寒冷地区超轻泡沫混凝土的制备与性能

发布时间：2019-05-23 11:44

【摘要】：泡沫混凝土由于内部的疏松多孔结构使其具有轻质、保温、隔音、抗震等优点，广泛应用于节能保温墙体当中。其中超轻泡沫混凝土的应用更加具体，以作为保温和填充材料在建筑施工中现浇成型为主。随着目前节能减排政策的大力实施，泡沫混凝土的应用也更加广泛，随之而来的各方面问题也日益突出，其中就包括在严寒地区的应用有很大困难。本文以超轻泡沫混凝土为研究对象，旨在以其在严寒地区的应用为视角，通过具体试验和测试的方法，力图为严寒地区应用泡沫混凝土保温节能以及现场施工浇筑提供参照。通过各种方法技术对泡沫混凝土的制备和性能进行提高。本文中首先通过对市场上常见的九种不同类型的发泡剂在不同温度条件下的发泡性能和稳泡性能进行试验测试，并将试验结果进行对比分析，确定出温度对泡沫混凝土用发泡剂性能的影响。同时优选出稀释倍数为20倍的植物型和复合型两种发泡剂进行超轻泡沫混凝土的配制。通过超轻混凝土的成型情况对其配合比参数进行调整，，得出适宜成型的浆体流动性、水灰比、减水剂、掺合料、以及促凝剂掺量等，同时研究这些因素对泡沫混凝土制备的影响规律。并且针对较低的温度下超轻泡沫混凝土的成型规律和问题，寻找其原因并解决，以实现能够在较低温度下获得稳定良好的超轻泡沫混凝土。研究结果表明，在温度较低时发泡剂的变化和影响甚微，主要问题在于水泥的水化和硬化时间增加，导致气泡难以稳定试件塌陷。掺入促凝剂和纤维素醚能够在一定程度上改善低温成型效果，可以满足使用要求。通过对泡沫混凝土的不同性能试验研究，确定泡沫混凝土中各项实用性能的影响因素和影响规律。主要有导热系数、孔隙率、吸水率、抗冻性和孔结构，分析他们之间的关系和差别，并从理论上提出能够改善这些性能的方法，然后对其可行性和难易程度以及改善效果进行试验研究，最终确定在超轻泡沫混凝土的制备和应用中可行的性能提高措施。试验中制备的253kg/m3泡沫混凝土的导热系数在0.063W/（m K），与预期的低于0.06W/（m K）有微小差距。
[Abstract]:Foam concrete is widely used in energy-saving thermal insulation wall because of its loose porous structure, which has the advantages of light weight, heat preservation, sound insulation, earthquake resistance and so on. Among them, the application of ultra-light foam concrete is more specific, mainly as heat preservation and filling materials in the construction of cast-in-place molding. With the implementation of energy saving and emission reduction policy, the application of foam concrete is more extensive, and the following problems are becoming more and more prominent, including the application in severe cold areas. In this paper, ultra-light foam concrete is taken as the research object, in order to provide reference for the application of foam concrete heat preservation and energy saving and field construction in severe cold area from the perspective of its application in severe cold area, through the method of concrete test and test. The preparation and properties of foam concrete are improved by various methods and techniques. In this paper, the foaming properties and foam stability of nine different types of foaming agents in the market under different temperature conditions were tested, and the test results were compared and analyzed. The effect of temperature on the properties of foaming agent for foam concrete was determined. At the same time, the plant type and compound foaming agent with dilution multiple of 20 times were selected for the preparation of ultra-light foam concrete. According to the molding condition of ultra-light concrete, the mixture proportion parameters are adjusted, and the suitable slurry flowability, water-cement ratio, water reducing agent, admixture and the content of accelerator are obtained. At the same time, the influence of these factors on the preparation of foam concrete is studied. Aiming at the forming law and problems of ultra-light foam concrete at lower temperature, the causes are found and solved in order to obtain stable and good ultra-light foam concrete at lower temperature. The results show that the foaming agent has little change and influence when the temperature is low. The main problem is that the hydration and hardening time of cement increases, which leads to the collapse of bubble stable specimen. Adding coagulant and cellulose ether can improve the low temperature molding effect to a certain extent, and can meet the requirements of use. Through the experimental study on the different properties of foam concrete, the influencing factors and laws of practical properties in foam concrete are determined. There are mainly thermal conductivity, porosity, water absorption, frost resistance and pore structure, and the relationship and difference between them are analyzed, and the methods that can improve these properties are put forward theoretically. Then the feasibility, difficulty and improvement effect are studied, and the feasible performance improvement measures in the preparation and application of ultra-light foam concrete are finally determined. The thermal conductivity of 253kg/m3 foam concrete prepared in the experiment is slightly different from the expected lower than 0.06W/ (m K) in 0.063W/ (m K),.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528.2

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