RRC breaks hard rock by burning propellant to generate gas, which is injected into the lower part of a short drill hole.
Step 1 Drill Holes into rock 1-1/4” – 2” depending on size of cartridge needed.
Step 2 Remove RRC from packaging.
Step 3 Place RRC into drilled hole wires down, check continuity.
Step 4 Place Stemming in ' the Hole Manually or Pneumatically
Step 5 Attach Electric Match to Firing Cable
Step 6 Attach Firing Cable to Firing Box and Initiate Cartridge
RRC technology fractures rock or concrete by introducing a pulse of high-pressure gas at the base of a short drill-hole, typically 600 — 1200 mm deep. The generated gas penetrates into small micro- fractures created from the percussive drilling process or any natural ﬁssures in-the rock. –These man-made and natural micro-fractures are forced to expand and propagate into tensile cracks causing the rock to fail. The result is a characteristic conical failure or penetrating cone fracture.
Fragmentation from the RRC system is typically coarse, although natural jointing and geological factors affect both the size and the geometry of the fragments produced.
The fracture characteristics of RRC differ in comparison to explosives because RRC allows a more controlled breakage of rock or concrete material. This is due to the fact that rock/concrete is fractured in tension rather than in compression. The tensile breakage mechanism of RRC allows for a lower amount of energy than detonating explosives. This results in low vibration, low noise, reduced overpressure and minimal ﬂy rock compared with explosive blasting.
Field-testing has shown that the method performs better in harder, competent rock types than in softer, highly fractured rock masses. This can be partly attributed to the development of the cone fracture which has been observed to be less pronounced in the softer materials or in fractured
rocks where the gases prematurely escape along the existing fracture planes