GB625264A - Improvements in building units and in the methods of producing the same - Google Patents

Abstract

625,264. Moulding composite building slabs. SCHWARZ, A. July 1, 1946, No. 19652. Convention date, July 3, 1945. [Classes 22 and 87 (ii)] [Also in Group X] A building block, Fig. 3, having an inner core of gypsum 17, is made by casting a layer of concrete 14 on the bottom 34, Fig. 4, of a mould, inserting a wooden or metal frame 46 into the mould with parts 49 extending into the concrete layer, casting the inner core of gypsum, removing the frame, filling the mould with concrete and levelling the top surface of the concrete. The parts 49 prevent the penetration of the gypsum underneath the frame 46. The gypsum is poured onto a baffle plate 59, Fig. 10f, to prevent disturbance of the still wet concrete and to mark the height of the core required. The moulds are moved along a conveyer consisting of rollers having spaced wheels between which U-shaped supports 35 for the mould are guided. The travel of the moulds on the rollers causes a slight vibration of the moulds. After moulding, the blocks are stacked and cured by passing hot air over them. The mould comprises angle irons 37, 38 (not shown) connected by wing nuts 39 and bolts which engage in spaced holes in the angle irons. Liners 40 may be provided on the walls of the mould for forming grooves in the side and end walls of the blocks. The blocks may be reinforced with wire meshes and rods. The reinforcement may be pre-stressed. One side of the block has reinforced load bearing flanges. To make blocks containing pipes for the passage of heating or cooling fluid, a layer of dry sand, clay or cinders is placed on the first concrete layer, the pipes are pressed into the sand until about half protrudes, then a thin spray of hot paraffin or a sheet of oil paper is placed on the pipes and the sand layer, then a light gypsum layer is added, and the biock finished as before with a gypsum core and concrete sides. The gypsum composition, which is quick-setting, is made by mixing 10 pounds of infusorial earth with 16¢ gallons of water at 60 to 70‹ F., then adding and mixing 45 pounds of semi-hydrated gypsum. The excess water in this mixture, which water evaporates during curing, improves the bond between the gypsum and the concrete.