|
Contact Information
Links
Current Research:
EIT Demonstration Project and Workshop
NSF: Development of a Blast and Ballistic Resistant Precast Concrete Armored Wall System
NEES-CR: Impact Forces from Tsunami-Driven Debris
Inspection Methods & Techniques to Determine Non Visible Corrosion of Prestressing Strands in Concrete Bridge Components
Daniel P. Jenny PCI Fellowship: Analytical Assessment of the Resistance of Precast Strucutres to Blast Effects
Development of a Seismic Design Methodology for Precast Diaphragms
Use of Polyurea for Blast Hardening of Concrete Construction
Estimation of Concrete Respone Under Varying Confinement
Past Research Projects
Performance of Bulb Tees with Self Consolidating Concrete
Evaluation of Bond Mechanics in Prestressed Concrete Applications
FRP Bridge Decks with RC
Parapets
Blast Resistance of a Load
Bearing Shear Wall Building
Lehigh@NEES
Equipment Site
Reserarch Experinece for
Undergraduates
Seismic Evaluation of a Three Story
WoodFrame Apartment Building with Tuck-Under Parking
Design of RC Bridge Beam-Column
Connections
Response of Waffle Slab
Building Systems to Seismic Loads
|
Horizontal Shear Capacity of Composite Beams Without Ties
Abstract:
In current US bridge construction, precast Bulb Tee, box beam, or AASHTO-I
beams up to 160 ft. in length are used. These beams span between the supporting bridge bents or abutments.
To provide integrity to the bridge system a field cast deck is installed. The deck is often designed to
act as both a wearing surface and as a composite section with the beam. If the demand is great enough, the
bond (or cohesion) between the topping and beam could be compromised and the elements will begin to slide
relative to one another. The role of horizontal shear ties is to help maintain monolithic behavior after
cohesion is lost. Typically horizontal shear ties are made up of an extension of the shear reinforcement from
the precast beam section and are subsequently cast into the deck.
To enhance the economics of precast/prestressed members in bridge construction a research program on horizontal
shear ties is underway. The project is examining the viability of increasing the nominal horizontal concrete
shear stress capacity between precast/prestressed bridge beams and field cast decks. The current requirements
prescribed by ACI and AASHTO provide a conservative but potentially unrepresentative estimate of shear capacity
for bridge beams. A rational increase in the horizontal shear interface capacity of the concrete topping to beam
will provide considerable advantages to precast bridge construction. In particular, the research has the potential
for reducing fabrication costs, improving construction safety, and providing numerous initial and long-term economic
benefits to the producer and owner.
Researchers:
Clay Naito, Principal Investigator
Dean Deschenes, Research Assistant
Matt Walsh, Research Assistant
Sponsors:
Pennsylvania Infrastructure Technology Alliance
Schuylkill Products, Inc.
Publications:
1. Walsh, M., Deschenes, D., Naito, C., "Horizontal Shear Capacity of Composite
Concrete Beams Without Ties Literature Review and Test Program," ATLSS Report No.05-09,
ATLSS Center, Lehigh University, June 2005, 70 pages.
2. Kovach, J., Naito, C., "Horizontal Shear Capacity of Composite
Concrete Beams Without Interface Ties," ATLSS Report No.08-05,
ATLSS Center, Lehigh University, June 2008, 236 pages.
Download (12Mb)
Page Last Updated Thursday, 24-Jul-2008 16:38:47 EDT
|
