I am student of GLA university Mathura and this is project report of various tests on hair reinforced concrete and compare the properties with PCC

1. PROJECT REPORT
ENHANCING THE
PROPERTIES OF CONCRETE
BY ADDING HAIR FIBER
A report submitted in partial fulfillment of the
requirements for the award of the certificate of
Diploma
in
CIVIL ENGINEERING
Submitted By
Rohit chaudhary (143000247)
Santosh fozdar (143000254)
Satish chand (143000255)
Shekhar yadav (143000266)
Under the supervision of
Mr. Krishan murari sharma
Department of Civil Engineering
GLA University Polytechnic
May-June, 2017

2. ENHANCING THE
PROPERTIES OF CONCRETE
BY ADDING HAIR FIBER
A report submitted in partial fulfillment of the
requirements for the award of the certificate of
Diploma
in
CIVIL ENGINEERING
Submitted By
Rohit chaudhary (143000247)
Santosh fozdar (143000254)
Satish chand (143000255)
Shekhar yadav (143000266)
Under the supervision of
Mr. Krishan murari sharma
Department of Civil Engineering
University Polytechnic
May-June, 2017

3. DECLARATION
I hereby declare that the work which is presented in Diploma Sixth semester.
“Enhancing the properties of concrete by adding hair fiber ” in partial
fulfillment of the requirements for the award of the Diploma in Civil Engineering
and submitted to the Department of Civil Engineering of GLA University
Polytechnic, Mathura is an authentic record of my own work carried under the
supervision of Mr. krishan murari sharma
(Lecturer in GLA University ).
Name of the candidates:
Rohit chaudhary (143000247)
SantoshFozdar (143000254)
SatishChand (143000255)
Shekhar Yadav (143000266)

4. CERTIFICATE
Certified that this project report “ENHANCING THE
PROPERTIES OF CONCRETE BY ADDING HAIR FIBER” is the
bonafide work of “Rohit, Santosh, Satish, Shekhar” who carried
out the project work under my supervision.
Signature of Project Guide
Mr. Krishna Murari Sharma
Lecturer
GLA University Polytechnic

5. ACKNOWLEDGEMENT
It gives me a great sense of pleasure to present the progress report work,
undertaken during Diploma Six Semester. I owe special debt of gratitude to Mr.
(Mr. Krishan murari sharma), Department of Civil Engineering, GLA University
Polytechnic, Mathura for their constant support and guidance throughout the
course of my work. His sincerity, thoroughness and perseverance have been a
constant source of inspiration for me. It is only their cognizant efforts that my
endeavors have seen light of the day.
We also take the opportunity to acknowledge the contribution of Dr. Diwakar
Bhardwaj and Dr. Vikas Sharma, Principals University Polytechnic, GLA University,
Mathura for their full support.
I also do not like to miss the opportunity to acknowledge the contribution of Mr.
Sanjay Agarwal, Mr.Pravesh Tiwari, Mr.Prashant sharma, Mr. Mayankesher
Singh and all faculty members of the department for their kind assistance and co-
operation during the development of my report. Last but not the least, I
acknowledge my friends for their contribution in the completion of the project.
Sign:
Rohit chaudhary (143000247)
Santosh Fozdar (143000254)
Satish Chand (143000255)
Shekhar Yadav (143000266)
DATE:

6. Abstract
This project is intended to analyze the Performance of Hair Reinforced
Concrete. Fibre reinforced concrete can offer a convenient, practical and
economical method for overcoming micro-cracks and similar type of
deficiencies. Since concrete is weak in tension hence some measures must
be adopted to overcome this deficiency. Human hair is strong in tension;
hence it can be used as a fibre reinforcement material. Hair Fibre (HF) an
alternate non-degradable matter is available in abundance and at a very
cheap cost. It also creates environmental problem for its decompositions.
This particular project has been undertaken to study the effect of human
hair on plain cement concrete on the basis of its compressive strength,
flexural strength, and rheological parameter. Experiments were conducted
on concrete beams and cubes with various percentages of human hair fibre
i.e. 0%, 0.5%, 1%, 1.5% by weight of cement. For each combination of
proportions of concrete one beam and three cubes are tested for their
mechanical properties. By testing of cubes and beams we found that there is
an increment in the various properties and strength of concrete by the
addition of human hair as fibre reinforcement.

7. Objective
 Develop suitable mix design.
 Develop characterization tests for the fiber.
 Demonstrate the use of steel fiber from use of waste natural fiber.
 For checking the effect on properties and strength of concrete by using hair fiber as
reinforcement.
Introduction
Definition & History of concrete is a material used in building construction, consisting of a
hard, chemically inert particulate substance, known as an aggregate (usually made from
different types of sand and gravel), that is bonded together by cement and water. In 1756,
British engineer, John Smeaton made the first modern concrete (hydraulic cement) by adding
pebbles as a coarse aggregate and mixing powered brick into the cement. In 1824, English
inventor, Joseph Aspdin invented Portland cement, which has remained the dominant cement
used in concrete production. Joseph Aspdin created the first true artificial cement by burning
ground limestone and clay together. The burning process changed the chemical properties of
the materials and Joseph Aspdin created stronger cement than what using plain crushed
limestone would produce.
Biological fibers have been already used some 3000 years ago in composite systems in the
ancient Egypt, where straw and clay were mixed together to build the walls. In the last few years,
biological fibers have become an attractive reinforcement for polymeric composites from
economical and ecological point of view. There is an increase in the environmental awareness in
the world which has aroused an interest in the research and the development of biodegradable
materials. Biological/Natural fibers can be obtained from natural resources such as plants,
animals or minerals .
With the increase of global energy crisis and ecology risk, the unique advantages of biological
fibers such as its abundance quantity, non-toxic, non-irritation of the skin, eyes, or respiratory
system, noncorrosive property, biological fiber reinforced polymer composites have attracted
much interest owing to their potential of serving as alternatives reinforcement to the synthetic

