Page 1 of 5
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 808
Finite Element Modeling Of Reinforced Concrete Beams Bonded With
Fibre Reinforced Plastic Laminates
K. JEYACHANDRAN
DEPARTMENT OF CIVIL ENGINEERING
PRIST(Deemed to be University), THANJAVUR
ABSTRACT
In order to improve the performance of a Reinforced Cement Concrete (RCC) structure, it is
better to repair or upgrade the structure by retrofitting. This study revealed the results of
anonlinear finite element analysis conducted on reinforced cement concrete
beamsstrengthened with Glass Fiber Reinforced Polymer (GFRP) laminates, Carbon
FiberReinforced Polymer (CFRP) laminates and Aramid Fiber Reinforced Polymer (AFRP)
laminates. Five beams with different fiber length and orientation for each fiber
retrofittedbeams were cast and analyzed for the present study. All the beams were tested
under fourpointbending till failure. The results obtained through non liner Finite Element
Method (FEM) analysis using ANSYS software can be used to study how different
parameters affect retrofitted beam behavior and investigate how Externally Bounded
Reinforcement (EBR) should be applied in order to obtain the maximum load carrying
capacity.
INTRODUCTION
Reinforced Concrete (RC) structures often
have to face modification and
improvement of their performance during
their service life. In such circumstances
there are two possiblesolutions:
replacement or retrofitting. Full structural
replacement might have
determinatedisadvantages such as high
costs for material and labour, a stronger
environmental impactand inconvenience
due to interruption of the function of the
structure, e.g., traffic problems.
When possible, it is often better to repair
or upgrade the structure by retrofitting in
the lastdecade, the development of strong
epoxy glue has led to the growth of
Externally BondedReinforcement (EBR)
strengthening techniques which has great
potential in the field ofupgrading
structures.Basically the technique involves
gluing steel plates or Fiber Reinforced
Page 2 of 5
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 809
Polymer (FRP)laminates to the surface of
concrete. FRP can be convenient
compared to steel for a number
of reasons. These materials have higher
ultimate strength and lower density than
steel. Theinstallation is easier and
temporary support until the adhesive gains
its strength is not requireddue to the low
weight. They can be formed on site into
complicated shapes and can also beeasily
cut to length on site. Composite materials
of fibers in a polymeric resin, also known
asFiber Reinforced Polymers (FRP), have
emerged as an alternative over steel to
repair, retrofitand strengthen buildings and
bridges. FRP materials may offer a number
of advantages oversteel plates which
include: light weight, noncorrosive, and
exhibit high tensile strength. Thiswork is
comparative study of the behavior of
concrete beams retrofitted with Carbon
FiberReinforced Polymer (CFRP), Glass
Fiber Reinforced Polymer (GFRP), and
Aramid FiberReinforced Polymer (AFRP)
with different wrapping techniques. Finite
Element Analysis isused to model the
behavior numerically and is used to
determine the overall behavior of
astructure by dividing it into number of
simple elements, each of which has well
definedmechanical and physical
properties.
FINITE ELEMENT MODELING OF
REINFORCED CONCRETE
BEAMSSTRENGTHENED WITH FRP
LAMINATES
Externally bonded FRP laminates and
fabrics can be used to increase the shear
strength ofreinforced concrete beams and
columns. Figure1 shows examples of
possible FRP shearstrengthening
configurations. It can be seen that the
shear strength of columns can be
easilyimproved by wrapping with a
continuous sheet of FRP to form a
complete ring around themember. Shear
strengthening of beams, however, is likely
to be more problematic when theyare cast
monolithically with slabs. This increases
the difficulty of anchoring the FRP at the
beam/slab junction and increases the risk
of debonding failure. Nevertheless,
bonding FRP oneither the side faces, or the
side faces and soffit, will provide some
shear strengthening forsuch members. In
both cases, it is recommended that the FRP
is placed such that the principalfiber
orientation, β, is either 45o or 90o to the
longitudinal axis of the member. There is
someevidence that the shear resistance of
Page 3 of 5
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 05
May 2019
Available online:https://ejbss.org/ P a g e | 810
beams can be further improved by bonding
additionalsheets with their fibers
orientated at right angles to the principal
fiber direction. In FiniteElement Modeling
of Reinforced Concrete Beams
Strengthened with FRP Laminates.
FRPstrengthened beams failuremay occur
due to beam shear, flexural compression,
FRP rupture, FRP debonding or concrete
cover ripping
Reinforcing steel
Modelling of reinforcing steel in finite
elements is much simpler than the
modelling ofconcrete. A Link8 element
was used to model steel reinforcement.
This element is a 3D sparelement and it
has two nodes with three degrees of
freedom – translations in the nodal x,
y,and z directions. This element is also
capable of plastic deformation. A perfect
bond betweenthe concrete and steel
reinforcement considered. However, in the
present study the steel 18reinforcing was
connected between nodes of each adjacent
concrete solid element, so the twomaterials
shared the same nodes. The same approach
was adopted for FRP composites
FRP Laminates
FRP composites are materials that consist
of two constituents. The constituents are
combinedat a macroscopic level and are
not soluble in each other. One constituent
is the reinforcement,which is embedded in
the second constituent, a continuous
polymer called the matrix. Thereinforcing
material is in the form of fibers, i.e.,
carbon and glass, which are typically
stifferand stronger than the matrix. The
FRP composites are orthotropic materials;
that is, theirproperties are not the same in
all directions. Figure below shows a
schematic of FRPcomposites.
OBSERVATIONS AND DISCUSSIONS
This chapter deals with study of the
behaviour of concrete beams retrofitted
with CarbonFiber Reinforced Polymer
(CFRP), Glass Fiber Reinforced Polymer
(GFRP), and AramidFiber Reinforced
Polymer (AFRP) with different wrapping
techniques. Finite ElementAnalysis is used
to model the behaviour numerically and is
used to determine the overallbehaviour of
a structure by dividing it into number of
simple elements, each of which haswell
defined mechanical and physical
properties.
One control beam and the five retrofitted
beams each with AFRP, CFRP and GFRP
