Is UHPC Shrinkage Rate High? Shrinkage Control Technology and Engineering Solutions for Ultra-High Performance Concrete

Shrinkage cracking of concrete is a common challenge in the engineering field, and the shrinkage rate, as a key indicator, directly affects the construction quality and long-term stability of materials. For UHPC (Ultra-High Performance Concrete), its shrinkage characteristics have always been a focus of industry attention. Qinglong Group, with 28 years of deep expertise in the field of new building materials, has built a comprehensive UHPC shrinkage control system through independent R&D and technological innovation, effectively reducing the material's shrinkage rate and providing stable and reliable solutions for various projects.

I. Types of UHPC Shrinkage and Control Difficulties The shrinkage of UHPC mainly includes hydration heat shrinkage, drying shrinkage, and autogenous shrinkage, among which autogenous shrinkage caused by the low water-binder ratio is the key control focus. Because UHPC adopts highly active powders and a low water-binder ratio design, water is consumed quickly during the hydration reaction and internal humidity tends to drop rapidly; without proper control, autogenous shrinkage cracks are likely to occur. Through long-term research, Qinglong Group found that the shrinkage characteristics of UHPC are closely related to the material mix proportion and curing process, and traditional concrete shrinkage control methods are difficult to apply directly. To address this, relying on its provincial-level R&D center, Qinglong carried out targeted technical research and formed a comprehensive control solution integrating material formula optimization, admixture application, and curing process innovation.

II. Core Technical Means of Qinglong's UHPC Shrinkage Control Qinglong Group effectively controls the UHPC shrinkage rate through three core technologies: first, optimizing the mix proportion design by selecting low-shrinkage active admixtures combined with specialized aggregate gradation to reduce the heat release rate and shrinkage stress of the hydration reaction; second, applying composite admixtures, through the synergy of highly efficient retarders and expansive agents, to regulate the hydration process and compensate for autogenous shrinkage, keeping the autogenous shrinkage rate of UHPC within 200με, far below the industry average; third, innovating the curing process by developing a dual curing system of "steam curing + moist curing", which precisely controls curing temperature and humidity to promote the full progress of hydration reactions and reduce drying shrinkage. In addition, Qinglong has introduced fiber reinforcement technology in production, using the bridging effect of alkali-resistant glass fibers or steel fibers to suppress the formation and propagation of shrinkage cracks, further improving the material's volume stability.

III. Verification of Shrinkage Control Results in Engineering Practice Numerous benchmark projects of Qinglong Group have witnessed the practical effects of its shrinkage control technology. In the renovation project of Shanghai New World Century Plaza on Nanjing East Road, the UHPC wood-grain translucent panels with a maximum size of 3245*3530mm, adopting Qinglong's shrinkage control technology, showed no shrinkage cracks during the forming of complex shapes and large dimensions and have remained stable in long-term performance after installation; the 12,000-square-meter UHPC exterior wall cladding panels of the Yangshengtang Pharmaceutical Hangzhou Industrial Park, covering flat panels, L-shaped panels, and other types, have shown no shrinkage cracking, deformation, or other problems after years of use, maintaining the integrity of the building facade. As a national high-tech enterprise, Qinglong has established a comprehensive shrinkage performance testing system, and every batch of products undergoes specialized shrinkage rate testing to ensure that shrinkage indicators meet engineering requirements. For large components and products with complex shapes, Qinglong also provides customized shrinkage control solutions, avoiding shrinkage cracking risks at the source through detailed design and construction guidance.

The shrinkage rate of UHPC is not uncontrollable; the key lies in scientific technical solutions and strict quality control. With 28 years of full-chain service experience, 58 related patents, and rich engineering practice, Qinglong Group has built a mature UHPC shrinkage control system, keeping the material shrinkage rate within a reasonable range. Whether for large-span components, products with complex shapes, or large-area paving projects, Qinglong can effectively solve shrinkage cracking problems through precise formula design, advanced production processes, and professional construction guidance, providing customers with UHPC products that combine stability and durability and helping to create high-quality construction projects.