Research on the application of airbag support system for double shear wall formwork at deformation joints

The narrow width of building expansion joints presents significant challenges in constructing shear walls on both sides of the joint. The limited working surface prevents entry into the expansion joint, making template support and removal difficult, often resulting in templates being left within the joint. This paper examines construction methods for double-shear wall formwork at deformation joints to address these concerns. Inspired by the bridge inflatable core mold, the research creatively incorporates the rubber airbag used in bridge construction into the project. A special rubber airbag is developed to support the double-shear wall formwork at the deformation joint. When inflated, the airbag forms a compressive elastic body to support the side formwork pressure of the shear wall. The shear wall formwork on both sides of the deformation joint is then reinforced with tension bolts at intervals between the airbags. This combination creates a complete and stable system. Experimental studies on the airbag’s deformation characteristics under external force and calculations of the overall support system’s stability demonstrate that the deformation value meets the requirements for stable support of the formwork side pressure, confirming the system’s stability and reliability. This technology is highly innovative, scientifically sound, simple to operate, and provides reliable quality assurance, offering guidance for constructing similar projects with the same structure.