8. ones [2]. The lower weight and higher volume of the biological fibers as compared to the
synthetic fibers improve the fuel efficiency and reduced emission in auto applications .
Hair is a protein filament that grows from follicles found in the dermis or skin. It is one of the
defining characteristics of mammals. The human body, apart from areas of glabrous skin, is
covered in follicles which produce thick terminal and fine vellus hair. Most common interest in
hair is focused on hair growth, hair types and hair care, but hair is also an important biomaterial
primarily composed of protein, notably keratin. Keratins are proteins, long chains (polymers) of
amino acids. In terms of raw elements, on an average, hair is composed of 50.65% carbon,
20.85% oxygen, 17.14% nitrogen, 6.36% hydrogen, and 5.0% sulphur. Amino acid present in
hair contain cytosine, serine, glutamine, threonine, glycine, leucine, valine and arginine [5].
The word “hair” usually refers to two distinct structures:
The part beneath the skin called the hair follicle or when pulled from the skin, called the bulb.
This organ is located in the dermis and maintains stem cells, which not only re-grow the hair
after it falls out, but also are recruited to regrow skin after a wound.
The shaft, which is the hard filamentous part that extends above the skin surface.
The cross section of human hair shaft may be divided roughly into three zones:
The cuticle, which consists of several layers of flat, thin cells laid out overlapping one another as
roof shingles.
The cortex, which contains the keratin bundles in cell structures that remain roughly rod like.
Fiber
Fiber Reinforced Concrete can be defined as a composite material consisting of mixtures of
cement, mortar or concrete and discontinuous, discrete, uniformly dispersed suitable fibers. Fiber
reinforced concrete are of different types and properties with many advantages. Continuous
meshes, woven fabrics and long wires or rods are not considered to be discrete fibers. Fiber is a
small piece of reinforcing material possessing certain characteristics properties. They can be
circular or flat. The fiber is often described by a convenient parameter called “aspect ratio”. The

9. aspect ratio of the fiber is the ratio of its length to its diameter. Typical aspect ratio ranges from
30 to 150.
Advantages of fibre reinforced concrete
(1) FRC is used in civil structures where corrosion is to be avoided at the maximum.
(2) FRC is better suited to minimize cavitations erosion damage in structures where high
velocity flows are encountered.
(3) A substantial weight saving can be realized using relatively thin FRC sections having the
equivalent strength of thicker plain concrete sections.
(4) When used in ridges it helps to avoid catastrophic failures. In quake prone areas the
use of fibre reinforced concrete would certainly minimize the human casualties.
(5) Fibre reduces internal forces by locking microscopic cracks from forming within the
concrete.
(6) Studies have been proven that fibre reinforced concrete is found to improve the following
mechanical properties of ordinary concrete: Compressive Strength, Modulus of Elasticity and
flexural strength, Toughness, Splitting Tensile Strength, Fatigue Strength, and Impact
Resistance..
Disadvantages
The fibres have to be uniformly mixed and spread throughout the concrete mix. At times, this is
found to be a difficult process and time consuming. If this limitation has been overcome by new
and effective methods of fabrication, fibre reinforced concrete is found to be more adaptable for
common concreting works.
Why Fibres are used in Concrete?
Fibres are usually used in concrete for the following reasons:
i. To control cracking due to both plastic shrinkage and drying shrinkage.
ii. They also reduce the permeability of concrete and thus reduce bleeding of water.

10. iii. Some types of fibres also produce greater impact, abrasion and shatter resistance in
concrete.
iv. The fineness of the fibres allows them to reinforce the mortar fraction of the concrete,
delaying crack formation and propagation. This fineness also inhibits bleeding in the
concrete, thereby reducing permeability and improving the surface characteristics of the
hardened surface.
Main Properties of Fibre in FRC:
Type of fibres used,Volume percent of fibre (vf =0.1 to 3%), Aspect ratio (the length of a fibre
divided by its diameter), Orientation and distribution of the fibres in the matrix, It prevents
spalling of concrete, Shape, dimension and length of fibre is important,Strength of the fibre.
Effect of Fibers in Concrete
Fibers are usually used in concrete to control plastic shrinkage cracking and drying shrinkage
cracking. They also lower the permeability of concrete and thus reduce bleeding of water. Some
types of fibers produce greater impact, abrasion and shatter resistance in concrete. Generally
fibers do not increase the flexural strength of concrete, so it can not replace moment resisting or
structural steel reinforcement. Some fibers reduce the strength of concrete. Some recent research
indicated that using fibers in concrete has limited effect on the impact resistance of concrete
materials. This finding is very important since traditionally people think the ductility increases
when concrete reinforced with fibers. The results also pointed out that the micro fibers is better
in impact resistance compared with the longer fibers.
Necessity of Fiber Reinforced Concrete:
1. It increases the tensile strength of the concrete.
2. It reduce the air voids and water voids the inherent porosity of gel.
3. It increases the durability of the concrete.
4. Fibers such as graphite and glass have excellent resistance to creep, while the same is not
true for most resins. Therefore, the orientation and volume of fibers have a significant
influence on the creep performance of rebars/tendons.

11. 5. Reinforced concrete itself is a composite material, where the
reinforcement acts as the strengthening fiber and the concrete as the
matrix. It is therefore imperative that the behavior under thermal stresses
for the two materials be similar so that the differential deformations of
concrete and the reinforcement are minimized.
6. It has been recognized that the addition of small, closely spaced and uniformly dispersed
fibers to concrete would act as crack arrester and would substantially improve its static
and dynamic properties.
Factors Affecting Properties of Fiber Reinforced Concrete
Fiber reinforced concrete is the composite material containing fibers in the cement matrix in an
orderly manner or randomly distributed manner. Its properties would obviously, depends upon
the efficient transfer of stress between matrix and the fibers. The factors are briefly discussed
below:
1. Relative Fiber Matrix Stiffness
2. Volume ofFibers
3. Aspect Ratio ofthe Fiber
4. Orientation ofFibers
5. Workability and Compaction ofConcrete
6. Size ofCoarse Aggregate
7. Mixing
Fiber reinforced concrete
Fiber reinforced concrete (FRC) is concrete containing fibrous material which increases its
structural integrity. It contains short discrete fibers that are uniformly distributed and randomly
oriented. Fibers include steel fibers, glass fibers, synthetic fibers and natural fibers. Within these

12. different fibers that character of fiber reinforced concrete changes with varying concretes, fiber
materials, geometries, distribution, orientation and densities.
Different Types of Fiber Reinforced Concrete
Following are the different type of fibers generally used in the construction industries.
 Steel Fiber Reinforced Concrete
 Polypropylene Fiber Reinforced (PFR) cement mortar & concrete
 GFRC Glass Fiber Reinforced Concrete
 Asbestos Fibers
 Carbon Fibers
 Organic Fibers
Organic Fibers/Natural fiber:
Organic fiber such as polypropylene or natural fiber may be chemically more inert than either
steel or glass fibers. They are also cheaper, especially if natural. A large volume of vegetable

13. fiber may be used to obtain a multiple cracking composite. The problem of mixing and uniform
dispersion may be solved by adding a super plasticizer. We prefer hair fiber.
Why Hair as a Fibre?

14. Hair is used as a fibre reinforcing material in concrete for the following reasons: i. It has a high
tensile strength which is equal to that of a copper wire with similar diameter. ii. Hair, a non-
degradable matter is creating an environmental problem so its use as a fibre reinforcing
material can minimize the problem. iii. It is also available in abundance and at a very low cost.
iv. It reinforces the mortar and prevents it from spalling.

