【摘要】：根據(jù)規(guī)定,輕骨料混凝土是指(Lightweight Aggregate Concrete,簡稱為LWC)利用輕粗骨料、輕砂(或普通砂)、水泥和水配制而成,干表觀密度低于1950kg/m3的混凝土。輕骨料混凝土因?yàn)槭褂锰樟５茸鳛榇止橇?其混凝土的密度比傳統(tǒng)普通混凝土的密度低20%~30%。對于需要大量混凝土的建筑來說,采用低密度、強(qiáng)度高的輕骨料混凝土,會(huì)帶來經(jīng)濟(jì)和施工技術(shù)方面非常大的優(yōu)勢。但是對于輕骨料混凝土來說,相對于普通混凝土,后期收縮量大是輕骨料混凝土的一個(gè)極大的劣勢,這也是導(dǎo)致輕骨料混凝土未大量普及利用的原因之一。在自由狀態(tài)下,混凝土制成品的自由收縮不會(huì)對其本身產(chǎn)生有害的影響。在自由狀態(tài)下,任何物體的收縮均不會(huì)對物體本身產(chǎn)生副作用。但混凝土在結(jié)構(gòu)中應(yīng)用時(shí),由混凝土澆筑成的結(jié)構(gòu)構(gòu)件由于處于超靜定狀態(tài)之下,當(dāng)自身發(fā)生收縮變形時(shí),收縮會(huì)產(chǎn)生收縮應(yīng)力,而在約束條件下收縮應(yīng)力不能釋放,當(dāng)收縮應(yīng)力的大小大于混凝土自身的抗拉強(qiáng)度時(shí),就會(huì)產(chǎn)生裂縫,最終影響整個(gè)結(jié)構(gòu)的耐久性能。本文利用云南寶珠頁巖陶粒配制出陶粒混凝土,針對試驗(yàn)中的輕骨料混凝土主要展開了以下試驗(yàn)研究:(1)本文以實(shí)驗(yàn)?zāi)康囊笈渲贸龈邚?qiáng)LC60輕骨料混凝土,并對高強(qiáng)LC60陶�；炷猎谧杂蔂顟B(tài)下的自由收縮進(jìn)行試驗(yàn)研究。試驗(yàn)對八種不同配合比的試塊進(jìn)行了自由收縮試驗(yàn)。仔細(xì)研究了不同膨脹劑摻量以及不同聚丙烯摻量下的LC60輕骨料混凝土的收縮狀況。結(jié)果表明:膨脹劑對輕骨料混凝土又很顯著的抗收縮性能,并且三個(gè)摻量中,綜合力學(xué)指標(biāo)以及限制收縮的作用,試驗(yàn)得出結(jié)論在輕骨料混凝土中摻加8%時(shí),既能滿足混凝土試件的力學(xué)性能,并且收縮量也很理想;而對于摻加聚丙烯纖維,發(fā)現(xiàn)摻加有聚丙烯纖維的混凝土試塊也會(huì)減小其收縮。試驗(yàn)中進(jìn)行了雙摻聚丙烯纖維和膨脹劑配合比的試驗(yàn),結(jié)果顯示雙摻組合的物理性能基本上沒有降低,并且對于減小輕骨料混凝土的收縮量具有很好的作用。(2)開裂是影響混凝土耐久性能的關(guān)鍵因素之一,輕集料混凝土的收縮量大無疑更加劇了開裂。文章中利用朱涵教授課題組多次改進(jìn)之后的外方內(nèi)圓試驗(yàn)?zāi)＞邔p集料混凝土約束狀態(tài)下的開裂進(jìn)行了研究。在混凝土中摻入聚丙烯纖維與膨脹劑均能緩解混凝土裂縫的產(chǎn)生,但是這兩種物質(zhì)阻止混凝土裂縫的產(chǎn)生卻是從兩個(gè)機(jī)理方向發(fā)揮作用的。本文著重研究了在不同摻量下的聚丙烯纖維和膨脹劑如何影響輕骨料的開裂。并且本實(shí)驗(yàn)還加入了傳統(tǒng)C60混凝土,并對輕集料混凝土與傳統(tǒng)C60混凝土進(jìn)行了比較研究。對五種配合比總共八個(gè)外方內(nèi)圓試驗(yàn)試件進(jìn)行了試驗(yàn),并采用應(yīng)變儀進(jìn)行了數(shù)據(jù)采集。結(jié)果表明:摻加膨脹劑以及聚丙烯都會(huì)提高混凝土的抗開裂能力,摻加0.9kg/m3的聚丙烯纖維以及8%摻量的膨脹劑對高強(qiáng)輕骨料混凝土的抗開裂性能有很大的提高。(3)試驗(yàn)對摻加膨脹劑與聚丙烯纖維對LC60混凝土的基本力學(xué)性能做了研究,研究了外摻假物對立方體抗壓強(qiáng)度、劈裂抗拉強(qiáng)度、抗折強(qiáng)度以及彈性模量的影響。
[Abstract]:According to the regulations, light aggregate concrete is a concrete (Lightweight Aggregate Concrete, referred to as LWC) using light coarse aggregate, light sand (or ordinary sand), cement and water, and the density of dry surface is lower than 1950kg/m3. The density of lightweight aggregate concrete is compared with the density of traditional concrete because of the use of ceramsite as coarse aggregate. Low 20%~30%. for a large number of concrete buildings, the use of low density, high strength lightweight aggregate concrete will bring a great advantage in economic and construction technology. But for lightweight aggregate concrete, relative to the ordinary concrete, the later shrinkage is a great disadvantage of the lightweight aggregate concrete, which is also a result. One of the reasons that the lightweight aggregate concrete is not widely used. In free state, the free shrinkage of the finished product will not have a harmful effect on it itself. In free state, the shrinkage of any object will not have side effects on the object itself. But when the concrete is used in the structure, the structure of the concrete is made of concrete. Under the condition of statically indeterminate state, shrinkage stress is produced when the contraction deformation occurs, and the shrinkage stress can not be released under the constraint conditions. When the shrinkage stress is larger than the tensile strength of concrete itself, it will produce cracks and ultimately affect the durability of the whole structure. This paper uses the Yunnan treasure shale ceramsite. The ceramsite concrete was prepared, and the following experimental research was carried out in light of the light aggregate concrete in the experiment. (1) the high strength LC60 lightweight aggregate concrete was configured in this paper, and the free shrinkage of high strength LC60 ceramsite concrete under free condition was tested. The test was carried out on the test blocks of eight different mix ratios. According to the shrinkage test, the shrinkage of LC60 light aggregate concrete with different expansive agents and different polypropylene content was carefully studied. The results showed that the expansive agent had significant anti shrinkage performance to light aggregate concrete, and in the three admixtures, the comprehensive mechanical index and the effect of limiting shrinkage were found, and the conclusion was concluded in the light aggregate concrete mixture. When adding 8% in the soil, it can not only satisfy the mechanical properties of the concrete specimen, but also the shrinkage is ideal. For the addition of polypropylene fiber, it is found that the shrinkage of concrete mixed with polypropylene fiber can also be reduced. The test of the mixing ratio of polypropylene fiber and expansion agent is carried out in the experiment, and the results show the physical properties of the double mixing. It can basically not be reduced, and it has a good effect on reducing the shrinkage of lightweight aggregate concrete. (2) cracking is one of the key factors affecting the durability of concrete. The shrinkage of lightweight aggregate concrete is undoubtedly more cracking. The cracking of lightweight aggregate concrete under constraint condition is studied. The addition of polypropylene fiber and expansive agent in concrete can alleviate the formation of concrete cracks, but these two substances play a role in preventing the production of concrete cracks from two mechanism directions. How does the expander affect the cracking of light aggregate, and the traditional C60 concrete is added in this experiment, and the comparison of the light aggregate concrete and the traditional C60 concrete is carried out. The test of the five combinations of eight outer inner circle test specimens is carried out and the data collection is carried out by the strain gauge. The results show that the expansion agent is added and the expansion agent is added as well. Polypropylene can improve the anti cracking ability of concrete. The anti cracking performance of high strength lightweight aggregate concrete is greatly improved by adding 0.9kg/m3 polypropylene fiber and 8% content of expansive agent. (3) the basic mechanical properties of LC60 concrete are studied by adding expansive agent and polypropylene fiber, and the cube is studied on the cube. The influence of compressive strength, splitting tensile strength, flexural strength and modulus of elasticity.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TU528

