Composite materials, useful e.g. as shaped bricks forming floors for drying clarified sludge, comprising porous, water-permeable layer covered by thicker layer of concrete with larger pores

摘要

New composite materials (A) comprise a first, porous, water-permeable layer (I), covered by a second, thicker, water-permeable layer (II) of concrete having larger pores than (I). An independent claim is included for the production of composite materials (A') (preferably, but not restricted to, (A)) comprising a first layer (I') and a second layer (II') of concrete, involving: (1) laying fresh concrete to form (II'); (2) applying fresh compounding material consisting of a non-aqueous binder and first aggregates to form (I') to the concrete while still wet or moist; (3) densifying the structure; and (4) allowing the concrete and compounding material to harden. Alternatively the layer (I') is formed first, followed by application of fresh concrete to (I') while still fresh to form layer (II').