玻化微珠保温砂浆的改性研究

发布时间：2018-02-05 23:49

本文关键词： 玻化微珠保温砂浆人工碳化碳酸钙　出处：《重庆大学》2014年硕士论文　论文类型：学位论文

【摘要】：玻化微珠保温砂浆的体积吸水率远低于珍珠岩保温砂浆，耐火性远高于聚苯乙烯颗粒保温砂浆，其产品的抗压强度相对较高，导热率也相对较低，因而迅速占领了市场。普通的玻化微珠保温砂浆在外墙外保温的施工过程中，由于产品质量的参差不齐，操作的不规范，现场难以监管，导致新建建筑的节能效果不够理想，因而在重庆、北京等城市已被禁止使用。鉴于此，我们在普通玻化微珠保温砂浆的基础上掺入18～20%的石灰对其进行改性研究，并为制成水泥钙基玻化微珠保温砂浆复合板制品提供参考。通过成型养护试验，确定了搅拌时间、用水量、养护条件对水泥钙基玻化微珠保温砂浆性能的影响；通过正交试验，确定初步的配合比，进一步通过单因素试验优化分析，确定120kg/m3玻化微珠的用量在44.8%，使用120kg/m3玻化微珠确定水泥的最佳用量（不包括粉煤灰的用量）为30%～34%，，粉煤灰或漂珠等量取代水泥的最优掺量为10%，憎水剂掺量可选用0.1%，乳胶粉的掺量为1.8～2.0%，羟丙基甲基纤维素醚的最佳掺量为0.2%，聚丙烯纤维的最佳用量为0.4%，聚苯颗粒取代玻化微珠的最佳用量为3%；最后以此优化后的配合比成型水泥钙基玻化微珠保温砂浆试块，并对其进行干密度、抗压强度、保温隔热性、收缩性、抗裂性、耐火性的试验分析。本文采用人工碳化试验，分析掺入18～20%的石灰对水泥钙基玻化微珠保温砂浆的特殊影响与作用。经过初步碳化试验后，采用扫描电子显微镜对试块进行微观形貌扫描，发现要利用氢氧化钙的碳化生成碳酸钙晶体来提高水泥钙基玻化微珠保温砂浆的致密度和强度，必须控制二氧化碳的浓度；通过不断改变试块碳化时二氧化碳的浓度，发现低二氧化碳浓度有利于生长的碳酸钙晶体被水泥水化产物包裹从而促使水泥钙基玻化微珠保温砂浆结构致密化，最终确定有利的二氧化碳浓度为20000PPM；再通过XRD、EDS能谱分析，确定水泥钙基玻化微珠保温砂浆碳化后生成了大量的碳酸钙晶体，这些碳酸钙晶体在水泥钙基玻化微珠保温砂浆的毛细孔中沉积，使得毛细孔细化，有利于后期强度的显著增长。
[Abstract]:The volume water absorption rate of glass microbead insulation mortar is far lower than that of perlite insulation mortar, and the fire resistance is much higher than that of polystyrene particle insulation mortar. The compressive strength of the product is relatively high and the thermal conductivity is relatively low. As a result, it quickly occupied the market. Ordinary glass microbead insulation mortar in the construction process of external insulation, because the product quality is uneven, the operation is not standard, the site is difficult to supervise. As a result, the energy efficiency of new buildings is not ideal, so cities such as Chongqing and Beijing have been banned from use. On the basis of ordinary vitrified microbead insulation mortar, 1820% lime was added to modify the mortar, and a reference was provided for the preparation of cement calcium based glass microbead thermal insulation mortar composite board. The effects of mixing time, water consumption and curing conditions on the properties of cement calcium based vitrified microbeads thermal insulation mortar were determined by forming and curing test. Through the orthogonal test, the initial mix ratio was determined, and the amount of vitrified beads of 120kg / m3 was determined to be 44.8% by further optimization analysis of single factor test. The optimum dosage of cement (excluding fly ash) was determined by using 120 kg / m ~ 3 glass microbeads. The optimum amount of cement replaced by fly ash or drifter was 10%. The dosage of hydrophobic agent is 0.1, the content of latex powder is 1.80.The optimum dosage of hydroxypropyl methyl cellulose ether is 0.2, and the optimum dosage of polypropylene fiber is 0.4%. The optimum dosage of polystyrene particles to replace glass beads is 3. Finally, the optimized mix ratio is used to form the cement calcium based vitrified microbead insulation mortar, and the dry density, compressive strength, thermal insulation, shrinkage, crack resistance and fire resistance of the mortar are analyzed. In this paper, artificial carbonization test was used to analyze the special effect and effect of 18 ~ 20% lime on cement calcium based vitrified microbead thermal insulation mortar. Scanning electron microscope (SEM) was used to scan the microstructure of the samples, and it was found that calcium carbonate crystals should be formed by carbonation of calcium hydroxide to improve the density and strength of cement calcium based vitrified microbeads thermal insulation mortar. The concentration of carbon dioxide must be controlled; By changing the concentration of carbon dioxide during carbonization, it was found that the calcium carbonate crystals with low carbon dioxide concentration were encapsulated by the hydration products of cement, thus promoting the structure densification of cement calcium based glass microbeads thermal insulation mortar. The beneficial carbon dioxide concentration was determined to be 20 000 PPMs; Through the energy spectrum analysis of XRDX EDS, it was determined that a large number of calcium carbonate crystals were formed after carbonization of cement calcium based glass bead heat preservation mortar. These calcium carbonate crystals are deposited in the capillary pores of the cement calcium based vitrified microbeads, which make the capillary pores fine, which is conducive to the significant increase of the later strength.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU551;TU578.1

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