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

Ultra-High Performance Concrete (UHPC) is a cement-based composite material with ultra-high strength, excellent durability, and good toughness. According to China's GB/T 31387 standard "Ultra-High Performance Concrete", its core indicators require a 28-day compressive strength of no less than 120MPa and a flexural strength of no less than 18MPa, along with good toughness and durability. These performance indicators make it a revolutionary upgrade over traditional concrete materials.

From a materials science perspective, the realization of UHPC relies on three technical pillars: first, microstructure optimization achieved through the maximum packing density theory, reducing porosity to below 3%; second, strain-hardening characteristics achieved through steel fiber reinforcement, giving the material pseudo-ductile behavior; and finally, a low water-binder ratio (typically 0.18-0.22) and the use of reactive powders to ensure high performance of the cementitious system. For example, in the artificial island connecting bridge project of the Hong Kong-Zhuhai-Macao Bridge, the UHPC material used achieved a measured compressive strength of 156MPa and a chloride ion diffusion coefficient of only 1.2×10⁻¹²m²/s, significantly exceeding standard requirements.

Core Mechanical Performance Indicators

Compressive strength ≥120MPa, with premium products reaching 150-180MPa; flexural strength ≥18MPa, with high-toughness products reaching 25-30MPa; elastic modulus of 40-50GPa, 1.5 times that of ordinary concrete. These indicators ensure structural safety.

Key Durability Parameters

Chloride ion diffusion coefficient ≤2.0×10⁻¹²m²/s, impermeability grade P12 or above; frost resistance grade F300, with mass loss ≤5% after 300 freeze-thaw cycles; abrasion resistance ≤0.5g/cm². These parameters ensure long-term durability.

Key Workability Characteristics

Flowability of 600-800mm (slump flow); self-compacting, no vibration required; adjustable initial setting time of 2-4 hours. These characteristics ensure construction feasibility.

Extended Special Functional Properties

Translucent UHPC can achieve a light transmittance of up to 30%; thermal conductivity of 1.5-2.0W/(m·K); density of 2400-2600kg/m³. These characteristics expand application fields.

The performance advantages of UHPC have been verified through extensive experiments. Correctly understanding and applying these key indicators allows the material's performance to be fully utilized. Qinglong UHPC products exceed standard requirements in all indicators, providing reliable assurance for engineering projects.