RFB-OC069-08 - Catch Basins and Manholes

Summary of Specifications:
This specification includes the fabrication of pre-cast concrete catch basins and pre-cast concrete manhole units. Frames and grates are not included in this bid. Pre-cast concrete drainage units shall be machine made or cast at the manufacturer's yard to the sizes and shapes outlined below. A) Machine made units are those made by the following methods--roller suspension, centrifugal, packerhead, machine tamped, machine vibrated, or any other method provided Orange County Department of Public Works approves beforehand. B) Cast units are those made from concrete placed and consolidated by conventional equipment. These units develop resistance to freeze-thaw damage through the use of entrained air in the concrete. Cast units include bottom slabs, bases, top slabs, conical top sections as well as the riser units.