What Are the Material Requirements for Embedded Parts Used in UHPC Component Installation?

The core material requirements for embedded inserts used in UHPC component installation are corrosion resistance, high strength, and good compatibility with UHPC. Commonly used materials include stainless steel (grades 304/316), galvanized/nickel-plated carbon steel, and weathering steel. Qinglong performs precise material selection based on the service environment (standard, coastal, or industrially corrosive areas) to ensure that embedded inserts work in coordination with the components, achieving a service life of ≥50 years and meeting various building installation needs.

I. Core Material Types and Applicable Scenarios

Embedded inserts of different materials suit different environments and require targeted selection. Stainless steel 304: contains 18% chromium and 8% nickel, with good corrosion resistance, suitable for ordinary indoor and outdoor environments (non-coastal, non-industrial areas). Qinglong used 304 stainless steel embedded inserts for the indoor components of the Shenzhen Yirui Biotechnology Building, which offer moderate cost and stable performance. Stainless steel 316: molybdenum is added to the 304 composition, greatly improving resistance to chloride ion corrosion, suitable for coastal and salt-spray environments. Qinglong used 316 stainless steel in coastal projects such as Hainan and Algeria, with no rust after 5000h of salt-spray corrosion resistance. Galvanized/nickel-plated carbon steel: a carbon steel substrate with zinc plating (plating thickness ≥85μm) or nickel plating, at a lower cost, suitable for dry indoor environments. Qinglong used galvanized carbon steel embedded inserts for indoor decorative moldings, which require proper moisture protection. Weathering steel: contains alloying elements such as copper, chromium, and nickel, with strong atmospheric corrosion resistance, suitable for large outdoor components (such as sculptures and landscape features). Qinglong used weathering steel embedded inserts for the Shanghai Astronomy Museum public art project, blending well with the natural environment.

II. Key Technical Requirements for Materials

Embedded insert materials must meet multiple requirements including strength, compatibility, and workability. Strength requirements: tensile strength ≥500MPa and yield strength ≥300MPa, ensuring the inserts can bear loads such as component self-weight, wind load, and seismic forces. Qinglong's 316 stainless steel embedded inserts achieve a tensile strength of 620MPa, far exceeding the requirements. Compatibility requirements: the material must not react chemically with UHPC or affect the strength development of the components. Qinglong strictly prohibits the use of insert materials containing chlorine, sulfur, or other harmful elements to avoid corroding the cement matrix. Workability: good welding and drilling properties are required to facilitate forming with UHPC and connection to the main structure. Qinglong's stainless steel inserts are welded by argon arc welding, with weld strength ≥ the strength of the base material. Durability requirements: the service life of embedded inserts must match that of the UHPC components (≥50 years), and inserts in coastal areas require additional anti-corrosion coatings (such as fluorocarbon coatings). Qinglong applies fluorocarbon coatings to 316 stainless steel embedded inserts in coastal projects for double corrosion protection.

III. Qinglong's Embedded Insert Material Control and Project Applications

Qinglong has established a strict material control process for embedded inserts to ensure reliable quality. Material selection process: material selection is carried out based on the project environment (humidity, corrosive media, and service life), a material selection report is issued, and procurement proceeds after confirmation by the client and the designer. Quality inspection: before entering the site, inserts are tested for material composition (spectral analysis), mechanical properties (tensile testing), and anti-corrosion coating thickness, and may only be used after passing inspection; Qinglong's material inspection pass rate reaches 100%. Production process: embedded inserts are formed integrally with UHPC, with anchor bars (length ≥100mm) or anchor plates reserved to enhance the bond with UHPC. Qinglong uses threaded rebar for anchor bars, with bond strength ≥3.0MPa. Project cases: curtain wall components of the Shenzhen Pingshan High-tech Zone Comprehensive Service Center use 304 stainless steel embedded inserts, and the Hainan Changying Global 100 Fantasy Park uses 316 stainless steel embedded inserts; both have been verified through more than 5 years of use with no corrosion or loosening.