CONCRETE BRIDGES

Evening Post, Volume CVII, Issue 16, 19 January 1924, Page 16

CONCRETE BRIDGES

INCREASED STANDARD OF

LOADING.

Considerable sums have recently been voted by the Government for the construction of new roads, and for' thia development many new bridges must necessarily be required, states the "Daily Telegraph."' Interest '*must attach, therefore, to the further application of reinforced concrete, which lias figured so largely in recent bridge construction. There is nbjv no need to look abroad for examples of such bridges. . They are: becoming very numerous at home. One of tho most'notable of "recent construction is that ovyer the Thames at Heading opened a few weeks ago. , The main, span is" lbuf t long, with an 18ft rise, while the width {betweehparaj pets is 40ft, comprising a 27ft roadway" and two footpaths, each 6ft 6in wide. The slope, on the'southern bank is 1 in 30 and on the northern bank 1 iv 35. The bridge is instructed1 oh the Hennebique systemj'-and the constructional details 'appear in"' the November issue of "Concrete." For the test a load of 372 tons was applied by thirty-one loaded vehicles, and this produced a deflection at the ecntro of the arch of less than £in. ' In view of the great developments in roau icMiic nu.w i^uia-wuiib us iv uiu loa'umg ol bridges have now b't-en mtroaucea. ioimeriy bridges met local needs. Wow, .However, some sMnuaiU oi loading ior highway bridges uas become' necessary, a hd experiments are still "In eouise or p,ogress iroin winch some demnte jaata may l)c iortheoming as to tne allowance winch snould be made for impact over Head load. . 'lhe standard loauing specined consists'of a traction engine wwgning twenty' tons drawing a number oi trailers loaded to thirteen tons each. Provision lias to be' inaue lor future' increases in traffic loads, iand in special cases of industrial centres where high indivisible loads must be i catered tor. in the same issue of^ the journal a number of illustrations of recent concrete bridges arc given, together with a list of reinforced concrete bridges recently completed, or at present in progress. .-•..-'.. L ■