Curtain wall construction quality
(1) improper construction of structural sealant affects structural safety: (1) before plate processing, the bonding strength and compatibility test of structural sealant and its contact material is not done; The use of expired structural adhesive, weather resistant adhesive in the process of processing; Structural adhesive is mixed with the use of structural adhesive brands not certified by relevant qualification testing institutions, and even the use of imported fake brands. ② No mixing test, tensile bonding test, peel test; Does not follow the relevant operation procedures to clean the work; The size of the glue injection has negative deviation, the glue injection is not dense, there are bubbles and other defects. (3) The temperature and humidity of the glue injection and maintenance environment do not meet the requirements of curtain wall structure, the maintenance time is insufficient, and the structural glue strength is not transported and installed. (4) The insulating glass in the hidden frame glass curtain wall does not use silicone structural sealant or the size of the sealant seam has not been calculated. ⑤ More serious is the scene injection silicone structure sealant. ⑥ Glass panel and aluminum frame cleaning work is not according to the “two wipe” method of cleaning.
(2) glue size provisions: (1) the width and thickness of structural glue of hidden frame glass curtain wall and semi-hidden frame glass curtain wall should be determined according to the thickness, which should not be less than 6mm, and should not be greater than 12mm, width should not be less than 7mm, and should not be greater than the thickness. The thickness of building glue should be greater than 3.5mm, generally controlled at 4.5mm, the width should not be less than twice the thickness. (2) The relevant provisions of glue injection maintenance and environmental temperature and humidity: the glass panel and aluminum frame should be injected within 1h after cleaning. If the structural glass curtain wall is contaminated again before glue injection, it should be cleaned again. The glass plate should be injected in a clean and ventilated room. The processed glass plate should be maintained in a clean room with a temperature of 20°C and humidity of more than 50%. The single-component silicone structural sealant should be preserved for 14~21d and the two-component silicone structural sealant for 7~10d. Except for all glass curtain wall, glue is not allowed on site.
(3) Analysis of the causes of quality problems in the construction of curtain wall structure: project management personnel do not pay attention to or do not understand the application specifications and material characteristics of silicone structural adhesive, and lack of necessary technical knowledge; Do not understand the importance of mandatory provisions, lack of strict operating procedures and quality inspectionof curtain wall system.
(4) preventive measures: to strengthen the procurement of raw materials and acceptance inspection work, to prevent inferior materials, expired products and counterfeit products into the construction site, to eliminate the construction glue instead of structural glue phenomenon.