Brisance is the shattering capability of an explosive. It is a measure of the rapidity with which an explosive develops its maximum pressure. The term originates from the French verb "briser", which means to break or shatter. Brisance is of practical importance for determining the effectiveness of an explosion in fragmenting shells, bomb casings, grenades, structures, and the like.
A brisant explosive is one that attains its maximum pressure so rapidly that a shock wave is formed. The net effect is to shatter (by shock resonance) the material surrounding or in contact with the supersonic detonation wave created by the explosion. Even within high explosives which build up a supersonic shock front, some build up faster than others, yield higher detonation velocities, and tend more towards controlled shock fronts in bulk, all of which lead to higher brisance.
Thus, brisance is a measure of the overall shattering ability of an explosive and is not necessarily correlated with the explosive's total work capacity. It cannot be predicted with full certainty as of now, but has to be quantified empirically.
The sand crush test is commonly employed to determine the relative brisance in comparison to TNT. No single test is capable of directly comparing the explosive properties of two or more compounds; it is important to examine the data from several such tests (sand crush, trauzl, and so forth) in order to gauge relative brisance. True values for comparison will require field experiments.
One of the most brisant of the conventional explosives is cyclotrimethylene trinitramine (also known as RDX or Hexogen).[1]