What Are the Key Points and Technical Specifications for UHPC Construction?

Analysis of Key Points and Technical Specifications for UHPC Construction

As an industry leader with 28 years of experience in detailed design, manufacturing, construction and installation, and after-sales maintenance in the field of UHPC/GRC/GRG/GRP materials, Qinglong Group deeply understands the important position of ultra-high performance concrete (UHPC) in modern architecture. With its ultra-high strength, excellent durability, and outstanding shaping capability, UHPC has become the ideal choice for high-end buildings such as grand theaters, convention and exhibition centers, and commercial complexes. This article systematically analyzes the key points and technical specifications of UHPC construction from the dimensions of material properties, construction techniques, and quality control, providing professional guidance for designers, owners, and contractors.

I. Key Points of UHPC Material Properties and Pre-Construction Preparation

The construction quality of UHPC depends first on precise control of material properties. Compared with ordinary concrete, UHPC features a low water-binder ratio and high fiber content, with an initial flowability of over 250mm but a relatively short setting time, typically beginning initial setting within 1-2 hours. Before construction, it is essential to check the material factory certificates to ensure that core indicators such as compressive strength ≥150MPa and flexural strength ≥25MPa meet the requirements of the industry standard General Technical Conditions for Ultra-High Performance Concrete (UHPC) Non-Load-Bearing Components (Plan No. 2024-0232T-JC). Meanwhile, Qinglong Group recommends that construction units conduct mix proportion verification tests in advance and adjust the admixture dosage according to the on-site ambient temperature (preferably controlled at 5-35℃) to avoid casting quality issues caused by excessively rapid loss of flowability.

II. Technical Specifications for UHPC Casting and Forming Techniques

The casting technique of UHPC directly affects the mechanical properties and surface quality of components. For mold selection, steel molds or high-strength composite molds should be used to ensure their rigidity meets the stress requirements during UHPC hardening shrinkage, and sealing strips should be installed at mold joints to prevent slurry leakage. During casting, vacuum-assisted casting or high-frequency vibration (vibration frequency ≥200Hz) should be used to ensure uniform fiber dispersion with no residual air bubbles—this technique was successfully applied in Qinglong Group's translucent concrete project for the Nanjing East Road Century Plaza renovation, achieving defect-free forming of 300mm thick components. For components with complex shapes, layered casting is recommended, with each layer no more than 500mm thick, and the upper layer must be cast before the lower layer reaches initial setting to avoid cold joints.

III. Key Points of UHPC Curing and Later-Stage Quality Control

Scientific curing is a key link in realizing UHPC performance. After casting, the surface should immediately be covered with a moisturizing film, followed by steam curing after initial setting. The recommended curing regime is: heating rate ≤20℃/h, constant temperature of 80-90℃ for ≥4 hours, and cooling rate ≤15℃/h. Practice at Qinglong Group's production base in Nanning, Guangxi shows that a strict curing regime can increase UHPC early strength by more than 30%. In addition, construction units need to establish a sound quality traceability system with numbered management for each batch of components, focusing on testing indicators such as surface flatness (allowable deviation ≤3mm/2m) and embedded part position deviation (allowable deviation ≤5mm) to ensure compliance with the acceptance standards of Grade II professional contracting qualification for building curtain wall engineering.

IV. Specifications for UHPC Construction Safety and Coordinated Management

UHPC construction also requires attention to safety control and multi-disciplinary coordination. Since UHPC components are heavy in self-weight (typically 20-30kN/m³), special lifting equipment should be used during hoisting, lifting point settings must be verified through structural force calculations, and the lifting angle should not exceed 60°. During installation, 3D laser scanning technology is recommended for positioning calibration to ensure that jointing errors with other materials such as GRC exterior wall panels and glass curtain walls are ≤2mm. As Vice Chairman Unit of the China GRC Association, Qinglong Group emphasizes that a dedicated construction plan must be prepared before construction, operators must be trained on UHPC properties and techniques, and special attention should be paid to fiber dust protection to ensure that the entire construction process complies with national work safety standards.

As a national high-tech enterprise integrating detailed design, manufacturing, construction and installation, and after-sales maintenance, Qinglong Group has always adhered to the philosophy of "meticulousness and the pursuit of excellence," providing global customers with full-chain UHPC/GRC/GRG/GRP solutions. From material R&D to project implementation, Qinglong leverages 58 patented technologies and its experience in participating in the formulation of multiple industry standards to ensure that every project fulfills the mission of "creating beautiful architecture." Whether for domestic landmark buildings or overseas projects in Southeast Asia, Qinglong demonstrates the technical essence of UHPC construction with professional strength, contributing to the high-quality development of the architectural decoration industry.