This Report covers the technique of retrofitting of existing as well as worn out structures using FRP laminates. Thermal stresses are imposed into the samples to mimic fire in a building. It is then tested for strength, repaired using 250 gsm glass fiber reinforced polymer and then tested for strength again. It was observed that the lost strength of the samples subjected to thermal stresses was regained.

1. RETROFITTING USING FRP LAMINATES
2014-2018
A Dissertation Submitted to
Guru Gobind Singh Indraprastha University (GGSIPU), Delhi
Towards Partial Fulfillment of the Degree of
BACHELOR OF TECHNOLOGY
Specialization in
CIVIL ENGINEERING
Guided by: Submitted By:
Mr. Vikas kataria Praveen Choudhary (017)
Mr. Ashwani Shubham Jain (044)
Sabin Shaji (046)
Gaurav Gupta (067)
Department of Civil Engineering
Northern India Engineering College, New Delhi
An Institute Affiliated to Guru Gobind Singh Indraprastha University
Nov-2017

2. DEPARTMENT OF CIVIL ENGINEERING
NORTHERN INDIA ENGINEERING COLLEGE,
NEW DELHI
Affiliated to GGSIPU
CERTIFICATE
This is to certify that the project titled ‘Retrofitting using FRP laminates’, submitted by
Praveen Chaudhary, Shubham Jain, Sabin Shaji and Gaurav Gupta to Northern India
Engineering College affiliated to Guru Gobind Singh Indraprastha University, for the award
of degree of Bachelor of Technology, is a bonafide record of the project work done by them
under my supervision. The contents of this work, in full or in part have not been submitted to
any other institute or university for the award of any degree.
Internal Examiner External examiner
Date: Date:

3. ii
ACKNOWLEDGEMENT
We take this opportunity to express my profound gratitude and deep regards to our
Director Professor Dr. G. P. Govil (Director, NIEC) to encourage student to gain
valuable practical experience through the Minor Project.
We also take this opportunity to express a deep sense of gratitude to Mrs. Maninder
Kaur, Head of Department of Civil Engineering for her cordial support, valuable
information and guidance, which helped us in completing the task through various
stages.
We are thankful to Mr. Vikas Kataria and Mr. Ashwani Bharadwaj and the
faculty members of Department of Civil Engineering, NIEC, and others for their
valuable information provided by them in their respective fields. We are grateful for
their cooperation during the period of our project.
Lastly, we thank our parents, batch mates & friends for their constant encouragement
without whom this project would not have been possible.
PRAVEEN CHAUDHARY (01715603414)
GAURAV GUPTA (06715603414)
SHUBHAM JAIN (04415603414)
SABIN SHAJI (04615603414)

4. iii
ABSTRACT
Rehabilitation and strengthening of old structures using advanced materials is a
contemporary research in the field of Structural Engineering. Over the past decades,
much research has been carried out on shear and flexural strengthening of reinforced
concrete beams using different types of fiber reinforced polymers and adhesives.
Strengthening of old structures is necessary to obtain an expected life span. Such a
method of strengthening of old structures by the help of new technology is termed as
‘retrofitting’. Life span of Reinforced Concrete structures may be reduced due to
many reasons, such as deterioration of concrete and development of surface cracks
due to ingress of chemical agents, thermal stresses induced by fire in a structure,
abrasion and cavitation in hydraulic structures caused by fast moving water, improper
design and unexpected external lateral loads such as wind or seismic forces acting on
a structure, which are also the reasons for failure of structural members. High tensile
strength of specific fibers like glass fibers, carbon fibers etc. found its application in
increasing the strength of new RCC structures as well as strengthening of older and
worn out structures.
It was observed that the lost strength of the concrete due to fire activity was regained
to around 98% of the normal concrete strength for 2 layer of wrapping. The strength
can further be increased by increasing the number of wrappings.
Keyword: GFRP, Retrofitting, Rehabilitation, Epoxy, Fire Activity

5. iv
TABLE OF CONTENTS
CERTIFICATE i
ACKNOWLEDGEMENT ii
ABSTRACT iii
TABLE OF CONTENTS iv
LIST OF FIGURES vi
LIST OF TABLES/GRAPH vii
CHAPTER 1: INTRODUCTION……………………….………………………...1
1.1. GENERAL 1
1.2. HISTORY ON FRP 1
1.3. ADVANTAGES 2
1.4. OBJECTIVES 2
CHAPTER 2: LITERATURE RIVEW…………...……………………...………3
2.1. GENERAL 3
2.2. RESEARCH PAPERS 3
2.3. CRITICS 8
CHAPTER 3: EXPERIMENTAL STUDY…………………………………....….9
3.1. METHODOLOGY 9
3.2. MATERIALS USED 9
3.3. MATERIAL TESTING 11

6. v
CHAPTER 4: PROCEDURE……………………………………………………..14
4.1. GENERAL PROCEDURE 14
4.2. HEAT ACTIVITY 21
4.3. REPAIR AND RETROFITTING 23
CHAPTER 5: RESULTS AND OBSERVATIONS……………………………...25
5.1. MATERIAL TEST RESULTS 25
5.2. CTM TEST RESULTS 26
5.3. HEAT TRANSFER THROUGH CONCRETE AT VARIOUS DEPTHS 30
CHAPTER 6: CONCLUSIONS…………………………………………………...31
CHAPTER 7: FUTURE IMPLEMENTATIONS………………………………...32
CHAPTER 8: BIBLIOGRAPHY AND REFERENCES…………………………33
APPENDIX………………………………………………………………………….35

7. vi
LIST OF FIGURES
Fig 1: Batching of Concrete 15
Fig 2: Admixture 15
Fig 3: Mixing of Concrete 16
Fig 4: Slump Test 16
Fig 5: Table Vibrator 17
Fig 6: CTM Test of Normal Concrete 18
Fig 7: Thermal Stresses on Concrete 19
Fig 8: FRP Wrapped Sample 21
Fig 9: Failure Sample 21
Fig 10: Setup for Heat Activity 22
Fig 11: Placing on Burner 22
Fig 12: Rapid Cooling 22
Fig 13: Normal Cooling 22
Fig 14: Spalling of Concrete 23
Fig 15: Mortar Filling 23
Fig 16: Applying FRP 24
Fig 17: Wrapped Samples 24
Fig 18: Samples for Heat Transfer 30

8. vii
LIST OF TABLES/GRAPHS
Table No. 1: Ratio as per Design 14
Table No. 2: 7-Day Compressive Strength 26
Table No. 3: 14-Day Compressive Strength 27
Table No. 4: 28-Day Compressive Strength 28
Table No. 5: Heat Transfer at Various Depths 30
Graph 1: 7-Day Compressive Strength 26
Graph 2: 14-Day Compressive Strength 27
Graph 3: 28-Day Compressive Strength 28
Graph 4: Compressive Strength of Samples without FRP 29
Graph 5: Compressive Strength of Samples with FRP 29
Graph 6: Percentage Heat Transferred Through Various Layers 30

9. 1
CHAPTER 1
1. INTRODUCTION
1.1.General
Rehabilitation and strengthening of old structures using advanced materials is a
contemporary research in the field of Structural Engineering. During the past two
decades, much research has been carried out on shear and flexural strengthening
of reinforced concrete beams using different types of fiber reinforced polymers
and adhesives. Strengthening of old structures is necessary to obtain an expected
life span.
Life span of Reinforced Concrete (RC) structures may be reduced due to many
reasons, such as deterioration of concrete and development of surface cracks due
to ingress of chemical agents, improper design and unexpected external lateral
loads such as wind or seismic forces acting on a structure, which are also the
reasons for failure of structural members.
The superior properties of polymer composite materials like high corrosion
resistance, high strength, high stiffness, excellent fatigue performance and good
resistance to chemical attack etc., has motivated the researchers and practicing
engineers to use the polymer composites in the field of rehabilitation of structures.
1.2.History on FRP
The traditional method of repairing or strengthening of RC columns is by steel
jacketing, thin layers of heavily reinforced concrete or pre-tensioned steel cables
covered with thin layer of concrete. These methods involve difficult
implementation procedures and high cost. Then, FRP was introduced to the
market.
The development of fiber-reinforced plastic for commercial use was being
extensively researched in the 1930s. In the UK, considerable research was
undertaken by pioneers. It was particularly of interest to the aviation industry.
The first use of glass fiber reinforced polyester composites was in the aircraft
industry during the 1940s. This was followed some years later by the first non-
military application in the marine sector, where FRP proved a complete
innovation making a revolution in the way boats were built.

