榫卯式预制混凝土节点受力性能研究

Industrialization is one of the development trends of construction industry, the key objective of which is to build a industrialized structural system. Precast concrete mortise-and-tenon joint is proposed in this project based on a new type of precast concrete member. The precast member comprising at least one longitudinal hole and a longitudinal edge, wherein the longitudinal hole is disposed in the vicinity of the longitudinal edge, the longitudinal edge comprises a plurality of transverse recesses disposed at intervals, and the transversal recesses intersect with the longitudinal hole. The mortise-and-tenon joint composes of the concrete bonding surface, precast concrete and cast-in concrete fastened mutually, and anchorage connecting steel bars. Overall, the new joint has high crack resistance and it can improve the serviceability and integrity of structures. New type precast concrete structures formed by precast members and mortise-and-tenon joints have an advantage of high degree of industrialization, and there is no related research now. The project intends to study the key configuration, mechanical mechanism， theoretical model and design method of the new joint based on the combined methods of experimental research, numerical analysis, and theoretical study, mainly including: ①Key joint configurations and their impact on the mechanical behavior. ②Theoretical model for the prediction of load bearing capacity of this precast joint. ③Design formulas of the load-carrying capacity and corresponding practical design methods.

建筑工业化是建筑业的发展方向，核心是建立工业化结构体系。本项目基于一种新型带横向凹槽的预制混凝土构件，提出榫卯式预制混凝土节点。新型预制构件在靠近纵向边缘处开有纵向孔洞，纵向边缘间隔设置与纵向孔洞相交的横向凹槽；榫卯式节点包括新旧混凝土结合面、互相锁扣的预制混凝土与后浇混凝土以及锚连钢筋，抗裂性良好，可提高结构正常使用性和整体性。新型预制构件和榫卯式节点国内外未见相关研究，将形成工业化程度高的预制混凝土结构体系。本项目拟采用试验研究、数值分析和理论研究相结合的方法，研究榫卯式节点的关键构造、受力机理、理论模型和设计方法，包括：①研究新型节点受力机理，获得关键构造；②研究新型节点的受力性能，建立承载力理论分析模型；③研究新型节点的承载力计算公式，提出实用设计方法。

本项目基于一种新型带横向凹槽的预制混凝土构件，提出榫卯式预制混凝土节点。新型预制构件在靠近纵向边缘处开有纵向孔洞，纵向边缘间隔设置与纵向孔洞相交的横向凹槽。本项目进行了8个直剪足尺试件试验研究，包括1个钢筋混凝土试件、1个粗糙面键槽式连接界面和6个榫卯式连接节点试件，研究了界面粗糙度、凹槽深度、竖孔宽度、接缝宽度以及锚连钢筋构造措施对榫卯式连接节点受剪性能的影响。结果表明：在未配置锚连钢筋的情况下，榫卯式连接节点具有较高的承载力和良好的延性；增设锚连钢筋提升了节点的受力性能，提高其承载力和变形能力；在满足施工要求下，改变竖向孔洞和键槽尺寸等措施对连接节点的受力性能影响较小，基于研究，分析了榫卯式节点的受力机理，建议了预制混凝土构件的关键构造，提出了的节点受剪承载力计算公式。