EFFECTS OF IMPACT ON REINFORCED CONCRETE BEAMS

THE IMPACT RESISTANCE OF HIGH ELASTIC LIMIT STEEL BARS WHEN USED AS REINFORCEMENT WAS INVESTIGATED BY MEANS OF THE IZOD TENSION IMPACT TEST AND BY IMPACT TESTS OF REINFORCED CONCRETE BEAMS. IT WAS FOUND IMPOSSIBLE TO BREAK THE STEEL IN 8- AND 16- IN. BEAMS OF 8-FT. SPAN REINFORCED WITH EITHER ONE 1/2-IN. OR ONE 5/8-IN. ROUND BAR. REPEATED BLOWS FROM THE FULL HEIGHT AVALABLE, ABOUT 8 FT. 4 IN. CAUSED INCREASING DEFLECTION AND SHATTERING OF THE CONCRETE, AND IF CONTINUED LONG ENOUGH WOULD RIP THE BAR OUT OF THE BEAM. THIS INDICATES VERY CLEARLY THE REMARKABLE INSURANCE AGAINST COLLAPSE PROVIDED BY EVEN SMALL AMOUNTS OF REINFORCING STEEL. WITHIN THE LIMITS OF THE TESTS NO NOTICEABLE DIFFERENCE IN IMPACT RESISTANCE WAS DISPLAYED BY ANY OF THE GRADES OF STEEL USED, AN ALMOST IDENTICAL DROP BEING REQUIRED TO BREAK ALL GRADES WITH ONE BLOW. THE BEAMS REINFORCED WITH STRUCTURAL STEEL DEFLECTED MORE THAN THE OTHERS, PROBABLY THUS ABSORBING THE ENERGY THAT THE BEAMS REINFORCED WITH STRONGER STEELS WITHSTOOD BY DIRECT STRESS. THE FEW SHALLOW BEAMS TESTS DEFLECTED SO MUCH THAT IN SPITE OF THEIR LESSER MASS IT WAS QUITE AS IMPOSSIBLE TO BREAK THE 1/2 IN. ROUND BARS IN THEM AS IT WAS IN THE DEEPER SPECIMENS. IN THE IZOD TESTS, NO APPARENT RELATION BETWEEN THE STRENGTH OF THE IZOD TENSION IMPACET SPECIMEN AND THAT OF THE SAME STEEL WHEN USED AS CONCRETE REINFORCEMENT WAS FOUND. /AUTHOR/

• Record URL:
  https://onlinepubs.trb.org/Onlinepubs/hrbproceedings/18/18Part1-009.pdf
• Supplemental Notes:
  • Vol 18, Pt 1, PP 130-139, 10 FIG, 2 TAB; part of Report of Department of Design, Committee on Use of High Elastic Limit Steel as Concrete Reinforcement. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Mylrea, T D
• Publication Date: 1939

Media Info

• Media Type: Digital/other
• Monograph Title: Proceedings of the Eighteenth Annual Meeting of the Highway Research Board Held at Washington, D.C. November 28-December 2, 1938. Part I
• Serial:
  • Highway Research Board Proceedings
  • Volume: 18
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Beams; Concrete; Impacts; Reinforced concrete; Reinforcing steel
• Uncontrolled Terms: Concrete beams
• Old TRIS Terms: Resistance
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00209273
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Jun 1 1971 12:00AM