The use of blast resistant windows in blast resistant design
Walls, doors and windows in blast resistant architectural design are required to be in perfect harmony, so they provide the highest level of protection to people and equipment. Windows represent the greatest risk for injuries of personnel during a blast incident. Common annealed glass windows are not capable of withstanding high pressures, and therefore are very likely to shatter, which results in the fragmentation of the glazing unit. Consequently, the shattered pieces of glass may injure personnel, and might even be lethal.
To avoid this from happening it is not recommended to install windows in structures where there is a risk of a blast event. There is however a chance that windows are required by the project owner. In this case blast resistant windows provide a good solution. Such windows should minimize, if not eliminate, flying glass fragments during any explosion to protect people.
Blast resistant windows in high risk structures
The first and foremost requirement for windows is that the window design should be in line with the blast loads of the walls and doors. Furthermore, standard annealed glass does not provide sufficient safety, therefore glazing materials should be of high strength such a laminated glass, polycarbonate and plastic interlayer, depending on the overpressure. The frame of the window is of equal importance as the glazing unit. The frame must have sufficient strength to restrict edge deflection. This will prevent the glazing to dislodge in during a blast event. Generally, steel is the best solution for window frames because of its mechanical properties.
Choosing the most appropriate window therefore depends on the mechanical properties, blast loads, and the interior hazard from failed windows. Window failure that results in shattered glass may in some instances be acceptable as long as the glass fragments do not become flying projectiles, which might cause injuries to people.
For more information about blast resistant windows download our eBook Blast ratings for fire and blast protective products.