Common Problems in Glass Curtain Wall Inspection

As the external protective structure of a building, the glass curtain wall should not only have good appearance quality, but also have perfect physical properties, so as to better serve the entire building system and create a comfortable and harmonious living environment for people.

 

The physical performance inspection of the glass curtain wall not only verifies the feasibility of the curtain wall design scheme, but also includes the performance inspection of materials and components, as well as the inspection of installation technology and installation quality. When inspecting the glass curtain wall, the stress conditions of the assembly and installation of the test piece should be consistent with the actual situation of the project, and the consistency of the test piece with the design drawing should be ensured. During the installation of the test piece, if there is a difference in the component material model, the installer should be notified immediately to correct the error to avoid leaving hidden dangers for subsequent inspection work.

 

1. Performance inspection of materials and components

(1) Before the curtain wall is installed, the tensile strength of the post-embedded parts (anchor bolts) should be sampled on site for inspection.

(2) Before using silicone building (weather-resistant) sealants, the compatibility with the materials in contact with them should be tested.

(3) Before use, silicone structural sealants should be tested for compatibility and peeling adhesion with the materials they come into contact with, and the Shore hardness and standard tensile adhesion performance should be retested. Imported silicone structural sealants should have a commodity inspection report.

(4) Two-component silicone structural sealants consist of two components, a base and a curing agent. Before use, they should be subjected to a mixing (butterfly) test and a pull-off (glue cup) test to check the mixing degree of the structural sealant and whether the proportion of the two components of the structural sealant is correct.

(5) Randomly select 1% of the processed hidden frame and semi-hidden frame glass panels for peeling tests to check the curing degree of the structural sealant and the bonding strength between the structural sealant and the aluminum ore.

(6) During the installation of the full-glass curtain wall, the horizontality and verticality of the panel and glass ribs should be checked and adjusted at any time.

(7) Aluminum-plastic composite panels should be tested for peeling strength. (8) Testing of bending strength, radioactivity, and frost resistance of stone panels. Strength testing of structural adhesives for stone curtain walls and testing of contamination of sealants.

(9) In addition to the materials that are retested according to the general curtain wall requirements, the curtain wall energy-saving project should also retest the following properties of the following materials: the heat transfer coefficient, shading coefficient, visible light transmittance, dew point of the insulating glass of the curtain wall, the thickness, density, thermal conductivity, combustion performance, compressive strength of the insulation material, and the tensile strength and shear strength of the insulation profile.

 

2. Glass curtain wall testing is divided into laboratory testing and on-site glass curtain wall reliability testing

(1) The following problems may be encountered when sending the glass curtain wall to the laboratory for testing:

① Problems with glass curtain wall airtightness testing.

The airtightness performance of the glass curtain wall is related to the thermal insulation and energy-saving effect of the curtain wall. The airtightness testing of the glass curtain wall can find problems in the curtain wall design and installation process. By solving the problems, the airtightness index of the curtain wall can be improved to achieve the purpose of thermal insulation and energy saving.

② Common problems in glass curtain wall watertightness testing.

Rainwater leakage is the most common form of functional failure during the use of glass curtain walls. Factors that cause rainwater leakage include cracks or holes on the surface of the specimen, the presence of rainwater, and the pressure difference between the inside and outside of the specimen. Laboratory testing can easily find the cause of rainwater leakage in curtain wall specimens, and then take measures to adjust the design and construction plan so that the watertight performance test indicators of the specimens meet the design requirements.
③ Common problems in curtain wall wind pressure resistance testing.

At present, the wind pressure resistance design of curtain walls is mostly based on relevant design specifications and calculation software. With the continuous improvement of curtain wall related specifications and the gradual maturity of calculation software, the specimens can generally meet the design requirements when undergoing wind pressure resistance testing. There are two points to note during the testing process.

(2) The contents of the curtain wall on-site reliability test and evaluation are:

① Testing of glass curtain wall materials;

② Verification of the structural bearing capacity of glass curtain walls;

③ Testing of glass curtain wall structure and construction.

 

3. Under what circumstances is it necessary to perform glass curtain wall testing?

There are mainly the following situations:

(1) Failure to design, construct, and accept the glass curtain wall under the specifications;

(2) Incomplete engineering technical data and quality assurance data;

(3) Before the glass curtain wall project is suspended and resumed;

(4) Curtain wall damage occurs after an earthquake, fire, or strong wind;

(5) Curtain wall glass breaks, the open part falls, or components are damaged;

(6) Quality problems are found during the use of the glass curtain wall, and the owner requires an assessment.