Title:
Large Diameter Shear Connector Systems for Full-Depth Precast Overhang Panels: Evaluation and Design
Author(s):
Young Hoon Kim and David Trejo
Publication:
Structural Journal
Volume:
112
Issue:
4
Appears on pages(s):
439-450
Keywords:
full-depth; precast overhang panel system; shear friction; shear-transfer mechanism
DOI:
10.14359/51687703
Date:
7/1/2015
Abstract:
Accelerated bridge construction (ABC) is increasingly being used to replace aged and deteriorated bridge structures. Recently, a full-depth precast overhang deck system was developed for ABC projects. This system was reported to minimize construction time, enhance constructibility, ensure structural integrity, and improve safety during the construction process. Although the system was reported to exhibit significant benefits, standardized design methodologies were not fully developed to reliably estimate the shear capacity of the shear connector/coupler system in these precast overhang panels. Required shear capacity should be achieved for the composite action of the precast deck and girders in service. Therefore, the objective of this study is to develop design equations that can reliably predict the shear capacity of shear connectors placed between the girders and deck for composite action. Developing a reliable equation will minimize the number of shear pockets required per panel, thereby improving constructibility and reducing costs. This research investigated the use of 1.25 in. (32 mm) diameter shear connectors with different confinement systems. The two types of confinement systems included conventional reinforcing bar and high-strength steel tubes. The reinforcing bar confinement system consisted of extra steel reinforcement being embedded in the precast panel around the shear pocket and reinforcement hoops being placed within the pocket around the connector (referred to herein as inner and outer confining reinforcement). The steel tube was embedded in the precast overhang panel and defined the outside edge of the shear
pocket. A total of nine specimens were subjected to shear loadings. Results indicate that the steel tube confinement system effectively increases the shear-transfer capacity for large-diameter shear connector systems. A new design equation is presented for determining the shear capacity of connector systems for precast panels.