15. Treatment of hair fibre
The hair needed for the preparation of concrete cubes was collected from salons and beauty
parlours. It needs treatment before to be added in the concrete specimens. It is carried out as in
the following steps:
• Separating hair from other waste: Depending on the source, the collected hair may contain
wastes. This has to be removed.
• Washing: After sorting, the hair is washed with acetone to remove impurities.
• Drying: The hair is then dried under sun or in oven. After drying, the hair can be stored without
any concern for decay or odor.
• Sorting: The hair is then sorted according to length, color, and quality. The hair fibres are
checked at random for its length and diameter.
Hair as Fibre in Fibre Reinforced Concrete
Hair is used as a fibre because it has a high elasticity which is equivalent to that of a copper wire
with comparable width. Hair, a non-degradable matter is making an ecological issue so its
utilization as a fiber fortifying material can minimize the issue. It is additionally accessible in
wealth and with ease. It fortifies the mortar and keeps it from spalling for this project we have
used hair with fibre length between 15 mm to 60mm.
Mechanical properties of human hair fiber
Ganiron investigated the effects of human hair additives in compressive strength of asphalt
cement mixture and concluded that addition of hair to the asphalt cement mixture greatly
improves its capability to bear more loads applied to it. Choudhry and Pandey studied the
mechanical behaviour of polypropylene matrix and human hair fiber and founded that composite
with 3-5 wt.% of human hair fiber shows higher flexural strength, flexural modulus and Izod
impact strength than non-reinforced polymer but at 10-15 wt.% it lowers the flexural strength,

16. flexural modulus and Izod impact strength as compared to the non-reinforced polymer.
Fueghelman examined the mechanical properties and structure of alpha-keratin fibers such as
wool, human hair and related fibers and concluded that the human hair possesses the highest
tensile strength amongst the compared fibers. He further unlocked the exceptional properties of
human hair such as its unique chemical composition, slow degradation rate, high tensile strength,
thermal insulation, elastic recovery, scaly surface, and unique interactions with water and oils
that has led to many diverse uses of the corresponding fiber.
Thompson manufactured a hair based composite material by manipulating a plurality of cut
lengths of hair to form a web or mat of hair and combining with a structural additive to form the
required composite material. Jain and Kothari studied on human hair fiber reinforced concrete
and concluded that there is tremendous increment in properties of concrete according to the
percentages of hairs by weight of in concrete. The addition of human hairs to the concrete
improves various properties of concrete like tensile strength, compressive strength, binding
properties, micro cracking control and also increases spalling resistance. Barone has also shown
that the human hair fiber is a non-homogeneous complex material made of keratin fibers oriented
along the longitudinal axis which offer anisotropic mechanical properties. According to them, it
is possible to measure the mechanical properties of hairs with the classical tests, but most often,
these tests are destructive and make hard to measure the influence of some external factors or
treatments on the behaviour of a same hair fiber. They utilized vibrations induced by a non-
contact impact as a representative response of the mechanical behaviour of hair. The
characteristics of the vibratory response allow measuring the variation in the mechanical
properties and the instantaneous effect of an external factor on the properties of a same sample.
First, load relaxation tests have been performed on hair samples after moisturisation and for
different times of an air-drying process in order to characterize the change in the visco-elastic
behaviour of hair during the water desorption. The vibratory response has then been correlated to
the mechanical properties of the hair fiber.
Barone and Ahmad prepared composites taking human hair as the fiber and polymers as the
matrix and firmed that the human hair is an emerging engineering composite fiber. They

17. collectively wrapped up with the conclusion that the tensile and flexural properties decrease
when the fiber loading percentage increases. Utilizing whole fiber not only provided good
properties but will also eliminate the need for processing the fiber leading to lower costs and
superior characteristics. The tensile properties can be enhanced with the increasing percentage of
the human hair fiber and also with different matrix. Another way to enhance the composite
properties is to determine an effective treatment to eliminate lack of adhesion between matrix
and fiber, which was approved by Ganiron and Belani et al. who took concrete and fly ash
respectively, as the matrix. Due to the above discussed incomparable mechanical properties of
human hairs, which are in relative abundance in nature and are nondegradable.
Chemical experimentations on human hair fiber
Hair is a proteinaceous fiber with a strongly hierarchical organization of subunits, from the α-
keratin chains, via intermediate filaments to the fiber, as suggested by Popescu and Hocker.
Thomas et al.determined that the hair contains a high amount of sulphur because α-amino acid
cysteine (HO2CCH(NH2)CH2SH) is a key component of the keratin proteins in hair fiber,
focused on the comparative study of chemical composition of the human hair on different races
of different continents. Hu et al. studied on protein based composite biomaterials which can be
formed into a wide range of biomaterials with tunable properties, including control of cell
responses. They provided new biomaterials which is an important need in the field of biomedical
science, with direct relevance to tissue regeneration, nano-medicine and disease treatments.
Volkin and Klibanov identified and characterized the processes leading to destruction of cysteine
residues. They compared proteins from different species, including those of thermophilic
bacteria living near the boiling point of water.
Hernandez and Santos studied on keratin which is a fiber, found in hair and feathers. Keratin
fiber has a hierarchical structure with a highly ordered conformation, is by itself a bio-composite,
product of a large evolution of animal species. Through their research it was concluded that the
keratin fibers from chicken feathers shows an eco-friendly material which can be applied in the
development of green composites. Hernandez et al. have previously developed a matrix solid
phase dispersion (MSPD) method and it proved to offer quantitative results when isolating
cocaine, benzoylecgonine (BZE), codeine, morphine and 6-monoacethylmorphine (6-MAM)

18. from human hair samples which further determined the chemical composition of human hair.
Overall they scrutinized the dynamical, mechanical and chemical analysis of polymeric
composites reinforced with keratin biological fiber from human hair composites and founded the
capability of human hair as a proficient fiber in the industry.
Renju et al.founded an innovative chemical technique of improving the soil fertility by using
human hair fibers. Robbins described the hair as a protein filament that grows from follicles
found in the dermis, or skin. Most common interest in hair is focused on hair growth, hair types
and hair care, but hair is also an important biomaterial primarily composed of protein, notably
keratin.
Preparation of specimen:
It is the most common test conducted on hardened concrete as it is an easy test to perform and
also most of the desirablecharacteristic properties of concrete are qualitatively related to
compressive strength. The compression test is carried out on specimens cubical in shape as
shown in figure of the size 150 × 150 × 150 mm. The test is carried out in the following steps:
First of all the mould preferably of cast iron, is used to prepare the specimen of size 150 × 150 ×
150 mm. During the placing of concrete in the moulds it is compacted with the tamping bar with
not less than 25 strokes per layer. Then these moulds are placed on the vibrating table and are
compacted until the specified condition is attained. After 24 hours the specimens are removed
from the moulds and immediately submerged in clean fresh water. After 28 days the specimens

19. are tested under the load in a compression testing machine.