10. 2
Carbon fiber production began in the late 1950s and was used, though not widely,
in British industry beginning in the early 1960s. Repair and rehabilitation of
reinforced concrete (RC) columns was the first successful applications of FRP
composites that were initiated in early 1990.
1.3. Advantages
 FRP has a high s/w ratio.
 FRP doesn’t show any yielding or plastic behavior.
 FRP composites have tensile stiffness lower than that of steel
 Resistance to corrosion so it can be utilized on interior and exterior
structural members in all almost all types of environments
 They are devoid of any magnetic field and can offer considerable
resistance to electric sparks, hence it is a very good option for the power
industry.
 FRP is characterized by the ease of application since heavy equipment is
not needed for the rehabilitation hence social effects are witnessed.
 Resistance to chemicals and other corrosive materials.
 Commendable thermal insulation.
1.4.Objectives
 The main objective is to study the increase in strength of existing as well
as old and worn out buildings by the application of fiber reinforced
polymer so as to either achieve the expected life or to increase the life of
the structure.
 To compare the values of strength reduced by fire activity in a structure
with that of a normal structure.
 To plot a curve for the effect of fire penetrating into different depths of the
structural members.
 To determine the percentage increase in strength by the application of
FRP.

11. 3
CHAPTER 2
2. LITERATURE REVIEW
2.1.General
The development of fiber-reinforced plastic for commercial use was being
extensively researched in the 1930s. In the UK, considerable research was
undertaken by pioneers. It was particularly of interest to the aviation industry.
The study of following articles gives us bigger perspective of understanding.
2.2.Research Papers
Pradeep Bhargava (2015) (1)
This paper deals with the methods to regain the strength using glass fiber
reinforced polymer (GFRP) that was lost due to high temperatures.
A series of T-beams were casted. After 90 days of ageing, the beams were
heated to 600°C and 900°C temperatures in an electric furnace. While three
control beams were treated at room temperature, eighteen beams were heat
damaged. The heat damaged beams were strengthened with FRP laminates
and then tested until complete failure. Two different strengthening patterns of
GFRP strengthening materials were used. The strengthened beams were then
tested in a loading frame under 4 point loading condition. The load-deflection
curves for the beams were examined to evaluate the capability of various
strengthening patterns.
It was observed that the beams exposed to different temperatures experienced
a reduction in ultimate load carrying capacity ranging from 14 % to 61%. The
study shows that GFRP wraps were quite capable of restoring the flexural
strength of heat damaged beams.
J. G. Teng (2009) (2)
This paper has addressed many issues in the application of fiber-reinforced
polymer (FRP) composites in civil engineering structures. While the main
focus of the programme has been on the behaviour and modelling of
reinforced concrete (RC) and metallic structures strengthened with bonded
FRP reinforcement, increasing attention has also been devoted to the use of
FRP composites in new construction. This paper presents a brief summary of
some of the latest advances of the research programme, covering the
strengthening of RC structures with bonded FRP reinforcement, seismic

12. 4
retrofit of RC structures, durability of FRP-strengthened RC structures, hybrid
FRP concrete structures, and smart FRP structures.
A.R. Rahai (2008) (3)
This paper presents the results of experimental studies about concrete
cylinders confined with high-strength carbon fiber reinforced polymer (CFRP)
composites. Forty small scale specimens (150×300 mm) were subjected to
uniaxial compression up to failure and stress-strain behaviours were recorded.
The various parameters such as wrap thickness and fiber orientation were
considered. Different wrap thicknesses (1, 2, 3, and 4 layers), fiber orientation
of 0º, 90º, ±45º and combinations of them were investigated. The results
demonstrated significant enhancement in the compressive strength, stiffness,
and ductility of the CFRP-wrapped concrete cylinders as compared to
unconfined concrete cylinders.
Wiss, Janney (2007) (4)
In this paper we learned that despite the promising developments in the
implementation of fiber reinforced polymers (FRP) for the repair and retrofit
of reinforced concrete (RC) structures, many challenges exists that have
prevented additional growth of this market. Such challenges include: potential
brittle behaviour of FRP-strengthened RC structures due to sudden failure
modes such as FRP rupture or debonding; deterioration of the FRP mechanical
properties due to harsh environmental conditions such as wet-dry cycles and
freeze–thaw conditions; a reduction in strength due to the effects of improper
installation procedures; and lack of agreement among debonding behavior and
bond strength models.
This paper focuses on another of these challenges: the stated need for
mechanical anchorage systems to improve FRP strength in situations where
debonding or lack of development length is a problem (ACI Committee
440 2008), and the lack of anchorage-related research data to support
widespread implementation of FRP anchorage systems (Ceroni et al. 2008).
Amir Shaat (2009) (5)
This paper describes the research progress to date in the field of strengthening
and repair of steel structures using fiber reinforced polymers (FRP). While this
subject has been extensively covered for concrete structures, retrofit of steel
structures using FRP has not yet gained the same wide acceptance.
This paper provides review of research work on retrofit of steel members
including repair of naturally corroded beams, repair of artificially notched

13. 5
beams, strengthening of intact beams, and strengthening of steel/concrete
composite flexural members as well as the retrofit efforts of thin-walled
tubular sections.
The paper also discusses important topics related to the subject such as fatigue
behaviour, bond and force transfer mechanisms between steel and FRP and the
durability of retrofitted systems, particularly the issue of galvanic corrosion.
Research findings have shown that FRP sheets and strips are not only effective
in restoring the lost capacity of a damaged steel section but are also quite
effective in strengthening of steel sections to resist higher loads, extend their
fatigue life and reduce crack propagation, if adequate bond is provided and
galvanic corrosion is prevented.
P.A. Buchan (2011) (6)
In this paper we studied that the recent world events such as bombings in
London, Madrid and Istanbul have highlighted the susceptibility of many
civilian structures to terrorist attack. Explosives directed towards vulnerable
structures may cause considerable damage and loss of life. As a result, there is
now a desire to increase the blast resistance of many types of existing
structures. This has led to experimental and finite element (FE) research in
retrofitting concrete and masonry structures with fiber reinforced polymer
(FRP) composites for blast protection.
This paper presents a review of the publicly available literature and highlights
areas where research is lacking.
S.T Smith (2009) (7)
This paper states that bonding of a fiber-reinforced polymer (FRP) plate to the
tension face of a beam has become a popular flexural strengthening method in
recent years. As a result, a large number of studies have been carried out in the
last decade on the behaviour of these FRP-strengthened beams. Many of these
studies reported premature failures by debonding of the FRP plate with or
without the concrete cover attached. The most commonly reported debonding
failure occurs at or near the plate end, by either separation of the concrete
cover or interfacial debonding of the FRP plate from the RC beam.
This paper is concerned with strength models for such plate end debonding
failures. In this paper, a comprehensive review of existing plate debonding
strength models is presented. Each model is summarised and classified into
one of the three categories based on the approach taken, and its theoretical
basis clarified.

