Timothy A Mathews

US Patent:

20020187730, Dec 12, 2002

Filed:

Jan 11, 2001

Appl. No.:

09/758913

Inventors:

Gordon Bristol - El Cajon CA, US
Robert Grogan - El Cajon CA, US
Timothy Mathews - San Diego CA, US
Stephen Rader - San Diego CA, US
James Rogers - Ramona CA, US

International Classification:

B24B001/00

US Classification:

451/036000, 451/028000, 451/064000

Abstract:

A gantry is constrained to move around the walls of a cylindrical, concrete tank. A rotating, high pressure water spray nozzle is mounted to a moveable platform on the gantry and connected to a source of water at a pressure of over 20,000 psi. The distance between the nozzle and an opposing surface of the wall of the tank is selected so the nozzle can remove the surface of the concrete and produce a selected surface roughness. The platform is moved vertically, with the gantry moving around the tank, so the surface of the concrete is systematically removed and roughened. A shotcrete or gunnite sprayer is then mounted to the platform, and the roughened surface sprayed with shotcrete or gunnite which sticks to the roughened surface. A tensioning head is then mounted to the platform, and wires or cables are tensioned as they are wrapped around the walls.