Lined concrete pipe prodn. method - delivers hardening material between lining and pipe before latter has set

摘要

The method produces a concrete pipe with corrosion-resistant lining. A thin-walled tube forming the lining and of corrosion- resistant material such as PVC is inserted in the concrete pipe and the intervening space filled with hardening material such as cement. This material is delivered into the intervening annular space at a moment when the concrete of the pipe has not yet set. It can be injected under pressure, and while the concrete pipe is still enclosed in shuttering, the tube being stiffened by an internal core. The inner pipe surface can be roughened before insertion of the material.