14. 6
The review not only brings together for the first time all existing plate end
debonding strength models into a unified framework for future reference, but
also provides the necessary background information for them to be assessed in
the companion paper using a large test database assembled by the authors from
the published literature.
Prof. K. C. Biswal (2007) (8)
In this paper we studied that the strengthening of structures via external
bonding of advanced fiber reinforced polymer (FRP) composite is becoming
very popular worldwide during the past decade because it provides a more
economical and technically superior alternative to the traditional techniques in
many situations as it offers high strength, low weight, corrosion resistance,
high fatigue resistance, easy and rapid installation and minimal change in
structural geometry. Although many in-situ RC beams are continuous in
construction..
In this paper an experimental investigation is carried out to study the
behaviour of continuous RC beams under static loading. The beams are
strengthened with externally bonded glass fiber reinforced polymer (GFRP)
sheets. Different scheme of strengthening have been employed. The beams are
grouped into two series and each series have different percentage of steel
reinforcement. One beam from each series was not strengthened and was
considered as a control beam, whereas all other beams from both the series
were strengthened in various patterns with externally bonded GFRP sheets.
The study examines the responses of RC continuous beams, in terms of failure
modes, enhancement of load capacity and load deflection analysis. The results
indicate that the flexural strength of RC beams can be significantly increased
by gluing GFRP sheets to the tension face. In addition, the epoxy bonded
sheets improved the cracking behaviour of the beams by delaying the
formation of visible cracks and reducing crack widths at higher load levels.
Hesham M. Diab (2013) (9)
From this paper we found that de-bonding problems stand as a critical barrier
against a wide range of usages of FRP composites in structural strengthening
and repairing applications. Results of an experimental campaign on FRP-
concrete debonding are presented in this study. Specimens with different types
of FRP sheets bonded to concrete prism using flexible adhesive were
conducted to determine the effective bonding length and ultimate bond
capacity of FRP-concrete interface. The experimental results from double lap
shear specimens indicated that the flexible adhesive has increased both of the

15. 7
effective bonding length and the ultimate bond capacity of FRP-concrete
interface. Increase of fracture energy of FRP-concrete interface has been
clearly observed due to flexible adhesive for all different types of FRP sheets.
Analytical models available in the literature were adopted to evaluate the bond
strength and the effective bond length of the experiment results in this study.
Consequently, the existing models need to be modified to consider the type of
adhesive layer.
Cem YALÇIN (2004) (10)
In this paper an experimental study was conducted on the determination of
strengthening reinforced concrete columns using FRP material. Four
reinforced concrete cantilever columns, representing the old construction
practice, were tested. One lap-spliced and one continuous longitudinally
reinforced as build control columns, and their strengthened columns were
tested under constant axial load and reversed cyclic lateral load. FRP sheets
were wrapped around the potential hinging zones. Test results showed that
lap-splicing dominates the behaviour where no difference in force-deformation
relationship between control and strengthened columns were observed.
However, the columns with continuous longitudinal reinforcement showed
significant increase in ductility.
Khaled Abdelrahman (2014) (11)
In this research paper, steel fiber reinforced polymers (SFRP) sheets have been
introduced for the repair and rehabilitation of concrete structures. The
behaviour of the concrete columns wrapped with SFRP sheets were studied;
however, several critical parameters such as the cost and ductility
effectiveness of the SFRP wrapped concrete columns have been lightly
addressed. Thus, the main objective of this paper is to study the cost and
ductility effectiveness of SFRP wrapped concrete columns and compare the
results with the conventionally used carbon FRP (CFRP) wrapped concrete
columns. In addition, an analytical procedure to predict the cost effectiveness
of SFRP wrapped concrete columns is also suggested, from which, a
parametric study was conducted. The parametric study investigated the effect
of the concrete strength, the number of SFRP layers, and the size and
slenderness effects on the cost effectiveness of the concrete columns wrapped
with SFRP sheets. The results from the cost and ductility effectiveness study
indicated that the SFRP wrapped concrete columns showed enhanced
performance over the CFRP wrapped concrete columns. The parametric study

16. 8
showed the significant impact of the investigated parameters on the cost
effectiveness of concrete columns wrapped with SFRP sheets
2.3. Critics
From these research papers we studied that the different materials as FRP
provide different strengths to the concrete members. Various types of
deteriorations were studied including fire, blasting, chemical attacks, abrasion,
cavitation etc. It was also observed that wrapping at different angles provide
different efficiencies of strength as well as more the number of layers of
wrapping; more the strength gained thus improving the structure. Different
types of adhesives were used and the resulting samples were tested against
strength, chemical attacks and were subjected to harsh conditions to evaluate
their bonding as well as their stability. A comparison was made between
retrofitting using FRP and adhesives, and using steel tubes as casings and it
was concluded that FRP turned out to be advantageous in most of the cases.

17. 9
CHAPTER 3
3. EXPERIMENTAL STUDY
3.1.Methodology
1. Design of M30 mix as per IS 10262:2009
2. The GFRP fibres are used for wrapping.
3. Epoxy is used as an adhesive and the ratio of epoxy and hardener used is
1:5.55 as per specifications.
4. The wrapping is done at an angle of 0º.
5. Maximum temperature to be achieved is around 400º.
6. Samples are cooled rapidly by using water and normally in the air.
7. Two layers of wrappings are provided around the sample and the resulting
sample is left for a minimum of 1 day.
3.2.Material Used
3.2.1. Cement
Cement is a binder, a substance used in construction that sets, hardens
and adheres to other materials, binding them together. Cement is seldom
used solely, but is used to bind sand and coarse (aggregate) together.
Cement is used with fine aggregate to produce mortar for masonry, or
with sand and coarse aggregates to produce concrete.
Cements used in construction are usually inorganic and
often lime or calcium silicate based.
3.2.2. Fine Aggregate
Fine aggregates generally consist of natural sand or crushed stone with
particles passing through 4.75mm sieve. The purpose of the fine
aggregate is to fill the voids in the coarse aggregate and to act as a
workability agent.
3.2.3. Coarse Aggregate
When the aggregate is sieved through 4.75mm sieve, the aggregate
retained is called coarse aggregate. Gravel, cobble and boulders come
under this category. The maximum size aggregate used may be
dependent upon some conditions. In general, 40mm size aggregate is
used for normal strengths and 20mm size is used for high strength
concrete.

