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Publication Number:  FHWA-HRT-20-005    Date:  November 2019
Publication Number: FHWA-HRT-20-005
Date: November 2019


Strength and Fatigue Resistance of Clustered Shear Stud Connectors in Composite Steel Girders

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This report documents fatigue and static testing of shear stud composite connections between steel girders and precast (PC) concrete decks. The purpose of the testing was to assess American Association of State Highway and Transportation Officials (AASHTO) shear stud-fatigue, strength, and spacing design provisions and how they relate to using PC concrete decks on top of steel girders as a means of accelerated bridge construction (ABC).(1) The static test results suggest current AASHTO shear stud-strength design provisions are unconservative. However, this is balanced by fatigue test results suggesting current AASHTO shear stud-fatigue provisions are probably too conservative, which explains why there have not been widespread in-service performance problems. The results from the testing regime also showed current AASHTO minimum and maximum spacing limits for shear studs could be relaxed in both the longitudinal and transverse directions. Relaxing these spacing requirements would greatly benefit the constructability of the full-depth PC concrete deck panels needed in some ABC construction techniques for steel superstructures.

This report will benefit those interested in the design, fabrication, and construction of steel bridges and PC concrete decks, including State transportation departments, bridge design consultants, and PC concrete facilities.

Cheryl Allen Richter, P.E., Ph.D.
Director, Office of Infrastructure
Research and Development


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.

Quality Assurance Statement

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.

Technical Report Documentation Page

1. Report No.


2. Government Accession No. 3 Recipient's Catalog No.
4. Title and Subtitle

Strength and Fatigue Resistance of Clustered Shear Stud Connectors in Composite Steel Girders

5. Report Date

November 2019

6. Performing Organization Code
7. Author(s)

Jason T. Provines, Justin M. Ocel (ORCID 0000-0002-0176-7276), and Kevin Zmetra (ORCID 0000-0002-1329-7443)

8. Performing Organization Report No.
9. Performing Organization Name and Address

Professional Service Industries, Inc.
13873 Park Center Rd., Suite 315
Herndon, VA 20171

Rao Research and Consultants, LLC
1775 Tysons Blvd., Fifth Floor
Tysons Corner, VA 22102

10. Work Unit No. (TRAIS)
11. Contract or Grant No.

DTFH61-10-D-00017, DTFH61-17P-00006, and DTFH61-D-17-00015

12. Sponsoring Agency Name and Address

Office of Infrastructure Research and Development
Federal Highway Administration
6300 Georgetown Pike
McLean, VA 22101-2296

13. Type of Report and Period Covered

Final Report; January 2012–May 2018

14. Sponsoring Agency Code


15. Supplementary Notes

The work reported herein was conducted in the Turner-Fairbank Highway Research Center Structures Laboratory under various support service contractors. Justin Ocel (HRDI-40) of the Federal Highway Administration provided technical oversight and assistance to the contractors. The Contracting Officer's Representative was Fassil Beshah (HRDI-40), Mark Swanlund (HRDI-1), or Justin Ocel (HRDI-40), depending on the contract.

16. Abstract

Accelerated bridge construction (ABC) is a technique in which large bridge elements are fabricated offsite or next to the site and are then connected onsite to complete the bridge. One such ABC method is the use of full depth precast (PC) concrete deck panels, which are placed on top of steel girders connected via shear studs. The PC concrete deck panels typically have pockets cast into them so that they fit around the shear studs. These pockets are then filled with grout to form the composite connection with the girder. When using PC deck panels, it is beneficial to place the shear studs in clusters (i.e., close together longitudinally and transversely). The clusters of studs can then be spaced at greater distances apart. By reducing the number and size of the pockets in the PC concrete deck panels, panel fabrication and constructability can be simplified.

Large- and small-scale fatigue and static tests were conducted in this study to evaluate the American Association of State Highway and Transportation Officials (AASHTO) fatigue, strength, and spacing design provisions for shear studs. The large-scale tests in this study were constructed with PC concrete deck panels and steel beams. Twelve shear studs were used in each shear span but were spaced at intervals of 1, 2, 3, and 4 ft between specimens. The small-scale tests were similar to historical tests and served as a comparison between the historical small-scale test data and the current large-scale tests. Results of the study showed that the AASHTO shear stud-fatigue design provisions can be overly conservative, requiring more studs than are necessary. Testing also showed that the AASHTO shear stud-strength design provisions overpredict a shear stud's strength, making them unconservative. The results also demonstrated that the AASHTO shear stud-spacing requirements can be relaxed to allow for details more conducive to using PC concrete deck panels. Proposed alternative design provisions for the fatigue, strength, and spacing of shear studs are included.

17. Key Words

Shear studs, fatigue testing, static testing, steel bridges, accelerated bridge construction, ABC

18. Distribution Statement

No restrictions. This document is available through the National Technical Information Service, Springfield, VA 22161.

19. Security Classification
(of this report)


20. Security Classification
(of this page)


21. No. of Pages


22. Price


Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
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