循环荷载下PVA纤维再生骨料混凝土力学性能研究  

Study on mechanical properties of polyvinyl alcohol fiber recycled aggregate concrete under cyclic loading

作　　者：林桂武[1] 刘康 陈宇良[1,2] LIN Guiwu;LIU Kang;CHEN Yuliang(School of Civil Engineering and Architecture,Guangxi University of Science and Technology,Liuzhou 545006,China;Liuzhou Key Laboratory of Advanced Civil Engineering Materials and Applications,Liuzhou 545006,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]柳州市先进土木工程材料及应用重点实验室,广西柳州545006

出　　处：《广西大学学报（自然科学版）》2023年第4期801-810,共10页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金项目(51908141);中国博士后科学基金项目(2021M693854);广西科技大学博士基金项目(校科博18Z09);广西重点研发计划项目(桂科AB19259011)。

摘　　要：为了研究聚乙烯醇纤维再生骨料混凝土(polyvinyl alcohol-fiber recycled aggregate concrete,PVA-FRAC)在循环受压状态下的力学性能,设计并制作了32个混凝土试件,进行了单调和循环受压加载试验,观测了试件的破坏过程及形态,分析了不同聚乙烯醇(poly vinyl alcohol,PVA)纤维体积掺量、再生骨料取代率和加载速率对混凝土力学性能的影响。结果表明:循环荷载下PVA-FRAC主要发生斜向劈裂破坏,随着再生骨料取代率的增加,主裂缝突显且裂缝宽度不断增大;适当的PVA纤维体积掺量和再生骨料取代率能够有效提高混凝土的延性及耗能能力,PVA纤维体积分数为0.10%时耗能能力最好,提升幅度为26.19%,总体改性最好;加载速率由0.005 mm/s降至0.002 mm/s,试件的峰值应力平均提升了8.27%;刚度退化率最终稳定在0.4左右,应力退化率稳定在0.8左右。In order to study the mechanical properties of polyvinyl alcohol fiber recycled aggregate concrete(PVA-FRAC)under cyclic compression,32 concrete specimens were designed and made.Monotonous and cyclic loading tests were carried out,and the failure process and morphology of the specimens were observed.The effects of different volume content of PVA fiber,replacement ratio of recycled aggregate and loading rate on the mechanical properties of recycled concrete were analyzed.The experimental results show that oblique splitting failure mainly occurs in PVA-FRAC under cyclic loading.The main crack is prominent and the crack width is increasing with the increase of the replacement rate of recycled aggregate.PVA fiber and appropriate replacement ratio of recycled aggregate can effectively improve the ductility and energy dissipation capacity of concrete.The energy dissipation capacity is the best when the volume content of PVA fiber is 0.10%,increasing 26.19%,and the overall modification is the best.When the loading rate reduces from 0.005 mm/s to 0.002 mm/s,the peak stress of the specimen increased by 8.27%on average.The stiffness degradation rate is finally stable at about 0.4 and the stress degradation rate is stable at about 0.8.

关 键 词：循环荷载 聚乙烯醇纤维 再生骨料混凝土 力学性能 破坏机制 

分 类 号：TU528[建筑科学—建筑技术科学]