Which Risks Require Key Control in Mass UHPC Construction? Analysis of Key Technologies and Response Strategies

In the field of modern architecture, UHPC (Ultra-High Performance Concrete) has become the ideal material for large-scale landmark buildings and complex curtain wall systems thanks to its ultra-high strength, excellent durability, and outstanding formability. However, mass UHPC construction involves multidimensional challenges including material properties, process control, and structural safety; the slightest oversight may trigger risks such as cracking or insufficient strength. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group draws on its full-chain technical experience to explain key construction risk control points and critical response strategies for designers and owners.

I. Core Risk Identification in Mass UHPC Construction

Mass UHPC construction differs from ordinary concrete: its mix proportions (steel fiber content can reach 2%-5%), hydration heat reactions, and shrinkage characteristics all require special control. The primary risk lies in internal temperature-difference cracks caused by concentrated hydration heat: UHPC has a high cementitious material content and releases hydration heat rapidly at an early age; if heat is not dissipated in time, thermal stress with an internal-external temperature difference exceeding 25℃ easily forms, causing through cracks. The second is the contradiction between material flowability and construction workability: during mass pouring, honeycombing and voids easily occur due to insufficient vibration, or structural strength is reduced by uneven steel fiber distribution. In addition, problems such as instability of the formwork support system and insufficient strength growth caused by improper later-stage curing may also affect project quality and safety.

II. Key Technologies and Whole-Process Risk Response Strategies

In response to the above risks, Qinglong Group, drawing on the technical accumulation of its national-level R&D center, has formed a full-chain “material-design-construction-curing” solution:

1. Material Optimization: Controlling Hydration Heat and Shrinkage at the Source
By using “double admixture technology” (fly ash + mineral powder) to replace part of the cement, the hydration heat peak is reduced by up to 30%; customized steel fibers (length 12-20mm, Aspect Ratio=80) ensure uniform dispersion, and combined with a dedicated high-efficiency water reducer, a slump of over 200mm is achieved while controlling water consumption. Laboratory data shows that the optimized UHPC reaches a strength of 80MPa at 3 days and over 150MPa at 28 days, with a drying shrinkage rate below 0.03%.

2. Construction Technique: Combining Layered Pouring with Intelligent Temperature Control
Using the “inclined-plane layered advancement pouring method”, each layer thickness is controlled within 500mm, and high-frequency vibrators (vibration time 15-20s/point) are used to ensure compactness. Embedded temperature sensors are installed simultaneously to monitor internal temperature in real time; when the temperature difference approaches 20℃, a circulating water cooling system is activated, dynamically adjusting the water flow rate to keep the temperature difference within a safe range. This technique was successfully applied in the Nanjing East Road Century Plaza translucent concrete project, achieving zero cracks in 300㎡ of mass UHPC components.

3. Formwork and Support: Dual Safeguards of BIM Simulation and Load Verification
BIM technology is used to simulate the stress state of the formwork during pouring; an 18mm thick multi-layer board + 50×100mm square timber wales + Φ48 steel pipe support system is adopted, with vertical pole spacing ≤600mm and bottom sweep braces 200mm above the ground, ensuring that overall stiffness meets the pouring load requirements (≥25kN/㎡). For special-shaped components, 3D-printed molds are used, with precision error controlled within ±2mm, providing an accurate benchmark for subsequent installation.

4. Curing Regime: “Wet Curing + Temperature Control” Working Together to Enhance Durability
Immediately after pouring, the surface is covered with geotextile and sprayed with water to retain moisture; for the first 7 days, the surface temperature is kept no lower than 20℃ and relative humidity ≥90%; after 7 days, film-sealed curing is adopted, using UHPC's own hydration heat for “heat storage curing” to promote continuous strength growth. For severely cold regions, electric heat-tracing curing can be adopted to ensure winter construction strength meets standards. In an airport project in Malaysia, Qinglong applied this curing scheme to achieve a 28-day strength of 165MPa for UHPC components, meeting the durability requirements of marine environments.

III. Empowering with Industry Experience: From Project Practice to Standard Development

As a contributing unit to the industry standard “General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)”, Qinglong Group has transformed experience from 2000+ projects into a standardized risk control system. For example, in the Dongguan Women and Children's Activity Center GRC/UHPC composite curtain wall project, the three-step strategy of “material trial mixing – process simulation – on-site monitoring” successfully solved the construction challenges of large-span curved UHPC components, winning the Silver Award of the First GRC Building Engineering Innovation Award. For designers and owners, choosing a UHPC manufacturer with full-chain service capabilities (such as Qinglong) not only provides technical solution support, but also relies on its integrated advantages in detailed design, manufacturing, and construction installation to fundamentally reduce project risks.

Risk control in mass UHPC construction is a comprehensive test of material performance, engineering experience, and technological innovation. Guided by the values of “Honesty, Striving, Trust, and Collaboration”, Qinglong Group, through 28 years of technical accumulation and continuous R&D, provides safe and reliable UHPC solutions for high-end building projects, helping to realize the corporate mission of “Creating Beautiful Architecture”. In the future, as UHPC is widely applied in municipal engineering, bridges, real estate, and other sectors, professional, whole-process risk management capability will become the key guarantee of project success.