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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
REPORT |
This report is an archived publication and may contain dated technical, contact, and link information |
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Publication Number: FHWA-HRT-17-093 Date: February 2018 |
Publication Number: FHWA-HRT-17-093 Date: February 2018 |
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With the ever-increasing congestion and deterioration of the Nation’s highway system, there is a need to develop highly durable and rapidly constructed infrastructure systems. Durable bridge structures that require less intrusive maintenance and exhibit longer life spans, thus maximizing the use of the facilities, are highly desirable. Expediting bridge construction can minimize traffic flow disruptions. The precast prestressed concrete box beam bridge is one type of bridge system that can be constructed in an accelerated process with wide applications in short- and medium-span bridges in the United States.
The study presented herein was completed as part of the Federal Highway Administration’s Structural Concrete Research Program. It investigated the connection design details for this type of bridge, including novel connection details whose performance surpasses common practice. The findings provide an innovative solution that could advance the state of the practice in bridge construction. An executive summary of the information contained in this report has been published as a TechBrief titled Adjacent Box Beam Connections: Performance and Optimization.(1) This report will be of interest to engineers, academics, researchers, and industry partners who are involved the design, fabrication, construction, or maintenance of short- and medium-span bridges.
Cheryl Allen Richter, Ph.D., P.E.
Director, Office of Infrastructure
Research and Development
Notice
This document is disseminated under the sponsorship of the U.S. Department of Transportation (USDOT) in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document.
The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of the document.
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The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.
1. Report No. FHWA-HRT-17-093 |
2. Government Accession No. | 3. Recipient’s Catalog No. | ||||
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4. Title and Subtitle Adjacent Box Beam Connections: Performance and Optimization |
5. Report Date February 2018 |
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6. Performing Organization Code: | ||||||
7. Author(s) Jiqiu Yuan, Benjamin A. Graybeal, and Kevin Zmetra |
8. Performing Organization Report No. | |||||
9. Performing Organization Name and Address Office of Infrastructure Research & Development Federal Highway Administration 6300 Georgetown Pike McLean, VA 22101-2296 |
10. Work Unit No. | |||||
11. Contract or Grant No. DTFH61-10-D-00017 |
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12. Sponsoring Agency Name and Address Office of Infrastructure Research & Development Federal Highway Administration 6300 Georgetown Pike McLean, VA 22101-2296 |
13. Type of Report and Period Covered Final Report; March 2013–September 2016 |
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14. Sponsoring Agency Code HRDI-40 |
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15. Supplementary Notes This report was developed by research staff at the Turner-Fairbank Highway Research Center. Jiqiu Yuan and Kevin Zmetra are contract researchers who support the Federal Highway Administration’s (FHWA) structural concrete research efforts, and Ben Graybeal of FHWA manages the FHWA Structural Concrete Research Program and leads the Bridge Engineering Research team. |
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16. Abstract Precast prestressed concrete adjacent box beam bridges are widely utilized for short- and medium-span bridges throughout North America. However, a recurring issue with this bridge type is the deterioration of the shear key connection, resulting in substandard performance of the overall bridge system. This research investigated partial- and full-depth connection designs utilizing conventional non-shrink grout and ultra-high performance concrete (UHPC) by conducting full-scale structural testing. Quantitative measures to evaluate the connection performance that may assist in examining similar types of bridges are suggested in this study. A model to calculate the shear force in the connection is proposed, and both the shear and tensile stresses at the connection are analyzed. The findings can be used to assist in the design of connections for this bridge type. The performance of conventionally grouted and UHPC connections are presented and compared. It was found that the adjacent box beam bridges with UHPC connections can be a resilient bridge superstructure system, providing an innovative solution that can advance the state of the practice in bridge construction. This report corresponds to the accompanying TechBrief, Adjacent Box Beam Connections: Performance and Optimization.(1) |
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17. Key Words Box beam bridge, Connection, Shear key design, Transverse post-tension, Transverse shear, Transverse tension, Ultra-high performance concrete, UHPC |
18. Distribution Statement No restrictions. This document is available to the public through the National Technical Information Service, Springfield, VA 22161. https://www.ntis.gov/ |
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19. Security Classif. (of this report) Unclassified |
20. Security Classif. (of this page) Unclassified |
21. No. of Pages 129 |
22. Price N/A |
Form DOT F 1700.7 (8-72) Reproduction of completed page authorized.
SI* (Modern Metric) Conversion Factors
Abbreviations | |
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AASHTO | American Association of State Highway and Transportation Officials |
EA | exposed aggregate |
FHWA | Federal Highway Administration |
LRFD | Load and Resistance Factor Design |
LVDT | linear variable differential transformer |
PT | post-tensioning |
SB | sandblasted |
UHPC | ultra-high performance concrete |
Symbols | |
b | distance from each end support to each loading point |
EI | beam stiffness |
EIeff | effective beam stiffness |
EIeff,δ | effective beam stiffness based on deflection measurements |
EIeff,ε | effective beam stiffness based on strain measurements |
f′c | compressive strength of concrete |
l | span length |
M | moment at the mid-span |
Mequivalent | equivalent moment transferred through the connection |
Mmax | maximum moment transferred through the connection |
P | load at each load point |
v′max | maximum distributed shear force |
Vy | transverse shear distribution |
V′y | triangular shear distribution |
y | distance from where the tensile strain is measured to the neutral axis of the cross section |
δ | deflection at the mid-span |
δA | deflection of beam A at the mid-span |
δAE | deflection from the loaded beam on the exterior linear variable differential transformer |
δAI | deflection from the loaded beam on the interior linear variable differential transformer |
δB | deflection of beam B at the mid-span |
δBE | deflection from the unloaded beam on the exterior linear variable differential transformer |
δBI | deflection from the unloaded beam on the interior linear variable differential transformer |
δcalculated | calculated deflection of the beam |
δmeasured | measured deflection in beam B when beam A is loaded at the maximum load and beam B is loaded at the minimum level |
Δδ | differential deflection |
ε | longitudinal tensile strain at the mid-span |
ε′ | additional strain in beam B due to the equivalent moment |
ε5kip | strain in beam B when both beams are loaded at 5 kip (22 kN) |
εA | longitudinal tensile strain in beam A |
εB | longitudinal tensile strain in beam B |
εcalculated | calculated strain |
εmeasured | measured strain in beam B when beam A is loaded at the maximum load and beam B is loaded at the minimum load |