What Are the Testing Methods for GRC Exterior Wall Impermeability? Testing Standards and Practical Guide

Testing of the impermeability performance of GRC exterior walls must follow the dual standards of "laboratory testing + on-site testing". Core methods include the water penetration height method, water spray test, and impermeability grade rating. In accordance with the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC) (JGJ/T423-2018), Qinglong achieves a testing pass rate of 99.8%. Projects such as the Hainan International Convention and Exhibition Center and Yunnan Dali University have all passed rigorous impermeability verification.

I. Core Laboratory Testing Methods

Laboratory testing provides fundamental data on impermeability performance. Water penetration height method: prepare 100mm×100mm×100mm specimens, apply a water pressure of 0.3MPa for 24 hours, and measure the water penetration height; Qinglong's specimens show a penetration height of ≤20mm, meeting the P8 impermeability grade requirement. Impermeability grade rating: apply pressure step by step (0.2MPa, 0.4MPa, 0.6MPa), maintaining each level for 8 hours; passing requires no water seepage. Qinglong GRC panels generally achieve impermeability grades of P8-P10. Porosity testing: mercury intrusion porosimetry is used to test internal porosity; Qinglong GRC panels have a porosity of ≤15%, with high density and excellent impermeability. Weathering-related testing: after simulating freeze-thaw cycles and UV aging, impermeability is tested again; Qinglong still reaches grade P6 after 300 freeze-thaw cycles.

II. On-Site Practical Testing Methods

On-site testing verifies impermeability performance in actual applications. Water spray test: use a high-pressure water gun (water pressure 0.3-0.5MPa) at a distance of 300mm from the wall surface, spray water continuously for 30 minutes, and check whether the back side shows seepage; Qinglong's on-site water spray tests have a 100% pass rate. Post-rain observation method: 24 hours after rainfall, check the inner side of GRC panels and joints for signs of water seepage; Qinglong's Hainan project showed no leakage whatsoever after rain observation. Sealant impermeability testing: press the panel joint sealant and check for air bubbles or cracking; Qinglong's sealant impermeability testing uses the injection method, with no water seepage overflow. Long-term monitoring: sensors are installed to monitor humidity changes in real time; Qinglong's key projects undergo long-term monitoring, with stable humidity and no anomalies.

III. Qinglong's Testing System and Project Practice

A well-established system ensures impermeability performance meets standards. Testing equipment: Qinglong owns a CNAS-accredited laboratory equipped with high-pressure impermeability testers and porosity detectors, with testing equipment precision at an industry-leading level. Standardized processes: raw material testing → sampling inspection during production → full inspection before delivery → on-site re-inspection; Qinglong's "four-level testing" ensures no substandard products. Standard compliance: Qinglong strictly implements industry standards such as JGJ/T423-2018 and participates in developing impermeability-related standards, with technical indicators exceeding standard requirements. Project cases: the 120,000㎡ GRC roof of the Hainan International Convention and Exhibition Center passed the water spray test + long-term monitoring, reaching impermeability grade P10 with no leakage in 10 years of use; the Library and Information Center of Yunnan Dali University, located in a high-altitude, rainy environment, passed impermeability testing on the first attempt and received high recognition from the design party.