18. 10
3.2.4. FRP laminates
FRP plate is a high strength, pre-manufactured carbon/epoxy laminate.
These laminates are used as externally bonded reinforcement providing
additional strength and stiffness to concrete, masonry, and wood
structural elements.
Fiberglass Reinforced Polyester (FRP) sheet laminates are the perfect
support components across a wide variety of applications. They offer
dimensional stability, low creep, and high flexural strength. Thermoset
laminates’ excellent insulating properties and resistance to melting at
high heat render them extremely useful as primary and secondary
electrical insulation and thermal barrier
The resulting repair is lightweight, non-corrosive and is much easier to
install than steel.
3.2.5. Epoxy Resin
Epoxy resins are low molecular weight pre-polymers or higher
molecular weight polymers which normally contain at least two epoxide
groups. The epoxide group is also sometimes referred to as a glycidyl or
oxirane group.
A wide range of epoxy resins are produced industrially. The raw
materials for epoxy resin production are today
largely petroleum derived; although some plant derived sources are now
becoming commercially available (e.g. plant derived glycerol used to
make epichlorohydrin).
Epoxy resins are polymeric or semi-polymeric materials, and as such
rarely exist as pure substances, since variable chain length results from
the polymerisation reaction used to produce them.
3.2.6. Sikament
It is a highly effective dual action liquid superplasticizer for production
of free flowing concrete or as a substantial water reducing agent for
promoting high early and ultimate strength.
It is suitable for use in tropical and hot climatic conditions.

19. 11
3.3.Material Testing
3.3.1. Cement
1. Fineness of Cement - Test Sieve 90 microns is used to determine
consistency of Cement. The fineness of cement has an important bearing
on the rate of hydration and hence on the rate of gain of strength and also
on the rate of evolution of heat. Finer cement offers a greater surface area
for hydration and hence faster the development of strength. The fineness of
grinding has increased over the years. But now it has got nearly stabilized.
Different cements are ground to different fineness. Increase in fineness of
cement is also found to increase the drying shrinkage of concrete.
2. Normal Consistency of Cement - Vicat apparatus conforming to IS:
5513-1976. For finding out initial setting time, final setting time and
soundness of cement, and strength a parameter known as standard
consistency has to be used. The standard consistency of a cement paste is
defined as that consistency which will permit a Vicat plunger having 10
mm diameter and 50 mm length to penetrate to a depth of 33-35 mm from
the top of the mould.
3. Initial and final setting time of Cement - IS : 4031 ( Pat 4 ) -1988, IS :
4031 ( Pat 5 ) - 1988, IS : 5513-1976. For convenience, initial setting time
is regarded as the time elapsed between the moments that the water is
added to the cement, to the time that the paste starts losing its plasticity.
The final setting time is the time elapsed between the moment the water is
added to the cement, and the time when the paste has completely lost its
plasticity and has attained sufficient firmness to resist certain definite
pressure.
4. Soundness of Cement - Le Chatelier’s apparatus. Once of the most
important properties of cement is its soundness. Unsoundness in cement is
caused by undue expansion of some of the constituents like free lime
produced in the manufacturing process of cement. Another possible case
of unsoundness is the presence of too high a magnesia content in the
cement. As the cement absorbs moisture, free lime expands to many times
its original volume and develops considerable force when hydrated, its
delayed hydration may readily disrupt the mass. One advantage of slow
setting cement is that more time is given to hydrate the lime before the
mass becomes rigid. In the soundness test a specimen of hardened cement

20. 12
paste is boiled for a fixed time so that any tendency to expand is speeded
up and can be detected.
5. Specific Gravity of Cement - Le-Chatelier Flask conforming to IS: 4031-
PART 11-1988. The specific gravity of a cement is not a property
normally determine for its own sake, but it is required in the measurement
of its specific surface. The specific gravity is defined as the ratio between
the weight of a given volume of cement and weight of an equal volume of
water. The test for finding the specific gravity of Portland cement was
originally considered to be of much importance in view of the fact that
other tests lead to more definite conclusions. The most popular method of
determining the specific gravity of cement is by the use of a liquid such as
water free kerosene which does not react with cement. A specific gravity
bottle or a standard Le-Chatelier flask may be used.
3.3.2. Fine Aggregate
1. Fineness Modulus of Fine Aggregate - Fineness modulus is generally
used to get an idea of how coarse or fine the aggregate is. More fineness
modulus value indicates that the aggregate is coarser and small value of
fineness modulus indicates that the aggregate is finer. Generally sand
having fineness modulus more than 3.2 is not used for making good
concrete. Sieve the aggregate using the appropriate sieves (4.75 mm, 2.36
mm, 1.18 mm, 600 micron, 300 micron & 150 micron). Record the weight
of aggregate retained on each sieve. Calculate the cumulative weight of
aggregate retained on each sieve. Calculate the cumulative percentage of
aggregate retained. Add the cumulative weight of aggregate retained and
divide the sum by 100. This value is termed as fineness modulus.
2. Specific Gravity of fine aggregate - The fine aggregate specific gravity
test is used to calculate the specific gravity of a fine aggregate sample by
determining the ratio of the weight of a given volume of aggregate to the
weight of an equal volume of water using Density Bottle. Specific gravity
is a measure of a material’s density (mass per unit volume) as compared to
the density of water at 73.4°F (23°C). Therefore, by definition, water at a
temperature of 73.4°F (23°C) has a specific gravity of 1.

21. 13
3. Water Content of Fine Aggregate Test - This test is used to determine
the water content of a material by drying a sample to constant mass at a
specified temperature i.e. 105degree Celsius. The water content of a given
soil is defined as the ratio, expressed as a percentage, of the mass of the
pore water to the mass of the solid material. This test results are very
useful in the Mix Design of Concrete. The water content of fine aggregate
depends upon the origin of fine aggregate and the stress history of the
aggregates.
3.2.3. Coarse Aggregate
1. Fineness Modulus of Coarse Aggregate - Fineness modulus of coarse
aggregates represents the average size of the particles in the coarse
aggregate by an index number. It is calculated by performing sieve
analysis with standard sieves. Fineness modulus of coarse aggregates
represents the average size of the particles in the coarse aggregate by an
index number. It is calculated by performing sieve analysis with standard
sieves. Coarse aggregate means the aggregate which is retained on
4.75mm sieve when it is sieved through 4.75mm. To find fineness
modulus of coarse aggregate we need sieve sizes of 80mm, 40mm, 20mm,
10mm, 4.75mm, 2.36mm, 1.18mm, 0.6mm, 0.3mm and 0.15mm. Fineness
modulus is the number at which the average size of particle is known when
we counted from lower order sieve size to higher order sieve. So, in the
calculation of coarse aggregate we need all sizes of sieves.
2. Specific Gravity and Water Absorption of Coarse Aggregate - The
specific gravity of an aggregate is considered to be a measure of strength
or quality of the material. Stones having low specific gravity are generally
weaker than those with higher specific gravity values. The size of the
aggregate and whether it has been artificially heated should be indicated.
ISI speci-fies three methods of testing for the determination of the specific
gravity of aggregates, according to the size of the aggregates. The three
size ranges used are aggregates larger than 10 mm, 40 mm and smaller
than 10 mm. The specific gravity of aggregates normally used in road
construction ranges from about 2.5 to 3.0 with an average of about 2.68.
Though high specific gravity is considered as an indication of high
strength, it is not possible to judge the suitability of a sample road
aggregate without finding the mechanical properties such as aggregate
crushing, impact and abrasion values. Water absorption shall not be more
than 0.6 per unit by weight

22. 14
CHAPTER 4
4. PROCEDURE
4.1. GENERAL PROCEDURE
Applying FRP wraps to structural concrete isn't difficult, but does require
experience. One hundred per cent of the quality is due to workmanship. All of
the FRP strengthening system manufacturers consulted require some level of
expertise in an installer.
Step-1
Casting of cylindrical concrete samples based on the M30 grade of concrete.
 Prepare the cylindrical mould by properly cleaning the insides, tightening
it with the bolts and oiling the insides of the mould.
 Batching of cement, sand, fine aggregates and coarse aggregates according
to the ratio determined by mix designing for M30 grade.
Table No. 1: Ratio as per Design
CEMENT SAND AGGREGATE
1 2.144 2.759
QUANTITY FOR ONE CYLINDER
 Volume of cylinder = (π/4)*(0.152
)*(0.3) = 0.0053m3
 Cement = 2.014 kg
 Water = 966.72ml
 Sand = 4.318 kg
 Aggregate = 5.557 kg
 Add mixture = 7.85g

23. 15
Fig 1: Batching of concrete
 Take a measured grade of water and add mixture as a percentage of weight
of cement according to the design.
Fig 2: Admixture
 Place all the dry ingredients into the mixer and conducting a dry mix.

