SHRINKAGE AND TENSION STIFFENING IN NEGATIVE MOMENT REGIONS OF COMPOSITE BEAMS

Results are given of bending tests in the elastic range on seven composite beams with the concrete slab in tension. They show that, when cracks in the concrete first occur, they are wider than would be predicted by the existing theory for cracking in reinforced concrete members. The reason is that cracking releases the locked-in stresses due to the restraint of shrinkage of the slab by the steel beam. When account is taken of this, the accuracy of the methods of BS 5400: part 5 for the prediction of hogging curvature and mean tensile strain at a given bending moment, is much improved. It is shown in another paper that these results also enable the widths and spacings of cracks in the concrete slab to be predicted more accurately. (Author/TRRL)

  • Availability:
  • Corporate Authors:

    Institution of Structural Engineers

    11 Upper Belgrave Street
    London,   United Kingdom  SW1X 8BH
  • Authors:
    • Johnson, R P
    • Allison, R W
  • Publication Date: 1981-3

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 10-16
  • Serial:
    • Structural Engineer
    • Volume: 59B
    • Issue Number: 1
    • Publisher: Institution of Structural Engineers
    • ISSN: 1466-5123

Subject/Index Terms

Filing Info

  • Accession Number: 00335238
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Oct 28 1981 12:00AM