GB/T 38264-2019 in English

1. Background and significance of the standard

GB/T 38264-2019 "Classification and testing methods for impact resistance of building curtain walls" was proposed by the Ministry of Housing and Urban-Rural Development of the People's Republic of China to regulate the resistance of building curtain walls to external or internal impacts. The standard combines the practical experience of the curtain wall industry at home and abroad to ensure the safety and durability of buildings.

2. Comparison of standard frameworks

3. Interpretation of the core content of the standard

3.1 Definition and indicators of impact resistance

Impact resistance (resistance against impact) refers to the ability of the curtain wall to resist damage when it is hit by a soft or hard object of specified mass. Its classification is based on impact energy E and falling height h, and the calculation formula is: E=9.8m·h.

According to the classification standards in Table 1 and Table 2, the impact resistance of the curtain wall is divided into different levels, which are suitable for different requirements of the indoor and outdoor sides. For example, for indoor level 3, the soft weight mass is 70kg, and the impact energy E is 1029J; for outdoor level 4, the drop height h is 2000mm, and the impact energy E is 980J.

4. Detection methods and implementation suggestions

4.1 Detection device requirements

• Soft weight detection device: It consists of 3 close-fitting tires, counterweights and other connecting parts, with a total mass of 50kg and 66.7kg respectively. The drop height error is controlled within ±20mm, and the horizontal angle of the hanging wire rope should not be less than 14 degrees.
• Hard object detection device:Use a 1040g spherical hardened steel ball with a diameter of 63.5mm and a hanging wire rope with a diameter of 3mm. The center of the impact point is aligned with the suspension line to ensure that there is no deviation in the free fall path.

4.2 Testing steps

1. Test piece installation inspection: Ensure that it meets the design requirements and some switches can be opened for no less than 5 times.
2. Hanging impact object: The geometric center of soft heavy objects should be within the range of 50mm with the impact point as the center of the circle; hard objects should be within 25mm.
3. Lift and release: After reaching the specified drop height, release the impact object and observe the reaction of the test piece.
4. Result judgment: Judge whether it is qualified based on whether the panel falls off, breaks or cracks.

4.3 Implementation Suggestions

• Strictly select testing equipment and parameters according to the standards to ensure data accuracy.
• Determine the specific test plan in combination with the curtain wall type (such as full glass, point support, etc.).
• Strengthen the control of on-site testing conditions to avoid interference from wind speed and weather factors.