A water-gel is a fuel sensitized explosive mixture consisting of an aqueous ammonium nitrate solution that acts as the oxidizer.[1] Water gels that are cap-insensitive are not strictly explosives and are referred to as blasting agents.
Tovex is an example of a water gel explosive.
Water gels contain a gelatinizing agent, also known as a thickener, that modifies their consistency, ranging from easily pourable gels to hard solids. Polyvinyl alcohol, guar gum, dextran gums, urea-formaldehyde resins are the typical gelling agents.
They tend to be less toxic and are less hazardous than dynamite to manufacture, transport, and store.[2] Water gels are also less expensive compared to conventional explosives.
They are frequently used as cartridge explosives because they are much easier to load into large casings. With water gel explosives, filling a bomb is merely a matter of pouring the material into the casing. Traditionally explosives are ordinarily cast into the casing. This process is laborious and the charge may begin to shrink creating multiple voids. A final advantage of slurry is that it can be stored in non-explosive component form and sensitized into field-manufactured explosive as it is needed. The explosive may be sensitized by the addition of gas, metal powder, or another explosive such as TNT, RDX, HMX, or PETN. The water in water-gel explosives is converted into a reactant by the addition of large amount of aluminum. Water-gel explosives represent the majority of the blasting agents used in the commercial market and have almost completely displaced dynamite.[3]