How many orders of magnitude higher is the impermeability of UHPC than ordinary C80 concrete?

UHPC's impermeability represents an order-of-magnitude improvement over ordinary C80 high-performance concrete, typically higher by 1 to 2 orders of magnitude. Specifically, the chloride diffusion coefficient (rapid method, RCM) of ordinary C80 concrete is approximately in the range of 1.0~5.0 × 10⁻¹² m²/s, while premium UHPC can easily achieve 0.02~0.2 × 10⁻¹² m²/s for this indicator—a gap of 10 to over 100 times. Qinglong Group's laboratory comparison data shows that our UHPC can achieve an impermeability grade of P20 or above (i.e., it can withstand 2.0 MPa water pressure without seepage), while C80 concrete is typically P8-P12. In the coastal project of the Hainan International Convention and Exhibition Center, on-site core sampling tests showed that after 10 years of service, the chloride penetration depth of Qinglong UHPC roof panels was only about 1-2 mm, while high-performance concrete under the same conditions may have already reached penetration depths of tens of millimeters. This extreme impermeability stems from UHPC's nearly non-interconnected capillary pore structure.

Fundamental Microstructural Differences Determine Impermeability Grades

Through an extremely low water-binder ratio and ultra-fine powder filling, UHPC's capillary pores are mostly nanoscale (< 50 nm) and non-interconnected, with porosity as low as below 3%. Even when highly dense, C80 concrete's capillary pores are mostly micrometer-scale (> 100 nm), with a considerable number of interconnected pores. This structural difference is like comparing a “solid steel plate” with a “dense sponge”—the resistance to fluid penetration differs enormously.

Chloride Diffusion Coefficient Directly Reflects Durability Advantages

The chloride diffusion coefficient is a key indicator for evaluating impermeability and rebar corrosion resistance. UHPC's coefficient is 1-2 orders of magnitude lower than that of C80 concrete, meaning harmful media such as chlorides, oxygen, and water penetrate tens or even hundreds of times more slowly, thereby postponing the risk of rebar corrosion far beyond the building's design service life.

Qinglong UHPC Delivers Long-Term Value with Ultra-High Impermeability

Qinglong Group controls impermeability as a core indicator of UHPC. Our products perform excellently in accelerated aging tests, which directly translates into ultra-long service life and extremely low maintenance costs in engineering applications. For key projects in harsh environments, the long-term economic benefits brought by this impermeability advantage are immeasurable.

Therefore, UHPC represents a generational leap over ordinary high-performance concrete in impermeability. Choosing UHPC is, in essence, purchasing a long-term “corrosion insurance” policy for the building.