20. MATERIALS USED:
Cement: This is the most common binding material used in concrete production. The cement
used in this study is Ultra-tech OPC of 53 grade confirming to IS: 12269-1987.Physical
properties of cement show in table no.1 which is given below.
Fineregate: Locally available fresh river sand, free from organic matter, was used. The result of
sieve analysis confirms-ΙI (according to IS: 383-1970)
Coarse aggregate: For this study the locally available good quality coarse aggregate is used.
The size of coarse aggregate varies from 10 mm to 20 mm, means the material passed from
20mm IS sieve but retained in 10mm IS sieve.
Properties of concrete:
Properties of concrete are influenced by many factors mainly due to mix proportion of cement,
sand, aggregates and water. Ratio of these materials control the various concrete properties
which are discussed below. Concrete has relatively high compressive strength, but significantly
lower tensile strength, and as such is usually reinforced with materials that are strong in tension
(often steel). The elasticity of concrete is relatively constant at low stress levels but starts
decreasing at higher stress levels as matrix cracking develops. Concrete has a very low
coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will
crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration
forces is prone to creep.
Tests can be made to ensure the properties of concrete correspond to specifications for the
application. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150
lb/cu ft).[1] As a result,[further explanation needed] without compensating, concrete would
almost always fail from tensile stresses – even when loaded in compression. The practical

21. implication of this is that concrete elements subjected to tensile stresses must be reinforced with
materials that are strong in tension.
Reinforced concrete is the most common form of concrete. The reinforcement is often steel,
rebar (mesh, spiral, bars and other forms). Structural fibers of various materials are available.
Concrete can also be prestressed (reducing tensile stress) using internal steel cables (tendons),
allowing for beams or slabs with a longer span than is practical with reinforced concrete alone.
Inspection of existing concrete structures can be non-destructive if carried out with equipment
such as a Schmidt hammer, which is sometimes used to estimate relative concrete strengths in
the field.
The ultimate strength of concrete is influenced by the water-cementitious ratio (w/cm), the
design constituents, and the mixing, placement and curing methods employed. All things being
equal, concrete with a lower water-cement (cementitious) ratio makes a stronger concrete than
that with a higher ratio. The total quantity of cementitious materials (portland cement, slag
cement, pozzolans) can affect strength, water demand, shrinkage, abrasion resistance and
density. All concrete will crack independent of whether or not it has sufficient compressive
strength. In fact, high Portland cement content mixtures can actually crack more readily due to
increased hydration rate. As concrete transforms from its plastic state, hydrating to a solid, the
material undergoes shrinkage. Plastic shrinkage cracks can occur soon after placement but if the
evaporation rate is high they often can actually occur during finishing operations, for example in
hot weather or a breezy day. In very high-strength concrete mixtures (greater than 70 MPa) the
crushing strength of the aggregate can be a limiting factor to the ultimate compressive strength.
In lean concretes (with a high water-cement ratio) the crushing strength of the aggregates is not
so significant. The internal forces in common shapes of structure, such as arches, vaults, columns
and walls are predominantly compressive forces, with floors and pavements subjected to tensile
forces. Compressive strength is widely used for specification requirement and quality control of
concrete. Engineers know their target tensile (flexural) requirements and will express these in
terms of compressive strength.

22. Elasticity
The modulus of elasticity of concrete is a function of the modulus of elasticity of the aggregates
and the cement matrix and their relative proportions. The modulus of elasticity of concrete is
relatively constant at low stress levels but starts decreasing at higher stress levels as matrix
cracking develops. The elastic modulus of the hardened paste may be in the order of 10-30 GPa
and aggregates about 45 to 85 GPa. The concrete composite is then in the range of 30 to 50 GPa.
Expansion and shrinkage

23. Concrete has a very low coefficient of thermal expansion. However, if no provision is made for
expansion, very large forces can be created, causing cracks in parts of the structure not capable
of withstanding the force or the repeated cycles of expansion and contraction. The coefficient of
thermal expansion of Portland cement concrete is 0.000008 to 0.000012 (per degree Celsius) (8
to 12 microstrains/°C)(8-12 1/MK).
Thermal Conductivity
Concrete has moderate thermal conductivity, much lower than metals, but significantly higher
than other building materials such as wood, and is a poor insulator.
A layer of concrete is frequently used for 'fireproofing' of steel structures. However, the term
fireproof is inappropriate, for high temperature fires can be hot enough to induce chemical
changes in concrete, which in the extreme can cause considerable structural damage to the
concrete.
Cracking
As concrete matures it continues to shrink, due to the ongoing reaction taking place in the
material, although the rate of shrinkage falls relatively quickly and keeps reducing over time (for
all practical purposes concrete is usually considered to not shrink due to hydration any further
after 30 years). The relative shrinkage and expansion of concrete and brickwork require careful
accommodation when the two forms of construction interface.
All concrete structures will crack to some extent. One of the early designers of reinforced
concrete, Robert Maillart, employed reinforced concrete in a number of arched bridges. His first
bridge was simple, using a large volume of concrete. He then realized that much of the concrete
was very cracked, and could not be a part of the structure under compressive loads, yet the
structure clearly worked. His later designs simply removed the cracked areas, leaving slender,
beautiful concrete arches. The Salginatobel Bridge is an example of this.

24. Concrete cracks due to tensile stress induced by shrinkage or stresses occurring during setting or
use. Various means are used to overcome this. Fiber reinforced concrete uses fine fibers
distributed throughout the mix or larger metal or other reinforcement elements to limit the size
and extent of cracks. In many large structures joints or concealed saw-cuts are placed in the
concrete as it sets to make the inevitable cracks occur where they can be managed and out of
sight. Water tanks and highways are examples of structures requiring crack control.
Shrinkage cracking
Shrinkage cracks occur when concrete members undergo restrained volumetric changes
(shrinkage) as a result of either drying, autogenous shrinkage or thermal effects. Restraint is
provided either externally (i.e. supports, walls, and other boundary conditions) or internally
(differential drying shrinkage, reinforcement). Once tensile strength of the concrete is exceeded,
a crack will develop. The number and width of shrinkage cracks that develop are influenced by
the amount of shrinkage that occurs, the amount of restraint present and the amount and spacing
of reinforcement provided.These are minor indications and have no real structural impact on the
concrete member.Plastic-shrinkage cracks are immediately apparent, visible within 0 to 2 days of
placement, while drying-shrinkage cracks develop over time. Autogenous shrinkage also occurs
when the concrete is quite young and results from the volume reduction resulting from the
chemical reaction of the Portland cement.

