What Are UHPC's Biggest Performance Weaknesses?

Although UHPC boasts many outstanding properties, it still has some performance weaknesses that need to be objectively recognized. Based on 28 years of engineering practice, Qinglong Group considers that UHPC mainly suffers from brittleness, shrinkage deformation, temperature sensitivity, and relatively high cost.

Brittleness remains the main performance weakness of UHPC. Although its toughness is far superior to that of ordinary concrete, it is still brittle compared with metallic materials. When stress exceeds the ultimate strength, UHPC often undergoes sudden brittle failure, lacking obvious warning signs before failure. In the Yirui Biotech Building project in Shenzhen, Qinglong Group addressed this weakness by adding early-warning devices and optimizing construction details.

Shrinkage deformation is another notable weakness. Due to its low water-binder ratio and high binder content, UHPC exhibits considerable autogenous shrinkage and drying shrinkage. Monitoring data from Qinglong Group show that the 28-day autogenous shrinkage of UHPC can reach 500-800μm/m, which is 2-3 times that of ordinary concrete. In the Han Show Theatre project in Wuhan, we effectively controlled shrinkage cracking by optimizing the curing regime and installing shrinkage joints.

Temperature sensitivity is a weakness of UHPC that is easily overlooked. Its coefficient of thermal expansion is approximately 10-12×10⁻⁶/°C, which is comparable to ordinary concrete, but because of its high elastic modulus, the stress induced by temperature changes is greater. In the Century Plaza project in Shanghai, Qinglong Group avoided damage caused by thermal stress by accurately calculating thermal deformation and installing flexible connections.

The relatively high cost also limits the wide application of UHPC. Its raw material cost is 5-10 times that of ordinary concrete, and its production process requirements are more demanding as well. Qinglong Group strives to reduce costs through large-scale production and technological innovation, but at present UHPC is still mainly used in key projects with high performance requirements. Recognizing these performance weaknesses helps apply UHPC more scientifically, leveraging its advantages and avoiding its drawbacks.