REPORT OF PROJECT COMMITTEE ON THE USE OF HIGH ELASTIC LIMIT STEEL AS REINFORCEMENT FOR CONCRETE SUSTAINED LOADING TESTS ON SLENDER CONCRETE BEAMS REINFORCED WITH HIGH ELASTIC LIMIT STEEL

PRIMARY TESTS WERE MADE ON 22 BEAMS, 3X6X11 FEET, TESTED UNDER SUSTAINED STATIC LOADING IN DRY AIR AFTER 28 DAYS OF MOIST CURING, FOLLOWED BY TWO OR FIVE MONTHS IN DRY LABORATORY AIR PRIOR TO APPLICATION OF LOAD. DESIGN STEEL STRESSES RANGED FROM 15,000 TO 46,000 LB/SQ IN AND CONCRETE STRESSES FROM 700 TO 1,920 LB/SWQ IN. DESIGN BOND AND DIAGONAL TENSION STRESSES WERE BELOW 70 AND 50 LB. PER SQ. IN. RESPECTIVELY. STEEL RATIOS VARIED BETWEEN 0.30 AND 1.21%, WITH THREE BEAMS REINFORCED FOR COMPRESSION WITH STEEL EQUAL TO THAT IN TENSION. APPLIED LOADS AT EACH POINT OF 10-FT. SPANS WERE 140 LB. ON THE PLAIN BEAMS AND FROM 185 TO 700 LB. ON REINFORCED BEAMS. CENTER DEFLECTIONS AND STRAINS ON STEEL AND CONCRETE WERE MEASURED. AUXILIARY WEIGHT AND SHRINKAGE DATA WERE TAKEN, AND CRACK SURVEYS WERE MADE. ELASTIC DEFLECTION WAS FOUND TO BE A FUNCTION OF THE STRESS IN BOTH STEEL AND CONCRETE, BUT FULL SHRINKAGE DEFLECTION SEEMS TO BE PRACTICALLY INDEPENDENT OF STEEL STRESS AND DIRECTLY PROPORTIONAL TO THE CONCRETE STRESS. SHRINKAGE IS IMPORTANT, TENDING TO LOWER THE TENSILE STEEL STRESS AND TO INCREASE COMPRESSIVE STRAINS AND BEAM DEFLECTIONS. WARPING FROM UNSYMMETRICAL PLACEMENT OF REINFORCEMENT WAS ONE OF THE SHRINKAGE EFFECTS NOTED ON AUXILIARY BEAMS. FOR THE SLEDNDER BEAMS, THERE WS NO INDICATION OF HAZARD OR OF UNUSUAL OR UNSATISFACTORY BEHAVIOR WITHIN THE MAXIMUM RANGE OF STRESS EMPLOYED. DEFLECTIONS WERE NOT EXCESSIVE, AND CRACKS WERE NOT WIDE, ALTHOUGH THERE IS LITTLE PRESENT BASIS FOR DEFINING THE LIMITING WIDTH OF CRACK THAT CONSTITUTES A CORROSION HAZARD.

• Record URL:
  • https://onlinepubs.trb.org/Onlinepubs/hrbproceedings/15/15-006.pdf
• Supplemental Notes:
  • Vol 15, pp 81-111, 16 FIG, 6 TAB; part of Report of Department of Design. 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:
  • Gilkey, H J
  • Ernst, G C
  • Hatt, W K
  • Withey, M O
  • Goldbeck, A T
• Discussers:
  • Diefendorf, A
• Publication Date: 1936

Media Info

• Media Type: Digital/other
• Monograph Title: Proceedings of the Fifteenth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 4-6, 1935
• Serial:
  • Highway Research Board Proceedings
  • Volume: 15
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Beams; Concrete; Corrosion; Cracking; Deflection; Elastic limit; Elasticity (Mechanics); Load tests; Reinforced concrete; Shrinkage; Steel; Stresses; Warpage
• Uncontrolled Terms: Concrete beams; Warping
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00209269
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Jun 11 1971 12:00AM