24. 16
 Add the add mixture and water to the dry mix and mix properly till it gains
a uniform composition.
Fig 3: Mixing of Concrete
 Perform a slump test for each batch that comes out from the mixer before
placing it in the mould.
Fig 4: Slump Test

25. 17
 If the slump height is sufficient then place the concrete mix into the
moulds in 3 layers and tamping each layer 25 times by a tamping rod.
 Place the filled mould onto the table vibrator and switch it on. The level of
concrete will fall. Now fill the mould till the top while it is on the vibrator
and when it is full scrape out the excess concrete with a trowel and level
the top.
Fig 5: Table Vibrator
Step-2
Curing the samples in the curing tank for specified number of days.
 After 24 hours, the concrete will set.
 Remove the concrete from the mould and place it in the curing tank with
the sample completely immersed in water for the required number of days
i.e. 7, 14 and 28 days.
Step-3
Compressive testing of a normal sample
 At the 7th
day of casting take out the sample from the curing tank and air
dry it.
 Place it in the CTM and start applying load.

26. 18
Fig 6: CTM test of normal concrete
 The point where both the top and bottom face of the sample is confined the
needle will start moving.
 The point where the needle stops give the maximum compressive load that
can be applied on the sample before failure.
 Divide this load by the cross sectional area of the cylindrical sample to
obtain the strength of the sample. This value is the compressive strength of
the sample at the 7th
day.
 Repeat the steps for 2 more samples and calculate the mean value.
 Repeat the above steps for samples on the 14th
and 28th
day to obtain the
respective compressive strengths.

27. 19
Step-4
Applying thermal stresses to the samples
 At the 7th
day of casting take out the sample from the curing tank and air
dry it.
 Use the plates and bolts arrangement to restrain the sample in position.
 Place the sample on the burner with its curved face in direct contact with
the flame.
 Raise the temperature of the concrete with the help of the burner to induce
thermal stresses to the concrete.
Fig 7: Thermal stresses on concrete
 Rotate the sample at certain intervals to impart thermal stresses on all the
faces of the sample.
 After covering all the faces remove the samples from the heat and cool
half of the samples in air for slow cooling and half by pouring cold water
for rapid cooling.
 Perform CTM test to obtain the compressive strength for slow cooling and
rapid cooling samples.
 Repeat the above steps for samples on the 14th
and 28th
day to obtain the
respective compressive strengths.

28. 20
Step-5
Wrapping of FRP around the test samples
 Surface preparation, starting with simply cleaning the concrete to remove
any chemicals or dirt. For most applications, this is followed by water
blasting to achieve a roughened surface profile.
 However, there are two types of applications to consider: bond critical and
contact critical. Bond-critical applications rely completely on the bond of
the material to the surface of the concrete to transfer the stresses. Contact-
critical applications are where the FRP is bonded to itself and creates
confinement of the structural member.
 Any defects in the concrete are repaired; holes and cracks are filled with
epoxy and mortar.
 Sharp edges, corners, and other form lines are smoothened to prevent
stress concentrations.
 Wear gloves to prevent direct contact with epoxy.
 Mix epoxy and hardener as per the specifications.
 Apply a coat of epoxy over the cylindrical sample.
 Wrap the sample with FRP carefully so that no air bubbles are left in
between.
 While wrapping, the FRP should be held stretched to prevent any wrinkles.
 Allow the sample to set for 1-2 days for the epoxy to set and harden.
Step- 6
Compressive testing of FRP wrapped samples
 Place the wrapped sample in the CTM.
 Start the machine to apply the load.
 Note the value of load at which the needle stops.
 Divide this value by the cross sectional area to obtain maximum
compressive strength of concrete before failure.
 This value of strength is compared with the value of strength without
wrapping and the increase in strength is computed.
 The value of strength for wrapping on normal concrete, concrete with
thermal stresses and slow cooling and concrete with thermal stresses and
rapid cooling is determined.
 All the values are compared and conclusions are made based on the results
obtained.

29. 21
Fig 8: FRP wrapped sample Fig 9: Failed Sample
4.2.HEAT ACTIVITY
Damaging the concrete cylinders with the help of burner at the maximum temperature
of 409.6ºC for the 20 minutes.
 Initially fixed the concrete cylinders between the 2 plates with the nut and
bolt assembly to control the expansion of concrete axially due to thermal
stresses.
 And then set the whole assembly upon the burner to produce thermal
stresses and cracks to the concrete cylinders.
 Heat up the each side of concrete cylinder for a period of 5 minutes to the
maximum temperature of 409.6 degree Celsius.
 Out of four concrete cylinders, two of them are cooled up rapidly with the
action of water and remaining two are cooling up normally with the help
of air.

30. 22
Fig 10: Setup for Heat Activity Fig 11: Placing on Burner
Fig 12: Rapid Cooling Fig 13: Normal Cooling

31. 23
4.3.REPAIR AND RETROFITTING
Heating the concrete causes two main problems to concrete structure are loss of
strength and Disintegration or spalling of concrete. So we decided to tackle
both the problems simultaneously.
4.3.1. Spalling of Concrete
 First of all, remove disintegrated part of concrete and clean the
disintegrated surface using brush or dry cloths.
 Apply the fresh coating of Mortar (1:3) to the disintegrated surface to fill
the cavity.
 Wait for 3-4 hours to dry the surface of concrete for further treatments.
Fig 14: Spalling of Concrete Fig 15: Mortar Filling
4.3.2. Retrofitting using FRP laminates
 Make a mixture of Epoxy Resin and hardener in the ratio of 100:18
respectively.
 Now apply the epoxy mixture on concrete cylinder with the help of brush
to paste the glass fiber reinforced polymer (GFRP).
 Wrapping the GFRP sheet or laminate tightly over a concrete cylinder in a
two layers and apply the epoxy coat over the sheets also to make a strong
bond.

