混凝土梁側(cè)嵌貼CFRP-PCPs復合筋的抗彎及抗剪加固試驗研究
發(fā)布時間：2019-02-11 21:36
【摘要】：近年來,隨著碳纖維(CFRP)等新型復合材料大量應用于土木結構工程中,將其嵌入加固混凝土結構等新技術的研究逐漸得到了工程界的廣泛關注,在取得了一些理論研究成果和工程實踐經(jīng)驗的同時,也面臨著一些理論及技術問題。非預應力CFRP筋在嵌入式加固鋼筋混凝土梁時,存在下列問題,如加載過程中梁的撓度過大,延性較差,裂縫寬度及高度較大,CFRP筋在試件極限承載力時遠未達到設計屈服強度,即其高強度無法有效發(fā)揮等。預應力CFRP筋嵌入式加固鋼筋混凝土梁時,目前為止與其配套的預應力張拉錨固體系與裝置較少,預應力張拉工藝復雜,錨具造價較高。針對以上所述問題,本課題組提出CFRP-PCPs復合筋(Carbon Fiber Reinforced Polymer prestressed concrete prisms,本文簡稱為CFRP-PCPs復合筋)嵌入式加固鋼筋混凝土梁的方法,并進行了試驗和理論分析,收到了預期的效果。本文采用自行研制的CFRP-PCPs復合筋,分別進行了鋼筋混凝土梁抗彎加固試驗研究和鋼筋混凝土梁抗剪加固試驗研究,主要研究內(nèi)容和成果如下:第一,本文基于國內(nèi)外關于復合筋混凝土構件試驗研究已取得成果的基礎上,分別完成了8根復合筋嵌入式抗彎加固混凝土梁的試驗研究,以及8根復合筋嵌入式抗剪加固混凝土梁的試驗研究,詳細描述了試驗過程和相關試驗現(xiàn)象,全面分析了所得的試驗結果。通過試驗現(xiàn)象觀察,獲得了各試驗梁的裂縫分布及發(fā)展形態(tài),通過試驗數(shù)據(jù)分析,得到了各試驗梁的荷載撓度曲線關系,繪出了各試驗梁復合筋內(nèi)CFRP筋的荷載-應力增量對比曲線。第二,通過嵌入式CFRP-PCPs復合筋抗彎加固鋼筋混凝土梁的試驗研究,對嵌入式CFRP-PCPs復合筋抗彎加固混凝土梁的破壞模式進行了系統(tǒng)的分析;提出了不同錨固長度復合筋加固混凝土梁剝離破壞時極限承載力的計算方法,計算結果與試驗結果吻合較好;提出了復合筋加固混凝土梁開裂荷載計算方法,對復合筋嵌貼加固混凝土梁的裂縫、撓度、延性等進行了分析,并提出了相關的計算方法。第三,通過嵌入式CFRP-PCPs復合筋抗剪加固鋼筋混凝土梁的試驗研究,對嵌入式CFRP-PCPs復合筋抗剪加固混凝土梁的破壞模式進行了分析;提出了加載過程中因復合筋棱柱體斷裂而導致試驗梁發(fā)生剪切破壞的承載力計算方法,與試驗結果吻合較好。
[Abstract]:In recent years, with the extensive application of carbon fiber (CFRP) and other new composite materials in civil engineering, the research on the new technology of embedding and strengthening concrete structures has been paid more and more attention by the engineering field. At the same time, it faces some theoretical and technical problems. The following problems exist in the reinforcement of reinforced concrete beams with unprestressed CFRP tendons, such as excessive deflection, poor ductility, large crack width and height during loading, and the CFRP bars are far from reaching the design yield strength in the ultimate bearing capacity of the specimens. That is, its high strength can not be played effectively. In the reinforcement of reinforced concrete beams with prestressed CFRP tendons, so far, there are fewer prestressed tensioning anchoring systems and devices, complex prestressing tensioning technology and high cost of anchors. In view of the above problems, our group put forward the method of strengthening reinforced concrete beam embedded with CFRP-PCPs composite reinforcement (Carbon Fiber Reinforced Polymer prestressed concrete prisms, which is referred to as CFRP-PCPs composite reinforcement in this paper, and carried out experimental and theoretical analysis. The desired effect was achieved. In this paper, the experimental research on flexural strengthening of reinforced concrete beams and shear strengthening of reinforced concrete beams are carried out using CFRP-PCPs composite tendons developed by ourselves. The main research contents and results are as follows: first, In this paper, based on the achievements of the experimental research on concrete members with composite reinforcement at home and abroad, eight concrete beams with embedded composite tendons have been tested and studied respectively. The experimental study of 8 composite tendons embedded shear strengthened concrete beams is carried out. The experimental process and related experimental phenomena are described in detail, and the experimental results are comprehensively analyzed. Through the observation of experimental phenomena, the crack distribution and development pattern of each test beam are obtained. Through the analysis of test data, the relationship of load deflection curve of each test beam is obtained. The load-stress increment contrast curves of CFRP tendons in the composite tendons of each test beam are plotted. Secondly, the failure mode of the reinforced concrete beams strengthened with embedded CFRP-PCPs composite tendons is analyzed systematically through the experimental research on the flexural strengthening of reinforced concrete beams with embedded CFRP-PCPs composite tendons. The calculation method of ultimate bearing capacity of concrete beams strengthened with different Anchorage length composite bars is put forward. The calculated results are in good agreement with the experimental results. This paper presents a method for calculating the cracking load of concrete beams strengthened with composite bars, and analyzes the cracks, deflection and ductility of concrete beams strengthened with composite tendons, and puts forward the relevant calculation methods. Thirdly, the failure mode of reinforced concrete beams strengthened with embedded CFRP-PCPs composite tendons is analyzed through the experimental research on the shear resistance of reinforced concrete beams strengthened with embedded CFRP-PCPs composite tendons. A method for calculating the shear failure of test beams caused by the fracture of prisms with composite tendons during loading is proposed, which is in good agreement with the experimental results.
