Strength of shear connection in composite bridges with precast decks using high performance concrete and shear-keys

10.1617/14034 ◽  
2005 ◽  
Vol 38 (276) ◽  
pp. 173-181 ◽  
Author(s):  
D. L. Araújo
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Shear Connection ◽  
Shear Keys ◽  
Composite Bridges

scholarly journals An Enhanced UHPC-Grout Shear Connection for Steel-Concrete Composite Bridges with Precast Decks

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yongtao Zhang ◽  
Hehui Zheng ◽  
Minghao Tang ◽  
Zhiqi He
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Frictional Resistance ◽  
Shear Capacity ◽  
Interface Shear ◽  
Element Analysis ◽  
Shear Connection ◽  
Composite Bridges ◽  
Push Out

This article develops an enhanced UHPC-grout shear connection for steel-concrete composite bridges with precast decks. The primary improvement is the use of ultra-high performance concrete (UHPC) as the connection grout. To validate the constructability and the mechanical performance of the new connection, two series of experimental tests (including grouting tests and push-out tests) were conducted. Results from the grouting tests show that both the pressure grouting method and the self-levelling grouting method are applicable to inject the UHPC grout into the channel void of the connection. Results from the push-out tests indicate that the advanced properties of UHPC allow for a significant improvement of the shear resistance of the adhesive connection over traditional cementitious grouts. The ultimate shear capacity of the adhesive connection is controlled by the interface shear strength between the embossed steel and the UHPC grout, with a cohesion value of approximately 5.87 MPa. Meanwhile, the residual frictional resistance can be taken as approximately one-half of the ultimate resistance. The results of the finite-element analysis show that the trilinear model is reasonable to simulate the shear-slip laws of the embossed steel-grout interface and the rough concrete-grout interface.

scholarly journals Experimental Behavior of Steel-Concrete Composite Girders with UHPC-Grout Strip Shear Connection

Buildings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 182
Author(s):  
Zhi-Qi He ◽  
Changxue Ou ◽  
Fei Tian ◽  
Zhao Liu
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Fatigue Testing ◽  
Ultimate Capacity ◽  
Horizontal Shear ◽  
Interface Failure ◽  
Interface Shear ◽  
Composite Action ◽  
Shear Connection ◽  
Push Out

This paper develops a new type of shear connection for steel-concrete composite bridges using Ultra-High Performance Concrete (UHPC) as the connection grout. The UHPC-grout strip shear connection is fabricated by preforming a roughened slot in the concrete deck slab, welding an embossed steel rib longitudinally to the upper flange of the steel girder, and casting the strip void between the slot and the steel rib with UHPC grout. The structural performance of the new connection was validated by two sets of experimental tests, including push-out testing of shear connectors and static and fatigue testing of composite beams. The results of push-out testing indicate that the UHPC-grout strip shear connection exhibits a significant improvement of ductility, ultimate capacity, and fatigue performance. The interface shear strength of the UHPC-grout strip connection is beyond 15 MPa, which is about three times that of the strip connection using traditional cementitious grouts. The ultimate capacity of the connection is dominated by the interface failure between the embossed steel and the UHPC grout. The results of composite-beam testing indicate that full composite action is developed between the precast decks and the steel beams, and the composite action remained intact after testing for two million load cycles. Finally, the trail design of a prototype bridge shows that this new connection has the potential to meet the requirements for horizontal shear.

Ultra-High-Performance Concrete Shear Keys in Concrete Bridge Superstructures

2020 ◽  
pp. 036119812096472
Author(s):  
Elsy Y. Flores ◽  
Jordan Varbel ◽  
William K. Toledo ◽  
Craig M. Newtson ◽  
Brad D. Weldon
Keyword(s):  
High Performance ◽  
Load Transfer ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Surface Preparation ◽  
Ultra High Performance Concrete ◽  
Direct Tension ◽  
Girder Bridges ◽  
Grouting Material ◽  
Shear Keys

