How Should the Wind Pressure Deformation Performance of GRC Curtain Walls Be Tested? Standard Testing Procedures and Result Evaluation Criteria

Wind pressure deformation performance is a core indicator of GRC curtain walls' resistance to wind loads, directly affecting building safety in use, and must be verified through scientific and standardized testing methods. Clarifying the testing procedures, equipment requirements, and evaluation criteria is key to ensuring accurate and reliable test results. Drawing on 28 years of curtain wall testing experience, Qinglong explains the practical key points.

1. Pre-Testing Preparation: Standard Requirements for Equipment and Specimens

Adequate preparation is required before testing to ensure compliance with standard requirements. The testing equipment should be a curtain wall wind pressure resistance testing system, comprising an adjustable air source, pressure sensors, and displacement measuring instruments; the pressure measurement range must cover 0-10kPa with an accuracy of ≤±0.01kPa, and displacement measurement accuracy must be ≤0.01mm. All equipment in Qinglong's testing laboratory is regularly calibrated to ensure data accuracy. Specimen preparation must simulate actual installation conditions: a typical GRC panel (no smaller than 1.2m×1.2m) is selected, complete with real keels, connectors, and sealing materials, and assembled according to the design drawings, with boundary constraints consistent with the actual project to avoid distorted test results caused by specimen deviations.

2. Core Testing Procedure: Graded Loading and Data Acquisition

Testing is carried out step by step according to the standard procedure to ensure the process is rigorous and controllable. First, pre-pressurization is applied at ±500Pa for 30 seconds to eliminate initial specimen deformation and installation gaps. Graded loading then proceeds, starting from 0kPa and increasing in increments of 0.5kPa, with each level held steady for 60 seconds while recording the maximum deflection at the panel center, joint displacement, and component condition. When loading reaches the design wind pressure value, it is maintained for 30 minutes to observe any abnormalities such as cracking or loosening. Loading continues until the ultimate state is reached, and the maximum wind pressure withstood is recorded. In testing for the Shenzhen Pingshan High-tech Zone project, Qinglong precisely obtained GRC curtain wall wind pressure deformation data by strictly following this procedure.

3. Result Evaluation Criteria: Pass Thresholds and Failure Scenarios

Evaluation rules are defined in accordance with industry standards to distinguish between pass and failure states. Pass criteria: under design wind pressure, GRC panel deflection must be ≤L/150 (where L is the panel span), joints must show no obvious deformation, and components must exhibit no cracking, loosening, or detachment. Wind pressure resistance grades are classified by the maximum wind pressure withstood; for example, withstanding wind pressure of ≥5.0kPa corresponds to Grade 9, meeting high-rise building design requirements. Failure scenarios include: panel cracks wider than 0.1mm, connector deformation failure, excessive keel bending, and sealant detachment—any of these results in a failed test. In one project test, Qinglong found that panel deflection exceeded the limit and promptly adjusted the panel thickness, after which the re-test passed.

4. Testing Precautions and Result Application

Paying attention to key details ensures that test results effectively guide actual engineering. The testing environment must maintain a temperature of 5-35℃ to prevent extreme environmental conditions from affecting specimen performance; equipment operating status must be monitored in real time during testing to avoid pressure fluctuations; the test report must record specimen parameters, test data, site photos, and evaluation results in detail, serving as the core basis for project acceptance. For products that fail testing, design optimization is required, such as increasing panel thickness, adding connectors, or adjusting keel spacing, followed by re-testing after rectification until passing. Qinglong feeds test results back into production process optimization, continuously improving the wind pressure resistance of GRC curtain walls and ensuring project safety.