- Open Access
- Total Downloads : 17
- Authors : C. Raghavendra Reddy, R. Vignesh, R. R. Tharini, , V. Jayakumar
- Paper ID : IJERTCONV4IS25013
- Volume & Issue : SNCIPCE – 2016 (Volume 4 – Issue 25)
- Published (First Online): 30-07-2018
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License: This work is licensed under a Creative Commons Attribution 4.0 International License
Experimental Investigation on Strengthening of RC Beam Both Internally and Externally by using GFRP and GFRP Wraps
Raghavendra Reddy1, R. Vignesp
UG Student1, UG Student2 Department of Civil Engineering IFET College of Engineering Villupuram, India
R. Tharini1,, V. Jayakumar2
Assistant Professor1, Assistant Professor2 Department of Civil Engineering
IFET College of Engineering, Villupuram, India
Abstract – To prove the strength for, reinforced cement concrete < reinforced cement concrete with GFRP wraps < reinforced cement concrete with 1% GFRP & GFRP wraps < reinforced cement concrete with 1.5% GFRP & GFRP wraps
< reinforced cement concrete with 3% GFRP & GFRP wraps. So the increasing the GFRP percentage and using GFRP wraps to increasing the beam flexural strength and load carrying capacity. The main aim of this study is to investigate the beam internal strength GFRP and external strength GFRP wraps.
Keywords – Both internally and externally strength of beam, GFRP, GFRP wraps.
Generally ordinary structural concrete possesses many disadvantages as a building material though it has great popularity in civil construction industry. On the material phase, concrete has low tensile strength, little ductile strength, and little resistance to cracking. For over fifty years there have been many attempts to overcome the drawbacks of concrete. All of your focus has been to replace fine aggregate and coarse aggregate of concrete. But we used GFRP as a additional materials to aggregate and GFRP wraps to provide strength both internally and externally respectively. The strengthening of concrete structures with externally bonded reinforcement is generally done by using GFRP laminates. The plate bonding technique is now established as a simple and convenient repair method of enhancing the flexural , shear and compressive performance of concrete structures.
Need for this GFRP wraps for, Increasing flexural strength, Increasing bonding strength, Resistant to environmental affect, Light weight reinforcing for GFRP wrapping, Resistant to corrosion, High strength, Resistant to chemicals, High stiffness scope of this GFRP wraps are, Low coefficient of thermal expansion, High strength to weight ratio as well as being light weight, Equally fibre alignment, High structural efficiency, Reduced periodic maintenance, Longer life spans and, Reduced labor costs,
The main objective of this project is experimental investigation on strengthening of RC beam both internally and externally by using GFRP and GFRP wraps.
Advantages of GFRP wraps
High strength, less weight, Load carrying capacity very high, Increasing tensile strength , Resists the salt water, chemicals, and the environment, Able to mold complex shapes.
Glass fibre reinforced polymer (GFRP) 1%, 1.5%, 3%.
Glass fibre reinforced polymer (GFRP) WRAPS Double layered (single side, double side , triple side
Why selecting GFRP as additive material
Fiber deformation to improve bond, Physical properties of the GFRP, Fiber packaging to simplify mixing, light weight reinforcing and to avoid environmental affect.
Properties of GFRP
The max percentage of GFRP is used in weight of cement for 3%, High Strength, Heavy bonding strength, light weight of concrete, Stiffness, Temperature dependent behavior, Corrosion resistance, Thermal insulation, Thermal conductivity.
GFRP wraps or laminates
GFRP wraps is the used for to cover beam for single side, double side, U shape and pasted the beam. Fibre reinforced polymer material systems composed of fibre embedded in a polymeric matrix, exhibit several properties which create the opportunity for their use as structural reinforcing elements. They are characterized by excellent tensile strength in the direction of the fibers.
GFRP composites do not exhibit yielding, but instead are elastic upto failure. They are also characterized by relatively low modulus of elasticity in tension and low compressive properties. Corrosion resistant and should perform better than other construction materials in terms of weathering behavior. In this study, bidirectional glass reinforced polymer laminate are used.
Density at 25 c g/cmÂ³
Properties of concrete with GFRP
In addition to improvement cracking behavior, (GFRP) in concrete increase the dynamic load and fatigue strength. Under equivalent stress, withstand greater no. of load cycles than plain concrete.
