本文選題：鋼筋混凝土 + 氯離子　； 參考：《長沙理工大學(xué)》2014年碩士論文

【摘要】：混凝土結(jié)構(gòu)耐久性是工程領(lǐng)域廣泛關(guān)注的熱點問題,氯離子侵蝕下的鋼筋銹蝕是影響混凝土結(jié)構(gòu)耐久性的重要因素之一,也是目前混凝土結(jié)構(gòu)耐久性研究的關(guān)鍵內(nèi)容。同時車輛超載現(xiàn)象在我國橋梁運營中普遍存在,車輛超載對鋼筋混凝土橋梁服役期結(jié)構(gòu)性能的影響不可忽視。因此研究荷載與氯離子復(fù)合作用對RC梁力學(xué)性能的研究顯得尤為重要。本文采取試驗研究與理論分析相結(jié)合的方法,系統(tǒng)研究了持續(xù)荷載對鋼筋混凝土梁(RC梁)鋼筋銹蝕率的影響,在此基礎(chǔ)上,建立了考慮持續(xù)荷載影響下的銹蝕鋼筋混凝土抗彎剛度及承載力計算方法,論文研究內(nèi)容如下：1)進(jìn)行無氯離子侵蝕作用梁的抗彎極限承載力試驗,并基于規(guī)范對撓度的規(guī)定確定了鋼筋混凝土梁超載狀態(tài)與正常使用狀態(tài)之間的界限。在此基礎(chǔ)上,采用電化學(xué)的方法實現(xiàn)了受拉鋼筋的加速銹蝕,并進(jìn)行了正常使用荷載狀態(tài)及兩級超載作用下鋼筋混凝土梁受氯離子侵蝕后的抗彎試驗。結(jié)果表明,超載對于鋼筋的銹蝕,撓度的增長有放大作用,對于承載力的減小有著明顯的影響。2)分析了不同狀態(tài)下構(gòu)件荷載—跨中撓度關(guān)系,分析了影響銹蝕梁抗彎剛度的因素,建立了持續(xù)荷載作用下鋼筋與混凝土間的應(yīng)變協(xié)調(diào)關(guān)系,并對鋼筋銹蝕率進(jìn)行數(shù)據(jù)擬合,尋找出持續(xù)荷載等級與鋼筋銹蝕率間的定量關(guān)系,并在此基礎(chǔ)上建立了銹蝕后RC梁抗彎剛度的計算公式。3)對鋼筋的銹蝕深度進(jìn)行數(shù)據(jù)采集,通過對試驗數(shù)據(jù)進(jìn)行擬合,找出荷載與鋼筋截面損失率之間的關(guān)系,對銹蝕梁進(jìn)行抗彎承載力分析,并與試驗數(shù)據(jù)進(jìn)行對比,對該計算模型進(jìn)行驗證。結(jié)果表明本文所建立的公式計算精度較好,可為鋼筋混凝土耐久性設(shè)計提供參考。
[Abstract]:Durability of concrete structures is a hot issue in the engineering field. Corrosion of steel bars under chloride ion erosion is one of the important factors affecting the durability of concrete structures, and it is also the key content of the research on durability of concrete structures at present. At the same time, the phenomenon of vehicle overloading is common in the operation of bridges in China. The influence of vehicle overload on the structural performance of reinforced concrete bridges during the service period can not be ignored. Therefore, it is very important to study the mechanical properties of RC beams. In this paper, the effect of continuous load on the corrosion rate of reinforced concrete beams and RC beams is systematically studied by combining experimental research with theoretical analysis. The calculation method of flexural stiffness and bearing capacity of corroded reinforced concrete under the influence of continuous load is established. The research contents are as follows: 1) the ultimate flexural bearing capacity of beams without chloride ion erosion is tested. The boundary between overloading state and normal service state of reinforced concrete beam is determined based on the deflection regulation of the code. On this basis, the accelerated corrosion of tensile steel bars was realized by electrochemical method, and the bending tests of reinforced concrete beams subjected to chloride ion erosion under normal service load and two-stage overload were carried out. The results show that overloading can amplify the corrosion of steel bar and increase the deflection of steel bar, and has obvious influence on the reduction of bearing capacity. 2) the load-span deflection relationship of members under different states is analyzed. The factors influencing the flexural stiffness of corroded beams are analyzed. The strain coordination relationship between reinforcement and concrete under continuous load is established, and the data fitting is carried out to find out the quantitative relationship between the grade of sustained load and the corrosion rate of steel bars. On the basis of this, the calculation formula of flexural stiffness of corroded RC beam is established. The data of corrosion depth of steel bar are collected. By fitting the test data, the relationship between the load and the loss rate of steel bar section is found out. The flexural bearing capacity of the corroded beam is analyzed and compared with the experimental data to verify the calculation model. The results show that the formula established in this paper has good calculation accuracy and can be used as a reference for the durability design of reinforced concrete.
【學(xué)位授予單位】：長沙理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U446.1
，

本文編號：1897243