蒸压加气混凝土砌块的抗冻性研究

发布时间：2018-01-08 19:27

本文关键词：蒸压加气混凝土砌块的抗冻性研究　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着国家可持续发展战略的实施,满足“节能、节土、节水、利废”要求的绿色墙体材料将取代传统墙体材料。蒸压加气混凝土具有质量轻、保温隔热性能好的特点,并能消耗大量的废弃粉煤灰,目前已成为我国主要的填充墙墙体材料之一。耐久性是填充墙非常重要的性能指标。目前,对蒸压加气混凝土耐久性尤其是抗冻性方面的研究还非常少。为了进一步完善蒸压加气混凝土抗冻性方面的研究,本文进行了一系列试验与理论分析,对绿色节能材料的应用与推广具有重大意义。研究和分析表明,材料的孔结构和其本身的物理力学性能是影响抗冻性的主要因素,而毛细吸水系数能够较好的反映孔结构的基本情况。本文在研究加气混凝土材料吸水特性与孔结构的关系时引用了吸水动力学的基本原理,并通过4组24块试件的吸水试验后,得到了吸水曲线图,建立了孔结构与毛细吸水系数之间的关系。研究表明,加气混凝土的孔径大小对抗冻性有很大影响,孔径很大以及孔径很小的孔对加气混凝土抗冻性影响很小。通过吸水动力学理论研究和试验分析,计算出不同吸水时间段内毛细孔的平均孔径,得到了对加气混凝土抗冻性的影响起主要作用的毛细吸水系数。通过对4组80块不同材料进行冻融循环试验,提出了以毛细吸水系数、无孔隙强度为主要参数来表征其抗冻性的方法。同时,基于这一方法提出了加气混凝土抗冻性指标,并根据不同地区抗冻等级的要求,得到不同地区的抗冻性指标和最低强度等级的限值。
[Abstract]:With the implementation of the national sustainable development strategy, green wall materials which meet the requirements of "energy saving, soil saving, water saving and waste benefit" will replace the traditional wall materials. The autoclaved aerated concrete has light quality. Heat preservation and heat insulation, and can consume a large number of waste fly ash, has become one of the main wall materials in China. Durability is a very important performance index of filled wall. The research on the durability of autoclaved aerated concrete, especially on its frost resistance, is very few. In order to further improve the research on the frost resistance of autoclaved aerated concrete, a series of experiments and theoretical analysis have been carried out in this paper. The research and analysis show that the pore structure of the material and its physical and mechanical properties are the main factors affecting the frost resistance. The capillary water absorption coefficient can better reflect the basic situation of the pore structure. In this paper, the basic principle of water absorption dynamics is cited in the study of the relationship between the water absorption characteristics of aerated concrete materials and the pore structure. The relationship between pore structure and capillary water absorption coefficient was established through the water absorption tests of 24 specimens in 4 groups. The results show that the pore size of aerated concrete has a great influence on the frost resistance. The effect of large pore size and small pore size on the freezing resistance of aerated concrete is very small. Through the theoretical research and experimental analysis of water absorption dynamics, the average pore size of capillary in different water absorption periods is calculated. The capillary water absorption coefficient which plays an important role in the frost resistance of aerated concrete is obtained. Through freeze-thaw cycle test of 80 different materials in 4 groups, the capillary water absorption coefficient is put forward. At the same time, based on this method, the frost resistance index of aerated concrete is put forward, and according to the requirements of different regions, the frost resistance of aerated concrete is studied. The freezing resistance index and the limit value of the lowest strength grade were obtained in different regions.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU522.3

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