填充EPS-石膏基复合材料的冷弯型钢组合墙体轴压与受剪性能研究

As the infilled material of cold-formed steel stud walls, the EPS-gypsum based composite material would promote the stiffness and strength, solve the empty-drum effect and improve fire resistant and heat preservation performance of cold-formed steel stud walls; The EPS-gypsum based composite material will be prepared by industrial waste-desulphurization gypsum and waste EPS particles, which would make waste profitable, reduce pollution and protect the environment. The axial and shear behavior of cold-formed steel stud walls with infilled EPS-gypsum based composite material will be studied by experimental investigation, theoretical analysis and finite element method, the failure mechanism of this new composite wall under the axial compression and shear force will be revealed; The computing theory of axial bearing capacity for walls will be put forward on the base of making clear the failure modes of cold-formed steel studs sheathed by the wall panels and embedded in the infilled material; The shear behavior of walls will be analyzed, and the calculation method of lateral stiffness and shear bearing capacity, as well as the elastic-plastic analysis model should be proposed; Also, the construction measures of this new composite walls will be suggested. This research should be provide the scientific basis and engineering references for the application and development of the cold-formed thin-walled steel structure buildings, the recycle of waste EPS and industrial waste gypsum.

以EPS-石膏基复合材料做为冷弯型钢组合墙体的填充材料，可以提高组合墙体的刚度和强度、解决墙体的“空鼓效应”和提高墙体的抗火和保温性能；以工业废弃物—脱硫石膏和废旧的EPS颗粒为原材料制备EPS-石膏基复合材料，可实现变废为宝，降低污染，保护环境。以试验研究、理论分析和有限元法相结合的技术路线，对填充EPS-石膏基复合材料的冷弯型钢组合墙体的轴压和受剪性能开展研究，揭示新型组合墙体在轴压和受剪模式下的破坏机理；明确冷弯型钢立柱在墙面板支撑和填充材料包裹下的破坏形态，提出组合墙体轴压承载力计算理论；研究组合墙体的受剪性能，提出墙体的抗侧刚度和受剪承载力计算方法；建立组合墙体的弹塑性分析模型；提出新型复合墙体的构造措施，为冷弯薄壁型钢结构房屋的应用与发展、EPS和工业石膏废弃物的利用提供科学依据和工程参考。

本项目以工业废弃物—脱硫石膏为主要原材料，通过材料改性制备出石膏基轻质复合材料，并以试验研究和理论分析相结合的技术路线，对填充该改性石膏基复合材料的冷弯型钢组合墙体的轴压和受剪性能开展研究。主要的研究内容和结论为：①针对脱硫石膏煅烧后水化速度快，浆体泌水严重，耐水性差、强度低、易造成钢材锈蚀等问题，利用激光粒度分析仪、孔隙率测定仪、扫描电子显微镜手段分析脱硫石膏的粒度分布及微观结构，采用水泥、粉煤灰和阻锈剂等相结合的方式进行材料改性，使其满足结构使用的基本要求。对新型材料的力学性能进行测试，通过对应力-应变全曲线形态的分析，采用分段拟合的方法，提出应力-应变全曲线方程；②设计8片足尺墙体试件，通过轴向加载试验，研究其在竖向荷载作用下的破坏模式、荷载-变形关系、荷载-应变关系、轴压刚度和轴压承载力。并采用有限元法进行参数分析，明确影响轴压性能的各个因素，结果表明：在轴压荷载作用下，填充墙体主要发生强度破坏，而非屈曲失效，墙体的轴压承载力、轴向压缩刚度显著提高。在试验研究与数值分析数据基础上，提出了一种修正的叠加法来计算填充墙体的轴压承载力；③设计了4组共14个足尺墙体试件，通过低周反复加载试验研究墙体的抗震性能，分别考察填充材料强度、龙骨尺寸、加载方式和螺钉加强形式等因素对墙体抗震性能的影响，研究新型墙体在低周反复荷载作用下的破坏模式，揭示墙体的受剪破坏机理，对墙体的弹性刚度、承载能力、刚度退化、滞回特性、延性、耗能性能及螺钉连接损伤特性进行系统分析。提出新型墙体受剪破坏计算模型，建立墙体弹性剪切刚度和受剪承载力的计算公式。本项目的研究成果将为脱硫石膏工业废弃物利用和冷弯型钢结构房屋的应用提供科学依据和技术参考。