FRP筋拉伸及与混凝土的粘结性能

发布时间：2018-12-13 06:02

【摘要】：本文制备了不同类型的玻璃纤维增强复合材料(GFRP)筋和钢绞线-玻璃纤维增强复合材料(S/GFRP)筋。通过FRP筋的拉伸试验,研究直径和钢绞线体积率对FRP筋抗拉强度和弹性模量的影响;通过FRP筋与混凝土的粘结拉拔试验,研究直径、肋深、肋间距和钢绞线体积率对FRP筋与混凝土粘结性能的影响。主要研究内容有:1.通过7组(每组5根)GFRP筋或S/GFRP筋的拉伸试验,研究了直径、钢绞线体积率对FRP筋抗拉强度和弹性模量的影响。结果表明,直径较小的GFRP筋和S/GFRP筋的抗拉强度较高;加入钢绞线可有效提高GFRP筋的弹性模量,但对抗拉强度无明显影响;S/GFRP筋的弹性模量显著提高,且随着钢绞线体积率的增大而增大;钢绞线体积率对FRP筋的抗拉强度无显著影响;引入钢绞线参与工作系数β,反映钢绞线体积率对S/GFRP筋弹性模量的影响,建议β的取值为0.45。2.通过8组(每组3个)GFRP筋或S/GFRP筋与混凝土的粘结拉拔试验,研究了直径、肋深和肋间距对GFRP筋与混凝土粘结性能的影响;直径和钢绞线体积率对S/GFRP筋与混凝土粘结性能的影响。结果表明,在粘结试件发生混凝土劈裂破坏时,随着直径的减小和肋深的增加,GFRP筋与混凝土的粘结强度显著提高;肋间距对GFRP筋与混凝土粘结强度无明显影响;S/GFRP筋与混凝土的粘结强度较GFRP筋有明显提高;钢绞线体积率对S/GFRP筋与混凝土的粘结强度无显著影响。3.根据FRP筋与混凝土的粘结拉拔试验结果,提出了FRP筋与混凝土之间粘结强度计算公式和基本锚固长度计算公式;利用现有BPE模型对试验得到的FRP筋与混凝土粘结-滑移曲线上升段进行拟合,模型曲线与试验曲线吻合良好。
[Abstract]:In this paper, different types of glass fiber reinforced composites (GFRP) tendons) and steel strand-glass fiber reinforced composites (S/GFRP) tendons have been prepared. The effects of diameter and volume ratio of steel strand on tensile strength and elastic modulus of FRP tendons were studied by tensile test. The effects of diameter, rib depth, rib spacing and volume ratio of steel strands on the bond properties of FRP tendons and concrete were studied by means of the bond pull-out test between FRP tendons and concrete. The main research contents are as follows: 1. The effects of diameter and volume ratio of steel strands on tensile strength and elastic modulus of GFRP tendons and S/GFRP tendons were studied through tensile tests of 7 groups (5 bars per group). The results show that the tensile strength of GFRP bars and S/GFRP tendons with small diameter is higher, and the elastic modulus of GFRP tendons can be improved effectively by adding steel strands, but the tensile strength is not affected obviously. The elastic modulus of S/GFRP tendons increases significantly, and increases with the increase of the volume ratio of steel strands, while the volume ratio of steel strands has no significant effect on the tensile strength of FRP tendons. The effect of the volume ratio of steel strand on the elastic modulus of S/GFRP tendons is reflected by introducing the working coefficient 尾 of steel strands, and the value of 尾 is suggested to be 0.45.2. The effects of diameter, rib depth and rib spacing on the bond properties of GFRP tendons and concrete were studied by eight groups (3 in each group). The influence of diameter and volume ratio of steel strand on bond property of S/GFRP bar and concrete. The results show that with the decrease of diameter and the increase of rib depth, the bond strength of GFRP bar and concrete increases significantly, while the intercostal spacing has no obvious effect on the bond strength between GFRP bar and concrete. The bond strength of S/GFRP bar and concrete is obviously higher than that of GFRP bar, and the volume ratio of steel strand has no significant effect on the bond strength of S/GFRP bar and concrete. Based on the experimental results of bond drawing between FRP bars and concrete, the formula of bond strength between FRP bars and concrete and the formula of basic anchoring length are put forward. The existing BPE model is used to fit the rising section of the bond-slip curve between the FRP bar and the concrete, and the model curve is in good agreement with the experimental curve.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU377.9

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