REINFORCEMENT PLACEMENT IN CONCRETE SLABS

Reinforced concrete construction is not exact; some imprecision or tolerance must be expected. The thesis is primarily an investigation of the tolerances on the positioning of reinforcement bars in slabs and the way in which this affects the cover, effective depth and strength of the slab. The investigation consisted of site measurements of reinforcement placement at 12 major building sites in Melbourne, Sydney, and on the Gold Coast, covering a total of 353 slab panels. Additional data on the measurements of slab thickness variations at one site, the 28- day compressive strength tests of concrete cylinders from three Melbourne sites, and the yield strength tests of cold- worked deformed reinforcement bars by a major reinforcement supplier in Victoria were also collected. The data measured and collected were statistically evaluated and analysed which ensured that the samples were derived from coherent populations. Using the data collected, a Monte- Carlo analysis of slab strength was performed. This analysis of the mid- span section strength of a typical one- way slab panel using the worst variations measured, revealed strength variations, as reflected by the coefficient of variation, of approximately 9 per cent and ratios of mean theoretical strengths to design effective strengths ranging from 1.16 to 1.36, depending on the loading conditions. The site measurements revealed that the current provisions (cl. 6.6 and cl. 6.12) in as 1480-1974 for the tolerances on fixing reinforcement were not met by any of the sites investigated by quite wide margins. Recommendations, based on these site measurements, are made to any future code committees in reference to the question of more realistic tolerances on fixing reinforcement. The thesis was submitted in partial fulfilment of the requirements for the degree of Master of Engineering Science, University of Melbourne, July 1980. (Author/TRRL)

  • Corporate Authors:

    Melbourne University, Australia

    Grattan Street
    Parkville, Victoria 3052,   Australia 
  • Authors:
    • Ng, T E
  • Publication Date: 1980-7

Media Info

  • Pagination: n.p.

Subject/Index Terms

Filing Info

  • Accession Number: 00381051
  • Record Type: Publication
  • Source Agency: ARRB
  • Report/Paper Numbers: Monograph
  • Files: ITRD, TRIS, ATRI
  • Created Date: Apr 30 1984 12:00AM