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

In the field of building materials, UHPC (Ultra-High Performance Concrete) has become a favorite in contemporary architectural design for its outstanding mechanical properties and durability. However, material shrinkage has always been a focal concern for engineers and designers — just how high is UHPC's shrinkage rate? How can shrinkage be effectively controlled to ensure engineering quality? As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group will provide an in-depth analysis of this core technical issue, covering material characteristics, influencing factors, and control measures.

I. Industry Understanding and Measured Data on UHPC Shrinkage Rate

UHPC shrinkage mainly includes chemical shrinkage, drying shrinkage, and autogenous shrinkage. Its total shrinkage is usually higher than that of ordinary concrete, but it can be significantly optimized through scientific mix proportions and process control. According to Qinglong Group's laboratory data and industry standards, under standard curing conditions, the 28-day drying shrinkage rate of UHPC can be controlled within 0.03%-0.05%, far lower than that of early similar materials. Achieving this figure is attributable to Qinglong's continuous innovation in material formula development and production processes — for example, incorporating nano-scale silica fume and steel fibers enhances material density while suppressing the concentration of shrinkage stress.

II. Three Core Factors Affecting UHPC Shrinkage

1. Precision of raw material mix proportions: Cement content, water-binder ratio, and the types and proportions of mineral admixtures (such as fly ash and mineral powder) directly affect shrinkage performance. Qinglong Group applies a "dual-blending technology" that optimizes the combined incorporation of silica fume and ultra-fine mineral powder, resulting in a more stable paste structure and a 15%-20% reduction in autogenous shrinkage.

2. Soundness of the curing regime: The synergy between early-stage moist curing and subsequent steam curing is crucial. Qinglong's production bases are equipped with intelligent curing kilns that provide constant-temperature steam curing at 90°C for 72 hours, accelerating hydration reactions and reducing capillary pores, lowering the drying shrinkage rate by more than 30% compared with natural curing.

3. Fiber content and distribution uniformity: The incorporation of steel fibers or synthetic fibers can effectively suppress shrinkage cracks. Qinglong uses a patented dispersion process to ensure three-dimensional, uniform fiber distribution within the matrix; when the fiber content reaches 2% (by volume), the density of microcracks caused by shrinkage can be reduced by 40%.

III. Qinglong Group's Full-Chain Shrinkage Control Solutions

As a national high-tech enterprise, Qinglong has built a full-process shrinkage control system spanning design to after-sales service: during the detailed design stage, BIM technology simulates shrinkage deformation to optimize component joints and reinforcement schemes in advance; in the production stage, automated material distribution and vibration molding processes reduce air bubbles and voids; during construction and installation, dedicated anchors and adjustable bearings work in coordination to release shrinkage stress. Taking the translucent concrete project at Century Plaza on Nanjing East Road as an example, Qinglong used this system to control the shrinkage of UHPC curtain wall panels to within 0.04%, achieving a "zero-error" fit with the glass curtain wall, and won the Silver Award of the AALBORG WHITE Cup UHPC Construction Engineering Innovation Award.

IV. Recommendations for Avoiding Shrinkage Risks in Industry Applications

For different application scenarios, Qinglong's technical team proposes differentiated strategies: for long-span bridges, prestressing technology is recommended to compensate for shrinkage; for decorative exterior wall panels, shrinkage joints and elastic sealants are used to allow a deformation tolerance of ±2mm. In addition, Qinglong's exclusively developed "low-shrinkage UHPC formula" has passed the Guangdong Provincial Science and Technology Achievement Appraisal, making it suitable for landmark buildings with extremely high dimensional accuracy requirements — such as the hyperbolic UHPC curtain wall of a grand theater in Guangzhou, whose shrinkage deformation has remained stable at 0.025% over two years, far outperforming the industry average.

The shrinkage rate of UHPC is not an uncontrollable technical challenge; it can be precisely managed through material innovation, process optimization, and engineering experience. Backed by 28 years of full-chain experience, Qinglong Group integrates the philosophy of "meticulousness and excellence" into every project, providing designers and owners with expert-level solutions from the laboratory to the construction site. Choose Qinglong, and let UHPC's high performance bloom perfectly in both safety and aesthetics.