【摘要】：自20世紀以來,公路預應力混凝土小箱梁在我國發(fā)展非常迅速,然而混凝土結構中的鋼筋隨著時間推移,將會發(fā)生銹蝕,甚至銹斷,特別是橋位處空氣中含有大量酸、堿、鹽等化學物質(zhì)的情況,極易發(fā)生電化學腐蝕。加上很多預應力混凝土結構混凝土密實性未達到要求或者混凝土保護層不足,致使預應力筋暴露與含有大量水分、酸、堿等腐蝕性成分的空氣中。為了更好的讓預應力小箱梁能夠滿足這些特殊環(huán)境對預應力筋的要求,本文探討了采用CFRP筋(碳纖維增強復合材料筋)代替普通預應力筋用于公路預應力混凝土小箱梁,因其具有質(zhì)量輕、強度高以及抗腐蝕性好等諸多優(yōu)于普通預應力鋼絞線的特點,有望從根本上解決公路預應力混凝土小箱梁橋遇到的一些問題。為此本文探索性的對公路CFRP預應力混凝土小箱梁設計方法進行了研究,研究的主要內(nèi)容包括:CFRP預應力筋小箱梁的基本特點。包括CFRP筋的基本性能、CFRP預應力筋的錨固方式、CFRP筋作為預應力筋的可行性分析等。詳細如下:①公路CFRP預應力混凝土小箱梁設計原理和方法研究。給出小箱梁破壞界定公式、抗彎承載力極限狀態(tài)計算方法、抗剪承載力極限狀態(tài)計算方法。②CFRP預應力混凝土小箱梁受力特點研究。建立公路普通預應力和CFRP預應力混凝土小箱梁仿真模型,研究分析其受力特點。③CFRP預應力混凝土小箱梁設計的關鍵性技術進行分析研究。主要是CFRP筋彎折問題、錨固問題和預應力損失問題。④設計施工要點研究。針對以上分析,給出CFRP預應力混凝土小箱梁設計注意事項,并結合實際情況,給出公路CFRP預應力混凝土小箱梁施工注意事項。⑤經(jīng)濟性分析。將CFRP筋預應力混凝土小箱梁標準設計與普通預應力筋小箱梁標準設計進行對比,比較分析采用CFRP作為預應力筋的經(jīng)濟價值。
[Abstract]:Since the 20th century, the highway prestressed concrete small box girder has developed very rapidly in our country. However, the reinforcement in the concrete structure will be corroded or even rusted over time, especially in the air at the bridge site, there is a lot of acid and alkali in the air. In the case of salt and other chemical substances, electrochemical corrosion is easy to occur. In addition many prestressed concrete structure concrete compactness does not meet the requirements or the concrete cover is insufficient resulting in prestressed tendons exposed to a large amount of water acid alkali and other corrosive components of the air. In order to make the prestressed small box girder meet the demand of these special environments, this paper discusses the use of CFRP tendons (carbon fiber reinforced composite tendons) instead of ordinary prestressed tendons for highway prestressed concrete small box girders. Because of its characteristics of light weight, high strength and good corrosion resistance, it is expected to solve some problems of highway prestressed concrete small box girder bridge fundamentally. In this paper, the design method of CFRP prestressed concrete small box girder is studied in this paper. The main contents of the study include the basic characteristics of the small box girder reinforced by CFRP. The basic performance of CFRP tendons and the feasibility analysis of CFRP tendons as prestressing tendons are discussed in this paper. The design principle and method of CFRP prestressed concrete small box girder are studied below. The failure definition formula of small box girder, the calculation method of ultimate state of flexural bearing capacity and the calculation method of ultimate state of shear bearing capacity are given. The simulation model of highway prestressed concrete and CFRP prestressed concrete small box girder is established, and the key technology of the design of prestressed concrete small box girder is analyzed and analyzed. The main points of design and construction are CFRP reinforcement bending, Anchorage and Prestress loss. In view of the above analysis, this paper gives the matters needing attention in the design of CFRP prestressed concrete small box girder, and combining with the actual situation, gives the economic analysis of the construction matters 5 of the highway CFRP prestressed concrete small box girder. The standard design of prestressed concrete small box girder reinforced by CFRP is compared with the standard design of small box girder with common prestressing tendons. The economic value of using CFRP as prestressing tendons is compared and analyzed.
【學位授予單位】：重慶交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U442.5

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本文編號：2251593