EXPERIMENTAL STUDY ON CURVED COMPOSITE I-GIRDER BRIDGE SUBJECTED TO IRAQI LIVE LOADING FOR ROAD BRIDGES

Experimental programme was carried out to investigate the flexural behaviour of horizontally curved composite I-girder decks subjected to Iraqi Standard bridge live loads. This program included fabricating and testing five scaleddown, simply supported, curved bridge models, 3 m in central span length. Each model included four steel girders, with 175 mm girder spacing for the first two models, which had curvature (L/R) of 0.2 and 0.3, respectively. The other three models had 200 mm girder spacing, with curvature of 0.1, 0.2 and 0.3, respectively. The applied loads were equivalent to the self-weight and superimposed dead load to achieve that of the full scale designed bridge plus one of the Iraqi bridge live load cases (Lane, Military loading: composed of tracked vehicles class 100 and wheeled vehicles class 100) sequentially. The experimental results revealed that the Iraqi Wheeled load case controlled the behaviour of most of the bridge models; all the girder deflections were below the permissible AASHTO LRFD 2012 limit. The longitudinal mid-span bottom flange girder strain was less than the girder yield strain and the maximum longitudinal mid-span concrete strain at the top surface was (469 micro-strains) which was lower than the ultimate concrete strain of (3000 micro-strains). The deflection and the longitudinal girder strains increased with the increasing curvature, whereas the girder spacing exerted only a very slight effect.