本文選題：鋼管混凝土 + 膨脹劑�。� 參考：《蘭州交通大學》2014年碩士論文

【摘要】：把混凝土填充到鋼管里面形成了鋼管混凝土組合材料，這是利用鋼管約束住核心混凝土，使內部混凝土在鋼管作用下處于三向受壓狀態(tài)，這樣提高了鋼管混凝土組合材料的抗壓強度和塑性變形能力。鋼管混凝土有許多力學性能方面的優(yōu)點，如強度高、耐疲勞、重量輕、延性好、耐沖擊等優(yōu)越的外，也有許多施工性能方面的優(yōu)勢如有省工省科、架設輕便、施工快速等，鋼管混凝土結構在這些優(yōu)勢下，有了很快的發(fā)展。 在工程實際運用中，徐變的影響對于鋼管混凝土不可忽略。鋼管混凝土與一般混凝土相比有很多方面優(yōu)勢和不同，所以其徐變更加復雜，徐變在應力增加量、拱肋撓度、混凝土應力減小量等方面對鋼管混凝土構件的鋼管影響都很大。從材料學設計原理上來講，鋼管混凝土是一種復合材料，而微膨脹鋼管混凝土是一種新型的建筑材料，由于鋼管混凝土有很多優(yōu)越新能，近年來鋼管膨脹混凝土在工程中得到廣泛應用�；炷恋男熳円恢币詠硎且粋�熱點，也是一個難點，關于混凝土徐變到現在還沒有一個統(tǒng)一的結論，而對于鋼管膨脹混凝土徐變的研究更是少之又少。 本文以實驗為依據，介紹了國內外鋼管混凝土拱橋的發(fā)展概況及鋼管混凝土的力學性能；對其關鍵問題進行研究，主要包括鋼管混凝土徐變的特點及機理；鋼管混凝土徐變的主要影響因素；UEA型膨脹劑對鋼管混凝土徐變、承載力、彈塑性變形及微觀結構的影響，結合實驗和理論分析既軟件模擬得出結論：當膨脹劑摻量為8%—12%時，能提高鋼管混凝土的承載力，膨脹劑的微膨脹作用能使核心混凝土更加密實，相應的鋼管混凝土的承載力值越大，其對應的徐變也就越小。膨脹劑摻量的不同影響鋼管混凝土縱向變形，影響規(guī)律與其對構件的承載力相反，，在一定范圍內，膨脹劑摻量的增加，其縱向變形隨之降低。在重復荷載作用下，當膨脹劑摻量的變化時，鋼管混凝土的縱向塑性變形和彈性變形也隨之變化，膨脹劑摻量與構件的塑性變形（約為40%）呈成反相關，但是和彈性變形（約為60%）呈正相關，即膨脹劑能使改善鋼管混凝土的性能，起到了“增韌減脆”的作用。 在全面總結本文工作的基礎之上，提出了本課題仍需進一步研究的若干問題，為今后鋼管混凝土拱橋的施工控制提供參考和借鑒。
[Abstract]:The concrete filled into the steel tube forms the composite material of the concrete filled with the steel tube, which uses the steel tube to restrain the core concrete and makes the internal concrete under the action of the steel tube in three directions under compression. In this way, the compressive strength and plastic deformation ability of concrete-filled steel tubular composite materials are improved. Concrete filled steel tube (CFST) has many advantages in mechanical properties, such as high strength, fatigue resistance, light weight, good ductility, shock resistance and so on. Under these advantages, concrete filled steel tube (CFST) structure has developed rapidly. In practical application, the influence of creep on concrete-filled steel tubular (CFST) can not be ignored. Compared with ordinary concrete, CFST has many advantages and differences, so its creep is more complex. Creep has a great influence on CFST steel tube in the aspects of stress increase, arch rib deflection, concrete stress reduction and so on. In terms of material design principle, concrete-filled steel tube (CFST) is a kind of composite material, and concrete-filled steel tube (CFST) is a new type of building material. In recent years, expansive concrete filled steel tube has been widely used in engineering. The creep of concrete has always been a hot spot and a difficult point. There is not a unified conclusion about the creep of concrete, and the research on the creep of expansive concrete filled steel tube is rare. Based on experiments, this paper introduces the development and mechanical properties of concrete-filled steel tubular arch bridges at home and abroad, and studies its key problems, including the characteristics and mechanism of concrete filled steel tube creep. The main influencing factors of creep of concrete-filled steel tube (CFST) are the influence of UEA type expansion agent on creep, bearing capacity, elastic-plastic deformation and microstructure of CFST. Combined with the software simulation of experiment and theoretical analysis, it is concluded that when the amount of expansive agent is between 8% and 12%, It can improve the bearing capacity of concrete-filled steel tube (CFST), and the micro-expansion effect of expansive agent can make the core concrete more dense. The larger the bearing capacity of concrete filled steel tubular, the smaller the creep of concrete filled steel tube (CFST). The longitudinal deformation of concrete-filled steel tube (CFST) is affected by the different amount of expansive agent, which is contrary to the bearing capacity of the members. In a certain range, the longitudinal deformation decreases with the increase of the content of the expansive agent. Under repeated load, the longitudinal plastic deformation and elastic deformation of concrete filled steel tube also change with the change of the amount of expansive agent, and the content of expansion agent is inversely correlated with the plastic deformation of the member (about 40%). However, there is a positive correlation with elastic deformation (about 60%), that is, the expansion agent can improve the performance of concrete filled steel tube and play the role of "toughening and reducing brittleness". On the basis of summing up the work of this paper, some problems that need further research are put forward, which can provide reference and reference for the construction control of concrete-filled steel tubular arch bridge in the future.
【學位授予單位】：蘭州交通大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：U441;U448.38

【參考文獻】

相關期刊論文 前9條

1 李庚英,王湛;膨脹混凝土在鋼管約束下的力學性能以及微觀特征[J];四川建筑科學研究;2002年03期

2 李恒堂;狄生奎;張禾;;祁家黃河大橋C55微膨脹鋼管混凝土試驗研究[J];甘肅科學學報;2010年04期

3 譚素杰,齊加連;長期荷載對鋼管混凝土受壓構件強度影響的實驗研究[J];哈爾濱建筑工程學院學報;1987年02期

4 鐘善桐，查曉雄;鋼管初應力對鋼管混凝土構件承載力影響的研究[J];哈爾濱建筑大學學報;1997年03期

5 成國強;高性能混凝土配合比設計與配制的研究[J];混凝土;1998年03期

6 鐘善桐;鋼管混凝土結構在我國的應用和發(fā)展[J];建筑技術;2001年02期

7 蔡紹懷;我國鋼管高強混凝土結構技術的最新進展[J];建筑科學;2002年04期

8 馮秀云;鋼管混凝土拱橋混凝土質量缺陷分析及處理[J];鐵道建筑技術;2001年05期

9 許漢錚,韓萬水,黃平明;輕質微膨脹混凝土配合比試驗研究[J];長安大學學報(自然科學版);2002年06期

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