本文選題：隧道二次襯砌 + 配合比設(shè)計參數(shù)��； 參考：《長安大學(xué)》2014年碩士論文

【摘要】：隧道二次襯砌混凝土的開裂不僅降低隧道的安全質(zhì)量及耐久性，而且影響隧道的施工與應(yīng)用環(huán)境。目前，實際工程中的二次襯砌混凝土強調(diào)強度等級與工作性能等基本要求，忽略了對長期抗裂性能的研究。為了提高二次襯砌混凝土的抗裂性能，應(yīng)對其影響因素進行分析，選擇確定合理配合比、研制抗裂復(fù)合材料，改善二次襯砌混凝土的抗裂性能。 本文對傳統(tǒng)的圓環(huán)約束法進行了改進，同時選擇收縮形變、彈性模量與劈裂抗拉強度作為評價指標(biāo)，進而從體積變形與力學(xué)性能的角度進行綜合的分析，準(zhǔn)確地表征出混凝土的抗裂性能。結(jié)果表明：采用改進后的圓環(huán)法測試混凝土的開裂時間，試驗周期得以縮短，可靠性得到提高；抗裂系數(shù)與圓環(huán)法測出的結(jié)果具有較強的相關(guān)性，可用來表征混凝土的抗裂性能。 從二次襯砌混凝土原材料與施工要求出發(fā)，研究了配合比設(shè)計參數(shù)、常用外加劑及摻合料對混凝土抗裂性能的影響。研究結(jié)果表明：配合比設(shè)計參數(shù)中，水灰比與膠凝材料總量對混凝土抗裂性能的影響較強，骨料最大粒徑與砂率的影響程度較弱；水灰比過高與過低都會對混凝土早期抗裂性能產(chǎn)生不利影響，膠凝材料總量的增加會增大混凝土的開裂敏感性；粉煤灰等量代替水泥摻入混凝土?xí)r，隨著摻量的增加，混凝土抗裂性能得到提高，但摻量較高時，提高程度增幅減緩；膨脹劑與減縮劑均可以對混凝土的收縮變形產(chǎn)生抑制作用，當(dāng)兩者分別以內(nèi)摻與外摻的方式摻入混凝土?xí)r，可以提高混凝土的抗裂性能，且隨著摻量增加，提高作用不斷加強；減水劑在合理范圍內(nèi)對抗裂性能有一定的減弱作用，但影響幅度較小。 在影響因素的研究分析基礎(chǔ)上，選擇粉煤灰、膨脹劑與減縮劑作為抗裂材料進行組成設(shè)計與抗裂性能研究。結(jié)果表明：通過正交設(shè)計方法，確定粉煤灰、膨脹劑與減縮劑的摻配比例為20%：8%：1.5%時，，復(fù)配材料的抗裂性能最好；將復(fù)配的抗裂材料與市售的復(fù)合抗裂外加劑對比分析，結(jié)果顯示各項性能均優(yōu)于后者。
[Abstract]:The cracking of the secondary lining concrete not only reduces the safety quality and durability of the tunnel, but also affects the construction and application environment of the tunnel. At present, the secondary lining concrete in practical engineering emphasizes the basic requirements of strength grade and working performance, and neglects the study of long-term crack resistance. In order to improve the crack resistance of the secondary lining concrete, the influencing factors should be analyzed, the reasonable mix ratio should be determined, the crack resistant composite material should be developed, and the crack resistance performance of the secondary lining concrete should be improved. In this paper, the traditional circumferential constraint method is improved, and the shrinkage deformation, elastic modulus and splitting tensile strength are selected as the evaluation indexes, and then the volume deformation and mechanical properties are comprehensively analyzed from the point of view of volume deformation and mechanical properties. The crack resistance of concrete is accurately characterized. The results show that the test period is shortened and the reliability is improved by using the improved ring method, and the crack resistance coefficient has a strong correlation with the results obtained by the ring method. It can be used to characterize the crack resistance of concrete. Based on the raw materials and construction requirements of secondary lining concrete, the effects of mix ratio design parameters, common admixtures and admixtures on the crack resistance of concrete are studied. The results show that the influence of water-cement ratio and total amount of cementing material on the crack resistance of concrete is stronger than that of the maximum particle size and sand ratio of aggregate. Too high water-cement ratio and too low water-cement ratio will have adverse effects on the early crack resistance of concrete, and the increase of aggregate amount of cementitious material will increase the cracking sensitivity of concrete. The crack resistance of concrete is improved, but when the content of concrete is high, the increase of increasing degree is slowed down, the expansion agent and shrinkage reducing agent can inhibit the shrinkage and deformation of concrete, when the concrete is mixed in and out of the concrete respectively, It can improve the crack resistance of concrete, and with the increase of the content of concrete, the improvement effect is strengthened, and the water-reducing agent has a certain weakening effect in a reasonable range, but the effect is small. On the basis of research and analysis of influencing factors, fly ash, expansion agent and shrinkage reducer were selected as crack resistant materials to design composition and crack resistance. The results show that when the proportion of fly ash, expansion agent and shrinkage reducer is 20: 8: 1.5%, the anti-crack performance of the composite material is the best by orthogonal design. The results show that each performance is superior to the latter.
【學(xué)位授予單位】：長安大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U455.91;U454

【參考文獻】

相關(guān)期刊論文 前10條

1 周群,王章夫,王桂祥,吳怡文;混凝土膨脹劑對補償收縮混凝土的有效作用[J];混凝土;2000年05期

2 劉愛新;粉煤灰混凝土的性能及其應(yīng)用[J];混凝土;2001年12期

3 陳波;蔡躍波;丁建彤;;大壩混凝土抗裂性綜合評價指標(biāo)[J];混凝土;2008年10期

4 趙順增;游寶坤;劉立;;混凝土膨脹劑行業(yè)的現(xiàn)狀和發(fā)展方向[J];混凝土與水泥制品;2009年03期

5 張坤;郭磊;;混凝土減縮劑研究進展[J];四川建材;2011年06期

6 曾力,方坤河,吳定燕,阮燕,劉永和;碾壓混凝土抗裂指標(biāo)的研究[J];水利水電技術(shù);2000年11期

7 周世華;董蕓;楊華全;;混凝土收縮開裂測試技術(shù)的研究現(xiàn)狀與評述[J];水力發(fā)電;2008年03期

8 祝和權(quán),李海燕;鐵路隧道防水技術(shù)的現(xiàn)狀及趨勢[J];鐵道建筑;2003年10期

9 楊書江;隧道襯砌混凝土裂縫的成因與防治[J];西部探礦工程;2002年S1期

10 朱常春;公路隧道襯砌裂縫病害治理技術(shù)[J];巖土工程界;2004年09期

本文編號：1923530