Study of a lightweight steel-concrete bridge deck concept

In this paper, a lightweight steel-concrete deck concept is presented, combining the advantages of both concrete and steel deck types and avoiding their disadvantages. In this concept, a network of longitudinal and transverse ribs transmit shear forces between thin steel top and bottom plates. In order to achieve a lightweight composite structure, the concrete volume is only 32 % of the volume between the plates. The first part of the paper describes static loading tests on a full scale bridge deck test panel (3.60 m x 1.50 m). First, the general behaviour is examined by applying a 100 kN wheelload on multiple positions thereby determining the amount of transverse load spreading. Second, the most adverse position is chosen for a static ultimate failure load test at 960 kN. Third, also the local behaviour, i.e. the transverse bending in the top plate and the ribs, due to direct load introduction is tested in failure due to shear for a 600 kN wheelload. In the second part, a finite element model of the test panel is created and verified with the experimental data set of the 100 kN static loading tests. Afterwards, a numerical study is carried out with this finite element model to optimize the bridge deck characteristics, such as rib thickness, rib spacing, and plate thicknesses. The results indicate that the lightweight steel-concrete sandwich bridge deck concept possesses the necessary static resistance to bridge loads.