GB486601A - Improvements in or relating to building construction - Google Patents

Abstract

486,601. Floors and like structures; beams. LEEMHUIS, J. C. P. Dec. 8, 1936, No. 33735. [Classes 20 (ii) and 20 (iv)] A hollow floor or roof structure comprises a series of lower beams supported at their extremities and having upper and lower flanges and a series of upper beams partly interjacent and resting upon said lower beams and having upper and lower flanges, adjacent upper and lower beams being locked together' in the direction of their load by means of at least one transverse rib secured to one of the adjacent beams and adapted to fit between the flanges of the other adjacent beam. The beams may be formed of reinforced-concrete or from sheet metal. As shown, the floor or roof structure is formed by a, series of closely assembled flanged beams which comprise upper beams A resting on lower beams B, Fig. 6, to provide a hollow structure. The beams are of T-shaped cross-section, each beam A, Fig. 3, having a narrow lower flange 10 and wide upper flange 11 joined by a vertical web 12, while each beam B, Fig. 2, has a narrow upper flange 13 and wide lower flange 14 joined by a vertical web 15, the webs 12, 15 being preferably flared as shown at 17, 18. The beams A, B are formed with transverse ribs 19, 20 arranged alternately on either side of the webs 12, 15, the disposition of the webs 20 to each side of the web 15 being in reverse rotation to that of the ribs 19 about the web 12 so that when the beams are assembled as shown in Fig. 6 with the ribs fitting between the flanges of an adjacent beam, the ribs are in aligned rows extending longitudinally of the structure. Clearance holes 22, 23 may be provided in the webs and ribs of the beams to permit the run of reinforcing members and /or service pipes, conduits and wire along the structure. When the beams are produced in concrete, a metallic reinforcing member built up as shown in Fig. 7 is preferably employed. In constructing such a member for producing an upper beam A, longitudinal rods 24 are secured together by transverse rods 26 for the upper flange 11 while a single longitudinal rod 25 of heavier gauge metal for reinforcing the lower flange 10 is secured to the rods 24, 26 by rods 27 which constitute reinforcements for the web 12. The rods 26, 27 are located in the requisite position for the ribs 19 and suitably shaped rods 28 are secured at these points as a reinforcement for the ribs. The various members of the framework may be secured together by spot welding. In the framework for producing the lower beams B, the middle rod 24 of the three longitudinal rods embedded in the lower flange 14 is formed of heavier gauge metal.