What is the impermeability test method for GRC exterior walls? Qinglong GRC waterproofing performance testing standard

GRC exterior wall impermeability performance testing mainly adopts three methods: the impermeability grade method, the water penetration height method, and the chloride ion diffusion coefficient method. The impermeability grade test is conducted according to the GB/T 50082 standard, with a maximum grade of P12 (no leakage under 1.2MPa water pressure); the water penetration height method requires a 48-hour water penetration height of ≤30mm; the chloride ion diffusion coefficient should be ≤2.0×10⁻¹²m²/s. These indicators ensure that GRC exterior walls have good waterproof performance.

Specific testing methods: The impermeability grade specimen dimensions are 175×185×150mm, with water pressure starting at 0.1MPa and increasing by 0.1MPa every 8 hours until the specimen shows water penetration. Test results of GRC panels from a certain project showed an impermeability grade of P10, a water penetration height of only 15mm, and a chloride ion diffusion coefficient of 1.5×10⁻¹²m²/s, fully meeting exterior wall application requirements.

Impermeability Grade Test

Specimens are grouped in sets of 6, water pressure is increased at a uniform rate, and the pressure value at the moment of water penetration is recorded. During testing, water pressure must be kept stable, with a pressure release rate of ≤0.05MPa/min.

Water Penetration Height Measurement

Specimens are held under 0.8MPa water pressure for 48 hours, and the water penetration height is measured after splitting. The average of the 6 specimens is taken as the test result.

Chloride Ion Diffusion Coefficient

Rapidly determined using the RCM method, with a specimen thickness of 50±1mm and a test duration of 24-96 hours. The diffusion coefficient is calculated by measuring the chloride ion penetration depth.

On-site Testing Method

On-site testing uses the water spray method with a water pressure of 0.3MPa for a duration of 30 minutes, checking the back surface for any leakage.

Impermeability performance is an important indicator of GRC exterior wall quality. Through strict testing and control, the waterproofing quality of projects can be ensured.