The main objective of this project is experimental investigation on strengthening of RC beam both internally and externally by using GFRP and GFRP wraps. Internally GFRP are added to 1%, 1.5%, 3% by weight of cement. Externally GFRP wraps are used to beams single side, double side, triple side and double layered. The experiment was carried out on M40 grade concrete with 0.40 water cement ratio.
prism specimens of sizes 700 x 150 x 150 mm made of concrete with cement, fine aggregate, coarse aggregate and GFRP.
The specified design strength of concrete is 40MPa at 28 days. The specific gravity of Fine Aggregates FA and Coarse Aggregates CA is 2.64 and 2.72 respectively. The standard deviation can be taken as 5MPa. Ordinary Portland cement was used of 43grade. Coarse aggregate is found to be Absorptive to the extent of 1% and free surface moisture in sand is found to be 2%.According to IS10262- 1982 clause 3.3 Table no 4. The mixing water content calculated is 185 kg/m3.
MATERIALS AND METHODOLOGY
In this experimental investigation Portland pozzolona cement (PPC) was used for all concrete mixes, the cement used was fresh and without lumps. The testing of cement was done as per IS 8112-1989.The specific gravity of cement was found to be 3.15.
Portable tab water is used for preparation of specimens and curing of specimens.
As per IS 383-1970, table4 sand used for experimental program was locally produced and was conforming zone- II. The specific gravity of fine aggregate was found to be 2.64.
locally available coarse aggregate passing from 20mm sieve and conforming IS 383-1970 were used in present work. The specific gravity of coarse aggregate was found to be 2.72
Glass fibre reinforced polymer (GFRP)
The max percentage of GFRP is 3% and specific gravity of GFRP was found to be 1.74.
The mix was designed as per IS 10262:2009 for M40 grade concrete with 0.40 water cement ratio. Concrete mixe are prepared by adding percentage of GFRP 0%, 1%, 1.5% and 3% for every mix.
Test specimens and test procedure
Cement, sand and aggregate were taken in mix proportion 1:1.81:3.75 which correspond to M40 grade of concrete respectively. The prism of size 700mm Ã— 150mmÃ— 150mm were used as test specimens to determine the compressive strength, tensile strength and flexural strength respectively.
RESULTS AND DISCUSSION
Analysis of beams for 28 days
All the beams are cured for 28 days were tested on the Flexural Testing machine. The following results are to prove increasing the strength for reinforced concrete beams, reinforced concrete beam with wraps, reinforced
concrete beams with 1%GFRP & wraps, reinforced concrete beam with 1.5% GFRP & Wraps, reinforced concrete beam with 3% GFRP & wraps. The
details of the load are thus given in the table below and 80
shows the graphical representation of the results.
Load in KN and flexural strength of beams 28 days:
Loa d in
Average load in
RC normal beam
RC beam with wraps
RC beam with 1% GFRP
RC beam with 1.5% GFRP
RC beam with 3% GFRP
28 days test results
A B C D E
Graphical representation of test results for 28 days
Flexural strength for 28 days
Flexural strength N/mmÂ²
A B C D E
beam – 1
beam – 2
beam – 3
A = Reinforced concrete normal beam
B = Reinforced concrete beam with wrapping
C = Reinforced concrete beam with 1% GFRP & Wrapping D = Reinforced concrete beam with 1.5% GFRP & Wrapping
A B C D E
E = Reinforced concrete beam with 3% GFRP & Wrapping
From the above results and graphs following observations are made:
Increasing in strength comparing with normal reinforced
concrete beam (%)
RC beam with wraps
RC beam with 1% GFRP & wraps
RC beam with 1.5% GFRP & Wraps
RC beam with 3% GFRP & Wraps
To proved the strength for, reinforced cement concrete
< reinforced cement concrete with GFRP wraps < reinforced cement concrete with 1% GFRP & GFRP wraps
< reinforced cement concrete with 1.5% GFRP & GFRP wraps < reinforced cement concrete with 3% GFRP & GFRP wraps .
Therefore, from the above results the beam strength are increased for the increasing the GFRP percentage and using GFRP wraps to increasing the beam flexural strength and load carrying capacity. Its concluded that through the provision of GFRP as a additive material to the concrete it will improves various mechanical properties (flexural strength) of the members (beams) internally. That to on providing wrapping by using GFRP & epoxy resin it will additionally its strength externally also.
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