Curtain wall specification

Engineering specification is a summary of mature experience rather than a prospect of future technology development. The principle of specification formulation is to include mature technologies and write a mature one. New technologies of curtain wall types that are still under development or on trial are not included for the time being. After extensive application, accumulation of more reliable experience, there is a basis for inclusion. Therefore, the specification does not limit the application of new technology, the content not included in the specification, as long as it is not prohibited by the specification, which can generally be applied in the project, in the application of experience, make it mature. The view that technologies not included in the specification should not be used is inappropriate. Of course, the adoption of new technologies not included in the specification should be based on sufficient basis, reliable, and curtain wall manufacturers should bear the corresponding technical responsibility.

In the recommended national standard “building curtain wall”, there is a requirement that the deflection of the beam column is not more than 30mm. The span of structural members can be less than one meter or more than 100 meters, so it is not appropriate to use absolute deflection value control in structural design. For example, the height of the glass curtain wall of wuhan high-speed railway station reaches 36m, and the deflection of the supporting steel column reaches 110mm, far greater than the limit of 30mm, but its relative deflection is only 1/327, which can fully meet the requirements of use. The span of the glass curtain wall of Terminal 3 of Capital Airport reaches 40m, obviously the limit of 30mm is not feasible at all.

Specifications are a summary of experience with mature technologies, so they only cover a certain range. A technology can be applied to a wide range of applications, but only a small range of applications, experience, technology maturity. The specification is based on this mature range of technology, so the provisions of the specification are also applicable to this predetermined range, this is the scope of application of the specification. It does not mean that the technology can only be used within this range. Of course, beyond the scope of application of the specification, only according to the specification of design and curtain wall construction, may not meet the requirements, which often also need more technical measures, if necessary, but also to carry out experiments, technical demonstration. Therefore, the scope of application of the specification can not be understood as the scope of use of the technology, and it is not allowed to use the technology beyond the scope of application of the specification, so that there will be many contradictions, but also restrict the development of technology.