Performance Evaluation of a New Precast Concrete Bridge Deck System

Precast concrete (PC) deck systems have several advantages over cast-in-place (CIP) concrete decks in bridge construction, such as improved quality, reduced construction duration, and less dependence on weather and site conditions. A new PC deck system was developed and implemented in the construction of the Kearney East Bypass project in Nebraska. The new system consists of full-depth full-width PC panels with covered shear pockets to minimize deck surface penetrations and eliminate deck overlay. Deck panels are pretensioned in the transverse direction and posttensioned in the longitudinal direction using a new approach that is ductless and easy to install. The study presents the live load testing of the twin bridges constructed in that project: the southbound bridge constructed using CIP concrete deck and the northbound bridge constructed using the new system. Two loaded trucks were used to evaluate and compare the performance of the two deck systems. Relative displacements between adjacent deck panels, and between deck panels and girders, were measured. Testing results indicated that the new system behaves as fully composite with the girders, and its posttensioned system is satisfactory. Finite-element analysis (FEA) was conducted to model the new deck system and compare measured and predicted strains and deflections.