My first individual presentation.It is unforgettable because the marks i got, was beyond my expectation.....(full marks).Thanks to galib sir and sabrina mam for arranging this presentation.special thank to razia mam for her valuable advices that helped me to enrich my presentation.

1. Axial Stress - Strain Curve
And
Modulus Of Elasticity
Yasin , Aust

2. Presented by
Name:
: Md. Yasin
Student No.
:10.01.03.038
Section
:A
4th Year 2nd Semester
Department of civil Engineering
Ahsanullah University Of Science and Technology
Yasin , Aust

3. STRESS
In trying to pull the object apart, internal resisting
forces are created and these internal forces are
known as stress.
Stress = Restoring force / area
= (F)/(A) ,
where F is the deforming force acting on an area A of the body 
Yasin , Aust

4. STRAIN
The ratio of change produced in the dimensions of
a body by a system of forces or couples, in
equilibrium, to its original dimensions is called
strain.
Yasin , Aust

5. LOAD
STRUCTURE
Stress
strain
Yasin , Aust

6. REQUIREMENT OF STRESS –STRAIN
RELATIONSHIP
To analysis and design members.
It is most important while dealing with reinforced
concrete which is a composite material.
Yasin , Aust

7. STRESS-STRAIN CURVE
CONCRETE
Yasin , Aust

8. STRESS—STRAIN CURVE OF CONCRETE
At first,
As load is applied ,the ratio between
stress-strain is approximate linear.
Concrete behaves almost as an
elastic material.
If load is removed,displacement is
recovered virtually.
Eventually,
The curve is no longer linear.
Behaves more and more as plastic
materia.
The shape of stress-strain curve
is mostly depend on length of time
of loading.
Yasin , Aust

9. STRESS-STRAIN CURVE OF CONCRETE
Yasin , Aust

10. Stress-strain relationship

11. It is interesting to note that although cement
paste and aggregates individually have
linear stress-strain relationships, the
behavior for concrete is non-linear. This is
due to the mismatch and micro cracking
created at the interfacial transition zone.
Yasin , Aust

12. STRESS-STRAIN CURVE
STEEL
Yasin , Aust

13. Material behavior is generally represented by a stress-strain diagram,
which is obtained by conducting a tensile test on a specimen of material.
Yasin , Aust

14. – Stress-strain
responseis linear.
– Slope = Modulus of
Elasticity (Young’s
modulus) = E
Yasin , Aust

15. – Begins at yield stress Σy
– Slope rapidly decreases
until it is horizontal or
near horizontal
– Large strain increase,
small stress increase
– Strain is permanent
Yasin , Aust

16. – After
undergoing large
deformations, the metal
has changed its
crystalline structure.
– The material has
increased resistance
to applied stress
(it appears to be
“harder”).
Yasin , Aust

17. – The maximum supported
stress value is called the
ultimate stress, σu.
– Loading beyond σu
results in decreased
load supported and
eventually rupture.
Yasin , Aust

18. Modulus of elasticity
It is defined as the slope of its stress-strain curve in the
elastic deformation level.
E= Stress/Strain
Yasin , Aust

19. The modulus of elasticity of concrete is a function of
modulus of elasticity of the aggregates.
the cement matrix.
their relative proportions.
Yasin , Aust

20. CHARACTERISTICS
Stress
At Low
At High
Modulus of Elasticity
Constant
Decreasing
(cracking)
Yasin , Aust

21. CHARACTERISTICS
Elements
Modulus of Elasticity
Cement harden paste
10-30 Gpa
Aggregates
45-85 Gpa
Concrete Composite
30-50 Gpa
Yasin , Aust

22. The modulus of elasticity to be calculated using the following
equation
Where,
W=weight of concrete
=
Compressive
strength of concrete at 28 days (psi)
Yasin , Aust

23. Yasin , Aust