不同含水状态下喷射型PP-PVA混杂纤维增强水泥基复合材料性能研究  

Study on properties of sprayed PP-PVA hybrid fiber reinforced cement-based composites under different water content

作　　者：程磊科 胡时 蔡海兵 陶犇 潘鑫 CHENG Leike;HU Shi;CAI Haibing;TAO Ben;PAN Xin(Anhui Transportation Holding Group Co.,Ltd.,Hefei 230088,China;School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽省交通控股集团有限公司,安徽合肥230088 [2]安徽理工大学土木建筑学院,安徽淮南232001

出　　处：《混凝土》2023年第8期169-173,177,共6页Concrete

基　　金：国家自然科学基金(51778004);安徽省交通控股集团交通科技攻关项目(JKKJ-2018-31)。

摘　　要：一些建筑结构长期工作在水环境中,处于不同含水状态,含水混凝土的抗压力学性能与干燥混凝土相比有较大的改变,这可能会对结构安全性造成一定的影响。与此同时将纤维增强水泥基复合材料(ECC)用于建筑结构已成为研究热点。因此主要研究不同含水状态下PP-PVA混杂纤维增强水泥基复合材料性能差异的研究。开展了4种含水状态下PP-PVA混杂纤维增强水泥基复合材料(HFRCC)单轴压缩试验,结合扫描电镜、X射线衍射和核磁共振试验研究其性能和破坏特征。结果表明:HFRCC的吸水量时程曲线呈指数函数增长,前0.5 h内快速增长,0.5~204 h内,增长速率逐渐降低,204~276 h内增长速率基本为0,开始趋于稳定;随着试件含水量增加,抗压强度、峰值应变和压缩韧性值均呈下降趋势,相反弹性模量呈上升趋势;典型破坏过程可看成裂而不散的延性破坏,大多为伴随着大量微裂纹的单剪面或共轭双剪面的拉剪破坏。Some building structures work in the water environment for a long time and are in different water containing states.The compressive mechanical properties of water containing concrete are greatly changed compared with dry concrete,which may have a certain impact on the structural safety.At the same time,the application of fiber reinforced cement-based composites(ECC)in building structures has become a research hotspot.It mainly studies the performance differences of PP-PVA hybrid fiber reinforced cementitious composites(HFRCC)under different water content.Then the uniaxial compression tests under four water-bearing conditions were carried out,and the properties and failure characteristics were studied by scanning electron microscopy,X-ray diffraction and nuclear magnetic resonance tests.Results demonstrate that the water absorption time history curve of HFRCC increases exponentially with a rapid growth in the first 0.5 h,a gradual decrease in the growth rate of 0.5~204 h,and a basically zero growth rate in the period of 204~276 h,which tends to be stable.With the increase of water content,the compressive strength,peak strain and compressive toughness of the specimen show a downward trend,while the elastic modulus shows an upward trend.The typical failure process can be regarded as the ductile failure of crack but not scattered,most of which are tension-shear failure with a large number of single shear plane or conjugate double shear plane of micro-cracks.

关 键 词：特长公路隧道 纤维增强水泥基复合材料 混杂纤维 微观结构 压缩韧性 

分 类 号：TU528.36[建筑科学—建筑技术科学]