Abstract: Paste of the water-ammonium nitrate-fuel type, free of explosive elements, inert in manufacture, shipping and storage due to the fact that it does not contain air or not in a sensitizing form. A gum is used as a cross-linking agent. The product is an explosive pumpable on site by the incorporation of air.

Abstract: An anchoring cartridge for use in anchor bolting in a rock substrate such as an underground mine roof comprises a frangible casing formed from a liquid-impermeable material, the casing containing a particulate liquid-settable solid component, such as a hydraulic cement, which is in contact with a longitudinally extending absorbent material preferably both ends of which communicate with, or are adapted to communicate with, the exterior of the cartridge so that when the cartridge is immersed in an activating liquid for the solid component, such as water, the liquid is drawn into the cartridge by the absorbent material and thereby comes into contact with the solid component over its whole length within the casing. This helps to assist in the formation of a self-setting grouting composition of substantially uniform strength when the cartridge is used in a borehole drilled in the substrate.

Abstract: A string for a tennis racket and having a composite cross-section structure aving a central reinforcing core comprising twisted Kevlar aromatic polyamide and glass yarns or Kevlar aromatic polyamide yarns, this core layer having a peripheral protective coating of a polyamide.

Abstract: The invention relates to cartridges containing a mortar composition capable of being hardened by reaction with an aqueous liquid such as water. The cartridge is initially sealed and is perforated along its longitudinal axis just before use, after which the mortar composition is caused to come into contact with an aqueous liquid to cause hardening thereof. According to one method of application, the cartridge is immersed in water which causes a wetting of the mortar composition centrifugally, i.e. from the axis towards the outside. The advantages of such a cartridge are that rigidity can be maintained during activation of the mortar with ease of use and, if required, visual evidence of complete wetting of the mortar.

Abstract: Aqueous grouting compositions based on high alumina cement have the onset of setting delayed for upwards of one month by the incorporation therein of a set-inhibiting agent such as boric acid or gluconic acid delta lactone and can then be rapidly reactivated for use by the incorporation therein of a reactivator, for example lithium carbonate, to produce a high strength hardened cementitious composition. The reactivated composition can advantageously be used to anchor a reinforcing element such as a rockbolt or dowel in a borehole and for this purpose the set-inhibited cementitious composition and the reactivator can be packaged in the separate compartments respectively of a dual-compartment frangible cartridge.

Abstract: An anchoring cartridge suitable for use in anchoring a reinforcing or fixing element such as an anchor bolt in a borehole in a substrate contains a particulate liquid-settable solid component, such as a hydraulic cement, within a frangible liquid-impermeable casing. Through the solid component passes a discontinuous tube at least one end of which is located at one end of the cartridge so as to be in communication with the exterior. To activate the cartridge, it is placed within an activating liquid, such as water, which flows into the cartridge via the discontinuous tube and thus into contact with the solid component from within the cartridge over substantially its whole length, so that after a relatively short time, i.e. a few minutes, the activated cartridge can be positioned for use in a borehole.

Abstract: Reinforcing or fixing elements such as anchor bolts are anchored in a borehole drilled in a substrate such as an underground mine roof with an anchoring cartridge in which a particulate liquid-settable solid component, for example a hydraulic cement, is contained in a liquid-impermeable casing, the solid occupying a volume which is less than the normal free volume of the casing and the cartridge being at least partially evacuated so as to cause the casing to be in contact with the solid component over substantially its whole length within the casing. This ensures that when the cartridge is immersed in an activating liquid, for example water, and the casing perforated, the activating liquid is drawn rapidly into the evacuated space adjacent the solid component over its whole length thereby helping to ensure the formation of a self-setting grouting composition of uniform strength when the cartridge is used.