LONG-TERM DEFLECTIONS OF REINFORCED CONCRETE BEAMS: RECONSIDERATION OF THEIR VARIABILITY

It has been assumed that the variability of the ACI method for predicting long-term deflections is plus or minus 30% around the mean value; this assumption was supported by a 1972 variability study by ACI Committee 435 on a relatively small number of long-term experiments carried out in the U.S. This paper shows that this confidence interval is only valid for beams undergoing sustanied loading under rather dry conditions. When the ACI method is applied to a larger set of long-term experimental results, including other kinds of environmental conditions, a much wider variability (plus or minus 62%) is found. For the same set of results, lower variability (plus or minus 35%) is achieved with the new CEB method, which is much more complicated than the ACI method, but which explicitly accounts for more pavements.

• Record URL:
  http://www.concrete.org/Publications/InternationalConcreteAbstractsPortal.aspx.aspx?m=details&i=10622
• Availability:
  • Find a library where document is available. Order URL: http://www.aci-int.org/PUBS/JOURNALS/AbstractDetails.asp?srchtype=phrase&date=anytime&searchmonth=3&searchday=0&searchyear=1990&publication=Structural+Journal&volume=87&issue=2&title=LONG%2DTERM+DEFLECTIONS+OF+REINFORCED+CONCRETE+BEAMS%3A+RECONSIDERATION+
• Corporate Authors:

  American Concrete Institute

  P.O. Box 19150, Redford Station, 22400 Seven Mile Road
  Detroit, MI  United States  48219
• Authors:
  • Espion, B
  • Halleux, P
• Publication Date: 1990-3

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 232-236
• Serial:
  • ACI Structural Journal
  • Volume: 87
  • Issue Number: 2
  • Publisher: American Concrete Institute (ACI)
  • ISSN: 0889-3241
  • Serial URL: http://www.concrete.org/PUBS/JOURNALS/SJHOME.ASP

Subject/Index Terms

• TRT Terms: Beams; Building codes; Deflection; Forecasting; Reinforced concrete; Structural design; Variables
• Uncontrolled Terms: Reinforced concrete beams
• Subject Areas: Bridges and other structures; Highways; Law; Materials; I20: Design and Planning of Transport Infrastructure;

Filing Info

• Accession Number: 00492124
• Record Type: Publication
• Report/Paper Numbers: Tttle no. 87-S24
• Files: TRIS
• Created Date: Mar 31 1990 12:00AM