Key Points for Connecting GRC Exterior Walls with Door and Window Openings? — Key Technologies of Qinglong Group's Waterproofing and Sealing System

The connection between GRC exterior walls and door/window openings is a critical link for waterproofing, requiring comprehensive consideration of thermal deformation, structural displacement, and waterproof sealing. Qinglong Group has summarized three key points—precise positioning of embedded parts, multi-layer sealing design, and flexible structural connection—to ensure long-term reliability at the connection.

Positioning of embedded parts is the foundation of the connection. Galvanized steel plates with a thickness ≥2mm are embedded at the door/window frame installation positions and welded to the GRC panel reinforcement for fixation. Qinglong Group uses BIM technology for precise positioning, with position deviation ≤3mm. The areas around embedded parts are reinforced with additional φ4@50mm steel wire mesh to prevent shrinkage cracks. In a Shenzhen project, this precise positioning improved door/window installation efficiency by 30%.

Sealing system design is crucial. The "three-line sealing" principle is adopted: foam sealant filling on the inner side (density ≥20kg/m³), weather-resistant sealant sealing in the middle (displacement capacity ≥25%), and metal flashing on the outer side for water drainage. Qinglong Group prefers silicone sealant with a bond strength to GRC of ≥0.5MPa and a service life of over 20 years. The sealant thickness is 0.5 times the joint width to ensure sufficient deformation capacity.

Flexible connections accommodate deformation. Expansion joints of 10-15mm are set at the connection and filled with polyethylene foam rods. The connectors are made of stainless steel, allowing ±5mm displacement. In projects in typhoon-prone areas, Qinglong Group adds seismic bearings to meet seismic fortification requirements. This flexible design effectively prevents cracking caused by thermal stress.