32. 24
 And left the concrete cylinder for air curing for a period of minimum 24
hrs.
 After air curing, cut all the unwanted or unnecessary GFRP from top and
bottom portion of the concrete cylinder.
 Test the sample in CTM to determine its compressive strength.
Fig 16: Applying FRP
Fig 17: Wrapped Samples

33. 25
CHAPTER 5
5. RESULTS AND OBSERVATIONS
5.1.Material Test Results
5.1.1. Cement
 Fineness = 6%
 Normal consistency = 32%
 Initial setting time = 44min 55sec
 Final setting time = 9hrs 36min
 Soundness of cement = 3.5mm
 Density of cement = 3.08g/cc
5.1.2. Fine Aggregate
 Fineness modulus = 3.018
 Specific gravity = 2.67
5.1.3. Coarse Aggregate
 Fineness modulus = 7.2
 Specific gravity = 2.7

34. 26
5.2. CTM Test Results
Table No. 2: 7-Day Compressive Strength
S.No Description Weight of
sample
(Kg)
Density
(Kg/m3
)
Load at
failure
(KN)
Cube
Compressive
Strength
(N/mm2
)
1 Normal concrete 12.908 2482 325 18.4
2 Normal conc. + FRP 13.102 2519.6 380 21.51
3 Damaged conc. + Rapid
Cooling
12.685 2439.42 180 10.19
4 Damaged conc. + Rapid
Cooling + FRP
12.69 2440.38 320 18.117
5 Damaged conc. + Air
Cooled
12.33 2371.15 160 9.05
6 Damaged conc. + Air
Cooled + FRP
12.99 2498.07 315 17.83
Graph 1: 7-Day Compressive Strength
0
5
10
15
20
25
Normal
Concrete
Damaged
conc. + Rapid
Cooling
Damaged
conc. + Air
Cooled
7DayCompressiveStrength(N/mm2)
Without GFRP
With GFRP

35. 27
Table No. 3: 14-Day Compressive Strength
S.No Description Weight of
sample
(Kg)
Density
(Kg/m3
)
Load at
failure
(KN)
Cube
Compressive
Strength
(N/mm2
)
1 Normal concrete 12.845 2470.19 468 26.49
2 Normal conc. + FRP 13.029 2505.57 540 30.57
3 Damaged conc. + Rapid
Cooling
12.485 2400.96 252 14.26
4 Damaged conc. + Rapid
Cooling + FRP
12.59 2421.15 460 26.04
5 Damaged conc. + Air
Cooled
12.21 2348.07 220 12.45
6 Damaged conc. + Air
Cooled + FRP
12.82 2465.38 451 25.53
Graph 2: 14-Day Compressive Strength
0
5
10
15
20
25
30
35
Normal
Concrete
Damaged
conc. + rapid
cooling
Damaged
conc. + air
cooled
14DayCompressiveStrength(N/mm2)
without GFRP
with GFRP

36. 28
Table No. 4: 28-Day Compressive Strength
S.No Description Weight of
sample
(Kg)
Density
(Kg/m3
)
Load at
failure
(KN)
Cube
Compressive
Strength
(N/mm2
)
1 Normal concrete 12.798 2461.15 558 31.59
2 Normal conc. + FRP 13.102 2519.6 638 36.12
3 Damaged conc. + Rapid
Cooling
12.491 2402.11 344 19.47
4 Damaged conc. + Rapid
Cooling + FRP
12.71 2444.23 546 30.91
5 Damaged conc. + Air
Cooled
12.31 2367.31 310 17.55
6 Damaged conc. + Air
Cooled + FRP
13.02 2503.84 541 30.63
Graph 3: 128-Day Compressive Strength
0
5
10
15
20
25
30
35
40
Normal
Concrete
Damaged
conc. + rapid
cooling
Damaged
conc. + air
cooled
28DayCompressiveStrength(N/mm2)
without GFRP
with GFRP

37. 29
Graph 4: Compressive Strength of Samples without FRP
Graph 5: Compressive Strength of Samples with FRP
0
5
10
15
20
25
30
35
Normal
Concrete
Damaged
Concrete with
Rapid Cooling
Damaged
Concrete with
Normal Cooling
CompressiveStrength(N/mm2)
7 Day
14 Day
28 Day
0
5
10
15
20
25
30
35
40
Normal Concrete Damged
Concrete with
Rapid Cooling
Damged
Concrete with
Normal Cooling
7 Day
14 Day
28 Day

38. 30
5.3. HEAT TRANSFER THROUGH CONCRETE AT
VARIOUS DEPTHS
Table No. 5: Heat Transfer at Various Depths
S.No Depth
(mm)
Heat Applied
(ºC)
Heat Transferred
(ºC)
Per Cent Heat
Transferred
1. 30 98.3 77.2 78.54%
2. 43 98.8 48.3 48.9%
3. 70 97.5 30.6 31.4%
4. 85 96.4 29.6 30.7%
Graph 6: Percentage Heat Transferred through Various Layers
Fig 18: Samples for Heat Transfer
0
10
20
30
40
50
60
70
80
90
0 10 20 30 40 50 60 70 80 90
%HeatTransferred
Depth

39. 31
CHAPTER 6
6. CONCLUSIONS
 During the initial stages or in case of seepage conditions, the amount of
pore water present in the concrete structural member is higher. If fire
occurs in a concrete structure during this stage, the pore water tries to
escape out of the members as vapours. Since all the components of the
concrete are strongly bonded, there is no way for the pore water to escape
thus the vapours exert pressure on the concrete from the inside. When this
pressure exceeds the bond strength of the concrete, cracks and
consequently removal of surface materials takes place for the pore water to
escape thus causing spalling in the concrete members.
 It was observed that spalling in concrete showed relatively lower strength
as compared to samples without spalling. Thus the structures should be
repaired for spalling by filling it with mortar before wrapping it with FRP
to improve their load carrying capacity.
 After repair and retrofitting it was observed that the lost strength of the
concrete due to fire activity was regained to around 98% of the normal
concrete strength for 2 layer of wrapping. The strength can further be
increased by increasing the number of wrappings.
 It was also observed that out of the samples subjected to fire activity those
samples which were cooled rapidly by using water losses less strength as
compared to those cooled in air because the ones cooled in air are
subjected to thermal stresses for longer periods thus deteriorating the
strength more hence concluding that structural fires should be rapidly
cooled.

40. 32
CHAPTER 7
7. FUTURE IMPLEMENTATIONS
 The study can be extended to beams especially flanged reinforced concrete
beams where ways and means are to be devised for complete wrapping of
FRP composites for strengthening.
 Select the different FRP materials like carbon fiber, basalt fibers etc. for
strengthening the concrete members to compare the results with GFRP.
 The fiber orientations of FRP laminates have significant effect on the
ultimate strength of the members which were strengthened. Hence, the
study can be extended for different fiber orientations apart from 0º/90º and
±45º, to determine the appropriate fiber orientations of FRP laminates.
 Studies can be taken up on prestressed concrete structural components
strengthened with FRP composites.
 Many environmental factors involved during the life span of a retrofitted
structure need more attention. They include seasonal temperature
variation, degradation of material properties, creep and so on.

41. 33
CHAPTER 8
REFERENCES
 https://www.iitr.ac.in/departments/CE/pages/People+Faculty+bhpdpfce.ht
ml
 http://www.asce.org/
 https://www.intechopen.com/books/fiber-reinforced-polymers-the-
technology-applied-for-concrete-repair/introduction-of-fiber-reinforced-
polymers-polymers-and-composites-concepts-properties-and-processes
 http://www.sustainableconcrete.org.uk/concrete/constituents_of_concrete/
aggregates.aspx
 http://www.structuremag.org/?p=8643
 http://info.craftechind.com/blog/bid/393452/A-Beginner-s-Guide-to-Fiber-
Reinforced- Plastics-FRP-s
 http://info.craftechind.com/blog/bid/369492/Fiber-Reinforced-Plastic-
FRP-in-Action
 http://bedfordreinforced.com/why-our-material
 http://www.intertek.com/polymers/tensile-testing/matrix-composite/
 http://www.radyab.co/content/media/article/4403R_04_0.pdf
Research papers:
1. A B Danie Roy, Umesh Kumar Sharma
Indian Institute of Technology Roorkee, India
“STRENGTHENING HEAT DAMAGED REINFORCED CONCRETE
BEAMS USING GLASS FIBER-REINFORCED POLYMER”
2. J G. Teng, Hong Kong Polytechnic University
L Lam, Hong Kong Polytechnic University
J F. Chen, University of Edinburgh
J G. Dai, Hong Kong Polytechnic University
T Yu, Hong Kong Polytechnic University
“FRP COMPOSITES IN STRUCTURES: SOME RECENT RESEARCH”
3. A.R. Rahai, Professor, Dept. of Civil and Environmental Engineering, Amirkabir
University of Technology, Tehran, Iran
P. Sadeghian, Assistant Professor, Dept. of Civil Engineering, Islamic Azad
University of Qazvin, Qazvin, Iran
“EXPERIMENTAL BEHAVIOR OF CONCRETE CYLINDERS CONFINED
WITH CFRP COMPOSITES”

