New Advances of Connection Techniques in Concrete Modular Shear Wall Building Structures

Concrete modular integrated construction (MiC) buildings boast a high prefabrication rate. They are manufactured as three-dimensional volumetric units that integrate the structure, MEP (mechanical, electrical, and plumbing) systems, interior finishes, and sanitary facilities. Consequently, concrete MiC represents a crucial development direction for prefabricated concrete buildings. Ensuring reliable force transfer, simple detailing, and ease of fabrication and on-site assembly for inter-module connections is a core technical challenge in such buildings. However, existing concrete modular shear wall systems face problems in production, transportation, and construction due to protruding reinforcement at the joints, which ultimately affect production quality and increases costs. To address these issues, this paper reviews the connection techniques in traditional precast concrete buildings and proposes the application of the “rabbeted connections for prefabricated concrete slabs” to the joints of concrete modular shear wall buildings. Moreover, the recently “notched slab connection” technique for precast concrete elements is introduced, focusing on its technical characteristics, research progress, and project applications, and discusses its feasibility for the intended application. Based on existing relevant research findings and current code provisions, it is recommended that the groove length should not be less than 1.6 times the anchorage length of the tensile steel bar and no less than 300 mm, the groove width and depth should be 40 mm and 30 mm, respectively, the thickness of the precast panel should range from 30 mm to 35 mm, and the slope angle should be between 45° and 60°. This type of connection can effectively reduce the fabrication difficulty of modules, save transportation space, and improve construction efficiency, demonstrating engineering feasibility. However, the effects of interface roughness between new and existing concrete, groove dimensions, and reinforcement anchorage types on the seismic performance of shear walls require further verification through quasi-static tests and numerical simulations. Future research should establish standardized design methods within the “experiment-simulation-theory” framework.