Standard:AWWA C301,AWWA C304,AWWA M9
1.1PCCP is the abbreviation of prestressed concrete cylinder pipe which is a composite pipe material with excellent performance. Structurally, PCCP (see Figure 1) is composed of steel cylinder, core concrete, prestressed wire, cement mortar protection coating and epoxy coal pitch anticorrosion coating.
Structure Diagram 1 of PCCP
1.2 Features of PCCPCompared with other pressure pipes, PCCP has following features:1) High working pressure: with the maximum working pressure up to 2.0MPa. 2) Good structural rigidity: especially suitable able for the deep earth laying environment.3) Good pipe sealing property: the steel cylinder and the steel connector inside the pipe ensure the good sealing property of the pipe body.4) Long service life.5) Convenient and simple installation.1.3 Quality of Finished Product1.3.1 Core ConcreteThe core concrete at the bell and the spigot of the pipe shall not have such flaws as incomplete filling, corner missing, opening or hole, etc.The inner concrete surface of the pipe shall be flat and clean. The inner concrete surface of the lining type prestressed concrete cylinder pipe shall not have dross, stone and severe laitance layer, and the inner concrete surface of the embedded type prestressed concrete cylinder pipe shall not have opening or hole, or pit, or void and pit, etc. with the diameter or depth more than 10mm.The working surface of the steel ring at the bell and the spigot shall be clean, without concrete, cement mortar and other dirt matters.The external protection layer of the finished pipe shall not have the phenomena of empty, layering and desquamation. 1.3.2 Internal Surface CrackThe width of the circumferential crack or the helical crack on the internal surface of the pipe shall not be more than 0.5mm (except laitance crack), the width of the circumferential crack in the range of 300mm away from the spigot shall not be more than 1.5mm, and the longitudinal visible crack with the length more than 150mm shall not be allowed to appear in the range of which the included angle to the parallel line of the internal surface of the finished pipe along the longitudinal axis thereof is 150°. 1.3.3 External Surface CrackThe cement mortar protection coating covered on the surface of the prestressed wire is not allowed to have any visible crack while the cement mortar protection coating covered in the non-prestressed wire area is not allowed to have the visible crack with the width more than 0.25mm.The allowable deviation of the finished pipe shall be in accordance with the regulation in the following table. Unit: mm
Prestressed High-strength Steel Wire
Cement Mortar Protection Course