Common Types of UHPC Casting Methods and Key Construction Points Explained

In contemporary architecture, UHPC (Ultra-High Performance Concrete), with its outstanding mechanical properties and artistic expressiveness, is becoming a key material for shaping urban landmarks. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group has always upheld the mission of “creating aesthetically beautiful architecture,” accumulating rich experience across the entire chain from detailed design and manufacturing to construction and installation. This article systematically analyzes common UHPC casting methods and their key construction points, providing a professional reference for designers and owners.

I. UHPC Casting Technology System: From Process Characteristics to Application Scenarios

The selection of UHPC casting methods requires comprehensive consideration of component geometry, strength requirements, and the construction environment. Currently, mainstream industry technologies can be divided into three major categories:

1. Conventional Casting Process: An Efficient Solution for Standardized Components
Suitable for regular components such as flat wall panels and linear decorative profiles, using horizontal layered casting or vertical continuous casting. Qinglong Group's Nanning production base is equipped with an automated material distribution system that ensures concrete density through precise control of casting speed (recommended ≤0.5m³/min) and vibration frequency (200-300 times/minute). Key points include: formwork must have a load-bearing capacity of ≥50MPa, interface treatment before casting (such as applying a dedicated release agent), and secondary vibration before initial setting to eliminate air bubbles.

2. Spray Casting Technology: A Powerful Tool for Forming Complex Shapes
For irregular components such as double-curved curtain walls and openwork reliefs, Qinglong adopts a high-pressure spray casting process, spraying the UHPC mixture evenly into molds through dedicated spray guns (working pressure 3-5MPa). This process achieves precise forming with a minimum curvature radius of ≤300mm. In the Nanjing East Road Century Plaza renovation project, the Qinglong team successfully created a translucent concrete curtain wall using this technology, achieving a perfect fusion of structure and art. During construction, the spray angle (60°-90° relative to the working surface) and layer thickness (≤50mm per pass) must be controlled, combined with a high-frequency vibrator to eliminate interface air bubbles.

3. Precast Assembly Casting: Quality Assurance for Industrialized Construction
For large components (such as sunshades with spans ≥6m), Qinglong implements a factory precast casting model, using BIM technology for parametric mold design combined with steam curing (48 hours at a constant 80℃) to ensure strength meets standards. In the Dongguan Women and Children's Activity Center project, the precast assembly process achieved precise joining of GRC-UHPC composite components, with installation errors controlled within ±2mm. Precast casting requires special attention to rebar cage positioning accuracy (deviation ≤3mm) and anti-corrosion treatment of embedded connectors.

II. Full-Process Construction Control: Key Points from Qinglong's 28 Years of Experience

As a National High-Tech Enterprise, Qinglong has established a standardized control system covering “design-production-installation”:

1. Material Mix Ratio Optimization
A dual-admixture system of quartz sand and steel fiber is adopted, with steel fiber volume content controlled at 2%-3% and the water-binder ratio strictly ≤0.2, ensuring compressive strength ≥150MPa. At the Guangxi production base, a fully automatic mixing system achieves raw material metering errors of ≤±1%.

2. Formwork Engineering Technology
Customized steel molds or high-density resin formwork are selected, with surface finish reaching Ra1.6μm, and sealing rubber strips at joints to prevent slurry leakage. In view of UHPC's early shrinkage characteristics, formwork turnover is controlled at ≤3 times/week to prevent formwork deformation from affecting component precision.

3. Curing Process Innovation
Based on project requirements, a combined “steam curing + natural curing” scheme is adopted. During the steam curing phase, the heating rate is ≤20℃/h and the cooling rate ≤15℃/h to ensure full hydration reactions. Qinglong's self-developed curing kiln system achieves a temperature control accuracy of ±1℃.

III. Industry Applications and Development Trends
UHPC casting technology is developing toward intelligence and green practices. The industry standard “General Technical Conditions for Ultra-High Performance Concrete (UHPC) Non-Load-Bearing Components,” which Qinglong participated in formulating, will further standardize construction processes. From real estate curtain walls to municipal bridges, and from domestic landmarks to overseas projects in Southeast Asia, Qinglong has always maintained an attitude of “meticulousness and the pursuit of excellence,” providing customers with full-chain services from detailed design to after-sales maintenance. Choosing a professional UHPC manufacturer is not only a guarantee of engineering quality, but also a long-term investment in architectural aesthetics and structural safety.