Title: Evaluation of the Orientation of Concrete Finishing Machines in Skewed Bridges
Author(s): Faress Hraib, Li Hui, Brandon Gillis, Miguel Vicente, and Riyadh Hindi
Publication: Symposium Paper
Appears on pages(s): 129-142
Keywords: composite girder bridges, deck slab construction, screed machine orientation, skewed bridges, bridge construction loads
During bridge construction, the concrete finishing machine weight, along with other dead and live loads,
affects the stability of the structure during construction and the service life of the bridge. These eccentric unbalanced
loads lead to torsional moments in the exterior girders of the bridge, deflection of the overhang, and excessive rotations
in the exterior girders. In skewed bridges, the finishing (screed) machine can be oriented parallel to the skew or
perpendicular to the girders during construction. This study focused on evaluating different orientations of the machine
along the span of skewed bridges. Finite element models of bridges with different skew angles were developed using
SAP2000 to simulate construction conditions. These bridge models were then subjected to different machine
orientations to form a better understanding of this phenomenon and to find the most effective method to operate the
concrete finishing machines. The results showed that moving the screed machine parallel to the skew angle led to
rotations that were more balanced between the exterior girders compared to moving it perpendicular to the girders.
Therefore, a more leveled concrete surface can be obtained when running the machine parallel to the skew.