This research investigated the use of locally produced, non-proprietary ultra-high-performance concrete (UHPC) as a grouting material to repair deteriorated shear keys. Shear keys are used in adjacent girder superstructures to produce monolithic behavior and load transfer across the structure. Shear key degradation can jeopardize the integrity of the structure. Transportation agencies have reported that 75% of distress in adjacent girder bridges is because of cracking and de-bonding along shear keys. Previous research has shown that locally produced UHPC has excellent mechanical and durability properties. UHPC has also been shown to have good bonding characteristics that are desirable in a potential grouting material. Bond strength between UHPC grout and substrate concrete was evaluated using slant-shear and direct tension tests. Results showed that adequate bond was achieved at 7 days. Low strengths at 28 days were observed because of low strength of the substrate concrete. Shrinkage of UHPC grout was also investigated. Shrinkage at 28 days was less than 600 µstrain which is acceptable for repair practices. Full-scale testing was used to evaluate load-deflection behavior of channel girder assemblages with grouted shear keys. Results showed that UHPC grout and non-shrink grout had similar mechanical performance. Excellent bond was achieved with all grouts, even with minimal surface preparation. The similar performances of the non-shrink grout and the UHPC grout indicates that UHPC grout does not provide a mechanical benefit over the non-shrink grout.

New Trends in Prestressed Concrete Bridges

2000 ◽  
Vol 1696 (1) ◽  
pp. 238-272
Author(s):  
Michel Virlogeux
Keyword(s):  
Prestressed Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Structures ◽  
Concrete Bridges ◽  
Prestressed Concrete Bridges ◽  
External Prestressing ◽  
Different Types ◽  
Composite Bridges ◽  
Cable Stayed Bridges

An overview of the recent evolution in the design and construction of prestressed concrete bridges worldwide is provided. Several major trends are evidenced. Certainly those trends that have had greater influences on the industry because of their wide applications are the development of external prestressing, which is now systematically used in some countries for medium-span bridges; the emergence of high-performance concrete, which extends the possibilities at the same time as it improves the durability of concrete structures; and the more frequent association of steel and concrete for composite bridges of different types and composite elements in bridges, allowing the construction of many innovative structures. For more specific applications, cable-stayed bridges, for which interesting developments have been seen in the last 10 years, and the more extensive use of heavy prefabrication in large projects, with elements up to several thousands of metric tons, are also described. Bridge architecture is also discussed in terms of the fact that good structural designs can produce elegant prestressed concrete bridges.

Fiber Orientation in Ultra-High-Performance Concrete Shear Keys of Adjacent-Box-Beam Bridges

2018 ◽  
Vol 115 (2) ◽  
Author(s):  
Kenneth K. Walsh ◽  
Nathan J. Hicks ◽  
Eric P. Steinberg ◽  
Husam H. Hussein ◽  
Ali A. Semendary
Keyword(s):  
Fiber Orientation ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete ◽  
Box Beam ◽  
Shear Keys

scholarly journals Ultra-High-Performance Concrete Shear Keys in Concrete Bridge Superstructures

2019 ◽  
Vol 271 ◽  
pp. 07006
Author(s):  
Elsy Y. Flores ◽  
Jordan Varbel ◽  
Craig M. Newtson ◽  
Brad D. Weldon
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Ultra High Performance Concrete ◽  
Bridge Superstructures ◽  
Grouting Material ◽  
Ongoing Work ◽  
Shear Keys ◽  
Existing Bridges

Many existing bridges have adjacent girders that utilize grouted shear keys to transfer loads laterally across the superstructure. Cracking and leaking often cause degradation of the shear key and the girder. This work investigates the potential for using non-proprietary ultra-high performance concrete (UHPC) as a grouting material for repair of deteriorated shear keys by testing bond strength between UHPC and substrate concrete surfaces that were either formed or scarified by chipping. Bond strengths were adequate for both surface textures even though texture depth was substantially less than recommended by ACI 546. Scanning electron microscopy has also been used to investigate the bonded area. This microscopic scanning has shown fly ash residue remaining on the substrate after bond failure, indicating that the supplementary cementitious materials produce much of the bond. Ongoing work for this project also includes full-scale testing of UHPC shear keys between pre-stressed channel girders.

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