【作者】 贺红卫；

【导师】 赵军；

【作者基本信息】 郑州大学 ， 结构工程， 2013， 硕士

【摘要】 钢筋混凝土结构是土木工程领域中主要的结构形式,但是混凝土结构中钢筋的腐蚀造成的结构耐久性的降低和结构失去使用功能日益成为严重的问题,用纤维增强聚合物(FRP)筋替代钢筋用于工程结构中是一个有效的解决方法。FRP筋具有质量轻、强度高和耐腐性强的优点,已成为土木工程领域一种新型的结构材料,能够很好的解决钢筋混凝土结构中日益严重的钢筋腐蚀问题。大量的混凝土结构腐蚀的现象表明,结构的腐蚀最容易发生在角部,为了能够提高其耐久性,可以采用FRP箍筋代替钢筋,这样FRP箍筋可以把纵筋包围在角的四周,和混凝土一起保护纵筋。但是FRP筋材料不同于普通钢筋,具有明显的脆性,其应力应变为线弹性关系,没有普通钢筋那样的屈服平台,且弹性模量低,构件的破坏带有一定的脆性,用这种材料直接作为组合构件或结构的配筋,其极限状态、设计方法和可靠度问题以及设计指标都需重新考虑,针对其力学性能应采用合理的理论。从这个出发点,本文进行了FRP筋混凝土梁的受剪性能试验研究。本文的主要工作是研究GFRP箍筋混凝土梁的抗剪性能,通过6根集中荷载作用下FRP箍筋混凝土矩形截面简支梁的试验研究,分析了GFRP箍筋混凝土梁在集中荷载作用下的变形性能、斜裂缝的发展情况、箍筋的应变变化特点及破坏形态,研究GFRP箍筋混凝土梁斜截面受力特点。重点研究了剪跨比和配箍率对试验梁的变形性能、破坏形态和斜裂缝开展特点的影响。通过对试验数据的分析,采用我国规范中钢筋混凝土梁斜截面承载力设计中采用的桁架模型,对我国的梁受剪承载力公式进行修正,提出与规范相衔接的FRP筋混凝土梁的受剪承载力公式。为以后FRP筋受剪计算相关规范的建立提供了一定的参考。更多还原

【Abstract】 The reinforced concrete structure is the main structure form in the civil engineering, but the decrease in the durability and the lost in the use of the structure caused by the steel corrosion has become a serious problem in the concrete structures. To use FRP bars substitute steel bars is an effective solution in the structure design. FRP bars has the advantages of light weight, high strength and corrosion resistance, which has become a new type of structural materials., and can good enough to solove the increasingly serious reinforced corrosion problems in the concrete structure.A large number of phenomena, which is the corrosion of the concrete structures show that the corrosion of the structure most likely occur in the corner, FRP stirrups can be used instead of the reinforced in order to improve its durability, in which way longitudinal reinforcement can be surrounded by FRP stirrups around the corner, so the FRP stirrups can protect the longitudinal reinforcement together with concrete. But FRP bars is different from the steel bars, it is brittle material, shows the performance of the linear elastic until extraction, does not have the yield platform, and has low modulus of elasticity. So the member with these materials will have brittle damage. If we use the FRP materials as the composite members or the structural reinforcement directly, the limit state、design method and the reliability of the structure must be reconsidered, the rational design method should be adopted for its performance. Based on this, the experimental research of the shear behavior of the reinforced concrete beams with the FRP stirrups is carried out.The main work of this paper is to study the shear behavior of the reinforced concrete beam with the GFRP stirrups. Through the experimental study of six rectangular cross-section simply supported concrete beams, which are under the concentrated loads, the deformation behavior、the development of the diagonal cracks、the variation of the stirrup strain and the failure modes of the beams with the GFRP stirrups are analyzed, the destruction features of the GFRP bars is found under sheared beam. The shear span ratio and stirrup ratio which affect the deformation behavior、the development of the diagonal cracks and the failure modes of the experimental beams are researched. Through the analysis the test data, the truss model is adopted, which is the same with the one adopted by Chinese specification for calculating reinforced concrete beam bearing capacity. Through revising the beam shear equation in our concrete specification, a concrete beam with FRP stirrups shear equation is proposed, which is joined with our specification. And some reference is provided about established the calculation of the concrete shear capacity later.更多还原