42. 34
4. Associate II, Wiss, Janney, Elstner Associates, Inc. Irving USA, Department of
Civil, Architectural and Environmental Engineering Missouri University of
Science and TechnologyRolla, USA
“CHALLENGES FACED IN THE IMPLEMENTATION OF FIBRE
REINFORCED POLYMER”
5. AmirShaat, David Schnerch, Amir Fam, and Sami Rizkalla
“RESEARCH PROGRESS IN THE FIELD OF STRENGTHENING AND
REPAIR OF STEEL STRUCTURES USING FIBER REINFORCED
POLYMERS”
6. P.A. Buchan, J.F. Chen, Institute for Infrastructure and Environment, School of
Engineering and Electronics, The University of Edinburgh, The King’s
Buildings, Edinburgh, EH9 3JL, UK
“RESEARCH IN RETROFITTING CONCRETE AND MASONRY
STRUCTURES WITH FIBER REINFORCED POLYMER (FRP)
COMPOSITES FOR BLAST PROTECTION”
7. S.T Smith, J.G Teng, Department of Civil and Structural Engineering, The Hong
Kong Polytechnic University, Hong Kong, People's Republic of China
“BONDING OF A FIBER-REINFORCED POLYMER (FRP) PLATE TO THE
TENSION FACE OF A BEAM”
8. Prof. K. C. Biswal, Department of civil engineering, National Institute Of
Technology, Rourkela, India
“STRENGTHENING OF RC CONTINUOUS BEAM USING FRP SHEET”
9. Hesham M. Diab, Civil Engineering Department, Assiut University, Egypt
“PERFORMANCE OF DIFFERENT TYPES OF FRP SHEETS BONDED TO
CONCRETE USING FLEXIBLE ADHESIVE”
10. Cem YALÇIN, Osman KAYA, 13th World Conference on Earthquake
Engineering, Vancouver, B.C., Canada
“AN EXPERIMENTAL STUDY ON THE BEHAVIOUR OF REINFORCED
CONCRETE COLUMNS USING FRP MATERIAL”
11. Khaled Abdelrahman and Raafat El-Hacha, Department of Civil Engineering,
University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4,
Canada
“COST AND DUCTILITY EFFECTIVENESS OF CONCRETE COLUMNS
STRENGTHENED WITH CFRP AND SFRP SHEETS”

43. 35
APPENDIX
APPENDIX-A
1. TEST PROCEDURES
1.1. FINENESS OF CEMENT
1. Fit the tray under the sieve, weigh approximately 100 g of cement to
the nearest 0.01 g and place it on the sieve, being careful to avoid loss.
Fit the lid over the sieve. Agitate the sieve by swirling, planetary and
linear movement until no more fine material passes through it.
2. Remove and weigh the residue. Express its mass as a percentage, of
the quantity first placed in the sieve to the nearest 0.1 percent. Gently
brush all the fine material off the base of the sieve into the tray.
3. Repeat the whole procedure using a fresh 10 g sample to obtain R2.
Then calculate the residue of the cement R as the mean of R1, and R2,
as a percentage, expressed to the nearest 0.1 percent.
4. When the results differ by more than 1 percent absolute, carry out a
third sieving and calculate the mean of the three values.
1.2. CONSISTENCY OF CEMENT
1. The standard consistency of a cement paste is defined as that
consistency which will permit the Vicat plunger to penetrate to a point
5 to 7 mm from the bottom of the Vicat mould.
2. Initially a cement sample of about 400 g is taken in a tray and is mixed
with a known percentage of water by weight of cement, say starting
from 26% and then it is increased by every 2% until the normal
consistency is achieved.
3. Prepare a paste of 400 g of Cement with a weighed quantity of potable
or distilled water, taking care that the time of gauging is not less than 3
minutes, nor more than 5 min, and the gauging shall be completed
before any sign of setting occurs. The gauging time shall be counted
from the time of adding water to the dry cement until commencing to
fill the mould.

44. 36
4. Fill the Vicat mould with this paste, the mould resting upon a non-
porous plate. After completely filling the mould, smoothen the surface
of the paste, making it level with the top of the mould. The mould may
be slightly shaken to expel the air.
5. Place the test block in the mould, together with the non-porous resting
plate, under the rod bearing the plunger; lower the plunger gently to
touch the surface of 10 the test block, and quickly release, allowing it
to sink into the paste. This operation shall be carried out immediately
after filling the mould.
6. Prepare trial pastes with varying percentages of water and test as
described above until the amount of water necessary for making up the
standard consistency as defined in Step 1 is found.
1.3. INITIAL AND FINAL SETTING TIME OF CEMENT
1. Preparation of Test Block - Prepare a neat 400 gms cement paste by
gauging the cement with 0.85 times the water required to give a paste
of standard consistency. Potable or distilled water shall be used in
preparing the paste.
2. Start a stop-watch at the instant when water is added to the cement. Fill
the Vicat mould with a cement paste gauged as above, the mould
resting on a nonporous plate. Fill the mould completely and smooth off
the surface of the paste making it level with the top of the mould.
3. Immediately after moulding, place the test block in the moist closet or
moist room and allow it to remain there except when determinations of
time of setting are being made.
Determination of Initial Setting Time
1. Place the test block confined in the mould and resting on the non-
porous plate, under the rod bearing the needle; lower 11 the needle
gently until it comes in contact with the surface of the test block and
quickly release, allowing it to penetrate into the test block.
2. Repeat this procedure until the needle, when brought in contact with
the test block and released as described above, fails to pierce the block

45. 37
beyond 5.0 ± 0.5 mm measured from the bottom of the mould shall be
the initial setting time.
Determination of Final Setting Time
1. Replace the needle of the Vicat apparatus by the needle with an
annular attachment.
2. The cement shall be considered as finally set when, upon applying the
needle gently to the surface of 7 the test block, the needle makes an
impression thereon, while the attachment fails to do so.
3. The period elapsing between the time when water is added to the
cement and the time at which the needle makes an impression on the
surface of test block while the attachment fails to do so shall be the
final setting time.
4. Desired results: Initial settling time= Not less than 30 minutes
5. Final settling time = Not more than 600 minutes
1.4. SOUNDNESS OF CEMENT
1. The mould is placed on a glass sheet and filled with cement paste
formed by gauging cement with 0.78 times the water required to give a
paste of normal consistency.
2. The mould is then covered with another piece of glass sheet, a small
weight is placed on this covering glass sheet and the assembly is
immediately submerged in water at a temperature of 27ºC and kept
there for 24 hours.
3. The distance separating the indicator points is measured and the mould
was again submerged in water at the temperature prescribed above.
4. The water is then brought to boiling, with mould kept submerged for
25 to 30 minutes, and is kept there for three hours.
5. The mould is removed from water, allowed to cool and the distance
between the indicator points is measured.
6. The difference between these two measurements is found and reported
as the expansion of cement.

