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

In the field of UHPC materials, “three highs and one low” is a classic summary of its core performance characteristics. Based on 28 years of engineering practice, Qinglong Group interprets it specifically as high strength, high toughness, high durability, and low permeability. These four characteristics together constitute the core advantages that distinguish UHPC from conventional concrete, and they are the fundamental reason for its widespread application in high-end construction projects.

High strength is the most prominent characteristic of UHPC. Compressive strength typically reaches 120-180MPa, and flexural strength is no less than 15MPa—3 to 5 times the performance level of conventional concrete. The UHPC curtain wall panels used by Qinglong Group in the Shenzhen Yirui Biotechnology Building project achieved a compressive strength of 150MPa, allowing panel thickness to be reduced to 15mm and realizing a lightweight building design. High strength is achieved through a densely packed matrix and uniformly distributed fiber reinforcement, enabling the material to withstand greater loads.

High toughness is another outstanding feature of UHPC. Its fracture energy can exceed 20,000J/m², which is 100 times that of conventional concrete. This high toughness allows UHPC to absorb energy through numerous micro-cracks when subjected to impact, avoiding sudden brittle failure. In the translucent UHPC project at Shanghai Century Plaza, Qinglong Group optimized the dosage and distribution of steel fibers to achieve a flexural toughness ratio above 15, ensuring the safety of public spaces.

High durability enables UHPC to maintain stable performance even in harsh environments. After 300 freeze-thaw cycles, high-quality UHPC retains more than 90% of its relative dynamic elastic modulus, with a mass loss of no more than 5%. In the Algeria hotel project, perforated UHPC panels showed less than 5% performance degradation after 5 years in a high-temperature, high-humidity environment, demonstrating outstanding weather resistance. This durability stems from the material's high density and excellent impermeability.

Low permeability is the foundation for achieving high durability. The chloride ion diffusion coefficient of UHPC is typically below 2.0×10⁻¹²m²/s, with an impermeability grade exceeding P12. Qinglong Group's test data show that its UHPC products have a water absorption rate below 1%, significantly improving freeze-thaw resistance and resistance to chemical attack. These “three highs and one low” characteristics make UHPC an ideal choice for high-performance building materials.