Plastics reinforced cement pipe manufacture - by winding reinforcing filaments into the wall under zero tension

摘要

A reinforced cement pipe is made by forming a wet fibrocement sheet and winding it upon a pipe forming mandrel. A continuous reinforcement of an aromatic polyamide (such as KEVLAR RTM) is also wound onto the mandrel at zero tension without stretching and remains embedded in the fibro-cement. Several layers of fibro-cement and several polyamide layers, perhaps of opposite hand, may be applied. A pipe having a higher bursting strength than with tensioned reinforcement is formed. The pipe is useful in piping water.