摘要 |
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. The cartridge of the invention is safer for use, particularly in coal mines, than the conventional resinous cartridges. |