25. Tension cracking
Concrete members may be put into tension by applied loads. This is most common in concrete
beams where a transversely applied load will put one surface into compression and the opposite
surface into tension due to induced bending. The portion of the beam that is in tension may
crack. The size and length of cracks is dependent on the magnitude of the bending moment and
the design of the reinforcing in the beam at the point under consideration. Reinforced concrete
beams are designed to crack in tension rather than in compression. This is achieved by providing
reinforcing steel which yields before failure of the concrete in compression occurs and allowing
remediation, repair, or if necessary, evacuation of an unsafe area.
Creep
Creep is the permanent movement or deformation of a material in order to relieve stresses within
the material. Concrete that is subjected to long-duration forces is prone to creep. Short-duration

26. forces (such as wind or earthquakes) do not cause creep. Creep can sometimes reduce the amount
of cracking that occurs in a concrete structure or element, but it also must be controlled. The
amount of primary and secondary reinforcing in concrete structures contributes to a reduction in
the amount of shrinkage, creep and cracking.
Water retention
cement concrete holds water. However, some types of concrete (like Pervious concrete allow
water to pass, hereby being perfect alternatives to Macadam roads, as they do not need to be
fitted with storm drains.
Properties of Concrete are:

27.  Grades (M25)
 Compressive strength
 Characteristic Strength
 Tensile strength
 Durability
 Creep
 Shrinkage
 Unit weight
 Modular Ratio
 Poisson’s ratio
Grades of concrete:
Concrete is known by its grade which is designated as M25 etc. in which letter M refers to
concrete mix and number 15, 20 denotes the specified compressive strength (fck) of 150mm
cube at 28 days, expressed in N/mm2. Thus, concrete is known by its compressive strength. M20
and M25 are the most common grades of concrete, and higher grades of concrete should be used
for severe, very severe and extreme environments.
Data Required for Concrete Mix Design
(i) Concrete Mix Design Stipulation
(a) Characteristic compressive strength required in the field at 28 days grade designation — M
25
(b) Nominal maximum size of aggregate — 20 mm
(c) Shape of CA — Angular
(d) Degree of workability required at site — 50-75 mm (slump)
(e) Degree of quality control available at site — As per IS:456

28. (f) Type of exposure the structure will be subjected to (as defined in IS: 456) — Mild
(g) Type of cement: PSC conforming IS:455
(h) Method of concrete placing: pump able concrete
(ii) Test data of material (to be determined in the laboratory)
(a) Specific gravity of cement — 3.15
(b) Specific gravity of FA — 2.64
(c) Specific gravity of CA — 2.84
(d) Aggregate are assumed to be in saturated surface dry condition.
(e) Fine aggregates confirm to Zone II of IS – 383
Procedure for Concrete Mix Design of M25 Grade Concrete
Step 1 — Determination Of Target Strength
Himsworth constant for 5% risk factor is 1.65. In this case standard deviation is taken from
IS:456 against M 20 is 4.0.
ftargetftarget = fck + 1.65 x S
= 25 + 1.65 x 4.0 = 31.6 N/mm2
Where,
S = standard deviation in N/mm2 = 4 (as per table -1 of IS 10262- 2009)
Step 2 — Selection of water / cement ratio:-
Maximum water-cement ratio for Mild exposure condition = 0.55

29. Based on experience, adopt water-cement ratio as 0.5.
0.5<0.55, hence OK.
Step 3 — Selection of Water Content Table 2 of IS 10262- 2009,Maximum water content = 186
Kg (for Nominal maximum size of aggregate — 20 mm)
Step 4 — Selection of Cement Content
Water-cement ratio = 0.5
Corrected water content = 191.6 kg /m3
Cement content =
From Table 5 of IS 456,
Minimum cement Content for mild exposure condition = 300 kg/m3
383.2 kg/m3 > 300 kg/m3, hence, OK.
This value is to be checked for durability requirement from IS: 456.
In the present example against mild exposure and for the case of reinforced concrete the
minimum cement content is 300 kg/m3 which is less than 383.2 kg/m3. Hence cement content
adopted = 383.2 kg/m3.
AsAs per clause 8.2.4.2 of IS: 456
Maximum cement content = 450 kg/cm3.

30. Estimation

32. MIX PROPORSION M25
Quantity of cement (kg
6.68
Quantity of sand (kg)
6.68
Quantity of coarse aggregate (kg
13.36
Water cement ratio
0.55
Quantity of water (l
3.67
Estimation of the mix ingredients
a) Volume of concrete = 1 m3
b) Volume of cement = (Mass of cement / Specific gravity of cement) x (1/100)
= (383.2/3.15) x (1/1000) = 0.122 m3
c) Volume of water = (Mass of water / Specific gravity of water) x (1/1000)
= (191.6/1) x (1/1000) = 0.1916 m3
d) Volume of total aggregates = a – (b + c ) = 1 – (0.122 + 0.1916) = 0.6864 m3
e) Mass of coarse aggregates = 0.6864 x 0.558 x 2.84 x 1000 = 1087.75 kg/m3
f) Mass of fine aggregates = 0.6864 x 0.442 x 2.64 x 1000 = 800.94 kg/m3
Concrete Mix proportions for Trial Mix 1
Cement = 383.2 kg/m3
Water = 191.6 kg/m3
Fine aggregates = 800.94 kg/m3
Coarse aggregate = 1087.75 kg/m3

33. W/c = 0.5
For trial -1 casting of concrete in lab, to check its properties.
It will satisfy durability & economy.
For casting trial -1, mass of ingredients required will be calculated for 4 no’s cube assuming 25%
wastage.
Volume of concrete required for 4 cubes = 4 x (0.153 x1.25) = 0.016878 m3
Cement = (383.2 x 0.016878) kg/m3 = 6.47 kg
Water = (191.6 x 0.016878) kg/m3 =3.23 kg
Coarse aggregate = (1087.75 x 0.016878) kg/m3 =18.36 kg
Fine aggregates = (800.94 x 0.016878) kg/m3 = 13.52 kg
Correction due to absorbing / moist aggregate:-
Since the aggregate is saturated surface dry condition hence no correction is required.
Concrete Trial Mixes:-
Concrete Trial Mix 1:
The mix proportion as calculated in Step 6 forms trial mix1. With this proportion, concrete is
manufactured and tested for fresh concrete properties requirement i.e. workability, bleeding and
finishing qualities.
In this case,
Slump value = 25 mm
Compaction Factor = 0.844
So, from slump test we can say,
Mix is cohesive, workable and had a true slump of about 25 mm and it is free from segregation
and bleeding.
Desired slump = 50-75 mm . So modifications are needed in trial mix 1 to arrive at the desired
workability.
Concrete Trial Mix 2:

