考虑粘结滑移本构关系的FRP筋锚固长度

Study on the anchorage length of FRP bars with bond-slip constitutive relationship

在FRP筋混凝土拉拔试件微分单元受力分析的基础上,考虑FRP筋混凝土粘结本构关系,推导了随不同位置变化的滑移、FRP筋拉应力和粘结应力理论公式。根据这些理论公式进而得到了最小锚固长度的计算公式,并通过算例进行分析。研究表明,对于FRP筋混凝土构件在正常使用极限状态下,在粘结—滑移本构关系上建立起来的FRP筋锚固长度的限值是满足设计要求的。另外,在此基础上建立的FRP筋锚固长度是针对试件实际的粘结滑移关系,对于表面不同类型、不同组成成分的FRP筋均能较好地确定其最小锚固长度,这对FRP筋混凝土结构构件的设计具有一定的指导作用。

Based on the behavioral analysis of differential element of concrete reinforced with FRP bars in pullout test, the bend-sllp constitutive relationship were considered. The theoretical formula of the slip, stress of FRP bars and bond stress at different position were deduced. According to the theoretical formula, the min anchorage length was obtained with bond-slip constitutive relationship. The study showed that the basic development length of FRP bars which established by bond-slip relationship satisfied with design. In addition, the anchorage length accounted for the actual bond-slip constitutive law which obtained by experimental tests on different types of FRP bars. The analytical approach may be contributed to the design of concrete reinforced with FRP bars.