GB424268A - A new or improved concrete building block and method of manufacturing the same - Google Patents

Abstract

424,268. Moulding concrete &c. blocks. REINFORCED CONCRETE BUILDINGS, Ltd., and TEMPLE, J. E., 2, Robert Street, Adelphi, London. Aug. 15, 1933, No. 22781. [Class 87 (ii)] [See also Group X] Precast concrete or cement building-blocks are manufactured by separately moulding an outer face a under great pressure so that it is impervious to moisture and thereafter bonding the face a to a relatively weak porous body portion e by an intermediate layer b of concrete. The outer face may be formed with grooves or channels c<1> or with undercut or wedge-shaped frogs or projections and may have metal clips c partly embedded therein. The clips, Fig. 4, may be formed from wire bent to form two U-shaped loops in one plane with a third U-shaped loop at right angles thereto. The third loop is embedded in the outer face, preferably in the grooves c<1>, and the other loops are bent outward so that they may be embedded in the layer b. An aggregate of shingle, sand, ballast, stone chips or other impervious material may be used for the face a which may be white or tinted, and its external surface may be plain or patterned and may be wire-brushed or rubbed or ground to remove any adhering cement skin. It may be moulded in an hydraulic press with a pressure up to one ton per square inch exerted on the flat face or at the edge. The body portion may contain porous material such as broken brick or brick waste, pumice or well-burnt furnace clinker. When hard, the outer face is placed face downward in a mould, the layer b is poured in, wooden cores for cavities f may be positioned and the mould filled with the porous concrete and strickled or tamped. Plain, channeljointed, L-shaped corner, stanchion or stringer blocks may be produced. The Provisional Specification refers to Specifications 248,512, [Class 87 (i)], 292,425, [Class 87 (ii)], and 295,470, [Class 87 (i)].