EP 0407632 B1 19930303 - PROCESS FOR MAKING CONCRETE PIPES AND PRESS THEREFOR
Title (en)
PROCESS FOR MAKING CONCRETE PIPES AND PRESS THEREFOR
Publication
Application
Priority
DE 3807511 A 19880308
Abstract (en)
[origin: US5051223A] A concrete pipe is produced by introducing a wet concrete mass into a pipe form to produce a cylindrical mass having an inner wall, compacting the cylindrical concrete mass by applying pressing rollers to the inner wall, smoothing the inner wall of the compacted cylindrical concrete mass, and applying a liquid impregnation medium to the inner wall under pressure after the concrete mass has been compacted, the inner wall has been partially smoothed and the concrete mass is still damp. The pressure is sufficient to cause the impregnation medium to permeate the damp concrete mass to a depth of at least 10 mm.
IPC 1-7
IPC 8 full level
B28B 21/24 (2006.01); B28B 21/26 (2006.01); B28B 21/94 (2006.01)
CPC (source: EP US)
B28B 21/26 (2013.01 - EP US); B28B 21/94 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH DE ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
US 5051223 A 19910924; AT E86167 T1 19930315; DE 3807511 A1 19890921; DE 3807511 C2 19910613; DE 58903682 D1 19930408; EP 0407632 A1 19910116; EP 0407632 B1 19930303; ES 2041375 T3 19931116
DOCDB simple family (application)
US 40556089 A 19890911; AT 89112630 T 19890711; DE 3807511 A 19880308; DE 58903682 T 19890711; EP 89112630 A 19890711; ES 89112630 T 19890711