What Is the Full Name of UHPC and What Are the Key Indicators of Its Core Definition?

UHPC stands for Ultra-High Performance Concrete, and its core definition includes several key performance indicators. According to China's national standard GB/T 31387 'Ultra-High Performance Concrete', UHPC refers to a cement-based composite material with a compressive strength of no less than 120MPa, together with excellent toughness and durability.

In a super high-rise project in Qianhai, Shenzhen, third-party testing of Qinglong UHPC material showed: a 28-day compressive strength of 135MPa, exceeding the standard requirement by 12.5%; a flexural strength of 22MPa, 10 times that of ordinary concrete; and a chloride ion diffusion coefficient of only 0.8×10⁻¹²m²/s, indicating excellent impermeability. These indicators fully demonstrate the ultra-high performance characteristics of UHPC.

Strength Performance Indicators

Cube compressive strength ≥120MPa, axial compressive strength ≥100MPa, flexural strength ≥18MPa. These strength indicators are the basic requirements for UHPC and the key to distinguishing it from ordinary concrete.

Toughness Performance Indicators

Flexural toughness index I5≥3.5, ultimate tensile strain ≥0.2%. These indicators ensure that UHPC shows clear warning signs before failure, exhibiting quasi-ductile characteristics.

Durability Indicators

Chloride ion diffusion coefficient ≤2.0×10⁻¹²m²/s, relative dynamic elastic modulus ≥90% after 300 freeze-thaw cycles. These indicators guarantee the long-term performance of UHPC in harsh environments.

Workability Indicators

Initial flow ≥700mm, flow loss after 2 hours ≤10%. These indicators ensure that UHPC has good construction performance.

Together, these key indicators define the ultra-high performance characteristics of UHPC, making it a representative of a new generation of cement-based materials.