46. 38
1.5. SPECIFIC GRAVITY OF CEMENT
1. Weight of specific gravity bottle dry W1.
2. The bottle is filled with distilled water and the bottle is weighted W2.
3. The specific gravity bottle is dried and it is filled kerosene and
weighted W3.
4. Pour some of the kerosene out and introduce a weighted quantity of
cement into the bottle. Roll the bottle gently in the inclined position
until no further air bubble rise to the surface. The bottle is filled to the
top with kerosene and it is weighted W4.
1.6. FINENESS OF SAND
1. 2 kg of coarse aggregate was taken from a sample of about 50 kg by
quartering or through riffle box.
2. The relevant sieves were arranged one above the other with the sieve
size increasing from the top. The pan was put at the bottom. The
sample was placed in the top sieve and covered.
3. The set of sieves were shaken for 2 to 3 minutes in a sieve shaker.
4. The amount of aggregate retained on each sieve was weighed along
with the pan.
1.7. SPECIFIC GRAVITY OF SAND
The specific gravity of solid particles is the ratio of the mass density of
solids to that water. It is determined in the laboratory using the
relation:
Where,
M1 = mass of empty bottle
M2 = mass of the bottle and dry soil
M3 = mass of bottle, soil and water
M4 = mass of bottle filled with water only.

47. 39
1.8. SLUMP TEST
1. Clean the internal surface of the mould and apply oil.
2. Place the mould on a smooth horizontal non- porous base plate.
3. Fill the mould with the prepared concrete mix in 4 approximately
equal layers.
4. Tamp each layer with 25 strokes of the rounded end of the tamping
rod in a uniform manner over the cross section of the mould. For the
subsequent layers, the tamping should penetrate into the underlying
layer.
5. Remove the excess concrete and level the surface with a trowel.
6. Clean away the mortar or water leaked out between the mould and the
base plate.
7. Raise the mould from the concrete immediately and slowly in vertical
direction.
8. Measure the slump as the difference between the height of the mould
and that of height point of the specimen being tested.
1.9. COMPRESSION TEST
1. For cube test cubical moulds of size 15cm x 15cm x 15cm are
commonly used. This concrete is poured in the mould and tempered
properly so as not to have any voids. After 24 hours these moulds are
removed and test specimens are put in water for curing. The top
surface of these specimen should be made even and smooth. This is
done by putting cement paste and spreading smoothly on whole area
of specimen. These specimens are tested by compression testing
machine after 7 days curing or 28 days curing. Load at the failure
divided by area of specimen gives the compressive strength of
concrete.
2. Preparation of Concrete Cube Specimen -The proportion and material
for making these test specimens is taken from design mix prepared
above.
3. Specimen - cubes of 15 cm3 Mix M20 (normal and with sawdust)
4. Mixing of Concrete for Cube Test- Mix the concrete either by hand or
in a laboratory batch mixer.
 Hand Mixing
(i)Mix the cement and fine aggregate on a water tight none-absorbent
platform until the mixture is thoroughly blended and is of uniform
color

48. 40
(ii)Add the coarse aggregate and mix with cement and fine aggregate
until the coarse aggregate is uniformly distributed throughout the batch
(iii)Add water and mix it until the concrete appears to be homogeneous
and of the desired consistency
 Sampling of Cubes for Test
(i) Clean the mounds and apply oil
(ii) Fill the concrete in the molds in layers approximately 5cm thick
(iii) Compact each layer with not less than 25strokes per layer using a
tamping rod (steel bar 16mm diameter and 60cm long, bullet pointed at
lower end.
(iv)Level the top surface and smoothen it with a trowel.
 Curing of Cubes - The test specimens are stored in moist air for 24
hours and after this period the specimens are marked and removed
from the molds and kept submerged in clear fresh water until taken out
prior to test. Precautions for Tests The water for curing should be
tested every 7 days and the temperature of water must be at 27+-2oC.
 Procedure for Cube Test
(I) Remove the specimen from water after specified curing time and
wipe out excess water from the surface.
(II) Take the dimension of the specimen to the nearest 0.2m
(III) Clean the bearing surface of the testing machine
(IV) Place the specimen in the machine in such a manner that the load
shall be applied to the opposite sides of the cube cast.
(V) Align the specimen centrally on the base plate of the machine.
(VI) Rotate the movable portion gently by hand so that it touches the
top surface of the specimen.
(VII) Apply the load gradually without shock and continuously at the
rate of 140 kg/cm2 /minute till the specimen fails.
(VIII) Record the maximum load and note any unusual features in the
type of failure.

49. 41
APPENDIX-B
FINENESS MODULUS OF FINE AGGREGATES
I.S.
SIEVE
MATERIAL
RETAINED
(g)
PERCENTAGE
RETAINED (%)
CUMULATIVE
PERCENTAGE
RETAINED (%)
PERCENTAGE
CUMULATIVE
PASSING (%)
10mm 0 0 0 100
4.75mm 1 0.1 0.1 99.9
2.36mm 44 4.4 4.5 95.5
1.18mm 327 32.7 37.2 62.8
600µ 246 24.6 61.8 38.2
300µ 368 36.8 98.6 1.4
150µ 10 1 99.6 0.4
PAN 4 0.4 100 0

50. 42
FINENESS MODULUS OF COARSE AGGREGATES
I.S. SIEVE
MATERIAL
RETAINED
(g)
PERCENTAGE
RETAINED
(%)
CUMULATIVE
PERCENTAGE
RETAINED
(%)
PERCENTAGE
CUMULATIVE
PASSING (%)
80mm 0 0 0 100
40mm 0 0 0 100
20mm 138 7 7 93
10mm 180 91.15 98.15 1.85
4.75mm 26 1.3 99.45 0.55
2.36mm 11 0.55 100 0
1.18mm 0 0 100 0
600 0 0 100 0
300 0 0 100 0
150 0 0 100 0
PAN 0 0 100 0

51. 43
MIX-DESIGN FOR M30 GRADE OF CONCRETE
1. Target Mean Strength (f’ck) = fck + σ*1.65
= 30 + 5*1.65
= 38.25 N/mm2
2. According to this target mean strength:
 Assume water cement ratio = 0.48
 For 20mm maximum size of nominal aggregate, water content = 186 litres
(for 50mm slump)
 For 100mm slump, water content = 186 + (6/100)*186 = 197.16 litres
 Considering 7.5% efficiency of admixture,
 water content = 0.925*197.16 = 182.4 litres
 Cement content = 182.4/0.48 = 380 kg/m3
3. For 1m3
of concrete
 By sieve analysis, the fine aggregates comes under the category of ZONE-
I.
 Volume of cement = (380/3.08)*(1/1000) = 0.123m3
 Volume of water = 182.4 litres = 0.1824m3
 Volume of admixture = (0.39/100)*(380/1.415)*(1/1000) = 0.0011m3
 Volume of aggregates (fine and coarse) = 1-(0.123+0.1824+0.0011)
= 0.6935m3
 As 1.27per ZONE-I, the volume of C.A. per unit volume of aggregate =
0.56
 Volume of F.A. per unit volume of aggregate = 1-0.56 = 0.44
 Weight of C.A. = 0.6935*2.7*0.56*1000 = 1048.572 kg/m3
 Weight of F.A. = 0.6935*2.67*0.44*1000 = 814.724 kg/m3
HIGHLIGHTS
 Cement Content = 380 kg/m3
 Water content = 182.4 kg/m3
 Coarse aggregate = 1048.572 kg/m3
 Fine aggregate = 814.724 kg/m3
 Add mixture = 1.482 kg/m3