Abstract: A frangible cartridge for anchoring a reinforcing element such as a rock-bolt in a borehole drilled in rock strata, for example an underground mine roof, contains as separate constituents (A) an aqueous liquid and an alkali metal silicate and (B) a gelling agent for the alkali metal silicate, the gelling agent being capable of forming a gel from the alkali metal silicate when brought into contact therewith as a result of the reinforcing element being caused to break the cartridge and mix together the constituents (A) and (B) within the borehole so as to form a grouting composition around the reinforcing element, the grouting composition when hardened serving to anchor the reinforcing element in the borehole. In a preferred embodiment, a hydraulic substance such as a hydraulic cement is incorporated in constituent (B) and is hardened by the aqueous liquid present in constituent (A) when the contents of the cartridge are mixed by the reinforcing element.

Abstract: A method of reinforcing rock strata, such as that around underground openings in mines, is effected by using a first wooden reinforcing dowel to drive a second wooden reinforcing dowel into contact with resin capsules located at the inner end of a borehole. The first dowel is then removed from the borehole while additional resin capsules are positioned in the borehole and a further wooden dowel is then inserted into the borehole so as to become embedded in mixed resinous composition from the additional capsules. In this manner it is possible to reinforce the strata to a considerable depth, for example upwards of 16 feet, without the danger of metallic drill rods becoming jammed in the borehole and thereby obstructing subsequent cutting of the reinforced strata by mining machinery.