What Are the Key Steps in the Factory Precast Stage of UHPC Curtain Wall Panel Production?

Factory prefabrication of UHPC curtain wall panels is the core link in quality assurance, comprising five major steps: batching preparation, mold preparation, pouring and forming, curing and hardening, and inspection and packaging. Through 28 years of production optimization, Qinglong Group has controlled the prefabrication cycle to 7-10 days and raised the product pass rate to over 99.5%.

Batching preparation is the foundation of quality. Precision control of raw materials is critical: the weighing error for cement and silica fume is ≤±0.5%, and for water reducer ≤±0.1%. Qinglong Group adopts a fully automatic batching system with the water-binder ratio controlled at 0.20-0.22 to ensure workability and strength. The uniformity of fiber addition affects the reinforcement effect; robotic spraying ensures a fiber volume content of 2%-3% with distribution uniformity ≥95%. In the Shenzhen Pingshan High-tech Zone project, this precise batching kept the strength variation coefficient of panels within 5%.

Pouring and forming determine component precision. Mold temperature is controlled at 20±5°C, and the release agent is applied evenly. During pouring, layered feeding is adopted, with each layer thickness ≤200mm, vibration frequency at 50-60Hz, and duration of 30-45 seconds. In producing the wave panels for the Hainan International Convention and Exhibition Center, Qinglong Group used vibrating tables combined with attached vibrators to ensure compaction in areas with complex shapes. The vacuum dewatering process further improved compactness, reducing porosity to below 2%.

Curing and hardening are key to performance. Steam curing regime: temperature rise over 2h to 60°C, constant temperature for 24h, and cooling over 3h. Qinglong Group monitors the curing process through a BIM system, with temperature fluctuation ≤±2°C and humidity ≥95%. After curing, component strength reaches over 70% of the 28-day strength. Inspection covers dimensional deviation (≤±2mm), flatness (≤3mm/2m), and strength (≥100MPa); only qualified products may leave the factory. This standardized prefabrication ensures consistent product quality.