F. K. Kong MA, MSc, PhD, CEng, FICE, FIStructE, R. H. Evans CBE, DSc, D ès Sc, DTech, PhD, CEng, FICE, FIMechE, FIStructE (auth.)-Reinforced and Prestressed Concrete-Springer US (1987)

70 Axially loaded reinforced concrete columns
for short-term loading. Within the range of concrete mixes used in practical
design, the following general statements may be made:
(a) Up to about 50% of the maximum stress, the stress/strain curve may
be approximated by a strainght line.
(b) The peak stress is reached at a strain of about 0.002.
(c) Visible cracking and disintegration of the concrete does not occur
until the strain reaches about 0.0035.
For design purposes, BS 8110 uses the idealized curve in Fig. 3.2-2(b),
60
50
cii
cii
~ 20
.....
Vl
0001 0-002 0-003 0-004
Strain
(a) Actual stressl strain curves
C\I -­
E
-z
CI)
cii
CI)
L..
~
Initial siope
= 5·5 Jfcu/Ym kN/mm 2
4
I
I
Parabolic
curve
I
I
I
I
I
I
I
€o
(-!f/41oo)
€cu
(=0-0035)
Strain
(b) Design stress/strain curves(BS 8110)
Fig.3.2-2 Stress/strain curves for concrete in compression