Patent ID: 7909542
Filing Date: 2011-03-22
Classification: E21D

Abstract:
1. A mine support for use in an underground excavation with a hanging wall and an opposed foot wall, the mine support comprising: a single deformable tubular sleeve with a circular cross section which is made from a ductile metal and which has a first end and an opposed second end, the sleeve being positioned in the excavation with the first end directly engaged with one of the hanging wall and the foot wall and the second end engaged with the other of the hanging wall and the foot wall by means of a pre-stressing device, a first aerated cementitious material with a first strength characteristic inside a first interior portion of the sleeve and filling said first interior portion of the sleeve; a second aerated cementitious material with a second strength characteristic which differs from the first strength characteristic inside a remainder portion of the sleeve interior and filling said remainder portion of the sleeve interior; and the first interior portion having a length, in an axial direction of the sleeve, which is greater than the length of the remainder portion of the sleeve interior in the axial direction of the sleeve and wherein said second aerated cementitious material only overlies the first aerated cementitious material, wherein the first cementitious material is stronger than the second cementitious material.