PRACTICAL APPLICATION OF THE MATURITY CONCEPT TO DETERMINE IN SITU STRENGTH OF CONCRETE

The C.N. Tower will be the highest free-standing structure in the world. The foundations contain 10,000 cu yd 7646 cu m of low-heat cement concrete, and accelerated testing was used throughout the concreting period. The slip-formed concrete superstructure is 1,464 ft (450 m) high and contain 40,000 cu yd (30 580 cu m) of concrete. The accelerated test used during slip forming was the 48-hour autogenous test devised by Smith and Tiede. The last 3 months of slip forming were carried out from December 1973 to February 1974, the coldest period of the Canadian winter. Ambient conditions as low as 1 F (-17 C) were experienced, and wind-chill factors at heights above 1,000 ft (305 m) significantly increased the low-temperature effects. Maturity testing was done to check that, as the slip from rose, the concrete exposed to winter conditions achieved adequate strength. Thermocouples inserted during every shift were monitored at intervals throughout each 24-hour period, and in-place strengths were calculated. Monitoring continued until acceptable strengths has been achieved at each level. Evaluation were based on cores drilled from the structure and cylinder tests.

Media Info

  • Media Type: Print
  • Features: Figures;
  • Pagination: pp 45-49
  • Monograph Title: Recent developments in accelerated testing and maturity of concrete
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00131691
  • Record Type: Publication
  • ISBN: 0309024668
  • Files: TRIS, TRB
  • Created Date: Jun 5 1976 12:00AM