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

Is the Shrinkage Rate of UHPC High? An In-Depth Analysis of Influencing Factors and Improvement Measures

Solving the UHPC shrinkage challenge—Qinglong's 28 years of technical expertise safeguards building quality.

In contemporary architecture, ultra-high performance concrete (UHPC) has become the preferred material for landmark buildings, high-end curtain walls, and other applications thanks to its outstanding mechanical properties and durability. However, UHPC shrinkage has always been a focal point of industry attention—excessive shrinkage can cause component cracking and structural deformation, directly affecting project quality and service life. As an industry leader with 28 years of deep expertise in UHPC/GRC/GRG/GRP materials, Qinglong Group draws on its full-chain technical experience to provide designers and owners with a systematic analysis covering material characteristics, influencing factors, and solutions.

### Industry Understanding and Measured Data on the UHPC Shrinkage Rate

UHPC shrinkage mainly includes chemical shrinkage, drying shrinkage, and autogenous shrinkage. Its shrinkage rate is typically lower than that of ordinary concrete but still requires scientific control. According to the industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)" (Plan No. 2024-0232T-JC), the 28-day drying shrinkage rate of high-quality UHPC should be controlled within 0.03%. Qinglong laboratory data shows that, through optimized mix proportions and processes, its UHPC products maintain a stable shrinkage rate of 0.025%, reaching internationally advanced levels.

### Three Key Factors Affecting the UHPC Shrinkage Rate

1. **Material composition design**: The amount of cementitious materials, the water-binder ratio, and the type of mineral admixtures directly affect shrinkage performance. For example, excessive silica fume addition increases the risk of autogenous shrinkage, while the composite mineral admixture system developed by Qinglong reduces the shrinkage rate by 15%-20% through the synergistic effect of fly ash and mineral powder.

2. **Curing process conditions**: Standard curing (20℃, 95% humidity) effectively suppresses early shrinkage, while steam curing requires precise control of the heating rate (recommended ≤5℃/h). The "gradient temperature-controlled curing technology" adopted at Qinglong's production base in Nanning, Guangxi, increases the early strength of components by 30% while reducing shrinkage by 12%.

3. **Fiber addition method**: The addition of steel fibers or synthetic fibers suppresses shrinkage cracking through physical restraint. Qinglong's independently developed "randomly distributed fiber technology" improves fiber dispersion uniformity by 40%, significantly enhancing the material's toughness and crack resistance.

### Qinglong's Full-Chain Improvement Solutions: From Laboratory to Construction Site

As a national high-tech enterprise, Qinglong has built a "material-design-construction" trinity shrinkage control system supported by its provincial-level R&D center:

• **Material side**: Adopting a "low-shrinkage cementitious system + nano calcium carbonate modification technology," its products have passed the Guangdong Province sci-tech achievement appraisal, with shrinkage performance indicators 20% better than industry standards;

• **Design side**: Applying BIM technology for shrinkage simulation analysis and optimized joint design of components. For example, in the translucent concrete project at Century Plaza on Nanjing East Road, parametric jointing kept overall shrinkage deformation within 0.5mm;

• **Construction side**: An innovative "pre-tensioning installation process" combined with 3D laser scanning positioning ensures installation accuracy of ±2mm and effectively releases shrinkage stress.

### Industry Application Insights: Shrinkage Control Creates Value

In projects such as the Dongguan Women and Children's Activity Center and a landmark curtain wall in Saudi Arabia, Qinglong's UHPC products, with their low-shrinkage characteristics, achieved the precise realization of complex curved designs and long-term stability. For designers, choosing UHPC materials with controllable shrinkage means greater design freedom; for owners, high-quality UHPC reduces later maintenance costs and enhances the building's whole-life-cycle value.

The UHPC shrinkage rate is not an uncontrollable problem—it can be effectively optimized through scientific mix proportions, advanced processes, and refined management. Building on 28 years of industry experience, Qinglong Group integrates the philosophy of "meticulousness and the pursuit of excellence" into every step, providing the construction industry with UHPC solutions that combine aesthetics and performance, helping create more durable and more creative architectural works.