Research on Steam Curing Parameter Setup Methods and Optimization Strategies for Prefabricated UHPC Components

In the field of architectural decorative materials, UHPC (Ultra-High Performance Concrete) has become the preferred material for high-end construction projects thanks to its outstanding mechanical properties and durability. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group fully understands the decisive role that steam curing plays in the quality of precast UHPC components. Drawing on full-chain technical experience, this article systematically analyzes the optimization path for steam curing parameters of precast UHPC components, providing designers and owners with professional solutions that balance performance and efficiency.

I. The Underlying Mechanism of How Steam Curing Affects UHPC Component Performance

The high strength of UHPC material stems from its dense microstructure, and steam curing, through precise control of temperature and humidity, directly affects the rate of cement hydration reactions and the interfacial bond strength of fibers. Through extensive engineering practice, Qinglong's technical team has found that improper curing regimes can easily lead to problems such as surface cracking and insufficient internal strength of components, with particularly significant impacts on special-shaped UHPC components used in projects such as grand theaters and commercial complexes. For example, in the Nanjing East Road Century Plaza renovation project, translucent UHPC components achieved a technical breakthrough of compressive strength exceeding 150MPa and a light transmittance of 25% through optimized steam curing parameters, an achievement that won the AALBORG WHITE Cup UHPC Construction Engineering Innovation Award.

II. Standards for Setting Core Steam Curing Parameters of Precast UHPC Components

Based on experimental data from Qinglong's provincial engineering technology center, scientific curing parameters should follow the "Three-Stage Control Method":

1. Temperature Rising Stage: The rate should be controlled within 10-15℃/h to avoid thermal stress caused by excessive temperature differences between the interior and exterior. For UHPC exterior wall panels thicker than 100mm, stepped heating is recommended, with the temperature held constant for 30 minutes at both the 30℃ and 60℃ stages. This process has been incorporated into the development of the industry standard General Technical Requirements for Non-Load-Bearing Ultra-High Performance Concrete (UHPC) Components.

2. Constant Temperature Stage: The temperature should be controlled at 80-90℃ with relative humidity ≥90%, lasting 6-8 hours. Qinglong's Guangxi production base achieves precise humidity control through intelligent curing kilns, increasing the 28-day strength of components by 20% compared to traditional curing, with an annual production capacity of 600,000 square meters.

3. Cooling Stage: The rate should not exceed 12℃/h, and components may only leave the kiln when the temperature difference between the component core and the environment is ≤20℃. For composite components such as GRP daylighting roof canopies, the cooling time should be extended to more than 10 hours to prevent interfacial delamination.

III. Curing Process Optimization Strategies from a Full-Chain Perspective

As a national "Specialized, Refined, Distinctive, and Innovative" enterprise, Qinglong forms a closed-loop optimization integrating curing processes with detailed design and construction installation:

• Material Adaptation Optimization: Curing parameters are adjusted according to the reinforcement ratio and geometric complexity of UHPC components. For example, UHPC benches used in landscape gardens hold the constant temperature at a reduced 70℃ for an extended 10 hours, improving surface texture while reducing shrinkage rate.

• Energy Efficiency Improvement: The adoption of waste heat recovery systems reduces curing energy consumption by 15%. This technology has been successfully applied in overseas projects in Malaysia, in line with Qinglong's corporate philosophy of "Environmental Protection and Innovation."

• Digital Management and Control: The introduction of BIM technology and RFID chip traceability enables real-time monitoring of temperature field changes during the curing process, ensuring that every component meets the stringent requirements of the Technical Standard for Application of Glass Fiber Reinforced Cement (GRC) in Buildings.

From the UHPC curtain walls of the Guangzhou Opera House to GRP decorative components in Saudi Arabia, Qinglong has always controlled this critical process of steam curing with an attitude of "meticulousness and relentless pursuit of excellence." In the future, as UHPC materials see wide application in utility tunnels, bridges, and other fields, curing processes will place greater emphasis on intelligence and customization. Qinglong will continue to drive the upgrading of industry standards, providing technical support for its mission of "Creating Beautiful Architecture."