Inorganic cement grouting system for use in anchoring a bolt in a hole

Abstract

In an inorganic cement grouting system for use in anchoring a reinforcing member such as a rock bolt in a hole, e.g., in a mine roof, by the reaction of the mixed components of the system so as to form a hardened grout around the reinforcing member, the two separate components of the system are: (1) a slush or sludgy mass of a particulate inorganic cement, e.g., an hydraulic cement, and a liquid which is nonreactive therewith, preferably a hydrocarbon, and (2) a liquid, e.g., water, which is reactive with the cement; and sand is present in the cement slush and/or the reactive liquid. The sand is graded to the extent that the deviation from the median particle size is more than about .+-. 20, and usually more than about .+-. 30, percent; and particles larger than about 600 microns constitute no more than about 10 percent, and preferably about 5 percent or less, of the total volume of the sand. The inorganic cement constitutes more than 10 percent, and the weight of the sand is no more than about 80 percent, of the total weight of the two components. The two components preferably are delivered into the hole separately, e.g., from separate feeding conduits or, more preferably, in separate compartments of a frangible package, which is broken by the penetration and rotation of the reinforcing member. Graded sand produces a grout having a higher shear strength than that produced from uniform sand, and the substantial absence of particles larger than about 600 microns facilitates packaging and insertion of the reinforcing member into the package.

Dependencies are inferred from the claim text.