2019/07/29 by Allen, D. E.
#contrainte (mécanique) #dilatation #elastic modulus #expansion #mechanical properties #module de Young #property (quality) #propriété #propriété mécanique #reinforcing bars #rond à béton #stresses
paper · doi:10.4224/40000624
The serviceability, strength and ductility of reinforced concrete structures depends to a large extent on certain properties of reinforcing bars - modulus of elasticity, yield stress, ultimate stress and elongation - properties controlled in practice by standard ASTM or CSA specifications. This Note presents information on the variability of these properties, information useful in assessing design safety factors such as those used in the ACI or National Building Code and methods of control such as those stipulated in ASTM or CSA specifications. The information was obtained from two sources: one a small sample of bars tested at the National Research Council of Canada (NRC); the other a larger sample of 132 test results obtained from a Canadian manufacturing plant. The NRC sample provided information on the variability along a bar as well as from bar to bar within a heat (or batch) of steel. The manufacturer's sample provided information on over-all variability from one manufacturing plant. In order to assess design safety factors over-all variability should be obtained in the future by sampling all reinforcing bars in Canadian construction, not just those from one manufacturing plant.