UHPC Construction: Key Points and Technical Specifications Explained

In the field of contemporary architecture, UHPC (Ultra-High Performance Concrete) is becoming the material of choice for landmark buildings and high-end projects thanks to its outstanding mechanical properties and design expressiveness. However, UHPC construction is a systematic undertaking whose technical barriers and process requirements far exceed those of traditional concrete. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP, Qinglong Group will draw on engineering practice to provide an in-depth analysis of the key points and technical specifications of UHPC construction, offering professional solutions for designers and owners.

I. Material Property Control: The Basic Prerequisite for UHPC Construction

The unique nature of UHPC materials means that strict performance verification must be carried out before construction. Its ultra-high strength (compressive strength up to 150-200MPa), low water-binder ratio (typically ≤0.2), and fiber reinforcement system place exacting demands on raw material proportioning and mixing processes. During the detailed design stage, Qinglong Group employs BIM technology to simulate material flow characteristics, and through practice at production bases with a capacity of 600,000 square meters, has developed the "three-stage mixing method": first dry-mix cement, silica fume, and other cementitious materials for 3 minutes, then add steel fibers and mix at low speed for 2 minutes, and finally add admixtures and mix at high speed until uniform, ensuring fiber dispersion of over 95%. Construction units should pay particular attention to the fact that the workability window of UHPC mixtures is only 45-60 minutes, and the retarder dosage must be dynamically adjusted according to the ambient construction temperature—this is also the core experience behind Qinglong's millimeter-level precision installation in the translucent concrete project at Century Plaza on Nanjing East Road.

II. Formwork Engineering Specifications: The Key Factor Determining UHPC Forming Quality

Unlike traditional concrete, UHPC places extremely high demands on formwork stiffness, sealing, and surface precision. Through participation in drafting the industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)," Qinglong's technical team has established three key indicators that formwork engineering must meet: load-bearing capacity of no less than 25kN/m², joint sealing deviation ≤0.5mm, and surface flatness error ≤2mm/2m. In the Dongguan Women and Children's Activity Center project, custom steel formwork combined with a PVC inner lining process achieved one-time forming of double-curved UHPC components with a mirror-like surface finish. Note in particular that formwork removal requires a curing age of ≥7 days and strength reaching 85% of the design value; after removal, sealed curing should be carried out immediately—this is the key measure to prevent early cracking.

III. Key Construction Process Points: Full-Process Control from Casting to Curing

UHPC construction requires a full-process quality traceability system. During the casting stage, high-position low-speed distribution should be adopted, with free-fall height controlled within 1.5 meters; complex-shaped components require vibrating pokers (frequency ≥150Hz) for assisted compaction, while avoiding over-vibration that could cause fiber breakage. Qinglong innovatively applied "vacuum-assisted casting technology" in overseas projects, increasing component density by 12% and improving impermeability by one grade. For curing, the "gradient temperature control method" is implemented: maintain an ambient temperature of ≥20°C within 24 hours after casting, then apply steam curing (temperature ≤60°C) for the following 72 hours, and finally natural curing until the 28-day age. This process increased the 28-day strength of UHPC components by 20% compared to standard curing in a landmark project in Malaysia.

IV. Engineering Acceptance Standards: Building a UHPC Quality Assurance System

As a vice-chairman unit of the China GRC Association, Qinglong Group emphasizes that UHPC construction acceptance must follow "dual standards": meeting both the basic requirements of the "Code for Acceptance of Construction Quality of Concrete Structures" GB50204 and UHPC-specific standards. Key acceptance indicators include: surface air bubble area ≤0.2%, edge and corner defect depth ≤5mm, and a 100% compliance rate for the strength of test blocks cured under the same conditions. In a commercial complex project in Guangzhou, the introduction of RFID chip implantation technology achieved full life-cycle traceability of each UHPC component from production to installation—an innovative practice that has been incorporated into Qinglong's corporate standards.

The technical complexity of UHPC construction requires participants to adopt systematic thinking spanning materials, design, and construction. With 28 years of full-chain experience and integrated services from detailed design to after-sales maintenance, Qinglong Group has successfully helped over 500 projects at home and abroad achieve flawless UHPC implementation. In the future, with the implementation of standards such as "Ultra-High Performance Concrete (UHPC) Exterior Wall Panels," the industry will embrace more standardized development opportunities. Choosing a UHPC manufacturer with proven technical expertise and engineering strength is key to ensuring project success—this is both Qinglong's responsibility as a national "Specialized, Refined, Distinctive, and Innovative" enterprise and the practice of its mission to "create beautiful architecture."