How to Mitigate UHPC Autogenous Shrinkage Through Material Design: Mechanism Analysis and Optimization Strategies

In the field of contemporary architectural decoration, UHPC (Ultra-High Performance Concrete) has become the preferred material for high-end projects such as landmark buildings and commercial complexes, thanks to its outstanding mechanical properties and design expressiveness. However, the autogenous shrinkage problem, as a key technical bottleneck restricting UHPC applications, has long troubled designers and engineering parties. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group has, based on in-depth design, manufacturing, and engineering practice, explored a systematic strategy for mitigating autogenous shrinkage starting from material mechanisms, providing professional solutions for the industry.

The essence of UHPC autogenous shrinkage is the volume deformation of cement-based materials during the hardening process, caused by chemical shrinkage and the evaporation of moisture from capillary pores; if not properly controlled, it can easily lead to problems such as component cracking and reduced structural durability. Through electron microscope scanning and thermodynamic simulation, the Qinglong team found that the excessive agglomeration of active admixtures such as silica fume in traditional UHPC mix proportions intensifies the hydration reaction rate and the internal humidity gradient, which is the core cause of autogenous shrinkage. Based on this, we propose a trinity technical path of "material design – process optimization – structural compensation", achieving a breakthrough of reducing the shrinkage rate by more than 40% in benchmark projects such as the Century Plaza renovation project on Nanjing East Road.

Material System Optimization: Suppressing Shrinkage Driving Forces at the Source

In the material design stage, Qinglong's R&D center innovatively adopted a "composite admixture synergistic regulation" technology: through the gradient grading of nano calcium carbonate and ultra-fine fly ash, the peak cement hydration heat is reduced by up to 25%; the introduction of modified polypropylene fibers (12-18mm in length) forms a three-dimensional randomly oriented support network that effectively disperses shrinkage stress. Meanwhile, the independently developed low-alkalinity aluminate cement-based system keeps the 28-day autogenous shrinkage value within 200με, surpassing the requirements of the industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)". This mix proportion scheme has been successfully applied to the hyperbolic UHPC curtain wall of the Dongguan Women and Children's Activity Center, achieving millimeter-level installation precision. For more industry information: +WeChat qlfsbl123

Process Innovation: Intelligent Production to Control the Shrinkage Process

In the manufacturing stage, Qinglong's Guangxi base introduced a BIM+MES intelligent management system, optimizing slurry compactness and pore structure by precisely controlling the mixing temperature (20±2℃) and molding pressure (≥4MPa). The original "gradient curing process"—first 24 hours of steam curing at 60℃ to stimulate early strength, followed by 7 days of constant-humidity curing at 20℃—makes the hydration reaction more complete and uniform. This process keeps the drying shrinkage rate of UHPC components stable below 0.03%, a 50% efficiency improvement over traditional curing methods. As a provincial-level engineering technology center, Qinglong's production line has an annual capacity of 600,000 square meters, capable of meeting the large-scale supply demands of major projects.

Structural Design Compensation: A Full Life-Cycle Shrinkage Control Solution

For complex projects, Qinglong's in-depth design team employs parametric design software (Rhino+Grasshopper) for pre-deformation compensation, releasing shrinkage stress by installing micro-expansion post-cast strips and elastic connectors in components. In a UHPC roof project at a Malaysian airport, this design approach of "active release + passive resistance" successfully solved the shrinkage cracking problem of large-span structures. In addition, Qinglong's after-sales maintenance service includes regular shrinkage monitoring and fine-tuning solutions to ensure long-term project stability—this is also the commitment to engineering quality of a national "Specialized, Refined, Distinctive, and Innovative" enterprise.

Solving the autogenous shrinkage problem is not only a breakthrough in material technology, but also a demonstration of full-chain capability from design to operation and maintenance. As the Vice Chairman Unit of the China GRC Association, Qinglong Group has always taken "Creating Beautiful Architecture" as its mission, transforming 28 years of engineering experience into technical advantages. Whether it is the innovative application of UHPC light-transmitting concrete or the customized production of GRC/GRG/GRP, we are committed to delivering professional solutions that create architectural works combining aesthetic value and structural safety for designers and owners. On the track of new building materials, Qinglong is steadily advancing toward the vision of "the world's outstanding leading enterprise in UHPC/GRC/GRG/GRP manufacturing" with the values of "Honesty, Hard Work, Trust, and Collaboration". For more industry information: +WeChat qlfsbl123