本文選題：超低溫 + 鋼筋混凝土��； 參考：《中國石油大學(xué)(華東)》2015年碩士論文

【摘要】：我國經(jīng)濟的快速發(fā)展推動著高端科技的不斷進步,建筑技術(shù)也向極端環(huán)境延伸,其中鋼筋混凝土在低溫及超低溫環(huán)境中被廣泛應(yīng)用,較為典型的特種結(jié)構(gòu)包括大型LNG儲罐。鋼筋混凝土的性能隨溫度變化較大,掌握其在低溫及超低溫下的材料性能是實現(xiàn)LNG儲罐建設(shè)安全性和經(jīng)濟性的基礎(chǔ)。本文通過試驗和有限元模擬相結(jié)合的研究方法,對鋼筋混凝土在不同低溫下的性能及LNG儲罐受力情況進行探索。本文作為山東省自然科學(xué)基金《大型LNG儲罐預(yù)應(yīng)力混凝土超低溫性能研究及其優(yōu)化設(shè)計》的一部分,主要工作內(nèi)容包括如下:1.介紹試驗所用設(shè)備和本試驗的特點。為克服現(xiàn)有試驗技術(shù)和設(shè)備的限制,使試驗操作簡單快捷安全,提高研究水平和試驗精準度,本文中自行設(shè)計新型試驗裝置。同時,為便于與常溫性能進行對比分析,文中依據(jù)相應(yīng)的常溫試驗規(guī)范設(shè)定方案。2.研究混凝土導(dǎo)熱性能在-160℃?T?20℃的變化規(guī)律,提出了低溫及超低溫下導(dǎo)熱速度與溫度的本構(gòu)關(guān)系,并探討了溫度差越大、含水率越高、凍融循環(huán)次數(shù)越多,混凝土的導(dǎo)熱速度越快。此外,試件尺寸和形狀也是影響導(dǎo)熱速度的因素。3.對低溫及超低溫下混凝土力學(xué)性能進行試驗,得到了其力學(xué)指標均隨溫度的降低而升高,且呈分段趨勢。擬合了混凝土劈拉強度和抗壓強度與溫度的關(guān)系,提出了尺寸效應(yīng)系數(shù)和強度換算系數(shù)在-160℃?T?20℃下的公式,并將結(jié)果與已有結(jié)論對比分析,為我國自主設(shè)計LNG儲罐和制定我國低溫及超低溫混凝土規(guī)范提供依據(jù)和支持。4.進行了鋼筋低溫及超低溫下的拉伸試驗,得到了鋼筋強度指標和塑性指標在不同溫度下的數(shù)值。5.利用規(guī)范公式對試驗數(shù)據(jù)進行換算得到了鋼筋混凝土在不同溫度下的設(shè)計值,采取ABAQUS有限元軟件對大型LNG預(yù)應(yīng)力混凝土儲罐進行模擬計算,對比分析低溫及超低溫材料性能對罐體溫度場和受力狀態(tài),得到了鋼筋混凝土性能有利于克服低溫環(huán)境中溫度應(yīng)力的不利影響,該材料在低溫領(lǐng)域有很大前景。
[Abstract]:The rapid development of economy in our country promotes the progress of high-end science and technology, and the construction technology also extends to the extreme environment, in which reinforced concrete is widely used in low and ultra-low temperature environments, and typical special structures include large LNG storage tanks. The performance of reinforced concrete varies greatly with temperature. It is the foundation to realize the safety and economy of LNG storage tank construction by mastering its material performance at low and ultra-low temperature. In this paper, the performance of reinforced concrete at different low temperatures and the stress of LNG storage tank are studied by means of the combination of test and finite element simulation. This paper is a part of Shandong Natural Science Foundation "Research and Optimization Design of Ultra-low temperature performance of Prestressed concrete of large LNG Tank". The main work includes the following: 1. The equipment used in the test and the characteristics of the test are introduced. In order to overcome the limitation of the existing test technology and equipment, to make the test operation simple, quick and safe, and to improve the research level and test accuracy, a new type of test device was designed in this paper. At the same time, in order to compare and analyze the performance at room temperature, the paper sets the scheme. 2. 2 according to the standard of normal temperature test. The variation of thermal conductivity of concrete at 20 鈩，

本文編號：1792520