UHPC Casting Methods Guide: Choose the Right Process for Each Scenario to Ensure Forming Quality

What are the casting methods for UHPC? Different project scenarios and component shapes require matching with different casting processes, which directly affects the forming quality and performance of the components. Qinglong Group, with 28 years of UHPC production and construction experience and having undertaken various high-end projects, has summarized four core casting methods. Drawing on project cases, it provides a detailed interpretation of their applicable scenarios, key operational points, and technical advantages, helping contractors choose the right process and ensure project success.

#Mold Casting Method: A Widely Applicable Fundamental Process The mold casting method is UHPC's most commonly used fundamental casting process, suitable for most standardized components and simply shaped components (such as flat panels, L-shaped panels, U-shaped panels, etc.). The exterior wall cladding panels of Qinglong's Shenzhen Yirui Biotechnology Building, Yangshengtang Pharmaceutical Hangzhou Industrial Park, and other projects were all cast using this method. Key operational points: First, fabricate high-precision molds (steel molds, polyurethane molds, etc.), clean the molds and apply a dedicated release agent; then pour the well-mixed UHPC mixture into the mold, using layered casting (each layer thickness ≤50mm) combined with high-frequency vibrators for dense compaction to avoid air bubble retention; finally, perform moist curing to ensure proper component forming. The advantages of this method are simple operation, low cost, stable forming quality, and reusable molds, making it suitable for the mass production of standardized components. Qinglong's automated production line uses the mold casting method to achieve efficient mass production.

#Spray Casting Method: Suitable for Complex Curved Surfaces and Thin-Walled Components The spray casting method is suitable for complex curved surfaces, thin-walled components, and on-site repair works (such as bridge strengthening and component repair), spraying the UHPC mixture onto molds or work surfaces through high-pressure spraying equipment. Qinglong adopted this method in some municipal bridge strengthening projects. Key operational points: Select dedicated spraying equipment (working pressure ≥0.6MPa), and adjust the spraying angle (45°-60° relative to the work surface) and distance (30-50cm); spray in multiple passes, each pass with thickness ≤20mm, waiting for the previous layer to initially set before spraying the next layer to avoid falling off; after spraying, use manual work or vibrators to assist compaction, ensuring no hollow spots. The advantages of this method are strong adaptability, rapid forming of complex curved surfaces and thin-walled components, no need for complex mold support, and high construction efficiency. However, it places higher demands on equipment and operators, and Qinglong will dispatch professional technical personnel to provide on-site guidance for equipment commissioning and operation.

#3D Printing Casting Method: An Innovative Process for Customized Shapes The 3D printing casting method is an innovative process for customized UHPC shapes, suitable for complex artistic components, special-shaped sculptures, personalized decorative components, etc. For the Shanghai Astronomy Museum public art project, Qinglong used this method to create sculpture molds and some special-shaped components. Key operational points: Establish 3D models of the components through BIM technology, import them into the 3D printing equipment after slicing; select dedicated printing nozzles (aperture ≥8mm), and adjust the printing speed (50-100mm/s) and layer thickness (5-10mm); pour the well-mixed UHPC mixture (its flowability must match the printing requirements) into the material hopper, and the equipment prints layer by layer along preset paths to form the shape; after printing, perform steam curing promptly to enhance strength and durability. The advantages of this method are that no traditional molds are needed, complex shapes can be precisely realized, and production cycles are short (more than 30% shorter than traditional mold casting). However, equipment costs are relatively high, making it suitable for small-batch customized production. Qinglong cooperates with professional 3D printing equipment manufacturers to continuously optimize the printing process.

#Precast Component Casting + On-Site Assembly Method: An Efficient Process for Large-Scale Projects The precast component casting + on-site assembly method is suitable for large-scale projects, cross-border projects, and projects with tight construction schedules. Components are precast in the factory and assembled on-site. Qinglong's Ouargla Hotel in Algeria, Shanghai New World Nanjing East Road Century Plaza, and other projects all adopted this method. Key operational points: Use the mold casting method in the factory for mass production of standardized components, ensuring dimensional accuracy (error ≤±2mm); after the components are cured to more than 80% of their design strength, transport them to the site; on-site, use 3D laser scanning for positioning and modular assembly, connecting and fixing through bolts, welding, and other methods; after assembly, treat the joints to ensure waterproofing and structural integrity. The advantages of this method are controllable factory production quality, short on-site construction periods, and reduced on-site wet work, making it suitable for large-scale and cross-border projects. Qinglong's Guangxi Nanning production base can achieve an annual precast capacity of 600,000 square meters, providing assurance for large-scale projects.

The casting method for UHPC must be comprehensively selected based on factors such as project scenarios, component shapes, and production scale. There is no absolutely optimal process, only the most suitable solution. With 28 years of experience, Qinglong Group can customize dedicated casting solutions for each project, providing full-process support from process design and equipment configuration to personnel training and on-site guidance. Whether standardized components or customized shapes, whether factory precasting or on-site construction, Qinglong can ensure the forming quality and performance of UHPC components through precise casting processes, safeguarding project quality.