VERFAHREN ZUM HERSTELLEN UND/ODER BEHANDELN VON BETONSTEINEN.

摘要

When concrete blocks are to be used as paving stones, they are given an artificially roughened surface by applying to them in the moulds the press rams on a press plate. The part in contact with the concrete and carrying the knobs and recesses is made of rubber or plastic which is vulcanised or bonded to the rams. Further roughening can be applied by blasting jets of air or water through nozzles over the surfaces.