Protection against blast & explosion
Explosions are the rapid transformation of one material into another which has a greater volume, usually in the form of a gas. The faster that this transformation occurs, the greater the pressurisation of the resulting material. As it expands until it reaches equilibrium with atmospheric pressure, it creates a deflagration blast or detonation blast, depending on its speed.
Explosions are therefore classified according to the speed of the waves that they produce:
- Deflagration occurs when the decomposition front moves at a speed which is less than the speed of sound in the surrounding medium. This is an explosion over an extended time period, which can reach 200m/sec.
- Detonation occurs when the flame front exceeds the speed of sound for the burning gases, and a shock wave is produced. These explosions occur over a short time period (of the order of 5 to 20 m/sec).
Explosions create a shock-wave or blast (referred to as the incident pressure) which, when it meets an obstacle, causes a pressure peak (referred to as the reflective pressure = about twice the incident pressure) over a given period of time. After the shock-wave has passed, a negative pressure is produced which is equivalent to about 1/3 of the reflected pressure peak.
Stop’Blast® is the range of laminated glass developed by V2S which provides security against blast and explosion. It provides a complete solution to the requirements for optimum protection in buildings where there is a significant risk of explosion (whether accidental or terrorist in nature).
