本文選題：玄武巖纖維布 + 抗剪加固　； 參考：《浙江大學(xué)》2013年碩士論文

【摘要】：混凝土構(gòu)件內(nèi)鋼筋銹蝕是其性能退化的主要原因,但當(dāng)前研究針對(duì)鋼筋銹蝕的機(jī)理和發(fā)展規(guī)律尚不明確,雖然大量工程檢測(cè)報(bào)告顯示,鋼筋銹蝕形態(tài)可大致區(qū)分為均勻銹蝕和局部坑蝕,局部坑蝕導(dǎo)致應(yīng)力集中明顯影響構(gòu)件受力性能,但這方面的系統(tǒng)試驗(yàn)和理論分析尚亟待開(kāi)展。工程中的銹蝕的鋼筋混凝土構(gòu)件必須及時(shí)采用加固措施,纖維布作為一種新型的加固材料,以其輕質(zhì)、高強(qiáng)、耐高溫、耐腐蝕等優(yōu)點(diǎn)在服役結(jié)構(gòu)工程加固領(lǐng)域具有可觀的應(yīng)用前景。在過(guò)去十年里,國(guó)內(nèi)外學(xué)者對(duì)FRP布的材料性能及其加固混凝土梁的力學(xué)性能進(jìn)行了大量的試驗(yàn)研究,并基于此建立計(jì)算方法和設(shè)計(jì)規(guī)程。由于剪切失效存在更多的不確定性和離散性,鋼筋銹蝕形態(tài)研究的不足加之纖維增強(qiáng)作用長(zhǎng)期耐久性研究的空白,導(dǎo)致采用纖維布加固存在銹蝕損傷的鋼筋混凝土構(gòu)件的抗剪承載力分析模型具有較大的誤差。針對(duì)以上問(wèn)題,本文具體開(kāi)展的研究工作如下： (1)采用試驗(yàn)室加速銹蝕法制備侵蝕環(huán)境下的混凝土構(gòu)件中銹蝕鋼筋樣本,針對(duì)局部銹蝕特征開(kāi)展統(tǒng)計(jì)分析,結(jié)合銹蝕鋼筋力學(xué)性能測(cè)試,研究了鋼筋銹蝕程度與蝕坑形態(tài)特征之間的關(guān)系,建立了更為合理的鋼筋銹蝕程度分類方法和更為準(zhǔn)確的鋼筋性能評(píng)估指標(biāo)；通過(guò)銹蝕鋼筋拉伸試驗(yàn),研究銹蝕鋼筋退化規(guī)律以及蝕坑參數(shù)對(duì)銹蝕鋼筋力學(xué)性能的影響；建立了鋼筋力學(xué)性能退化模型。 (2)針對(duì)銹蝕鋼筋建立3D有限元模型,與試驗(yàn)結(jié)果進(jìn)行對(duì)比,驗(yàn)證了有限元模型的有效性,研究了通用Ⅱ級(jí)鋼筋的蝕坑形狀參數(shù),包括蝕坑深度、蝕坑長(zhǎng)度、蝕坑寬度,以及相鄰蝕坑之間的相互作用對(duì)鋼筋力學(xué)性能的影響,并提出蝕坑應(yīng)力放大系數(shù)和蝕坑不均勻系數(shù)與蝕坑參數(shù)之間的關(guān)系,從而為鋼筋坑蝕的應(yīng)力集中現(xiàn)象提出定量分析方法。 (3)開(kāi)展了10根不同銹蝕程度和后續(xù)退化程度的纖維布抗剪抗彎加固梁靜載試驗(yàn),分析了不同初始退化程度以及不同加固材料對(duì)抗剪加固效果的影響；基于現(xiàn)有FRP抗剪加固混凝土梁計(jì)算模型和試驗(yàn)研究成果,分析了鋼筋銹蝕和長(zhǎng)期侵蝕作用對(duì)抗剪加固后構(gòu)件性能及破壞形態(tài)的影響,為FRP抗剪加固后承載力預(yù)測(cè)提供更為精確的預(yù)測(cè)模型。
[Abstract]:The corrosion of steel bars in concrete members is the main cause of its performance degradation. However, the mechanism and development law of reinforcement corrosion are not clear at present, although a large number of engineering inspection reports show that, The corrosion morphology of steel bars can be roughly divided into uniform corrosion and local pit corrosion. The stress concentration caused by local pit corrosion obviously affects the mechanical performance of the members, but the systematic tests and theoretical analysis in this respect need to be carried out urgently. Reinforcement measures must be adopted in time for corroded reinforced concrete members in engineering. As a new type of reinforcement material, fiber cloth is light, high strength and high temperature resistant. Corrosion resistance and other advantages in the field of structural engineering reinforcement has a considerable application prospects. In the past ten years, scholars at home and abroad have carried out a lot of experimental studies on the material properties of FRP cloth and the mechanical properties of reinforced concrete beams. Based on this, the calculation method and design rules have been established. Due to the more uncertainty and dispersion of shear failure, the lack of research on the corrosion morphology of steel bar and the lack of long-term durability study of fiber reinforcement. As a result, the shear capacity analysis model of reinforced concrete members strengthened with fiber sheets with corrosion damage has a large error. In view of the above problems, the specific research work carried out in this paper is as follows: 1) using laboratory accelerated corrosion method to prepare specimens of corroded steel bars in corroded concrete structures, and carrying out statistical analysis on local corrosion characteristics and testing the mechanical properties of corroded steel bars. The relationship between the corrosion degree of steel bar and the morphological characteristics of corrosion pit is studied. A more reasonable classification method of corrosion degree of steel bar and a more accurate evaluation index of steel bar performance are established, and the tensile test of corroded steel bar is carried out. The degradation law of corroded steel bar and the influence of corrosion pit parameters on the mechanical properties of corroded steel bar are studied, and the degradation model of mechanical properties of corroded steel bar is established. The 3D finite element model for corroded steel bar is established and compared with the experimental results. The validity of the finite element model is verified. The shape parameters of the corrosion pit of the universal grade 鈪，

本文編號(hào)：1886856