發(fā)布時(shí)間：2019-04-17 13:40

【摘要】：FRP抗剪加固鋼筋混凝土梁是當(dāng)前加固技術(shù)領(lǐng)域的一個(gè)研究熱點(diǎn)。然而,大多試驗(yàn)研究均基于新拌混凝土梁,缺乏考慮實(shí)際加固構(gòu)件中的鋼筋往往已處于銹蝕狀態(tài)對(duì)加固性能的影響。在處于濱海環(huán)境的混凝土結(jié)構(gòu),構(gòu)件可能因?yàn)槁入x子的滲透和混凝土的碳化導(dǎo)致鋼筋鈍化膜消失,進(jìn)而誘發(fā)鋼筋銹蝕。一旦發(fā)生銹蝕,將會(huì)導(dǎo)致其力學(xué)性能的下降、與混凝土的界面粘結(jié)性能退化以及造成混凝土表面開裂甚至剝落。另外,剪跨比是試驗(yàn)梁剪切破壞模式的主導(dǎo)因素,對(duì)FRP的加固效果影響顯著。因此本文利用三點(diǎn)受彎梁試驗(yàn),研究剪跨比和箍筋銹蝕兩者的耦合作用對(duì)外貼FRP抗剪加固鋼筋混凝土梁的影響機(jī)理和規(guī)律。首先,所有試驗(yàn)梁通過靜力加載試驗(yàn),得到的裂縫發(fā)展過程、最終破壞形態(tài)、荷載-撓度曲線、箍筋應(yīng)變、FRP條帶應(yīng)變及其應(yīng)變不均勻分布等試驗(yàn)結(jié)果,分析剪跨比和箍筋銹蝕的相互作用對(duì)FRP抗剪貢獻(xiàn)的影響,整體把握試驗(yàn)的宏觀現(xiàn)象和規(guī)律,為探索FRP-混凝土-箍筋在抗剪加固中的互動(dòng)關(guān)系建立理論基礎(chǔ)。其次,利用主剪斜裂縫經(jīng)過的FRP條帶和箍筋的計(jì)算公式,得到兩者的理論抗剪貢獻(xiàn)。通過分析FRP實(shí)際抗剪貢獻(xiàn)與理論抗剪貢獻(xiàn)之間的差別,以及加固后箍筋理論抗剪貢獻(xiàn)的變化規(guī)律,進(jìn)一步明晰加固梁中FRP-混凝土-箍筋三者之間的互動(dòng)關(guān)系,為建立考慮剪跨比和箍筋銹蝕耦合作用下FRP抗剪貢獻(xiàn)計(jì)算公式提供堅(jiān)實(shí)的理論依據(jù)。最后,在比較了現(xiàn)有設(shè)計(jì)規(guī)范預(yù)測(cè)值與實(shí)際試驗(yàn)值之間的差別之后,總結(jié)分析規(guī)范因未考慮剪跨比和箍筋銹蝕兩者的影響導(dǎo)致的適用性不佳,為此,根據(jù)剪跨比和箍筋銹蝕引起的FRP抗剪加固效果的規(guī)律性變化,引入考慮剪跨比的影響因子f(λ)和考慮箍筋銹蝕的影響因子f(C),探索性建立適用于不同剪切破壞模式下考慮箍筋銹蝕的FRP抗剪計(jì)算公式。
[Abstract]:FRP shear reinforcement of reinforced concrete beams is a hot spot in the field of reinforcement technology. However, most of the experimental studies are based on fresh concrete beams, the lack of consideration of the actual reinforced members of the reinforcement is often in the rusting state of the impact on the reinforcement performance. In the concrete structure in coastal environment, the penetration of chloride ions and the carbonation of concrete may lead to the disappearance of passivation film of steel bar and the corrosion of steel bar. Once the corrosion occurs, it will lead to the decline of its mechanical properties, the degradation of the interfacial bond between the concrete and the concrete, and the cracking and even spalling of the concrete surface. In addition, the shear-span ratio is the main factor of shear failure mode of the experimental beam, and has a significant effect on the strengthening effect of FRP. Therefore, the coupling of shear-span ratio and corrosion of stirrups is studied in this paper by using three-point bending beam test. The mechanism and rule of shear-reinforced concrete beams strengthened with FRP are studied in this paper. First of all, the experimental results of crack development process, final failure pattern, load-deflection curve, stirrups strain, FRP strip strain and its uneven distribution were obtained by static loading test of all test beams. The influence of the interaction of shear span ratio and corrosion of stirrups on the shear strength of FRP is analyzed, and the macroscopic phenomena and rules of the test are grasped as a whole. The theoretical basis for exploring the interaction between FRP- concrete and stirrups in shear reinforcement is established. Secondly, the theoretical contribution of the FRP strip and stirrups passing through the main shear inclined crack is obtained. By analyzing the difference between the actual and theoretical shear contribution of FRP and the variation rule of theoretical shear contribution of reinforced stirrups, the interaction between FRP- concrete and stirrups in reinforced beams is further clarified. It provides a solid theoretical basis for calculating the shear contribution of FRP considering the coupling of shear span ratio and corrosion of stirrups. Finally, after comparing the difference between the predicted value of the existing design code and the actual test value, the applicability of the code due to the failure to consider the influence of shear-span ratio and stirrups corrosion is summarized. According to the regular change of FRP shear reinforcement effect caused by shear span ratio and stirrups corrosion, the influence factors f (位) and f (C), considering shear span ratio and stirrups rust are introduced. The FRP formula for calculating shear strength of stirrups considering corrosion of stirrups under different shear failure modes is established.
【學(xué)位授予單位】：深圳大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TU375.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 張興才;李洪明;葉方潔;王冬冬;;箍筋銹蝕RC梁抗剪加固性能試驗(yàn)研究[J];低溫建筑技術(shù);2014年09期

2 張建仁;劉彬;王磊;馬亞飛;張旭輝;;箍筋銹蝕的配斜筋混凝土梁抗剪試驗(yàn)[J];中國公路學(xué)報(bào);2013年06期

3 陳輝;張偉平;顧祥林;;高應(yīng)變率下銹蝕鋼筋力學(xué)性能試驗(yàn)研究[J];建筑材料學(xué)報(bào);2013年05期

4 宋錦虎;賀瑞霞;馬歡;;縱向非均勻銹蝕鋼筋拉拔過程的有限元分析[J];四川建筑科學(xué)研究;2011年01期

5 曾嚴(yán)紅;顧祥林;張偉平;黃慶華;;混凝土中鋼筋加速銹蝕方法探討[J];結(jié)構(gòu)工程師;2009年01期

6 趙羽習(xí);金偉良;;銹蝕箍筋混凝土梁的抗剪承載力分析[J];浙江大學(xué)學(xué)報(bào)(工學(xué)版);2008年01期

7 余t爐，

本文編號(hào)：2459502