Concrete structures are prestressed when predetermined compressive stresses are applied to them to counter expected future tensile stresses as a result of field loads. In Prestressed Concrete Lined Cylinder Pipe (L-301), prestressing is achieved by helically wrapping, under measured tension and at uniform spacing, a high tensile strength wire around the concrete-lined steel cylinder. This wire wrap places the steel cylinder and concrete core in compression, developing the pipe’s ability to withstand specified hydrostatic pressures and external loads with a safety factor comparable to other waterworks piping materials.
