GB788735A - Improvements in or relating to bridges or other built-up structures - Google Patents

Abstract

788,735. Bridges; girders; trusses. ENGINEERING & INDUSTRIAL EXPORTS, Ltd. Feb. 9, 1956 [Feb. 17, 1955], No. 4777/55. Addition to 735,935. Classes 20(1) and 20(4) A bridge or other triangulated structure is built of triangulated solid concrete bars 5 provided with external reinforcing rods 6 which pass through hexagonal &c. concrete junction blocks 1 so that by screwing up the end nuts 6<SP>1</SP> on the rods 6 the ends of the bars 5 are held against the faces 2, 3, 4 &c. of the junction blocks, and the bars 5 are thereby prestressed in compression to the degree required for launching the bridge across a space as a cantilever, or later to compensate for any load crossing the bridge. As shown in Fig. 3 the bars 5 are of truncated Z crosssection so that the reinforcing rods 6 are accommodated in the corners of the Z from which they can be suitably spaced by eccentric spacers 6<SP>11</SP> Fig. 3. Similar concrete bars 5<SP>11</SP> with reinforcing rods 8 unite each lower transverse pair of blocks 1. Other section bars 7 span each upper transverse pair of blocks 1 and carry the decking. The decking Fig. 4 comprises a concrete surface 14 spread in situ on hollow concrete planks 12, Fig. 6 resting on transverse bearers 10 resting across each pair of blocks 1, and all secured by pins 11. The planks 12 at the sides of the bridge may be formed with kerbs 15, Fig. 4. Other similar bridge structures may be superposed.