reodata 4.0 - OneSteel Reinforcing

in as 3600 : 2001, Clause 13.1.2.1 requires that the development length
(Lsy.t) to develop the yield stress (fsy) of a straight, deformed bar in tension
shall be calculated as follows:
L sy.t = k 1k 2f syA b
(2a + d b)√f’ c
k1 = 1.25 for horizontal bars with more
than 300 mm of concrete cast
below the bars; or
= 1.0 for all other bars
k2 = 1.7 for bars in slabs and walls if the
clear distance between adjacent
parallel bars developing stress is
not less than 150 mm;
= 2.2 for longitudinal bars in beams
or columns with fitments; or
= 2.4 for all other longitudinal bars
fsy = characteristic yield stress of the
reinforcing bars (500 MPa)
≥ 29k 1d b where
db = nominal bar diameter (mm)
Ab = cross-sectional area of a single
reinforcing bar (mm 2 )
2a = twice the cover to the bars (c),
or the clear distance between
adjacent parallel bars developing
stress (sc), whichever is the lesser,
noting that in the formula its value
should be bounded according to
2db ≤ 2a ≤ 6db (mm)
f’c = the concrete compressive strength
grade, but not to exceed 65 MPa
when substituted into above
formula
stress Development & lap splicing
of straight Deformed Bars in tension
In accordance with Clause 13.2.2, the same formula shall be used to calculate
the tensile lap length (Lsy.t.lap), with due account taken of the presence of the
lapped bars when determining the clear distance, sc. For bars in the same
plane, the clear distance should be determined assuming contact lapped
splices, i.e. lapped bars touch each other, while non-contact lapped splices
are equally acceptable and have the same value of tensile lap length (Lsy.t.lap).
as 3600 : 2001 Quick Reference table – tensile
Development length (lsy.t) and tensile lap length (lsy.t.lap)
The AS 3600 : 2001 Quick Reference Table of tensile development
length (Lsy.t) and tensile lap length (Lsy.t.lap) has been derived based
on the same assumptions, when applicable, to those on which the
AS 3600 : 2009 Quick Reference Table is based. Also, k2 = 1.7 for bars
in slabs or walls, so clear distance (sc) has to be at least 150 mm.
note: Clear distance (sc) is represented by the symbol “a” in AS 3600 : 2009.
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