Research project work plan for performance of high-strength steel reinforcement in shear friction applications

The use of high strength steel reinforcement has the potential to provide economic and constructability benefits when used in reinforced concrete structures. Current design provisions limit the nominal yield strength of reinforcing steel bars to 60 ksi (420 MPa) for many bridge design applications. This report presents results from a laboratory testing program designed to evaluate the performance of concrete interface shear reinforced with ASTM A706 Grade 60 (420 MPa), ASTM A706 Grade 80 (550 MPa), ASTM A615 Grade 100 (690 MPa), and ASTM A1035 Grade 120 (830 MPa) reinforcing steel bars. Results are reported on the influence of reinforcing steel bar size, reinforcing steel bar spacing, shear interface surface preparation, and nominal concrete strength on shear friction performance. This report provides a summary of previous research regarding shear friction theory, a description of the test specimen design, and an overview of the materials used. Results indicate that using high-strength steel reinforcing bars did not have a significant impact on the peak loads reached, however they did allow for the development of greater post-peak sustained loads due to dowel action in the post-peak stage of the test specimen responses. Significant variation was observed when analyzing the effect of surface preparation. Additionally, in some cases, an exposed aggregate surface preparation enhanced the aggregate interlock and allowed it to contribute to the post-peak shear capacity. Overall, the results presented indicate that an increase in allowable nominal yield strength to 80 ksi (550 MPa) maintains a conservative design per AASHTO and ACI 318-14 code provisions.Final Report -- Appendix A. Interface shear friction resistance design -- Appendix B. Push-off test speciman strut-and-tie model -- [Appendix C. Test setups] -- [Appendix D]. Testing parameters.by Andre Barbosa, Ph.D., David Trejo, Ph.D., Nicolas Matus, and Naga Pavan Vaddey, Ph.D., Oregon State University, School of Civil and Construction Engineering ; for Oregon Department of Transportation Research Section and Federal Highway Administration.Title from PDF title page (viewed on October 28, 2020)."FHWA-OR-RD-21-02"--Technical report documentation page.Covers OCLC #1202206107 and OCLC #974499113."Project SPR 805."This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Includes bibliographical references.Sponsored by Oregon Dept. of Transportation, Research Section and Federal Highway Admin.Mode of access: Internet from the Oregon Government Publications Collection.Text in English.Final Repor