发泡剂的制备与泡沫混凝土的性能研究

发布时间：2018-04-13 20:11

本文选题：泡沫混凝土 + 发泡剂　；参考：《沈阳建筑大学》2015年硕士论文

【摘要】：泡沫混凝土是采用一定的方式引入气体而制备的具有大量气孔的水泥基材料,其轻质、保温隔热、隔音耐火等的特点使其广受关注,而作为制备泡沫混凝土的关键用料,发泡剂也同样受到广泛关注。目前,关于泡沫混凝土的研究较多,但是都或多或少存在着一定的局限性,对于低密度下泡沫混凝土的研究较少,发泡剂的质量不高也严重制约着泡沫混凝土的发展。所以,制备性能优异的发泡剂并通过系统研究各主要因素对泡沫混凝土性能的影响,优化原料及配比,提高泡沫混凝土的性能具有重要意义。本论文以普通硅酸盐水泥为主要原料,通过发泡剂复配,矿物掺合料,EPS轻骨料、早强剂,防水剂,制备工艺等方面去实验制备出具有较高强度、较低容重、热工性能良好且更经济和更实用的泡沫混凝土。发泡剂的研究结果表明:以AES为基础,AOS以40%的量取代部分AES进行复配,并辅以MPS作为稳泡组分,可以复配出性能良好的发泡剂,发泡倍数为38.8,1h泌水量为45ml,沉降距仅为1mm。泡沫混凝土的研究表明:水灰比的大小对抗压强度有较为明显的影响,干密度控制在450kg/m3,当水灰比低于0.5时,随着水灰比的增大,抗压强度随之增加,从0.33MPa增大至1.20MPa,当水灰比高于0.5时,抗压强度不再增大,且表现出小幅度下降趋势,从1.20MPa降低至1.12MPa。硅灰以等量替换水泥的方式掺入3%,一定程度上可以提高抗压强度,但同时也会使泡沫混凝土的吸水率升高。泡沫混凝土中分别掺入CaSO4,AlCl3,Al2(SO4)3,0.5%掺量下的CaSO4早强效果最好,干密度450kg/m3,3d强度可以达到0.64Mpa,而AlCl3,Al2(SO4)3掺入则使泡沫混凝土出现结球、粉化的现象,强度在0.21MPa以下。EPS可以有效降低泡沫混凝土的干密度,以体积占有率为50%作为轻骨料更易制备出300kg/m3以下的低密度泡沫混凝土,导热系数降到0.0795W/(m·K)。干密度的大小直接影响着吸水率和导热系数的大小,干密度与吸水率成反比,而与导热系数成正比关系。有机硅防水剂、石蜡乳液在3%的掺量下均可以有效降低泡沫混凝土吸水率,体积吸水率分别为13.1%和16.9%。通过对影响泡沫混凝土性能各因素的分析,优化出最佳配合比,即水胶比为0.5,硅灰掺量为3%,CaSO4掺量为0.5,EPS体积占有率为50%,并添加3%的有机硅防水剂,胶凝材料用量为225kg/m3,泡沫用量为475L/m3,可以制备出干密度270kg/m3左右,28d抗压强度达到0.51MPa,导热系数0.0795W/(m·K),体积吸水率13.1%的性能优异的泡沫混凝土。
[Abstract]:Foam concrete is a kind of cement-based material with a large number of pores, which is prepared by introducing gas in a certain way. Its light weight, heat insulation, sound insulation and fire resistance make it widely concerned, and it is used as the key material for the preparation of foam concrete.Foaming agents have also received widespread attention.At present, there are more and more researches on foam concrete, but more or less there are some limitations. The research on low density foam concrete is less, and the quality of foaming agent is not high, which seriously restricts the development of foam concrete.Therefore, it is of great significance to prepare foaming agent with excellent performance and to study the influence of main factors on the performance of foamed concrete, to optimize the raw material and proportion, and to improve the performance of foamed concrete.In this paper, ordinary Portland cement was used as the main raw material to prepare high strength and low bulk density through foaming agent compound, mineral admixture EPS lightweight aggregate, early strength agent, water repellent, preparation technology and so on.Good thermal performance and more economical and practical foam concrete.The results of the study on foaming agent showed that the foaming agent with good performance could be prepared by replacing part of AES with 40% amount of AES and adding MPS as foam stabilizer. The foaming ratio was 38.81h and the sedimentation distance was only 1 mm.The study of foam concrete shows that the ratio of water to cement has an obvious effect on the compressive strength. The dry density is controlled at 450 kg / m ~ (3). When the water / cement ratio is lower than 0.5, the compressive strength increases with the increase of water / cement ratio.From 0.33MPa to 1.20MPa, when the water-cement ratio is higher than 0.5, the compressive strength does not increase, and shows a small downward trend, from 1.20MPa to 1.12MPa.The addition of silica fume into cement in the same amount can improve the compressive strength to a certain extent, but it can also increase the water absorption of the foamed concrete.The early strength of CaSO4 with 0.5% CaSO _ 4 / AlCl _ 3 / Al _ 2SO _ 4 / O _ 3 / Al _ 2O _ 4 / Al _ 2O _ 4 / Al _ 2O _ 4 foam concrete has the best effect, and the dry density of 450kg / m ~ 3 / 3d strength can reach 0.64Mpa. however, the phenomenon of ball-forming and powdering occurs in the foamed concrete with the addition of AlCl3- AlCl-Al2SO4- _ 4 ~ (3 +).When the strength is below 0.21MPa, the dry density of foamed concrete can be reduced effectively. It is easier to prepare low density foamed concrete under 300kg/m3 by 50% weight aggregate, and the thermal conductivity can be reduced to 0.0795W/(m.The dry density has a direct effect on the water absorption and thermal conductivity. The dry density is inversely proportional to the water absorption and is proportional to the thermal conductivity.Silicone waterproofing agent and paraffin emulsion can effectively reduce the water absorption rate of foamed concrete with 3% content, and the volume water absorption rate is 13.1% and 16.9cm, respectively.Through the analysis of the factors affecting the properties of foamed concrete, the optimum mix ratio is optimized, that is, the ratio of water to binder is 0.5, the amount of silica fume is 3% CaSO4, the volume occupancy of EPS is 0.5%, and the organic silicon water-repellent is added 3%.The amount of cementitious material is 225 kg / m ~ (3) and the amount of foam is 475 L / m ~ (3). The foam concrete with excellent properties such as dry density 270kg/m3 (28d), thermal conductivity (0.0795W/(m) and volume water absorption (13.1%) can be prepared with 28d compressive strength of 0.51MPa.
【学位授予单位】：沈阳建筑大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528.2

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