 The hydrodemolition system consists of a high-pressure water pump(s), a robotic cutting tractor and a support vehicle or trailer, which carries the pump(s), cutting tractor, spare parts and tools and will have tanks for fuel and water. The pumps are connected to the cutting tractor using special high-pressure hoses. To minimize the loss in pressure, the pumps should be located as close as possible to the work area.
The pumps are designed to operate at a specified pressure and volume. Most pumps are powered by a diesel engine, which have an optimal operating rpm. The optimal rpm is matched to the pump, which results in the specified volume of water. When the proper nozzle is installed the diesel engine and pump deliver the specified volume water at the pumps designed pressure. Our pumps are powered by diesel and electric motors and provide 16 gpm at 36,000 psi. Two pumps power each hydrodemolition cutting tractor. However in some cases three pumps may be used if the compressive strength of the concrete is high, for deep removals or if there is a need to increase production. During hydrodemolition the pumps are set to operate at their designed pressure and volume. The quality and depth of removal are controlled at the cutting tractor. In basic terms it is simply the length of time, which the water jet is directed at the concrete surface that determines the depth of removal. This contact time is controlled at the robotic cutting tractor. There are five perimeters that determine the quality and depth of removal. They are: Rotation speed of the nozzle Angle of the nozzle to the surface Height of the nozzle above the surface Traverse speed Advance distance
Rampart uses a variable speed-rotating nozzle, which can be adjusted from 0 to 1,800 rpm. In addition, the nozzle can be angled between 5° and 30° from vertical. When rotating, the angled water jet creates a demolition cone. By raising and lowering the nozzle the base of the cone can be increased and decreased in diameter. The robotic tractor moves the rotating nozzle back and forth on a traverse beam perpendicular to the direction of the tractor and tractor advances following a preset number and time for the traverse. The following examples illustrate how these five functions work together to control the quality and depth of removal. Scarification: If the desired effect is to scarify the concrete by removing .25 to 1.0 inch in preparation for a bonded overlay the nozzle would be angled at 30°, raised to 3 inches above the surface, rotated at 1,500 to 1,800 rpm, the traverse speed set at two feet per second and the advance at 1.5-2.0 inches. During scarification the nozzle must move fast enough that the water jet contacts virtually the entire concrete surface momentarily thus insuring a uniform shallow removal. Partial Depth Removal: If the desired effect is to remove 4 inches of concrete the nozzle would be angled 15°-22°, lowered to within 0.5 inches of the surface, rotated at 200-500 rpm, the traverse speed set at 0.25 to 0.5 feet per second and the advance at 0.5 to 1.0 inch. During deep removal the water jet can dwell longer on the surface thus giving it sufficient time to remove the concrete to the desired depth. The contact or dwell time of the water jet on the concrete surface will determine the depth of removal. | 
