Abstract: The invention relates to a process for consolidating and sealing coal and/or rock, soil and brick formations in mining, tunnelling and construction by reacting polyisocyanates and aqueous alkali silicate solutions in the presence of a catalyst prompting the trimerization of the polyisocyanate. The catalyst is used in an amount of 6.0 to 14.5 mmole per mole of NCO groups in the reaction mixture.When the reaction mixture is introduced into the coal and/or rock, soil and brick formation to be consolidated and is cured, excellent consolidation results are achieved on account of the formation of an "interpermeated network" of inorganic and organic polymer.

Abstract: A tubular rock bolt of strong elastomeric material, inserted into a bore of a tunnel roof or a mine face, has an outlet end spaced from the remote end of the bore through which a hardenable adhesive mass is inserted under pressure by way of an inlet in the opposite bolt extremity. An obstruction inserted between the bore wall and the bolt allows only some of the adhesive mass to enter a proximal portion of the bore under considerably lower pressure, either by flowing through or past the obstruction or by exiting through one or more restricted openings in the bolt periphery.