目前新型墙体因砌筑材料热湿膨胀、吸水膨胀和干燥收缩而引起的开裂现象十分普遍，因热湿膨胀机理和相关实验方法复杂性，墙体的胀缩开裂控制措施和方法缺乏，现阶段以测量干缩值为实验方法的防治手段效果也不佳，因此，要从根本上防治开裂，首先应提出适用于墙材湿胀干缩变化机理模型，并建立精确测量的标准化实验方法。本课题重点研究内容包括：1.分析墙材热湿膨胀过程及机理，建立吸水膨胀过程的膨胀值和吸水率瞬态计算模型，提出全新的动态吸水膨胀测量标准化实验方法；2.探索墙材在水中吸水量的连续测量方法，提出测量标距定位等关键问题和解决方案，进而建立具备连续、自动、精确和稳定测量功能的动态吸水膨胀测量装置；3.研究环境湿度小范围变化条件下墙材的变形规律，建立动态吸湿干缩测量的标准化实验方法，研制动态干缩湿胀循环过程测量装置，并确定墙体在干湿循环状态下的变形发展规律。本课题成果将为新型墙体构造设计提供开裂控制理论依据。

Nowadays the wall cracking phenomenon is very common, which is caused by thermal and moisture expansion, water expansion, and drying shrinkage of the masonry materials. However, the complicated principle and experiment methods of thermal and moisture expansion result the lack of effective measures which is used to control the wall cracking for expansion-shrinkage deformation. Drying shrinkage test method as a common way of the thermal and moisture expansion research is actually not accurate and effective enough. Because of this, a principle model of wall material moisture expansion and drying shrinkage, as well as an exact and standardized experimental method are proposed to resolve the wall cracking problems.The main researches are as follows: 1. By analyzing the process and principle of the wall material thermal and moisture expansion, a dynamic measurement model of water absorption and expansion will be developed, and then a new experimental method to realize dynamic water expansion measurement standardization will be presented. 2. A solution to key points such as measuring the gauge length positioning system will be proposed by researching the method of dynamic measurement of water-absorption. And base on that, a dynamic water expansion measuring equipment will be developed which achieves the measurement of continuity, automaticity, accuracy and steady. 3. A standardized experimental method to measuring moisture expansion and drying shrinking dynamic will be proposed, by analyzing the deformation law of wall material with a small alteration of environment humidity. As well, a dynamic measuring equipment of moisture expansion and drying shrinking will developed, and the tendency of wall material deformation in dry-wet environment will be found.The achievement of this research will provide cracking control theoretical basis for novel design of wall structure.