Prestressed concrete pipe prodn. process - slides heated metal pipe over concrete one and shrinks into place

摘要

The process produces a pre-stressed concrete pipe, a pipe of concrete (1) and one of metal (2) being first produced. The ID of the metal pipe is the OD of the concrete one, and it is heated to expand it so that it can be shrunk onto the latter. The concrete pipe can be built up on a plastic one, and after the metal one has been shrunk on it can be coated with plastic or cement glue. The concrete one can be cooled before the metal one is slid over it.