How to Achieve the Integration of UHPC Shapes with Metal Components: Analysis of Bonding Methods and Practical Cases

Combining UHPC forms with metal components allows complementary advantages, achieving unity of function and aesthetics, which requires scientific combination methods and reliable connection technology. Drawing on project experience such as the Shenzhen Yirui Biotechnology Building, Qinglong analyzes the core combination methods and practical key points to ensure firm and durable connections.

1. Embedded Combination Method: Integrated Structural Design

Metal components are embedded inside UHPC to achieve coordinated load bearing. Embedded metal skeleton: During the production stage of UHPC components, a stainless steel or carbon steel skeleton is embedded in the mold, and UHPC slurry is poured to wrap and secure it. The metal skeleton must reserve anchoring nodes to ensure firm bonding with UHPC, with bond strength ≥2.5MPa. Qinglong adopted this method in large UHPC sculpture projects to improve overall flexural strength; Embedded connectors: Metal connectors (such as bolts and steel plates) are pre-embedded inside UHPC components. The connector surface must be treated for rust prevention (hot-dip galvanizing or fluorocarbon coating), and the exposed parts reserve connection interfaces for easy docking with external metal components. In the Shanghai New World project, pre-embedded connectors were used to connect UHPC with the metal support structure.

2. Surface Connection Method: Convenient Assembly and Decoration

Metal components are installed on the UHPC surface, suitable for decoration and local functional requirements. Bolt connection: Bolt holes are reserved on the UHPC component surface, and stainless steel bolts are used to fix metal decorative parts (such as metal lines and metal plaques). The bolt holes must be treated with waterproof sealing to prevent rainwater infiltration. Qinglong applied this method to combine UHPC with metal decorative lines in the Nanning Wuxiang China Resources MixC One project; Welded connection: For scenarios requiring high-strength connections, external metal components are welded onto the pre-embedded metal parts in UHPC. Cooling measures (such as wrapping with wet towels) must be taken during welding to avoid local UHPC cracking caused by high temperature, and the weld seams must be treated for rust prevention after welding; Snap-fit connection: Suitable for lightweight metal decorative parts. Slots are designed on the UHPC surface, and metal components are quickly assembled via snap-fits, making them easy to disassemble and replace, ideal for temporary decoration or later maintenance.

3. Protection and Durability Assurance of Connection Areas

Proper protective treatment prevents failure at connection areas. Anti-corrosion treatment: Metal components and connectors should use 304/316 stainless steel or hot-dip galvanized materials; 316 stainless steel is preferred in coastal areas with high salt spray, and surfaces are coated with fluorocarbon anti-corrosion coating to extend service life. Qinglong adopted dual anti-corrosion measures in its Hainan project; Waterproof sealing: Gaps at connection areas must be filled with high-modulus silicone sealant, especially in outdoor scenarios, to prevent rainwater infiltration that causes metal corrosion and UHPC aging. The sealant must have weather resistance and elasticity to accommodate thermal expansion and contraction deformation; Stress release design: Since UHPC and metal have different thermal expansion coefficients, elastic gaskets or slidable nodes should be set at connection areas to release thermal stress and avoid cracking. Qinglong solved stress problems with elastic gaskets in a project combining double-curved UHPC with metal keels.

4. Selection of Combination Methods and Practical Application Cases

Select appropriate combination methods based on project requirements to ensure effect and safety. Scenario adaptation principle: Embedded pre-embedding is preferred for load-bearing structural connections; bolt or snap-fit connections can be used for decorative connections; large load-bearing structure combinations require structural load verification; Qinglong practice cases: In the Shenzhen Yirui Biotechnology Building project, the embedded metal skeleton + bolt connection method was adopted to combine UHPC exterior wall panels with the metal support structure, with load-bearing capacity meeting design requirements; In the Shanghai Astronomy Museum public art project, welded pre-embedded metal parts achieved a firm connection between the UHPC sculpture and the metal base, with wind load resistance ≥0.7kPa; Precautions: Connection areas must undergo anti-pull-out and anti-shear tests to ensure connection strength meets standards. All Qinglong combination projects undergo third-party testing to ensure safety in use.