纤维改性效果最优,峰值应力和峰值刚度比分别提高了4.4%和7.4%。In order to study the mechanical properties of polypropylene fiber recycled aggregate concrete(PFRAC)under cyclic loading,designed the uniaxial cyclic loading test of 78 cylindrical specimens was designed with coarse aggregate replacement rate,fiber volume fraction,and loading rate as variation parameters.The failure mode of PFRAC was observed,and the stress-strain curve,peak stress,peak strain,stiffness degradation,and other important indexes were obtained.The influence of different parameters on the mechanical properties of PFRAC was studied,and the crack resistance mechanism of polypropylene fiber to recycled concrete under cyclic loading was obtained.The experimental results show that PFRAC specimens under cyclic loading primarily exhibit diagonal splitting failure,and that the main crack width of the specimen surface decreases as the polypropylene fiber volume fraction increases.The stress-strain curve envelope of PFRAC specimens compressed under cyclic loading agrees well with those under monotonic loading.The addition of polypropylene fibers significantly improved the mechanical properties of PFRAC under cyclic loading,and the peak stress and elastic stiffness ratio increased and then decreased with the increase of fiber volume fraction.When the fiber volume fraction is O.9%,the fiber modification effect is the best,and the peak stress and peak stiffness ratios increased by 4.4%and 7.4%.

关 键 词：再生混凝土 聚丙烯纤维 单轴循环受压试验 应力-应变曲线 刚度退化 

分 类 号：TU528[建筑科学—建筑技术科学]