【摘要】：鋼筋混凝土結(jié)構(gòu)的耐久性問題受到工程領(lǐng)域內(nèi)世界各國(guó)的廣為關(guān)注,而鋼筋的銹蝕是影響結(jié)構(gòu)耐久性的最主要因素,同時(shí)也是其結(jié)構(gòu)最為普遍的病害之一。鋼筋發(fā)生銹蝕后,其截面面積減小、力學(xué)性能退化、鋼筋與混凝土間的粘結(jié)性能降低、混凝土保護(hù)層開裂,易造成受彎構(gòu)件發(fā)生斜截面剪切脆性破壞,其后果比正截面破壞更加嚴(yán)重。目前,國(guó)內(nèi)外對(duì)銹蝕鋼筋混凝土構(gòu)件正截面承載力進(jìn)行了大量研究并取得了較好的成果,而對(duì)構(gòu)件斜截面抗剪承載力研究較少。由于箍筋直徑、保護(hù)層厚度均比較小,箍筋的銹蝕程度一般比較嚴(yán)重,從而更大程度上影響了斜截面抗剪承載力。本文在相關(guān)試驗(yàn)數(shù)據(jù)的研究基礎(chǔ)上,針對(duì)銹蝕的有腹筋的鋼筋混凝土簡(jiǎn)支梁,進(jìn)行了其斜截面抗剪承載力計(jì)算方法的分析以及研究,主要研究?jī)?nèi)容分為以下幾個(gè)方面：(1)對(duì)鋼筋混凝土結(jié)構(gòu)中鋼筋銹蝕機(jī)理以及銹蝕過程進(jìn)行了歸納和總結(jié),重點(diǎn)介紹了引起鋼筋銹蝕的主要影響因素。(2)對(duì)目前存在的抗剪模型以及理論方法,并詳細(xì)介紹了桁架模型理論、極限平衡理論、塑性理論等模型理論,并將各個(gè)模型的優(yōu)缺點(diǎn)做了對(duì)比。(3)本文基于桁架-拱模型的抗剪理論,通過分析得到改進(jìn)的桁架-拱模型抗剪公式,將計(jì)算結(jié)果與試驗(yàn)結(jié)果進(jìn)行對(duì)比分析,驗(yàn)證了該方法。(4)對(duì)于銹蝕梁的抗剪承載力計(jì)算,在本文抗剪承載力計(jì)算式上,引入鋼筋銹蝕后的屈服強(qiáng)度以及實(shí)際面積,同時(shí)考慮銹蝕造成的混凝土截面損傷、粘結(jié)強(qiáng)度的減小以及銷栓作用的退化,收集相關(guān)數(shù)據(jù)進(jìn)行線性回歸,得到了關(guān)于箍筋銹蝕率的修正系數(shù),從而建立了銹蝕梁的抗剪承載力計(jì)算公式。同時(shí)將本文計(jì)算方法與已有銹蝕梁的抗剪承載力計(jì)算方法進(jìn)行了對(duì)比分析,從整個(gè)數(shù)據(jù)而言,該公式計(jì)算結(jié)果與試驗(yàn)結(jié)果能較好地吻合。
[Abstract]:The durability of reinforced concrete structures has been paid more and more attention all over the world in the field of engineering, and the corrosion of steel bars is the most important factor that affects the durability of structures, and it is also one of the most common diseases of reinforced concrete structures. After corrosion, the cross-section area of the steel bar decreases, the mechanical property degrades, the bond performance between the steel bar and the concrete decreases, the concrete protective layer cracks, and the bending member is prone to shear brittleness failure of the inclined cross-section. The consequences are more severe than the normal section damage. At present, a great deal of research has been done on the bearing capacity of normal section of corroded reinforced concrete members at home and abroad, and good results have been obtained, but the research on shear capacity of inclined section of members is less. Because of the diameter of stirrups and the thickness of protective layer, the corrosion degree of stirrups is usually serious, which greatly affects the shear capacity of inclined cross-section. On the basis of relevant experimental data, this paper analyzes and studies the calculation method of shear capacity of inclined section of corroded simply supported reinforced concrete beams with web reinforcement. The main research contents are as follows: (1) the corrosion mechanism and process of reinforcement corrosion in reinforced concrete structure are summarized and summarized. The main influencing factors of steel bar corrosion are introduced in detail. (2) the existing shear models and theoretical methods are introduced in detail, and the truss model theory, limit equilibrium theory, plastic theory and other model theories are introduced in detail. The advantages and disadvantages of each model are compared. (3) based on the shear theory of truss-arch model, the improved shear formula of truss-arch model is obtained through analysis, and the calculated results are compared with the experimental results. The proposed method is verified. (4) for the calculation of shear capacity of corroded beams, the yield strength and actual area of steel bars after corrosion are introduced in this paper, and the damage of concrete section caused by corrosion is also considered. With the decrease of bond strength and the degradation of pin action, the relevant data are collected for linear regression, and the correction coefficient of corrosion rate of stirrups is obtained, thus the formula for calculating the shear capacity of corroded beams is established. At the same time, the calculation method in this paper is compared with the existing calculation method of shear capacity of corroded beams. From the whole data, the calculated results of this formula are in good agreement with the experimental results.
【學(xué)位授予單位】：長(zhǎng)沙理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TU375.1

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

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本文編號(hào)：2442836