34. To increase the workability from 25 mm to 50-75 mm an increase in water content by +3% is to
be made.
The corrected water content = 191.6 x 1.03 = 197.4 kg.
As mentioned earlier to adjust fresh concrete properties the water cement ratio will not be
changed. Hence
Cement Content = (197.4/0.5) = 394.8 kg/m3
Which also satisfies durability requirement.
Volume of all in aggregate = 1 – [{394.8/(3.15×1000)} + {197.4/(1 x 1000)}] = 0.6773 m3
Mass of coarse aggregate = 0.6773 x 0.558 x 2.84 x 1000 = 1073.33 kg/m3
Mass of fine aggregate = 0.6773 x 0.442 x 2.64 x 1000 = 790.3 kg/m3
Concrete Mix Proportions for Trial Mix 2
Cement = 384.8 kg/m3
Water = 197.4 kg/m3
Fine aggregate =790.3 kg/m3
Coarse aggregate = 1073.33 kg/m3
For casting trial -2, mass of ingredients required will be calculated for 4 no’s cube assuming 25%
wastage.
Volume of concrete required for 4 cubes = 4 x (0.153 x1.25) = 0.016878 m3
Cement = (384.8 x 0.016878) kg/m3 = 6.66 kg
Water = (197.4 x 0.016878) kg/m3 =3.33 kg
Coarse aggregate = (1073.33 x 0.016878) kg/m3 =18.11 kg
Fine aggregates = (790.3 x 0.016878) kg/m3 = 13.34 kg
In this case,
Slump value = 60 mm
Compaction Factor = 0.852
So, from slump test we can say,

35. Mix is very cohesive, workable and had a true slump of about 60 mm.
It virtually flowed during vibration but did not exhibit any segregation and bleeding.
Desired slump = 50-75 mm
So , it has achieved desired workability by satisfying the requirement of 50-75 mm slump value .
Now , we need to go for trial mix-3 .
Concrete Trial Mix 3:
In case of trial mix 3 water cement ratio is varied by +10% keeping water content constant. In
the present example water cement ratio is raised to 0.55 from 0.5.
An increase of 0.05 in the w/c will entail a reduction in the coarse aggregate fraction by 0.01.
Hence the coarse aggregate as percentage of total aggregate = 0.558 – 0.01 = 0.548
W/c = 0.55
Water content will be kept constant.
Cement content = (197.4/0.55) = 358.9 kg/m3
Hence, volume of all in aggregate
= 1 – [{(358.9/(3.15 x 1000)} + (19)
Water cement Ratio
We add water only to hydrate cement. Aggregates do not require water.
So water cement ratio is defined.
As the strength increase cement content increase, so water also increase.
Both water and cement increase so water cement ratio almost remain
same.
If we add less water…cement remain unhydrated
If we add more water….density decreases and strength decrease.

36. So.we have to add water to exactly hydrate cement. Amount of cement
changes from place to place due to change in shapes and sizes of
aggregate.
Till M25 grade 0.4 to 0.6 will be sufficient. We have to check till
sufficient workability is attained. It is not fixed with strength.
METHODS OF PROPORTIONING CONCRETE
(1) Arbitrary Method
The general expression for the proportions of cement, sand and coarse aggregate is 1 : n : 2n by
volume.
1 : 1 : 2 and 1 : 1.2 : 2.4 for very high strength.
1 : 1.5 : 3 and 1 : 2 : 4 for normal works.

37. 1 : 3 : 6 and 1 : 4 : 8 for foundations and mass concrete works.
(2) Fineness Modulus Method:
The term fineness modulus is used to indicate an index number which is roughly proportional to
the average size of the particle in the entire quantity of aggregates.
The fineness modulus is obtained by adding the percentage of weight of the material retained on
the following sieve and divided by 100.
The coarser the aggregates, the higher the fineness modulus.
Sieve is adopted for:
All aggregates : 80 mm, 40 mm, 20 mm, 10 mm, and Nos. 480, 240, 120, 60, 30 and 15.
Coarse aggregates : mm, 40 mm, 20 mm, 10 mm, and No. 480.
Fine aggregates : Nos. 480, 240, 120, 60, 30 and 15.
Proportion of the fine aggregate to the combined aggregate by weight

38. (3) Minimum Void Method (Does not give satisfactory result)
The quantity of sand used should be such that it completely fills the voids of coarse aggregate.
Similarly, the quantity of cement used shown such that it fills the voids of sand, so that a dense
mix the minimum voids is obtained.
In actual practice, the quantity of fine aggregate used in the mix is about 10% more than the
voids in the coarse aggregate and the quantity of cement is kept as about 15% more than the
voids in the fine aggregate.
(4) Water – Cement Ratio Method:
According to the water – cement ratio law given by Abram as a result of many experiments, the
strength of well compacted concrete with good workability is dependent only on the ratio.

39. The lower water content produces stiff paste having greater binding property and hence the
lowering the water-cement ratio within certain limits results in the increased strength.
Similarly, the higher water content increases the workability, but lower the strength of concrete.
The optimum water-cement ratio for the concrete of required compressive strength is decided
from graphs and expressions developed from various experiments.
Amount of water less than the optimum water decreases the strength and about 10% less may be
insufficient to ensure complete setting of cement. An increase of 10% above the optimum may
decrease the strength approximately by 15% while an increase in 50% may decrease the strength
to one-half.
According to Abram’s Law water-cement law, lesser the water-cement ratio in a workable mix
greater will be the strength.
If water cement ratio is less than 0.4 to 0.5, complete hydration will not be secured.
Some practical values of water cement ratio for structure reinforced concrete
0.45 for 1 : 1 : 2 concrete
0.5 for 1 : 1.5 : 3 concrete
0.5 to 0.6 for 1 : 2 : 4 concrete.
Concrete vibrated by efficient mechanical vibrators require less water cement ratio, and hence
have more strength.
Thumb Rules for deciding the quantity of water in concrete:
(i) Weight of water = 28% of the weight of cement + 4% of the weight of total aggregate
(ii) Weight of water = 30% of the weight of cement + 5% of the weight of total aggregate

40. PROCEDURE:
 Check the all component are use in mix design m25 grade concrete.
 After checking m25 to take a ratio 1:1:2.
 Take cement in 5.7 kg, sand 5.7 and aggregate 11.4 kg.
 Aggregate size is 20mm.
 To take the water to mix the concrete is to be 3135 ml.
 Mix the all component very carefully.
 Take a 2 specimen size is 10*10*50.
 Volume of one specimen is 0.005 m3.
 Fill their specimen for m25 grade concrete.
 After filling the specimen dry the specimen in 7 days.
 After 7 day the curing process is start in cuboid.
 Curing process is done in 28 days.
 Flexural strength is to be checked by the flexural test machine.
Test Performed:

