Tests of Prestressed Concrete Pipes Containing A Steel Cylinder

10.14359/8703 ◽  
1945 ◽  
Vol 42 (9) ◽  
Keyword(s):  
Prestressed Concrete ◽  
Steel Cylinder ◽  
Concrete Pipes

Steel-Cylinder Yielding Analysis of PCCP with Broken Wires

2012 ◽  
Vol 503-504 ◽  
pp. 819-823 ◽  
Author(s):  
Ri You ◽  
Hong Bo Gong
Keyword(s):  
Prestressed Concrete ◽  
Pipe Wall ◽  
Nonlinear Finite Element ◽  
Simplified Model ◽  
Pipe Failure ◽  
Prestress Loss ◽  
Element Analysis ◽  
Steel Cylinder ◽  
Limit Stress ◽  
Prestressed Concrete Cylinder Pipe

The prestressing wires of prestressed concrete cylinder pipe (PCCP) provide pipe wall with compressive stress to resist internal pressure. Broken wires may cause yielding of steel cylinder and increase the risk of pipe failure with time. In order to reveal the mechanism of steel-cylinder yielding in PCCP with broken wires, a simplified model is developed and the maximum number of broken wires to preclude exceeding limit stress in steel cylinder can be determined conveniently by the equations derived in this paper. Verification analysis shows that the solution of simplified model agrees well with that of nonlinear finite element analysis. By comparing the calculated maximum number of broken wires with the detected actual number of broken wires, steel-cylinder yielding in prestress loss zone can be predicted, thus aiding condition assessment of PCCP

Continuous Thickness Control of Centrifugally Cast Concrete Pipes by an Ultrasonic Echo-System

1968 ◽  
Vol 1 (2) ◽  
pp. 50-52
Author(s):  
J. A. de Raad ◽  
A. de Sterke
Keyword(s):  
Prestressed Concrete ◽  
Large Diameter ◽  
Ultrasonic Pulse ◽  
Centrifugally Cast ◽  
Concrete Pipes ◽  
Ultrasonic Echo ◽  
Cast Concrete ◽  
Large Diameter Pipes ◽  
Pulse Echo ◽  
Made In

Large diameter pipes of prestressed concrete with a length of 10–20 ft. used for water transport are made in rotating moulds. To control the thickness of these concrete pipes during production, an ultrasonic pulse-echo system mounted at the end of the feeder is used. Basically, the air gap between feeder and inner pipe wall is continuously measured, whereby deviations due to misalignment of the feeder are electronically compensated. A prototype version of the system has proved its usefulness. An accuracy of ±5% of the nominal wall thickness was obtained.

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