What Are the Casting Methods for UHPC? Three Core Methods and Scenario Adaptation Guide

The casting method for UHPC must be flexibly selected according to the component's shape, thickness, and dimensions. The core methods include spray casting, mold casting, and pump casting, each with its own applicable scenarios and process requirements. Drawing on 28 years of project experience, Qinglong has summarized the operational key points and scenario adaptations of different casting methods to ensure UHPC components are cast densely and formed beautifully.

Spray Casting Method: Suitable for thin-walled, special-shaped, and openwork components. Spray casting uses high-pressure air to spray the UHPC mixture into the mold. Its core advantages are the ability to fill complex cavities and achieve dense casting of thin-walled components (thickness ≥15mm), making it suitable for special-shaped components such as double-curved panels, openwork carved panels, and sculptures. Qinglong's spray casting equipment operates at a working pressure of 0.3-0.5MPa with a spray distance of 300-500mm, adopting a 'layered spraying + manual auxiliary vibration' process, with each spray layer 10-15mm thick to avoid hollowing and air bubbles caused by spraying too thick at one time. The UHPC sculptures over 3 meters tall at the Shanghai Astronomy Museum were produced using the spray casting method, perfectly achieving dense forming of complex artistic shapes; the 50mm-thick UHPC openwork panels of the Ouargla Hotel in Algeria ensured the forming precision and density of the openwork areas through spray casting.

Mold Casting Method: Suitable for thick panels and standardized components. Mold casting involves pouring the well-mixed UHPC mixture into the mold and forming it after vibration compaction. It is suitable for components such as flat panels, thick panels (thickness ≥50mm), and standardized moldings, with relatively simple operation and high production efficiency. Qinglong's mold casting adopts a 'pumped material distribution + high-frequency vibration' process: the mixture is conveyed into the mold via a concrete pump for uniform distribution and to avoid accumulation; a high-frequency vibrator (frequency ≥100Hz) is used for vibration, with a vibration time of 10-15 seconds per point and spacing ≤200mm, ensuring the mixture is dense and free of voids. The UHPC flat exterior wall panels (thickness 30mm) of the Yangshengtang Pharmaceutical Hangzhou Industrial Park were produced using the mold casting method, combined with automated molds, achieving a production efficiency of 100 square meters per day and a panel flatness deviation of ≤±1.5mm/m.

Pump Casting Method: Suitable for large-volume and long-distance casting. Pump casting uses a concrete pump to convey the UHPC mixture to the casting location, suitable for large-volume components, long-distance casting (conveying distance ≤50 meters), and high-altitude casting. Its core advantages are convenient construction and high efficiency. Qinglong's pump casting equipment uses a high-pressure concrete pump (working pressure ≥20MPa) with a conveying pipe diameter of ≥125mm to avoid pipe blockage caused by an overly small pipe diameter; the mixture must have a spread of ≥800mm to ensure pumping flowability; casting must be carried out continuously, with intervals ≤30 minutes, to avoid cold joints. For the UHPC bridge deck pavement project of a municipal bridge, Qinglong adopted the pump casting method, completing 1,000 square meters of bridge deck casting in one operation, with construction efficiency 30% higher than mold casting and bridge deck flatness meeting the standard.

Casting Method Selection and Qinglong Technical Support. The core principles for selecting a casting method: choose spray casting for thin-walled and special-shaped components, mold casting for standardized and thick panel components, and pump casting for large-volume and long-distance casting. Based on the project's component types, dimensions, and construction conditions, Qinglong can provide customized casting solutions, equipped with professional equipment and a technical team to guide casting operations throughout the process and ensure casting quality. Meanwhile, regardless of the method used, the casting temperature must be controlled (5℃-35℃), casting in extreme environments must be avoided, and after casting, the components should be promptly covered to retain moisture in preparation for subsequent curing.

UHPC casting methods should 'adapt to local conditions.' Qinglong's three core casting methods and scenario adaptation guide can meet the needs of different projects. Through professional casting solutions, advanced equipment, and strict process control, Qinglong ensures that every UHPC component is cast densely and formed precisely, laying the foundation for high-quality project delivery.