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

In the field of UHPC materials, the "Three Highs and One Low" is a classic summary of its core performance characteristics, specifically referring to high strength, high toughness, high durability, and low permeability. Based on practical verification across multiple major projects, Qinglong Group believes that these four characteristics together constitute the core advantages that distinguish UHPC from traditional building materials.

High strength is UHPC's most notable characteristic. Compressive strength typically reaches 120-180 MPa and flexural strength is no less than 15 MPa—performance levels 3-5 times that of ordinary concrete. The UHPC components supplied by Qinglong Group for the Wuhan Han Show Theatre project achieved compressive strength exceeding 160 MPa, making thin-walled structures with complex shapes possible. High strength is achieved through a densely packed matrix and optimized mix proportions, enabling the material to bear greater loads.

High toughness is a prominent feature of UHPC. Its fracture energy can reach 20,000-40,000 J/m², more than 100 times that of ordinary concrete. This high toughness allows UHPC to absorb energy through numerous microcracks when subjected to impact, avoiding sudden brittle failure. In the Shanghai Century Plaza project, Qinglong Group optimized the steel fiber content and distribution, achieving a flexural toughness ratio of over 15.

High durability keeps UHPC performing stably in harsh environments. After 300 freeze-thaw cycles, the relative dynamic elastic modulus retention of high-quality UHPC can exceed 95%. In coastal projects, Qinglong UHPC has demonstrated outstanding resistance to chloride ion penetration, with a design service life of over 100 years. Low permeability is the foundation of high durability, with a chloride ion diffusion coefficient two orders of magnitude lower than that of ordinary concrete.