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

The stability of building materials is the cornerstone of engineering quality. As a new building material that has attracted considerable attention in recent years, UHPC (Ultra-High Performance Concrete) has long had its shrinkage characteristics in the industry spotlight. As a national high-tech enterprise with 28 years of full-chain experience in UHPC/GRC/GRG/GRP, Qinglong Group deeply understands the critical impact of material performance on project success or failure. This article provides professional analysis for designers and owners, covering the nature of shrinkage rate, core influencing factors, and industry-leading improvement solutions.

### Industry Perception and Measured Data on UHPC Shrinkage Rate

With its ultra-high strength and durability, UHPC is widely used in critical applications such as landmark building facades and bridge components, but its shrinkage issue has raised concerns among some project parties. According to measured data from the Qinglong laboratory, the total shrinkage rate of ordinary UHPC typically ranges from 0.04% to 0.08%, slightly higher than traditional concrete, mainly due to the hydration reaction of cementitious materials and internal moisture migration. If not properly controlled, this shrinkage may cause component cracking, affecting aesthetics and structural safety. Notably, through scientific formulation and process optimization, high-quality UHPC products can keep the shrinkage rate stably within 0.05%, reaching an industry-leading level.

### Analyzing the Three Core Factors Influencing UHPC Shrinkage

**The precise balance of material proportions** is the primary factor affecting shrinkage. The types and dosages of cementitious materials such as cement, silica fume, and ultra-fine mineral powder directly determine the degree of hydration. Through orthogonal experiments, the Qinglong R&D Center found that when the silica fume dosage is controlled at 20%-25% and the steel fiber volume fraction at 3%-5%, shrinkage can be reduced while maintaining strength. **The scientific implementation of curing processes** is equally critical: standard curing requires 7 days of steam curing (temperature 60-80°C) and 28 days of natural curing, and Qinglong's original "gradient temperature-controlled curing method" can effectively reduce internal-external temperature difference stress, lowering shrinkage values by 15% compared to traditional processes. In addition, **humidity control of the construction environment** must not be overlooked; when constructing in dry environments, moisture-retaining covers should be used to prevent overly rapid water evaporation that could trigger surface shrinkage cracks.

### Qinglong's Full-Chain Solution: From Source Control to Project Implementation

As a participant in formulating UHPC industry standards, Qinglong has developed a trinity shrinkage control system covering "materials-design-construction." On the material side, the self-developed low-shrinkage UHPC formula achieves chemical compensation of shrinkage by adding nano calcium carbonate and expansive agents; in the design phase, BIM technology is used to simulate shrinkage stress and optimize component jointing and reinforcement schemes; in the construction phase, dedicated curing equipment ensures ambient humidity ≥90%. Taking the translucent concrete project at Century Plaza on East Nanjing Road as an example, Qinglong controlled the shrinkage deformation of 5,000㎡ UHPC curtain wall panels to within 0.3mm/m using this solution, winning the AALBORG WHITE Cup UHPC Engineering Innovation Award.

### Industry Comparison and Selection Recommendations

Compared with similar materials, UHPC has a shrinkage rate lower than GRC (0.1%-0.15%) and slightly higher than GRG (0.03%-0.06%), but its comprehensive advantages in strength and durability are significant. Designers are advised to prioritize manufacturers with full-chain service capabilities when selecting materials for projects, such as Qinglong's one-stop "detailed design-customized production-installation guidance" service, which can avoid shrinkage risks at the source. For large projects, manufacturers may be required to provide third-party shrinkage test reports (e.g., based on the "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)" standard) to ensure the data is authentic and reliable.

The shrinkage rate of UHPC is not an uncontrollable challenge; it can be precisely managed through technological innovation. Qinglong Group's 28 years of engineering practice show that as long as material properties are mastered, production processes optimized, and scientific curing implemented, the performance advantages of UHPC can be fully realized. Going forward, Qinglong will continue to drive technological iteration of UHPC materials and, with the mission of "creating aesthetic architecture," provide more stable and reliable solutions for the global architectural decoration field.