A method for pumping concrete by means of a foerderleitung and foerderleitungsabschnitt for exercise of the method

摘要

1416701 Pumping concrete TAYLOR WOODROW CONSTRUCTION Ltd 27 March 1973 [30 March 1972] 15220/72 Heading E1S [Also in Division F2] To reduce the resistance to flow of readymixed concrete when being pumped through a pipeline to an on-site point of use a boundary layer of water is pumped along the inner surface of the pipeline, the water content in the 'mix being reduced by an amount substantially equal to the amount of water in the boundary layer flow. Flow may be assisted by introducing into the boundary layer water agents such as methyl cellulose, sodium alginate or polyethylene oxide. A section 5 is inserted in the pipeline and this may have a water-jacket 6 surrounding perforations 7 around the circumference of the section 5, water being supplied by a pump 8. In an alternative arrangement, Fig. 5, not shown, the section 5 is formed with an external annular water chamber which communicates with the interior of the section through an annular slot which is angled so that the water is directed with a component in the direction of flow of the concrete.