密肋复合墙体填充轻质多孔混凝土材料力学性能及其与框格共同作用研究

As a new structural system, the multi-ribbed composite wall structure has been developed in recent years. The characteristics of this structure include light weight, high strength, energy saving and good aseismic performance. As one of the elements of the multi-ribbed composite wall, the light porous concrete not only takes the role of insulation and envelope, but also functions with the concealed frame in order to form the force participation, bear the vertical and horizontal loads of the structure and serve the anti-lateral stiffness. Thus, it is necessary to set up a special model in accordance with the features of strength criterion of the multiaxial stress of the ecological light porous concrete materials.A fundamental element of masonry infilled frame include the mechanical information of this structure system. It plays a key role to analyze the properties of the multi-ribbed slab wall with true mechanical model to simulate the interaction between the infilling materials and masonry infilled frame. From the material level to the component level,an in-depth analysis is done. This research may provide a more scientific basis to revise the specification in the future,and it has theoretical and application value to promote the development of the national wall reform and implementation of building energy efficiency policies.The research contents include:①The experimental study on mechanical performance and constitutive relationship of the light porous concrete;②The theory study on the strength criterion of the multiaxial stress and constitutive relationship of the light porous concrete; ③The experimental and theory studies on material performance of the masonry infilled frame. This research may provide a more scientific basis to revise the specification in the future,and it has theoretical and application value to promote the development of the national wall reform and implementation of building energy efficiency policies.

密肋复合墙结构是为适应国家墙体材料革新与建筑节能、可持续发展而开发的一种生态、节能、减震型建筑结构新体系。其中的轻质多孔混凝土不仅起到保温、围护作用，而且与框格共同承担竖向及水平荷载，同时提供抗侧刚度，因此得到轻质多孔混凝土的多轴强度准则及本构关系尤为重要。此外，密肋复合墙框格单元包含了该结构的所有基本力学信息，因此用真实的力学模型来模拟框格和填充砌块的整体共同作用对整块墙板的性能分析有关键性的作用。本项目从材料层次到构件层次，分别对轻质多孔混凝土的力学性能及其与框格共同作用进行更深入的试验和理论研究，主要内容包括：①轻质多孔混凝土材料基本力学性能及本构关系；②轻质多孔混凝土材料多轴强度准则；③轻质多孔混凝土框格单元材料的基本力学性能。本项目研究的目的是建立密肋复合墙填充材料的本构关系和多轴强度准则，揭示填充材料与框格的协同工作原理，为密肋复合墙设计理论及工程应用提供可靠的试验和计算依据。

密肋复合墙结构是为适应国家墙体材料革新与建筑节能、可持续发展而开发的一种生态、节能、减震型建筑结构新体系。本项目从材料层次到构件层次，分别对轻质多孔混凝土的力学性能及其与框格共同作用进行了深入的试验和理论研究，主要内容包括：①轻质多孔混凝土材料基本力学性能及本构关系：基于统一强度理论推导建立了轻质多孔混凝土材料的二维三参数强度准则，该模型的特点是力学概念明确，模型参数少，容易通过试验确定，并且能反映密肋复合墙板中的轻质加气混凝土砌块的实际受力特点，为密肋复合墙体结构的推广应用提供理论基础。②轻质多孔混凝土材料与普通混凝土之间粘结性能研究：采用棱柱体剪切试验的方法测定了轻质加气混凝土砌块与普通混凝土粘结界面性能，分析了粘结面倾斜角度对试件的破坏形态和界面强度的影响，确定了粘结界面在纯剪应力状态下的抗剪强度，为密肋复合墙结构构件层次和结构层次的力学性能提供理论和数值计算依据。③考虑粘结性能的轻质多孔混凝土框格单元的基本力学性能研究：运用内聚力界面单元模拟混凝土肋与填充砌块的粘结界面，与不考虑粘结界面性能的模型相比，其有限元分析结果与试验结果吻合的更加完好，说明考虑混凝土肋与填充砌块粘结界面性能并运用内聚力单元进行模拟，能够进一步改善框格单元的有限元计算，更好的表现实际模型受力过程中力学性能的变化。可以运用内聚力单元的损伤判定因子、损伤因子以及单元应力等参数来模拟粘结界面的开裂以及裂缝拓展等问题。并以开裂荷载、屈服荷载、极限荷载、破坏荷载等四个荷载特征值时试件的受力情况为出发点，完成了框格单元对角轴压试验的受力过程分析。