(China Glass Network)Semi-tempered glass belongs to heat strengthen glass with surface stress less than 70N/mm2 due to lower cooling rate after heating. The surface stress of semi-tempered glass used for curtain walls is 45N/mm2-54N/ mm2..
Intensity of semi-tempered glass can be twice of normal float glass with technology of heat strengthen. This kind glass is excellent in temperature tolerance and impact resistance, which is hardly broken by temperature jump or man-made impact. Even if it’s broken by accident, the radial cracks will reach the frame edge held by the glue or frame , to avoid falling of broken glass.
“ According to successful experience of foreign countries, we have adopted semi-tempered glass wide in the country before 2003.”
Zhao Xi’an researcher of China Academy of Building Research, famous expert in glass curtain wall state that,“It’s a pity that injury accident caused by self-destruction happened frequently after the rule of using tempered glass in curtain walls while report of injure by falling semi-tempered glass has never been heard in the past 10 years.”
“Skyscrapers as Shanghai Financial Center and Guangzhou TV Tower, the tallest freestanding tower in the world are too high to replace glass if the self-destruction happens. So it’s primary to avoid self-destruction, adoption of semi-tempered glass is essential.”
“We can’t totally repudiate use of tempered glass. It’s essential for parts of the constructions to ensure the intensity , such as glass panels for support. But when it comes to the components of the curtain wall, I prefer to use normal float glass than tempered glass, which can avoid the potential danger.”
“Practice is the sole criterion for testing truth. We should make reasonable selection of glass according to the specific circumstance of projects ,in order to get maximum safety.”
