Abstract: A method in the manufacture of steam-cured light-weight aerated concrete having hydrophobic properties, comprising preparing an aqueous expandable and solidifiable slurry, one or more hydraulic binders and one or more silica-containing materials casting the slurry in a mould; expanding and solidifying, and optionally cutting the solidified slurry; and steam-curing the resultant light-weight aerated concrete, wherein prior to casting said slurry it is admixed with silicone oil in a quantity of 0.05-0.50%, calculated on the dry weight of the starting mixture.

Abstract: Cellular lightweight concrete slabs are manufactured by cutting a still plastic block of cellular concrete mass resting on a first support horizontally into slices which are then moved over one by one to a second support and piled in reversed order thereon, at least one of the two broadsides of each body slice being subjected to a treatment before being covered by the next transferred slice. The treatment prevents the body slices from cementing together during the subsequent steam-hardening process and may also improve the quality of the slabs when hardened. An apparatus for each manufacture features a movable suction head for transferring the body slices as well as associated means for cutting and treating said slices.

Abstract: The present invention is concerned with a method of manufacturing porous concrete products in which there is first formed an at least approximately parallelepipedic body of concrete mass which is plastic at a given stage but still shape permanent, whereafter said body resting on a first support surface, while the concrete mass is still plastic, is divided into a multiplicity of slabs by means of horizontal cuts, the thickness of each slab being much smaller than the original height of the body, whereafter a multiplicity of the thus obtained slabs are charged to an autoclave in which they are steam-cured in a group resting on a further support surface. The invention is characterized in that one slab at a time is lifted from the remaining body resting on the first support surface and is transferred, while being turned through 90.degree., to the further support surface on which surface the transferred slabs are placed on one long-side edge thereof in mutually spaced apart relationship.

Abstract: Cellular lightweight concrete slabs are manufactured by cutting a still plastic block of cellular concrete mass resting on a first support horizontally into slices which are then moved over one by one to a second support and piled in reversed order thereon, at least one of the two broadsides of each body slice being subjected to a treatment before being covered by the next transferred slice. The treatment prevents the body slices from cementing together during the subsequent steam-hardening process and may also improve the quality of the slabs when hardened. An apparatus for such manufacture features a movable suction head for transferring the body slices as well as associated means for cutting and treating said slices.