PVA纤维橡胶混凝土力学性能及微观特征分析  

Analysis on mechanical properties and microscopic characteristicsof PVA fiber rubber concrete

作　　者：曾磊[1] 杨涛 马林玲 ZENG Lei;YANG Tao;MA Linling(School of Urban Construction,Yangtze University,Jingzhou 434023,Hubei)

机构地区：[1]长江大学城市建设学院,湖北荆州434023

出　　处：《长江大学学报（自然科学版）》2023年第6期125-133,共9页Journal of Yangtze University(Natural Science Edition)

基　　金：国家自然科学基金项目“基于改进离散粒子群算法的高层型钢混凝土混合结构地震失效模式优化”(51978078)。

摘　　要：为探究PVA纤维对橡胶混凝土力学性能和界面微观特征的影响,通过轴心抗压试验和抗折试验对不同纤维掺量下橡胶混凝土的破坏形态、抗压强度和抗折强度进行了对比分析,并采用扫描电子显微镜(SEM)和能谱分析技术(EDS)对其微观形貌和界面过渡区进行了研究。结果表明:掺入PVA纤维可以有效缓解橡胶混凝土强度的衰减趋势,最佳掺量控制在1%左右,试件抗压破坏模式由脆性破坏转变为延性破坏,应力应变曲线下降段更加平缓。橡胶颗粒减小了混凝土界面受荷面积,改变了集料与水泥基体界面处的元素含量,导致混凝土强度降低。掺入PVA纤维会降低橡胶混凝土的Ca/Si比值,较基准混凝土降低幅度为5%~10%,界面黏接处C-S-H的生成量有所提高,有效地改善了橡胶混凝土内部界面缺陷。In order to explore the influence of PVA fiber on the mechanical properties and interface microscopic characteristics of rubber concrete,the failure model,compressive strength and flexural strength of different fiber content were compared and studied through axial compression test and flexural test.The microscopic morphology and interface transition zone was analyzed through Scanning Electron Microscope(SEM)and Energy Dispersive Spectrometer(EDS).The results show that the blending of PVA fiber can effectively alleviate the strength attenuation of rubber concrete,and the optimal content is controlled at about 1%.The compression failure mode of the specimen has changed from brittle failure to ductile failure,while the degeneration segment of stress-strain curve becomes gentler.The rubber particles reduce the loaded area of concrete interface and change the element content at the interface between aggregate and cement matrix,resulting in a decrease on concrete strength.Compared with the benchmark concrete,incorporating PVA fibers will reduce the Ca/Si ratio of rubber concrete for 5%~10%.The generation of C-S-H at the bonding interface increases,and the internal interface defects of rubber concrete are effectively improved.

关 键 词：C-S-H凝胶 钙硅元素含量比 界面过渡区 孔隙结构 

分 类 号：TU528.58[建筑科学—建筑技术科学]