Design of shear connectors for precast concrete decks in concrete girder bridges.

摘要

Full-depth precast concrete deck systems have several advantages over traditional cast-in-place concrete decks. Higher concrete quality, accelerated construction, and reduced life-cycle cost are the main advantages. Full-depth precast concrete deck systems can be designed as composite or non-composite systems with the supporting girders. Composite systems are commonly used due to their superior structural performance and cost effectiveness. These systems require the use of shear connectors between the precast concrete deck panels and the supporting girders to transfer interface shear and achieve composite action. The use of discrete clustered shear connectors is highly preferred in order to simplify panel and girder fabrication and improve system constructability. However, existing code provisions for the design of shear connectors were developed for continuous small-diameter shear connectors and might not be adequate for the design of discrete clustered connectors especially when large diameter connectors are used.;The objective of this research is to develop design equation for discrete shear connectors in precast concrete bridge deck systems. The proposed design equation accounts for cohesion and friction between the deck and girder; and the dowel effects of clustered shear connectors. Interface shear test data obtained from the literature are used to validate the reliability of the proposed equation. Finite Element Analysis (FEA) of the connection between precast deck and girder is performed to understand its behavior of and stress distribution at shear connectors. Also the influence of concrete strength and shear connector properties on the interface shear capacity of connection is studied. In addition, several pullout tests, push-off tests, and one full-scale test were conducted to evaluate the performance of discrete clustered shear connectors and validate the proposed equation. Test results have indicated that the proposed equation can predict the capacity of discrete clustered shear connectors better than existing code provisions.