METHOD TO REPAIR PRESSED CONCRETE LINING OF UNDERGROUND RAILWAY Russian patent published in 2011 - IPC E21D11/00 E04G23/00 

FIELD: mining.

SUBSTANCE: method of repair consists in application of a repair layer along the whole area of the inner surface of the pressed concrete lining. Then at least one layer of reinforcement net from carbon or other similar (aramid or glass fibre) with elasticity module of at least 100 GPa and strength of at least 3 GPa on the inner surface of the repair lining layer with a polymer glue. The total area of cross section of longitudinal fibres of the reinforcement net must be at least 1.5 times more than the total area of cross fibres. Then the reinforcement mesh impregnated with glue is coated with an additional repair layer with thickness of 0.05-0.1 from thickness of the initial pressed concrete lining, having the following physical and mechanical characteristics: compression strength of at least 40 MPa; - bending strength of at least 10 MPa; tensile strength of at least 5 MPa; adhesion to concrete of at least 2.5 MPa. On the inner surface of the repair lining layer several layers of polymer reinforcement mesh may be attached by means of a polymer glue as separated with a repair layer.

EFFECT: reduced cost, improved strength characteristics.

2 cl, 4 dwg