Abstract: A machine and method of extruding concrete building product, e.g., brick, tile, paver, or shingles, and concrete mixture therefor. The mixture has aggregate, liquid and binder that includes fly ash and can include slag with moisture content controlled producing a zero or negative slump loose feed mixture compacted in a consolidation chamber of the machine into increased density consolidated mixture extruded from an extrusion chamber in communication with the consolidation chamber with compaction force being generally transverse to extrusion force. Compaction force is maintained during extrusion through a die of non-tapering construction. Where the extruded product is a brick, the extruded slug is cut into a plurality of bricks using a rotary cutter having an offset forming an increased moisture absorbing region in the cut surface of each brick formed from the slug that better bonds with mortar during bricklaying.

Abstract: A machine and method of extruding concrete building product, e.g., brick, tile, paver, or shingles, and concrete mixture therefor. The mixture has aggregate, liquid and binder that includes fly ash and can include slag with moisture content controlled producing a zero or negative slump loose feed mixture compacted in a consolidation chamber of the machine into increased density consolidated mixture extruded from an extrusion chamber in communication with the consolidation chamber with compaction force being generally transverse to extrusion force. Compaction force is maintained during extrusion through a die of non-tapering construction. Where the extruded product is a brick, the extruded slug is cut into a plurality of bricks using a rotary cutter having an offset forming an increased moisture absorbing region in the cut surface of each brick formed from the slug that better bonds with mortar during bricklaying.

Abstract: A system for making extruded cement-based articles. The process can include forming a cement-based feed mixture including water, aggregate and binder and directing the feed mixture to a vacuum zone, wherein sufficient vacuum is maintained in the vacuum zone to remove entrained air and, preferably, excess water, from the feed mixture. The feed mixture is held in the vacuum zone at a negative pressure for a time sufficient to form a vacuum-treated or densified mixture. The vacuum-treated or densified mixture is passed through an extruder at an elevated pressure to provide an extruded cement-based article.