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 季韜;張彬彬;陳永波;莊一舟;;Evaluation method of cracking resistance of lightweight aggregate concrete[J];Journal of Central South University;2014年04期

2 趙明霞;;輕集料混凝土的研究和應(yīng)用[J];散裝水泥;2011年02期

3 陳偉;錢覺時(shí);范英儒;;破碎陶粒表面處理與其對混凝土性能的影響[J];混凝土與水泥制品;2009年02期

4 孫海林;葉列平;丁建彤;郭玉順;;高強(qiáng)輕骨料混凝土收縮和徐變試驗(yàn)[J];清華大學(xué)學(xué)報(bào)(自然科學(xué)版);2007年06期

5 趙順增;劉立;;混凝土干燥收縮開裂評價(jià)及其試驗(yàn)新方法[J];膨脹劑與膨脹混凝土;2006年03期

6 張佚倫;詹樹林;錢曉倩;孟濤;錢匡亮;;聚丙烯纖維混凝土早期收縮性能試驗(yàn)研究[J];新型建筑材料;2006年01期

7 陳瑜,張起森;水泥混凝土早期抗裂性能的研究現(xiàn)狀[J];建筑材料學(xué)報(bào);2004年04期

8 高丹盈,湯寄予,趙軍;纖維高強(qiáng)混凝土彈性模量的試驗(yàn)研究[J];工業(yè)建筑;2004年10期

9 朱耀臺,詹樹林;混凝土裂縫成因與防治措施研究[J];材料科學(xué)與工程學(xué)報(bào);2003年05期

10 李光偉;聚丙烯纖維對混凝土抗裂性能的影響[J];水電站設(shè)計(jì);2002年02期

相關(guān)碩士學(xué)位論文 前5條

1 孫霽;混雜聚丙烯纖維混凝土損傷力學(xué)性能研究[D];重慶大學(xué);2013年

2 胡芯國;混凝土開裂及粘結(jié)性能的試驗(yàn)研究[D];天津大學(xué);2012年

3 王永平;混凝土收縮試驗(yàn)研究[D];天津大學(xué);2010年

4 吳俊華;水泥凈漿組合圓環(huán)試驗(yàn)的研究[D];天津大學(xué);2010年

5 張振利;碾壓橡膠混凝土變形性能研究[D];天津大學(xué);2008年

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本文編號：2151624