Cast-in-Place Prefabricated Assembled Housing

Cast-in-place prefabricated assembled housing typically refers to partially assembled buildings, where the main components are prefabricated and connected on-site with cast-in-place concrete to form an integrated assembled structure.

Key features are as follows:

1. Construction Efficiency and Resource Optimization
   This type of building achieves standardized production through factory-prefabricated components, significantly improving construction speed, especially beneficial for winter construction. The industrialized construction model replaces traditional wet operations, reducing material waste and construction waste emissions from the source, aligning with the concept of full-cycle green construction. For example, prefabricated wall panels, floor slabs, and other components are manufactured in the factory and transported to the site, requiring only cast-in-place concrete to connect key nodes, shortening on-site operation time.

2. Structural Performance and Safety
   The overall structural integrity and collapse resistance highly depend on the connection quality between prefabricated components. Under extreme loads such as earthquakes and impacts, the connection details at nodes and joints are crucial for ensuring safety. During design, it is essential to focus on the mechanical properties of the connection areas to ensure they possess sufficient strength, stiffness, and ductility. For example, when using steel bar grout sleeve connections, strict control over the matching of grout strength and sleeve dimensions is necessary to prevent connection failure leading to structural disintegration.

3. Connection Methods and Technical Requirements
   The connection method of prefabricated components directly affects structural reliability. Common methods include:

   • Grout sleeve connection: High-strength grout fills the gap between steel bars and sleeves, enabling indirect force transfer through the steel bars, suitable for connecting vertical components (such as columns and walls).
   • Lap connection: Steel bars in prefabricated components are directly lapped at the node area and wrapped with cast-in-place concrete to form an integral structure, commonly used for connecting horizontal components (such as beams and slabs).
   • Welding connection: Steel bars or steel plates in prefabricated components are connected through welding, suitable for scenarios requiring high connection stiffness, but welding quality must be controlled to avoid brittle failure.

Design Considerations
Structural design should combine building functions and seismic requirements to reasonably select connection methods and optimize node details. For example, in high-rise buildings, vertical component connections should prioritize grout sleeve or mechanical connections to enhance shear resistance; horizontal component connections must ensure coordinated work between the cast-in-place layer and prefabricated parts to avoid cracks caused by deformation incompatibility. Additionally, during construction, strict control over the quality of cast-in-place concrete pouring is necessary to ensure the compactness of node areas and avoid defects such as honeycombs and voids that affect structural performance.