CFRP-PCPs复合筋混凝土偏压柱受力性能试验及理论研究

发布时间：2018-10-21 19:30

【摘要】：CFRP-PCPs复合筋(carbon fiber reinforced polymer prestressed concrete prisms)是由碳纤维筋(carbon fiber reinforced plastics)和超高性能混凝土(ultra-high performance concrete)制成,采用先张法对碳纤维筋施加预应力后,用超高性能混凝土以CFRP筋为中心浇筑成小截面的预应力复合材料棱柱体。复合筋混凝土构件能有效克服钢筋锈蚀的缺陷并提高构件的承载力;同时作为复合材料构件,复合筋集两种组成材料的优势性能于一身,复合筋混凝土结构的挠度和裂缝宽度比CFRP筋混凝土结构的挠度和裂缝宽度要小。由此可知,复合筋在土木工程应用中具有较好的前景。复合筋构件的组成与碳纤维塑料筋或普通钢筋不同,因而复合筋混凝土梁、柱在受力分析、承载力计算、挠度、裂缝及复合筋混凝土的粘结性能上也一定与普通钢筋混凝土或碳纤维筋混凝土构件不同。在本课题组关于复合筋混凝土简支梁、连续梁受力性能的实验与理论研究已得成果的基础上,为了促进复合筋在混凝土结构中的广泛应用,对复合筋混凝土柱受力性能的理论研究工作就尤为必要。本文主要的研究工作如下:(1)完成了6根复合筋混凝土梁式试验。通过试验,详述了各试件的破坏现象,绘制并初步探讨了梁式试件荷载与CFRP筋应变关系、梁式试件荷载与混凝土应变关系和荷载与挠度关系曲线;对复合筋与混凝土之间的粘结性能进行了较为系统的理论分析,具体包括:复合筋与混凝土之间粘结应力的求解、复合筋混凝土构件粘结性能影响因素的探讨及复合筋混凝土构件的粘结应力-滑移曲线,并对比试验结果验证了计算理论的准确性。(2)进行了17根复合筋混凝土偏心受压柱的受力性能试验,试验中主要考察普通钢筋配筋率、CFRP-PCPs复合筋截面尺寸、复合筋预应力水平、偏心距和长细比对CFRP-PCPs复合筋混凝土偏压柱正截面的受力特点和破坏性形式的影响。通过试验结果,归纳了各试验柱的受力情况,简单分析了试验所测得的极限承载力与复合筋偏压柱复合筋中的CFRP筋应变、极限承载力与复合筋偏压柱侧向变形等各参数之间的关系。考虑不同影响因素对复合筋混凝土偏心受压柱关于承载能力计算进行了理论分析,具体包括:复合筋混凝土偏压柱的破坏特征、试验柱的极限承载力分析及复合筋混凝土偏压柱的二阶效应分析,并对比试验结果验证了计算理论的准确性。
[Abstract]:CFRP-PCPs composite reinforcement (carbon fiber reinforced polymer prestressed concrete prisms) is made of carbon fiber reinforced (carbon fiber reinforced plastics) and ultra-high performance concrete (ultra-high performance concrete). High performance concrete (UHPC) is used to form prestressing composite prism with small section with CFRP bar as the center. The composite reinforced concrete member can effectively overcome the defect of steel bar corrosion and improve the bearing capacity of the member. The deflection and crack width of composite reinforced concrete structure are smaller than that of CFRP reinforced concrete structure. It can be seen that the composite reinforcement has a good prospect in the application of civil engineering. The composition of composite reinforcement members is different from that of carbon fiber reinforced plastic bars or ordinary steel bars, so the composite reinforced concrete beams and columns are under stress analysis, bearing capacity calculation, deflection, The bond behavior of crack and composite reinforced concrete is also different from that of normal reinforced concrete or carbon fiber reinforced concrete member. On the basis of the experimental and theoretical research on the mechanical properties of composite reinforced concrete simply supported beams and continuous beams, in order to promote the wide application of composite tendons in concrete structures, It is necessary to study the mechanical behavior of composite reinforced concrete columns. The main work of this paper is as follows: (1) six composite reinforced concrete beams have been tested. Through experiments, the failure phenomena of each specimen are detailed, and the relationship between the load of beam specimen and the strain of CFRP bar, the relationship between load and strain of concrete and the curve between load and deflection are plotted and discussed preliminarily. The bond behavior between composite reinforcement and concrete is analyzed systematically, including the solution of bond stress between composite reinforcement and concrete. The influence factors of bond behavior of composite reinforced concrete members and the bond stress-slip curves of composite reinforced concrete members are discussed. The accuracy of the calculation theory is verified by comparing the experimental results. (2) the mechanical behavior tests of 17 eccentric columns of composite reinforced concrete are carried out. In the test, the reinforcement ratio of ordinary reinforcement, the section size of CFRP-PCPs composite reinforcement and the prestress level of composite reinforcement are investigated. The influence of eccentricity and aspect ratio of CFRP-PCPs reinforced concrete columns on normal section and destructive form. Through the test results, the stress of each test column is summarized, and the ultimate bearing capacity measured by the test and the strain of CFRP tendons in the composite tendons of the composite tendons are simply analyzed. The relationship between ultimate bearing capacity and lateral deformation of composite tendons. Considering different influence factors, the calculation of bearing capacity of composite reinforced concrete eccentrically compressed columns is theoretically analyzed, including: failure characteristics of composite reinforced concrete eccentric columns, The ultimate bearing capacity of test columns and the second-order effect analysis of composite reinforced concrete columns are analyzed, and the accuracy of the calculation theory is verified by comparing the experimental results.
【学位授予单位】：广西科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU377.9

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