BFRP网格布对超高性能混凝土粘结性能的影响

Effect of BFRP mesh cloth on bonding properties of ultra-high performance concrete

  • 摘要: 为分析玄武岩纤维增强树脂复合材料(BFRP)网格布对超高性能混凝土(UHPC)粘结性能的影响,以干/湿粘结类型、BFRP网格布锚固深度和网格布厚度3个参数,分别开展BFRP-UHPC界面正拉粘结试验(48块)和切向剪切试验(21块),研究了BFRP网格布对其与UHPC界面破坏模态、粘结性能、剪应力-滑移曲线、拉伸比和韧性的影响,同时利用SEM,揭示BFRP-UHPC界面破坏机制。结果表明:锚固深度直接决定BFRP-UHPC界面破坏模式;法向粘结应力和切向粘结应力在界面变化规律上具有正向相关性;BFRP-UHPC界面湿粘结强度高于干粘结工艺水平;随着BFRP厚度和锚固深度逐渐增加,BFRP与UHPC界面粘结应力均呈现逐渐减小的规律;钢纤维对BFRP-UHPC界面增韧效果显著,其端勾构造使UHPC损伤后仍具有残余刚度和强度;当BFRP锚固深度为5 mm时,此时界面粘结应力达到最大,正拉粘结试验中粘结应力最大提升幅度达到74%,拉伸强度比高达1.74。

     

    Abstract: In order to analyze the influence of basalt fiber reinforced polymer (BFRP) mesh on the bonding performance of ultra-high performance concrete (UHPC), the BFRP-UHPC interface pull-out bonding test (48 pieces) and shear test (21 pieces) were carried out respectively with three parameters of dry/wet bonding type, BFRP mesh anchorage depth and mesh thickness. The effects of BFRP mesh on the failure mode, bonding performance, shear stress slip curve, tensile ratio and toughness were studied. At the same time, the failure mechanism of BFRP-UHPC interface was revealed by SEM. The results show that the anchoring depth directly determines the failure mode of BFRP-UHPC interface. There is a positive correlation between tangential bonding stress and normal bonding stress. The wet bonding strength of BFRP-UHPC interface is higher than that of dry bonding process. With the increase of BFRP thickness and anchorage depth, the interfacial bonding stress between BFRP and UHPC shows a decreasing trend. Steel fiber has remarkable toughening effect on BFRP-UHPC interface, its end hook structure makes UHPC still have residual stiffness and strength after damage. When the anchoring depth of BFRP is 5 mm, the interface bonding stress reaches the maximum, the maximum increase of interface in the pull out bonding stress reaches 74%, and the tensile strength ratio is 1.74.

     

/

返回文章
返回