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Precast concrete deck-to-girder connection using Ultra-High Performance Concrete (UHPC) shear pockets
Highlights A new precast concrete deck-to-girder connection using ultra-high performance concrete (UHPC) shear pockets is proposed to simplify construction. The interface shear resistance of monolithic UHPC and between hardened conventional concrete and fresh UHPC were investigated experimentally. Prediction equations for the interface shear resistance of the two cases were developed using the shear friction model. The effect of UHPC flowability on the performance of the new connection was studied. Design procedure and design aids for the new connection are presented with a design example.
Abstract Precast concrete deck systems have been successfully used in Accelerated Bridge Construction (ABC). In most systems, precast concrete deck-to-girder connections use special shear connectors embedded in the girders and projecting into the deck block-outs (pockets or troughs) that are grouted to achieve composite sections. This requires tight production/erection tolerances that complicate deck and girder fabrication and compromises the economics of the precast concrete deck systems. In this paper, a new deck-to-girder connection is developed using ultra-high performance concrete (UHPC) to relax production/erection tolerances for both precast deck panels and girders. Typical girder shear reinforcement remains unchanged but terminated in the haunch below the soffit of deck panels to eliminate any conflict with the deck shear pockets. Loop bars are installed in the shear pockets that are filled with UHPC to provide required interface shear capacity while relaxing production/erection tolerances. Small scale push-off and double shear tests were conducted to evaluate the interface shear resistance of the connection. Full-scale push-off specimens are fabricated and tested to evaluate the structural performance and constructability of the proposed connection. Test results indicated that interface shear resistance of the connection can be predicted using the AASHTO LRFD shear friction model with different cohesion and friction factors that are dependent on the UHPC compressive strength. Also, UHPC fiber stability has a significant effect on the capacity of the proposed connection. Design example and design aids are presented to demonstrate the design of the new connection in a typical bridge.
Precast concrete deck-to-girder connection using Ultra-High Performance Concrete (UHPC) shear pockets
Highlights A new precast concrete deck-to-girder connection using ultra-high performance concrete (UHPC) shear pockets is proposed to simplify construction. The interface shear resistance of monolithic UHPC and between hardened conventional concrete and fresh UHPC were investigated experimentally. Prediction equations for the interface shear resistance of the two cases were developed using the shear friction model. The effect of UHPC flowability on the performance of the new connection was studied. Design procedure and design aids for the new connection are presented with a design example.
Abstract Precast concrete deck systems have been successfully used in Accelerated Bridge Construction (ABC). In most systems, precast concrete deck-to-girder connections use special shear connectors embedded in the girders and projecting into the deck block-outs (pockets or troughs) that are grouted to achieve composite sections. This requires tight production/erection tolerances that complicate deck and girder fabrication and compromises the economics of the precast concrete deck systems. In this paper, a new deck-to-girder connection is developed using ultra-high performance concrete (UHPC) to relax production/erection tolerances for both precast deck panels and girders. Typical girder shear reinforcement remains unchanged but terminated in the haunch below the soffit of deck panels to eliminate any conflict with the deck shear pockets. Loop bars are installed in the shear pockets that are filled with UHPC to provide required interface shear capacity while relaxing production/erection tolerances. Small scale push-off and double shear tests were conducted to evaluate the interface shear resistance of the connection. Full-scale push-off specimens are fabricated and tested to evaluate the structural performance and constructability of the proposed connection. Test results indicated that interface shear resistance of the connection can be predicted using the AASHTO LRFD shear friction model with different cohesion and friction factors that are dependent on the UHPC compressive strength. Also, UHPC fiber stability has a significant effect on the capacity of the proposed connection. Design example and design aids are presented to demonstrate the design of the new connection in a typical bridge.
Precast concrete deck-to-girder connection using Ultra-High Performance Concrete (UHPC) shear pockets
Abo El-Khier, Mostafa (author) / Morcous, George (author)
Engineering Structures ; 248
2021-08-21
Article (Journal)
Electronic Resource
English
Steel-concrete-UHPC (Ultra High Performance Concrete) combined bridge deck slab
| European Patent Office | 2022
| European Patent Office | 2022
European Patent Office | 2022