| 摘要 |
<p>728,917. Composite concrete beams. BRUCE, R. July 7, 1953 [July 9, 1952], No. 17327/52. Class 20 (4). A composite concrete beam for floors and ceilings comprises a number of spaced prestressed concrete planks a in parallel formation, cellular blocks b recessed at e to seat onthe planks a, a concrete mix undersurface d having moisture-absorbing and fire-resisting qualities, and a filling c of structural concrete covering the planks a. To form a beam the planks a are supported on a casting bed with side shutters, a space being left between the planks and the bed. The blocks b are placed in position, one or two being temporarily omitted to permit the pouring of the concrete mix to form the undersurface d whereupon the blocks b previously left out are placed in position and concrete of structural quality is introduced into the gaps over the planks a. In forming a floor the beams, of requisite length, are raised and supported at their ends on supporting walls, the space between adjacent beams being filled with grout. If desired, glass fibre, or sound-deadening material, may be applied to the upper surface of the floor, such material being subsequently covered by a layer of in situ concrete. In a modification, the blocks b are omitted, concrete of structural quality filling the gaps between the planks a.</p> |
