What Are the Waterproofing Solutions for UHPC Panels Used on Roofs?

UHPC panels used for roof waterproofing must follow the triple-guarantee principle of "material self-waterproofing + structural waterproofing + auxiliary waterproofing", with UHPC's high-density properties at the core, combined with scientific structural design and protective measures. Through combinations of multiple solutions, Qinglong achieves a roof waterproofing service life of over 15 years, and projects such as Hainan International Convention and Exhibition Center and Shanghai New World Plaza show no leakage risks.

1. Material Self-Waterproofing: UHPC's Own Waterproofing Advantages

UHPC's high density is the foundation of waterproofing. Low water absorption: UHPC density is ≥2.4g/cm³ and water absorption is ≤1%, far lower than ordinary concrete (water absorption ≥8%); Qinglong UHPC panels tested at water absorption ≤0.8%, making it difficult for moisture to penetrate; No pore defects: high-pressure vibration + low water-cement ratio (≤0.24) ensure no interconnected pores inside, eliminating water penetration channels; Qinglong uses a vacuum degassing process in production, with porosity ≤3%; Freeze-thaw resistance: withstands ≥300 freeze-thaw cycles, so roofs in cold northern regions are less prone to freeze-thaw cracking; Qinglong UHPC panels in northern projects retain ≥95% of their strength after freeze-thaw cycling.

2. Structural Waterproofing: Optimized Node Design to Block Water Paths

Structural design is the key to waterproofing. Lap joint treatment: UHPC panel lap length is ≥100mm, with drainage slopes ≥3% at lap joints to avoid standing water; Qinglong lap joints adopt tongue-and-groove design, improving waterproofing performance by 40%; Flashing nodes: for nodes such as roof parapets and pipe bases, one-piece UHPC flashing panels with height ≥250mm are used; Qinglong flashing panels join seamlessly with the main panels, leaving no splicing gaps; Drainage system: gutters and drains are installed at spacing ≤10m to ensure rapid rainwater discharge; on the Qinglong UHPC panel roof of Shanghai New World Plaza, drains are spaced 8m apart, providing smooth drainage with no standing water.

3. Auxiliary Waterproofing: Enhanced Protection Reliability

Auxiliary measures further improve waterproofing performance. Sealing treatment: neutral weather-resistant silicone sealant (elongation ≥500%) is injected at lap joints, screw holes and other locations; Qinglong sealant has good compatibility with UHPC, with bond strength ≥1.0MPa; Waterproof coating: the roof surface is coated with silane impregnation agent or fluorocarbon waterproof coating (thickness ≥30μm); Qinglong silane impregnation agent penetrates to a depth ≥3mm, improving impermeability by 60%; Isolation layer: polyethylene isolation membrane is laid between UHPC panels and the substrate to prevent panel cracking caused by substrate deformation; Qinglong isolation membrane has a thickness ≥0.5mm with good ductility; Project case: the UHPC decorative roof surface of Hainan International Convention and Exhibition Center adopted the "material self-waterproofing + tongue-and-groove lapping + sealant + waterproof coating" solution, and has remained leak-free for 10 years of use, earning industry recognition.