41. For determining the effect of hair as fibre in concrete following tests were performed:
i. Compression test: It is the most common test conducted on hardened concrete as it is an easy
test to perform and also most of the desirable characteristic properties of concrete are
qualitatively related to its compressive strength. The compression test is carried out on
specimens cubical in shape of the size 150 × 150 × 150 mm. The test is carried out in the
following steps: First of all the mould preferably of cast iron, is used to prepare the
specimen of size 150 × 150 × 150 mm. During the placing of concrete in the moulds it is
compacted with the tamping bar with not less than 35 strokes per layer. Then these moulds
are placed on the vibrating table and are compacted until the specified condition is attained. After
24 hours the specimens are removed from the moulds and immediately submerged in clean fresh
water. After 28 days the specimens are tested under the load in a compression testing machine. ii.
Flexural Strength test: Direct measurement of the tensile strength of concrete is difficult. Neither
specimens nor testing apparatushave been designed which assure uniform distribution of the
stress in bending depends on the dimensions of the beam and manner of loading.
pull applied to the concrete. The value of the extreme fibre
The system of loading used in finding out the flexural tension is Third-point Loading Method. In
this method the critical crack may appear at any section, not strong enough to resist the stress
within the middle third, where the bending moment is maximum. The test is carried out in the
following steps: First of all the mould preferably of cast iron, is used to prepare the
specimen of size 150 × 150 × 700 mm During the placing of concrete in the mould it is
compacted with the tamping bar weighing 2 kg, 400 mm long with not less than 35 strokes per
layer. Then this mould is placed on the vibrating table and is compacted until the specified
condition is attained. After 24 hours the specimen is removed from the mould and immediately
submerged in clean fresh water. After 28 days the specimen is taken out from the curing tank and
placed on the rollers of the flexural testing machine as shown in figure 5 for testing. Then the
load is applied at a constant rate of 400 kg/min. The load is applied until the specimen fails, and
the maximum load applied to the specimen during the test is recorded.The specimen for both the
test is made in the following manner: i. Compression test: Three cubes are made for each M-15,
M-2O and M-25 with 0%, 1%, 1.5%, 2%, 2.5% and 3% hair by weight of cement. ii. Flexural

42. Strength test: One beam is made for each M-15, M-2O and M-25 with 0%, 1%,1.5%, 2%, 2.5%
and 3% hair by weight of cement.
Methodology
The methodology adopted to test the properties and strength of hair reinforced concrete is
governed by: Compressive Strength, Workability test, Flexure test.
Compressive strength of concrete:
Like load, the strength of the concrete is also a quality which varies considerably for the same
concrete mix. Therefore, a single representative value, known as characteristic strength is used.
Characteristic strength of concrete:
It is defined as the value of the strength below which not more then 5% of the test results are
expected to fall (i.e. there is 95% probability of achieving this value only 5% of not achieving
the same)

43. Characteristic strength of concrete in flexural member
The characteristic strength of concrete in flexural member is taken as 0.67 times the strength of
concrete cube.
Design strength and partial safety factor for material strength
The strength to be taken for the purpose of design is known is known as design strength and is
given by
Design strength (fd) = characteristic strength/ partial safety factor for material strength
The value of partial safety factor depends upon the type of material and upon the type of limit
state. According to IS code, partial safety factor is taken as 1.5 for concrete and 1.15 for steel.

44. Design strength of concrete in member = 0.45fck
Tensile strength of concrete:
The estimate of flexural tensile strength or the modulus of rupture or the cracking strength of
concrete from cube compressive strength is obtained by the relations
fcr = 0.7 fck N/mm2
The tensile strength of concrete in direct tension is obtained experimentally by split cylinder. It
varies between 1/8 to 1/12 of cube compressive strength.
Creep in concrete:
Creep is defined as the plastic deformation under sustain load. Creep strain depends primarily on
the duration of sustained loading. According to the code, the value of the ultimate creep
coefficient is taken as 1.6 at 28 days of loading.
Shrinkage of Concrete:
The property of diminishing in volume during the process of drying and hardening is termed
Shrinkage. It depends mainly on the duration of exposure. If this strain is prevented, it produces
tensile stress in the concrete and hence concrete develops cracks.
Modular ratio:
Short term modular ratio is the modulus of elasticity of steel to the modulus of elasticity of
concrete.
Short term modular ratio = Es / Ec
Es = modulus of elasticity of steel (2×10 5 N/mm2
)
Ec = modulus of elasticity of concrete (5000xSQRT(fck) N/mm2
)

45. As the modulus of elasticity of concrete changes with time, age at loading etc the modular ratio
also changes accordingly. Taking into account the effects of creep and shrinkage partially IS
code gives the following expression for the long term modular ratio.
Long term modular ratio (m) = 280/ (3fcbc)
Where, fcbc = permissible compressive stress due to bending in concrete in N/mm2
.
Poisson’s ratio:
Poisson’s ratio varies between 0.1 for high strength concrete and 0.2 for weak mixes. It is
normally taken as 0.15 for strength design and 0.2 for serviceability criteria.
Durability of concrete:
Durability of concrete is its ability to resist its disintegration and decay. One of the chief
characteristics influencing durability of concrete is its permeability to increase of water and other
potentially deleterious materials.
The desired low permeability in concrete is achieved by having adequate cement, sufficient low
water/cement ratio, by ensuring full compaction of concrete and by adequate curing.
Unit weight of concrete:
The unit weight of concrete depends on percentage of reinforcement, type of aggregate, amount
of voids and varies from 23 to 26KN/m2. The unit weight of plain and reinforced concrete as
specified by IS:456 are 24 and 25KN/m3 respectively.
FACTORS AFFECTING THE CHOICE OF MIX PROPORTIONS
The various factors affecting the mix design are:

46. 1. Compressive strength:
It is one of the most important properties of concrete and influences many other describable
properties of the hardened concrete. The mean compressive strength required at a specific age,
usually 28 days, determines the nominal water-cement ratio of the mix. The other factor affecting
the strength of concrete at a given age and cured at a prescribed temperature is the degree of
compaction. According to Abraham’s law the strength of fully compacted concrete is inversely
proportional to the water-cement ratio.
2. Workability:
The degree of workability required depends on three factors. These are the size of the section to
be concreted, the amount of reinforcement, and the method of compaction to be used. For the
narrow and complicated section with numerous corners or inaccessible parts, the concrete must
have a high workability so that full compaction can be achieved with a reasonable amount of
effort. This also applies to the embedded steel sections. The desired workability depends on the
compacting equipment available at the site.
3. Durability:
The durability of concrete is its resistance to the aggressive environmental conditions. High
strength concrete is generally more durable than low strength concrete. In the situations when the
high strength is not necessary but the conditions of exposure are such that high durability is vital,
the durability requirement will determine the water- cement ratio to be used.
4. Maximum nominal size of aggregate :
In general, larger the maximum size of aggregate, smaller is the cement requirement for a
particular water-cement ratio, because the workability of concrete increases with increase in
maximum size of the aggregate. However, the compressive strength tends to increase with the
decrease in size of aggregate.