【學位授予單位】：廣西科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU375.1
[Abstract]:In recent years, with the extensive application of carbon fiber (CFRP) and other new composite materials in civil engineering, the research on the new technology of embedding and strengthening concrete structures has been paid more and more attention by the engineering field. At the same time, it faces some theoretical and technical problems. The following problems exist in the reinforcement of reinforced concrete beams with unprestressed CFRP tendons, such as excessive deflection, poor ductility, large crack width and height during loading, and the CFRP bars are far from reaching the design yield strength in the ultimate bearing capacity of the specimens. That is, its high strength can not be played effectively. In the reinforcement of reinforced concrete beams with prestressed CFRP tendons, so far, there are fewer prestressed tensioning anchoring systems and devices, complex prestressing tensioning technology and high cost of anchors. In view of the above problems, our group put forward the method of strengthening reinforced concrete beam embedded with CFRP-PCPs composite reinforcement (Carbon Fiber Reinforced Polymer prestressed concrete prisms, which is referred to as CFRP-PCPs composite reinforcement in this paper, and carried out experimental and theoretical analysis. The desired effect was achieved. In this paper, the experimental research on flexural strengthening of reinforced concrete beams and shear strengthening of reinforced concrete beams are carried out using CFRP-PCPs composite tendons developed by ourselves. The main research contents and results are as follows: first, In this paper, based on the achievements of the experimental research on concrete members with composite reinforcement at home and abroad, eight concrete beams with embedded composite tendons have been tested and studied respectively. The experimental study of 8 composite tendons embedded shear strengthened concrete beams is carried out. The experimental process and related experimental phenomena are described in detail, and the experimental results are comprehensively analyzed. Through the observation of experimental phenomena, the crack distribution and development pattern of each test beam are obtained. Through the analysis of test data, the relationship of load deflection curve of each test beam is obtained. The load-stress increment contrast curves of CFRP tendons in the composite tendons of each test beam are plotted. Secondly, the failure mode of the reinforced concrete beams strengthened with embedded CFRP-PCPs composite tendons is analyzed systematically through the experimental research on the flexural strengthening of reinforced concrete beams with embedded CFRP-PCPs composite tendons. The calculation method of ultimate bearing capacity of concrete beams strengthened with different Anchorage length composite bars is put forward. The calculated results are in good agreement with the experimental results. This paper presents a method for calculating the cracking load of concrete beams strengthened with composite bars, and analyzes the cracks, deflection and ductility of concrete beams strengthened with composite tendons, and puts forward the relevant calculation methods. Thirdly, the failure mode of reinforced concrete beams strengthened with embedded CFRP-PCPs composite tendons is analyzed through the experimental research on the shear resistance of reinforced concrete beams strengthened with embedded CFRP-PCPs composite tendons. A method for calculating the shear failure of test beams caused by the fracture of prisms with composite tendons during loading is proposed, which is in good agreement with the experimental results.
【學位授予單位】：廣西科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU375.1
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