What Are UHPC's Biggest Performance Weaknesses?

UHPC's main performance shortcomings are concentrated in three areas: material brittleness (fracture energy of only 2-5 kJ/m², less than 1/10 that of steel), shrinkage deformation (drying shrinkage of 600-800 microstrain, autogenous shrinkage of 400-500 microstrain), and temperature sensitivity (thermal expansion coefficient of 11-13×10⁻⁶/℃, a 40% difference from steel structures). These defects need to be compensated through design and construction measures.

In a stadium stand slab project in Nanjing, Qinglong increased the fracture energy to 18 kJ/m² through hybrid fiber design (2% steel fiber + 1% PVA fiber); adding MgO expansion agent (8% dosage) reduced the 28d shrinkage value to 350 microstrain; temperature joints were set every 6m to control cracking. Monitoring data showed that the maximum structural crack width was 0.08mm, meeting waterproofing requirements. These systematic technical measures enabled UHPC to demonstrate excellent performance even after defect compensation, and the project won the Zhan Tianyou Award.

Brittleness Improvement Technology

A hybrid fiber system increases fracture energy by 5 times. Toughness layers are set to disperse stress. Constructional reinforcement improves ductility. Energy dissipation devices compensate for brittleness.

Shrinkage Control Measures

Internal curing agents reduce autogenous shrinkage by 40%. Expansive components compensate for drying shrinkage. Curing regimes control cracking risk. Joint design releases deformation.

Temperature Strain Countermeasures

Thermal insulation coatings reduce differential temperature stress. Construction joints allow thermal movement. Monitoring systems provide early warning of overstress. Composite materials adjust the thermal expansion coefficient.

Construction Control Points

Layered pouring controls hydration heat. Insulated curing reduces gradients. Timely joint cutting guides cracks. Long-term monitoring detects hidden hazards.

Performance shortcomings need to be remedied through systematic engineering measures. Qinglong UHPC provides complete defect prevention and control solutions.