Secrets of UHPC Autogenous Shrinkage Control: Scientific Mitigation Solutions at the Material Design Level

Autogenous shrinkage is a core technical pain point in UHPC (Ultra-High Performance Concrete) applications; improper handling can easily cause microcracks, compromising structural durability and decorative finishes. As an industry leader with 28 years of deep expertise in UHPC, Qinglong Group has accumulated mature autogenous shrinkage control experience across thousands of major projects, solving this industry challenge through precise optimization of material design.

The low water-binder ratio of UHPC means its autogenous shrinkage risk is higher than that of ordinary concrete, and scientific material formulation design is the key to controlling shrinkage at the source. Leveraging the technical expertise gained from participating in the development of the industry standard "General Technical Conditions for Non-Load-Bearing Components of Ultra-High Performance Concrete (UHPC)," Qinglong has developed a systematic material optimization solution.

???? Cementitious Material System Optimization: Balancing Reaction Rate

By incorporating active admixtures such as fly ash and mineral powder to replace part of the cement content, the rate of hydration heat release can be slowed and volume shrinkage reduced. In the Yangshengtang Pharmaceutical Hangzhou Industrial Park project, Qinglong adopted a composite admixture system at a 40% ratio, reducing UHPC autogenous shrinkage by more than 35%. In addition, low-hydration-heat cement types were selected and combined with Qinglong's self-developed specialized composite cementitious materials to further improve paste volume stability.

⚖️ Precise Aggregate Gradation Blending: Improving Packing Density

Aggregates account for more than 60% of UHPC volume, and proper gradation is the foundation for reducing shrinkage. Qinglong uses continuously graded quartz sand and basalt aggregates, reducing porosity through tight particle packing, which lowers shrinkage potential while reducing cementitious material usage. In the UHPC hollow panel project for the Ouargla Hotel in Algeria, the optimized aggregate gradation kept material autogenous shrinkage within 200με, meeting the precision requirements of highly perforated components.

???? Synergistic Modification with Admixtures and Fibers: Suppressing Shrinkage Stress

High-performance polycarboxylate superplasticizers are selected to lower the water-binder ratio while maintaining workability, reducing autogenous shrinkage caused by negative pressure in capillary pores. Meanwhile, steel fibers or PVA fibers are added to disperse shrinkage stress through the bridging effect of the fibers, preventing crack formation. Qinglong's patented fiber blending technology enables UHPC to form a three-dimensional restraint system during shrinkage, improving shrinkage stress dispersion efficiency by 40%.

UHPC autogenous shrinkage control is a systematic engineering task involving materials, processes, and design, with material design as the source-level step that directly determines the upper limit of shrinkage control. Qinglong Group's 28 years of full-chain experience demonstrate that through the triple design of cementitious material optimization, precise aggregate gradation, and admixture-fiber synergy, UHPC autogenous shrinkage can be controlled at an industry-leading level. In the future, with continuous innovation in material technology, UHPC shrinkage control will become more precise and more efficient, providing more reliable material solutions for the architectural decoration field.