纤维聚合物筋混凝土梁力学性能的研究

Based upon the test results on the normal section cracking behavior of composite material with fiber reinforced polymer bars and concrete, the calculation method for normal section cracking load of composite material with fiber reinforced polymer bars and concrete, which gives coordination of that for normal section cracking load of composite material with steel reinforcement bars and concrete, is established. The unified calculating formula put forward in the paper can be referred to for the revision of the design and construction regulation in China, and also be made use of by the department of engineering design and construction.（2）On the basis of test results, the effect of reinforcement ratio of fiber reinforced plastic rebar (FRP) on the ultimate moment of FRP reinforced concrete beam is analyzed, the concept of specified yield point is put forward, the capacity reduction factor is suggested connected with the test results. Based on the modern design theory of steel reinforced concrete beam ,the calculating method of ultimate moment of FRP reinforced concrete beam is put forward, which is suitable to the characteristics of FRP reinforced concrete beam and correspondent with the current design code in china. .（3）The test study indicates that the load deflection curves of concrete beams reinforced with fiber reinforced polymer bars can be divided into two linear stages against the initial cracking of the section when the tension failure occurs. Before the normal section cracks, the load-deflection curve is basically linear and the section rigidity is larger. As soon as the normal section cracks, the crack firstly appears in the flexural region. At this moment, the load-deflection curve has a turning point. With the increase the load, the rigidity of the beam decreases compared with that before cracking because of the development of cracks in flexural region, and the formation and development toward the loading point of diagonal cracks. Generally, the load-deflection curve of this kind of beam is probably linear also. Based upon the stress-strain relationship of both fiber reinforced polymer bars and concrete, the nonlinear and whole-process numerical analytical method of concrete beams reinforced with fiber reinforced polymer bars is explored. The experimental curve of load-deflection is imitated through computer, and compared with the relevant data from the test. Through the simplification for the stress-strain curve of concrete in compression and the stress distribution of concrete in tensile region, this paper establishes the simplified method of whole process numerical analysis for concrete beams reinforced fiber reinforced plastic bars. In comparison to the test results and those got by other numerical analysis method, the rationality and usability of the method in the paper are tested..（4）According to the test results, the deflection characteristic of concrete beam reinforced by fiber reinforced plastic rebar (FRP) is analyzed. From the principle of rigidity analytic method, the calculating method of rigidity of FRP reinforced concrete beam is discussed, the calculating formulas for the rigidity of FRP reinforced concrete beam, which are coordinated with the calculating method of reinforced structure, are formed initially.（5）Based on the mechanical properties of fiber reinforced plastic rebar (FRP) and concrete beam, the expressions of cross section curvature at specified yield point of FRP and at failure of beam are established. On this basis, the calculating method of cross sectional ductility is studied. The results indicate that, according to two kinds of calculating methods in the thesis, the curvature ductility coefficients increase with the decrease of FRP reinforcement patio and increase of concrete strength.（6）Due to the difference on the behavior of fiber reinforced polymer bar (FRP) and steel reinforcement, it makes the obvious difference on the bond behavior between the concrete reinforced with FRP and the concrete reinforced with steel reinforcement. Therefore, the research on the

纤维聚合物筋以其耐腐蚀、强度高、重量轻、耐电磁等特点可以取代建筑钢筋用于增强混凝土，从根本上解决由钢筋腐蚀引进的钢筋混凝土结构的耐久性问题。本项目利用申请者在国外的研究工作基础，研究纤维聚合物筋与混凝土的粘结滑移性能、纤维聚合物筋混凝土梁的正截面受弯性能和斜截面受剪性能，建立纤维聚合物筋混凝土梁的基本理论。