Is UHPC Shrinkage Rate High? Analysis of Influencing Factors, Control Methods, and Engineering Applications

Amid the wave of technological innovation in building materials, ultra-high performance concrete (UHPC) has become a rising favorite in modern architecture thanks to its outstanding mechanical properties and durability. However, the controversy over UHPC shrinkage rate has always been a focal concern for designers and engineers. As an industry leader with 28 years of deep expertise in the UHPC/GRC/GRG/GRP field, Qinglong Group will provide an in-depth analysis of the core issues of UHPC shrinkage rate from four dimensions: material properties, influencing factors, control technologies, and engineering practice.

I. Characteristics of UHPC Shrinkage Rate: Not Absolutely "Large"

The shrinkage characteristics of UHPC need to be examined objectively in a scientific context. Compared with ordinary concrete, UHPC indeed exhibits more pronounced early autogenous shrinkage due to its ultra-high cementitious material content (usually exceeding 800kg/m³) and low water-binder ratio (0.15-0.25), with 7-day autogenous shrinkage values reaching 200-400με. However, by optimizing the mix proportion and curing process, its 28-day total shrinkage can be controlled within 600με, outperforming some high-performance concretes. Laboratory data from Qinglong Group show that UHPC components using a composite mineral admixture system achieve a 56-day drying shrinkage rate 32% lower than the control group, providing key technical support for engineering applications.

II. Multidimensional Influencing Factors: The Synergy of Materials, Process, and Environment

The shrinkage rate of UHPC is affected by the coupling of multiple factors. At the material level, every 10% increase in silica fume content raises autogenous shrinkage by about 15%, while the addition of steel fibers reduces shrinkage stress by suppressing crack development. In the production process, the steam curing regime is particularly critical—Qinglong Group's proprietary "three-stage temperature control method" (pre-curing at 40℃/2h → steam curing at 80℃/6h → slow cooling at 20℃/4h) keeps component shrinkage values stably within the design range. As for environmental factors, every 10% drop in relative humidity can increase the drying shrinkage rate by 25%, which requires precise humidity control measures during construction.

III. Full-Chain Control Technology: A Systematic Solution from Laboratory to Construction Site

To address UHPC shrinkage, Qinglong Group has built a whole-process control system. During the material R&D stage, nano-calcium carbonate modification technology is used to refine cement hydration products and reduce porosity; in production, a vacuum degassing process reduces internal defects, raising compactness above 98%; during construction and installation, an innovative "pre-tensioned anchoring system" is applied to offset shrinkage deformation through 0.2MPa of pre-compression stress. In a landmark project, this technology kept the cumulative shrinkage of 20m-long UHPC decorative cladding panels within 5mm, far exceeding industry standards.

IV. Engineering Evidence: Innovative Practice in UHPC Shrinkage Control

In the Century Plaza renovation project on Nanjing East Road, Qinglong Group used translucent UHPC components to create a 3000㎡ curved curtain wall. By simulating shrinkage deformation with BIM technology, combined with segmented casting and post-cast strip design, millimeter-level installation accuracy was achieved. The project won the Silver Award of the first AALBORG WHITE Cup UHPC Construction Engineering Innovation Award, confirming the maturity of the shrinkage control technology. In overseas markets, an airport terminal in Malaysia adopted Qinglong UHPC sunshades; after three years of natural exposure testing, shrinkage deformation remained stable at 0.3mm/m, meeting the requirements for long-term use in tropical climates.

As a national high-tech enterprise and a participant in developing UHPC industry standards, Qinglong Group has always taken "creating beautiful architecture" as its mission, building full-chain service capabilities from detailed design to after-sales maintenance through 28 years of technical accumulation. Facing the technical challenge of UHPC shrinkage, we firmly believe that there are no absolute material limitations—only application boundaries yet to be broken through innovation. Choosing a UHPC manufacturer with full industry chain integration capabilities is the only way to truly unlock the technical dividends of ultra-high performance materials and safeguard both architectural aesthetics and structural safety.