Non-explosive drill hole pressurization method and apparatus for controlled fragmentation of hard compact rock and concrete

A method for breaking rock, concrete and other hard materials comprising the steps of:

• drilling a hole in a material by a drilling means;
• inserting into the hole a cartridge containing a propellant charge, the cartridge having an external diameter slightly less than a diameter of the hole;
• stemming the hole with a relatively heavy bar having a diameter slightly less than the diameter of the hole and having a mass sufficient to limit the bar recoiling to less than one third the diameter of the hole;
• igniting the propellant by any one of electrical, optical or percussive means;
• fracturing the material by the initiation and propagation of controlled fractures from a bottom of the hole.

A cartridge apparatus for breaking rock, concrete and other hard materials by a hole-bottom pressurization process comprising:

• a cartridge containing a propellant charge;
• a primer at an up-hole end of the cartridge for igniting the propellant charge within the cartridge;
• an internal relief column within the cartridge to control the rate of propellant burning, hole pressurization and maximum hole pressure;
• the burning of the propellant such that high-pressure gases are generated and serve to fracture the material through the initiation and propagation of controlled fractures from a bottom of a drilled hole;
• and thus effectively breaking and removing a volume of the material.

A stemming bar apparatus for breaking rock, concrete and other hard materials by a controlled fracture process comprising:

• a massive bar, made from steel or other high strength material, which is slightly less in diameter than a drilled hole;
• a cartridge which contains a propellant charge and which is positioned at an end of the bar;
• a firing mechanism to initiate an initiating device contained in the cartridge;
• burning of the propellant charge to generate high-pressure gases a semicolon;
• fracturing the material through the initiation and propagation of controlled fractures from a corner of a bottom of the drilled hole by the high-pressure gases;
• and thus effectively breaking and removing a volume of the material.