Which Properties Do UHPC's "Three Highs and One Low" Characteristics Refer To?

UHPC's "three highs and one low" characteristics are a concentrated embodiment of its core competitiveness: high strength, high durability, high workability, and low porosity. These four performance attributes are interrelated and mutually reinforcing. With its accumulated technical expertise, Qinglong ensures the "three highs and one low" characteristics are fully realized in actual projects.

I. High Strength: A Core Breakthrough in Mechanical Performance

High strength is UHPC's most intuitive performance advantage, covering both compressive and flexural indicators. Compressive strength: cube compressive strength ≥120MPa, far exceeding ordinary C80 concrete (≥80MPa); Qinglong's mass-produced UHPC achieves compressive strength of 150-180MPa, with some special formulations exceeding 200MPa. Flexural strength: ≥15MPa, 3-5 times that of ordinary concrete, enabling "flexibility overcoming rigidity" and avoiding brittle fracture. Application scenarios: large sculptures, bridge components, and thin-walled decorative panels. Qinglong's UHPC sculptures over 3 meters at the Shanghai Astronomy Museum achieved unsupported forming thanks to their high strength, with excellent resistance to wind loads and dead loads.

II. High Durability: Performance Assurance for Long-Term Use

High durability stems from low porosity and premium raw materials, enabling adaptation to harsh environments. Freeze-thaw resistance: strength loss ≤5% after 300 freeze-thaw cycles, far superior to the 200-cycle standard for ordinary concrete; Qinglong's UHPC components in a municipal project in Northeast China have shown no freeze-thaw damage after 4 years of use. Impermeability and corrosion resistance: impermeability grade ≥P20 and chloride ion penetration coefficient ≤1.0×10⁻¹²m²/s, maintaining long-term stability in coastal high-salt-spray and industrial corrosive environments; Qinglong's UHPC hollow-out panels on the exterior walls of the hotel in Ouargla, Algeria, have shown no salt corrosion or fading after 5 years. Carbonation resistance: carbonation depth is nearly zero, preventing steel reinforcement corrosion (when steel fibers are incorporated) and extending structural service life to over 50 years.

III. High Workability and Low Porosity: The Foundation for Achieving Performance

High workability and low porosity are the prerequisites of the "three highs" and complement each other. High workability: fresh UHPC has a spread of ≥750mm, is self-compacting and vibration-free, and can fill complex mold cavities; in Qinglong's production of double-curved and hollow-out components, the material's flowability precisely adapts to mold details, with no bubbles or honeycombs after forming. Low porosity: total porosity ≤3%, mostly closed micropores (pore diameter <50nm), compared to approximately 15%-20% for ordinary concrete; low porosity both enhances strength and blocks the penetration paths of corrosive media. Through dense particle packing design and high-efficiency water reducer technology, Qinglong controls porosity within 2%, providing a structural foundation for high strength and high durability.