Is the Shrinkage Rate of UHPC High? Analysis of Influencing Factors and Improvement Measures

In the field of building materials, UHPC (Ultra-High Performance Concrete) has become a star material of modern architecture thanks to its outstanding mechanical properties and durability, but material shrinkage remains a focal point of industry concern. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group leverages its full-chain technical experience to provide an in-depth analysis of the factors influencing UHPC shrinkage rate and systematic improvement solutions, offering professional solutions for designers and owners.

Scientific Understanding of UHPC Shrinkage Rate: Material Properties and Engineering Challenges

UHPC shrinkage mainly includes chemical shrinkage, drying shrinkage, and autogenous shrinkage, and its shrinkage rate is typically higher than that of ordinary concrete. Data shows that the early autogenous shrinkage of unoptimized UHPC can reach 500-800με, with a drying shrinkage rate of approximately 0.04%-0.06%. If improperly controlled, this can easily lead to component cracking, affecting structural safety and aesthetics. Through more than 2,000 sets of comparative tests, Qinglong Group's laboratory found that raw material proportions, curing processes, and construction environments are the three core variables affecting shrinkage, providing a scientific basis for targeted improvement.

Multi-Dimensional Analysis: Key Factors Affecting UHPC Shrinkage

The raw material system plays a significant role in regulating shrinkage. The mineral composition of cementitious materials, silica fume content, and fiber type directly affect the hydration process: highly active silica fume can enhance strength, but excessive amounts will aggravate autogenous shrinkage; the combined addition of steel fibers and PVA fibers can inhibit shrinkage cracks through a bridging effect. When the fiber volume content is controlled at 2.0%-2.5% in Qinglong's patented formula, the shrinkage rate can be reduced by more than 30%.

The curing regime is the "last mile" of shrinkage control. Under traditional natural curing conditions, rapid moisture evaporation in UHPC easily triggers drying shrinkage. Qinglong's self-developed "gradient moist-heat curing process" uses 60℃ steam curing combined with a 90% humidity environment, raising early strength by 40% while keeping the 28-day drying shrinkage rate within 0.035%. This technology has been applied in benchmark projects such as the Century Plaza renovation on Nanjing East Road.

Full-Chain Improvement Solutions: Practical Achievements from Qinglong's 28 Years of Technical Accumulation

In terms of material formula optimization, Qinglong adopts "dual-admixture technology" — the synergistic addition of nano calcium carbonate and ultra-fine mineral powder refines the pore structure through the micro-aggregate filling effect, combined with a self-developed retarding admixture to reduce the hydration heat peak by 25% and effectively mitigate thermal shrinkage. This technology has passed the Guangdong Province Scientific and Technological Achievement Appraisal and was applied to the UHPC curtain wall panels of the Dongguan Women and Children's Activity Center project, achieving a record of zero shrinkage cracks.

In engineering applications, Qinglong innovatively adopts the "pre-tensioning + post-cast strip" construction method. When installing large UHPC components, a pre-compression stress of 0.3MPa is applied through prestressed tendons to offset shrinkage tension, combined with a segmentally cast post-cast strip design, successfully solving the shrinkage challenge of an 80-meter ultra-long UHPC sunshade panel in a commercial complex in Shenzhen. This full-process control solution has enabled Qinglong's UHPC products to withstand the test of tropical climates in overseas projects in Malaysia, Australia, and other countries.

As a National High-Tech Enterprise and a participant in setting UHPC industry standards, Qinglong Group has always upheld the mission of "creating aesthetically beautiful architecture," integrating material shrinkage control technology into its full-chain services spanning detailed design, manufacturing, and construction installation. From the UHPC curtain wall of Terminal 3 at Guangzhou Baiyun Airport to the shaped GRG ceiling of the Bund Finance Centre in Shanghai, Qinglong's 28 years of professional experience prove that through scientific material design and refined construction, UHPC shrinkage is fully controllable, and its application value in the high-end building sector will continue to be unleashed. Choosing Qinglong, a manufacturer with full-chain service capabilities, is undoubtedly a wise choice for achieving the unity of architectural aesthetics and structural safety.