A New Precast Concrete Deck System for Accelerated Bridge Construction

Abstract

Full-depth precast concrete deck systems have several advantages over cast-in-place (CIP) concrete decks in bridge construction, such as improved construction quality, reduced construction time and impact on traveling public, possible weight reduction, and lower life-cycle cost. This paper presents the development of a new full-depth precast concrete deck system for accelerated bridge construction. The new system overcomes the drawbacks of existing systems, such as the large number of panels, joints, and openings; complexity of panel production and erection; need for an overlay; and difficulty of post-tensioning and grouting operations. The developed deck system consists of full-width precast concrete deck panels that are 12 ft (3.6 m) long to minimize the number of panels and joints. Panels have covered pockets at 4 ft (1.2 m) spacing in each girder line for shear connectors. These pockets were designed to minimize deck surface penetrations and eliminates the need for a deck overlay. Deck panels are prestressed in both directions: pre-tensioned in the transverse direction and post-tensioned in the longitudinal direction using a new approach that eliminates duct installation and grouting operations. These unique features enhance deck durability and improve its economic competitive with CIP concrete decks. The paper also presents the construction sequence and a case study for the implementation of the new system.