Protecting civilian buildings from terrorist activity is one of the most critical architectural design challenges today. Glass producers are also working hard to analyse the effects of blasts on physical structures to identify the best possible blast-mitigation solution, in order to maximise protection whilst not compromising structural integrity. |
Shards of glass flying through the air cause many of the deaths and injuries from a bomb blast. In a bomb blast, shattered glass becomes thousands of tiny debris flying through the air. The energy of the pressure wave that is created by an explosive device must be absorbed by the building façade. A too-rigid glazing unit will simply transfer all of the forces to the frame, fixings and walls of the façade, increasing the chances of the blast penetrating the building. Effective blast-resistant glazing can itself deflect forces, absorbing as much of the blast energy as possible. It is also important that flying glass debris is reduced and that the window is retained in the frame, maintaining the integrity of the external building structure. To meet these necessary characteristics, laminated glass would seem to be the right choice. The PVB interlayer holds the glass in place even when the glass is broken, providing significant protection against dangerous flying or falling glass fragments from the structure. However not every laminated glass is right for the job. Many factors affect laminate protection including the interlayer's physical properties and thickness as well as how the finished laminate is incorporated into the frame, and then the frame into the building. Also, the size of blast, and its distance from the blast point are critical considerations. A total 'systems approach' is essential for optimum protection. More information about blast-resistant glass is available on the selected links |