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

【摘要】：我國(guó)經(jīng)濟(jì)的快速發(fā)展推動(dòng)著高端科技的不斷進(jìn)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(chǔ)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(shí)現(xiàn)LNG儲(chǔ)罐建設(shè)安全性和經(jīng)濟(jì)性的基礎(chǔ)。本文通過(guò)試驗(yàn)和有限元模擬相結(jié)合的研究方法,對(duì)鋼筋混凝土在不同低溫下的性能及LNG儲(chǔ)罐受力情況進(jìn)行探索。本文作為山東省自然科學(xué)基金《大型LNG儲(chǔ)罐預(yù)應(yīng)力混凝土超低溫性能研究及其優(yōu)化設(shè)計(jì)》的一部分,主要工作內(nèi)容包括如下:1.介紹試驗(yàn)所用設(shè)備和本試驗(yàn)的特點(diǎn)。為克服現(xiàn)有試驗(yàn)技術(shù)和設(shè)備的限制,使試驗(yàn)操作簡(jiǎn)單快捷安全,提高研究水平和試驗(yàn)精準(zhǔn)度,本文中自行設(shè)計(jì)新型試驗(yàn)裝置。同時(shí),為便于與常溫性能進(jìn)行對(duì)比分析,文中依據(jù)相應(yīng)的常溫試驗(yàn)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(duì)低溫及超低溫下混凝土力學(xué)性能進(jìn)行試驗(yàn),得到了其力學(xué)指標(biāo)均隨溫度的降低而升高,且呈分段趨勢(shì)。擬合了混凝土劈拉強(qiáng)度和抗壓強(qiáng)度與溫度的關(guān)系,提出了尺寸效應(yīng)系數(shù)和強(qiáng)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(duì)比分析,為我國(guó)自主設(shè)計(jì)LNG儲(chǔ)罐和制定我國(guó)低溫及超低溫混凝土規(guī)范提供依據(jù)和支持。4.進(jìn)行了鋼筋低溫及超低溫下的拉伸試驗(yàn),得到了鋼筋強(qiáng)度指標(biāo)和塑性指標(biāo)在不同溫度下的數(shù)值。5.利用規(guī)范公式對(duì)試驗(yàn)數(shù)據(jù)進(jìn)行換算得到了鋼筋混凝土在不同溫度下的設(shè)計(jì)值,采取ABAQUS有限元軟件對(duì)大型LNG預(yù)應(yīng)力混凝土儲(chǔ)罐進(jìn)行模擬計(jì)算,對(duì)比分析低溫及超低溫材料性能對(duì)罐體溫度場(chǎng)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(hào)：1792520