Is UHPC's Impermeability Good? Dual Protection from Dense Structure and Qinglong Waterproofing Technology

UHPC's water impermeability is among the industry's best. With its extremely dense internal structure and optimized production processes, its impermeability grade generally reaches P12 or above, far exceeding the P6 standard of ordinary concrete, and can even achieve "crack-free self-waterproofing," making it the preferred material for projects with high waterproofing requirements. As a participating unit in the formulation of UHPC exterior wall panel standards, Qinglong's products achieve an impermeability grade of up to P15, performing exceptionally well in coastal and humid-region projects.

Core of impermeability: high density blocks water penetration paths. UHPC has a porosity of ≤5%, mostly in the form of closed micropores, while ordinary concrete has a porosity of approximately 15%-20% with a large number of interconnected pores—this is the fundamental reason for the difference in impermeability between the two. Qinglong's UHPC uses a low water-cement ratio (0.25-0.3), continuously graded quartz sand (void ratio ≤35%), and high-efficiency water reducers. Through a high-pressure spray molding process (pressure 0.3-0.5MPa), the slurry fully fills internal voids, forming a structure with "no interconnected pores." Testing shows that Qinglong UHPC has a penetration height ratio of ≤5%, with no water seepage after 24 hours of full saturation, while ordinary concrete has a penetration height ratio of ≥30% and is prone to capillary seepage. The UHPC curtain wall of Poly Peninsula No. 1 in Hainan, located in a coastal area with annual rainfall exceeding 1800mm, achieves long-term leak-free performance without any additional waterproof coating.

Impermeability grades and project matching: meeting the needs of different scenarios. Industry standards divide UHPC impermeability grades into three levels: P12, P15, and P18. Qinglong's standard products have an impermeability grade of P15, while specially customized products can reach P18. For scenarios with long-term water contact such as underground works and water conservancy facilities, grades of P15 or above should be selected; for building exterior walls, curtain walls, and similar scenarios, grade P12 is sufficient. The UHPC exterior wall panels of Yangshengtang Pharmaceutical's Hangzhou Industrial Park, with an impermeability grade of P15, effectively resist the high-humidity environment of the Jiangnan plum rain season, with no wall dampness or mildew; the UHPC cover slabs of an underground utility tunnel, with an impermeability grade of P18, show no seepage even after long-term immersion in groundwater, protecting the safety of the equipment inside the tunnel.

Process assurance of impermeability: Qinglong's full-process control. Achieving impermeability depends on strict production and curing processes: Qinglong uses an automated batching system with a metering error of ≤±1%, avoiding pores caused by uneven mix ratios; the mixing stage adopts a three-stage "dry mixing - wet mixing - fiber dispersion" process to ensure a uniform and fine mixture; the curing stage uses intelligent constant-temperature curing kilns with 12-16 hours of steam curing at 90-95℃, promoting full cement hydration and reducing capillary pores. Compared with the natural curing used by some manufacturers, Qinglong's standardized curing improves impermeability by more than 30%. In addition, Qinglong applies a penetrating silane protective agent to the UHPC surface to further enhance water repellency, reducing the water absorption rate from 3% to below 1%.

Engineering value of impermeability: simplifying waterproofing construction and reducing costs. UHPC's high impermeability can greatly simplify waterproofing design. For example, when UHPC panels are used for building exterior walls, no additional waterproof coating is needed—only joint sealing is required—reducing construction costs by 20%-30% and minimizing future waterproofing maintenance risks. In Qinglong's project of over 70,000 square meters of GRC/UHPC components at Sanya Festival Plaza, the impermeability advantages of UHPC were used to simplify the waterproofing structure, and the project has had no leak complaints for many years since being put into use. For owners and designers, UHPC's high impermeability not only meets stringent waterproofing requirements but also optimizes project costs and construction processes. With professional products and technology, Qinglong provides dual assurance for waterproofing projects.