Breakage of prestressing wire wraps is an indication of damage in Prestressed Concrete Cylinder Pipe (PCCP) due to corrosion, hydrogen embrittlement, overloading, and manufacturing defects. The strength of the damaged pipe is not only related to the number of broken prestressing wire wraps but also to the location of the break regions along the length of the pipe. In this paper, a nonlinear Finite Element Method (FEM) was used to compare the structural integrity of a PCCP when wire wrap breaks occur at the spigot joint, the bell ring joint, and in the middle of the pipe section.
For the structural evaluation, stresses and strains developed in the damaged PCCP were recorded and compared using the FEM computer modeling software, (Abaqus). The Cracking and Ultimate Strength Limits, as defined in the American Water Works Association (AWWA) C304 Standard for Design of Prestressed Concrete Cylinder Pipe, of a damaged PCCP were investigated by increasing the internal pressure of the pipe while the severity of damage was manipulated by increasing the number of broken prestressing wire wraps. The results were obtained for a 60-inch embedded cylinder pipe (ECP) with 5, 35, 70, and 100 wire wrap breaks. The proposed model was applied to evaluate the effects of wire wrap breaks at the joints and in the middle of a pipe section. Based upon the obtained results, a comparison between wire break wrap in the middle of the pipe and the joint are presented and discussed.
Effects of the Location of Broken Prestressing wires wraps in structural integrity of a damaged PCCP