FRP筋和钢筋混合配筋增强混凝土梁受弯性能

根据FRP筋和钢筋的本构模型,提出了FRP筋和钢筋混合配筋增强混凝土梁2种名义配筋率和3种破坏模式的概念,并给出了3种破坏模式的判别条件.利用正截面受弯承载力计算基本假定和截面受力平衡条件,推导了FRP筋和钢筋混合配筋增强混凝土适筋梁正截面受弯承载力建议计算公式.设计制作了5根不同FRP筋和钢筋配筋面积比的混合配筋混凝土梁进行静力抗弯试验,并结合相关试验数据分析表明,适筋梁正截面受弯承载力建议公式计算值与试验实测值吻合较好,可供工程设计参考；建议在对承载能力要求较高而挠度控制较低的情况下使用混合配筋混凝土梁以充分利用材料的强度；合理控制混合配筋梁的配筋率及FRP筋和钢筋的配筋面积比,其延性性能满足设计要求.

Flexural behavior of concrete beam with hybrid reinforcement of FRP bars and steel bars

According to the characteristic of both fiber reinforced polymer(FRP) bars and steel bars,two nominal reinforcement ratios and three failure modes for concrete beams reinforced with FPR bars and steel bars are put forward,and the failure criterion of appropriate hybrid reinforcement beam is given.Flexural capacity of appropriate hybrid reinforcement beam was analyzed under the basic assumption and equilibrium condition of internal forces;further more flexural capacities simplified calculation formula of appropriate hybrid reinforcement beam is also proposed.Five different area ratio of FRP bars to steel bars hybrid reinforced concrete beams were prepared and their static flexural test were made.Relevant experimental data were analyzed,and it is shown that the flexural capacities calculated by proposed simplified formula are close to the test value and can be used in design for reference.In order to make full use of material,it is proposed to exploit hybrid reinforcement beam in the situation where deflection is not in control but bearing capacity is highly demanded.And its ductility performance can meet the code by appropriately controlling the reinforced ratio and the value of A_f/A_s.