47. 5. Grading and type of aggregate :
The grading of aggregate influences the mix proportions for a specified workability and water-
cement ratio. Coarser the grading leaner will be mix which can be used. Very lean mix is not
desirable since it does not contain enough finer material to make the concrete cohesive.
Analysis of Data collected:
The analysis of data collected is done in the following manner:
Compression test:
The results from the compression test are in the form of the maximum load the cube can carry
before it ultimately fails. The compressive stress can be found by dividing the maximum load by
the area normal to it. The results of compression test and the corresponding compressive stress .
Let,
P = maximum load carried by the cube before the failure
A = area normal to the load = 150 × 150 mm2 = 22500 mm2
σ = maximum compressive stress (N/mm2
Procedure: Compressive Strength Test of Concrete Cubes
For cube test two types of specimens either cubes of 15cm X 15cm X 15cm or 10cm X 10cm x
10cm depending upon the size of aggregate are used. For most of the works cubical moulds of
size 15cm x 15cm x 15cm are commonly used.

48. 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
ofhese 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 should be applied gradually at the rate of 140 kg/cm2 per minute till the Specimens
fails. Load at the failure divided by area of specimen gives the compressive strength of concrete.
Following are the procedure for testing Compressive strength of Concrete Cubes
APPARATUS
Compression testing machine
PREPARATION OF CUBE SPECIMENS
The proportion and material for making these test specimens are from the same concrete used in
the field.
SPECIMEN
6 cubes of 15 cm size Mix. M25
MIXING
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
(ii)Add the coarse aggregate and mix with cement and fine aggregate until the coarse aggregate
is uniformly distributed throughout the batch

49. (iii)Add water and mix it until the concrete appears to be homogeneous and of the desired
consistency
SAMPLING
(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 35strokes 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
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
The water for curing should be tested every 7 days and the temperature of water must be at 27+-
2oC.
PROCEDURE
(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

50. (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.
NOTE
Minimum three specimens should be tested at each selected age. If strength of any specimen
varies by more than 15 per cent of average strength, results of such specimen should be rejected.
Average of three specimens gives the crushing strength of concrete. The strength requirements of
concrete.
CALCULATIONS
Size of the cube =15cm x15cm x15cm
Area of the specimen (calculated from the mean size of the specimen )=225 cm2
Characteristic compressive strength(f ck)at 7 days =
Expected maximum load =fck x area x f.s
Similar calculation should be done for 28 day compressive strength

51. Compressive strength = (Load in N/ Area in mm2)= 24.99.N/mm2
REPORT
a) Identification mark
b) Date of test
c) Age of specimen
d) Curing conditions, including date of manufacture of specimen
f) Appearance of fractured faces of concre

52. σ = maximum compressive stress (N/mm2).
Compressive strength test results of cube-
Mix Design Avg. Compressive
strength(N/mm^2)
M25 : without hair 24.99
1% hair 25.1

53. Workability Test
The property of fresh concrete which is indicated by the amount of useful internal work required
to fully compact the concrete without bleeding or segregation in the finished product.
Unsupported fresh concrete flows to the sides and a sinking in height takes place. This vertical
settlement is known as slump. In this test fresh concrete is filled into a mould of specified shape
and dimensions, and the settlement or slump is measured when supporting mould is removed.
Slump increases as water-content is increased. For different works different slump values have
been recommended.
Procedure to determine workability of fresh concrete by slump test.
i) The internal surface of the mould is thoroughly cleaned and applied with a light coat of oil.
ii) The mould is placed on a smooth, horizontal, rigid and nonabsorbent surface.
iii) The mould is then filled in four layers with freshly mixed concrete, each approximately to
one-fourth of the height of the mould.
iv) Each layer is tamped 25 times by the rounded end of the tamping rod (strokes are distributed
evenly over the cross section).
v) After the top layer is rodded, the concrete is struck off the level with a trowel.
vi) The mould is removed from the concrete immediately by raising it slowly in the vertical
direction.
vii) The difference in level between the height of the mould and that of the highest point of the
subsided concrete is measured.
viii) This difference in height in mm is the slump of the concrete.

54. Reporting of Results
The slump measured should be recorded in mm of subsidence of the specimen during the test.
Any slump specimen, which collapses or shears off laterally gives incorrect result and if this
occurs, the test should be repeated with another sample. If, in the repeat test also, the specimen
shears, the slump should be measured and the fact that the specimen sheared, should be recorded
In case of a dry sample, slump will be in the range of 25-50 mm that is 1-2 inches. But in case of
a wet concrete, the slump may vary from 150-175 mm or say 6-7 inches. So the value of slump is
specifically mentioned along the mix design and thus it should be checked as per your
location.Slump depends on many factors like properties of concrete ingredients – aggregates etc.
Also temperature has its effect on slump value. So these parameters should be kept in mind.

55. Flexural Strength test
The value of the extreme fibre stress in bending depends on the dimensions of the beam and
manner of loading. The system of loading used in finding out the flexural tension is Third-point
Loading Method as shown in fig 4. In this method the critical crack may appear at any section,
not strong enough to resist the stress within the middle third, where the bending moment is
maximum. The test is carried out in the following steps: First of all the mould preferably of cast
iron, is used to prepare the specimen of size 100 × 100 × 500 mm. During the placing of concrete
in the mould it is compacted with the tamping bar weighing 2 kg, 400 mm long with not less than
25 strokes per layer. Then this mould is placed on the vibrating table and is compacted until the
specified condition is attained. After 24 hour specimen is removed from the mould and
immediately submerged in clean fresh water. After 28 days the specimen is taken out from the
curing tank and placed on the rollers of the flexural testing machine for testing as shown in

56. figure 4. Then the load is applied at a constant rate of 400 kg/min. The load is applied until the
specimen fails, and the maximum load applied to the specimen during the test is recorded
.
EQUIPMENT & APPARATUS
Beam mould of size 15 x 15x 70 cm (when size of aggregate is less than 38 mm) or of size 10 x
10 x 50 cm (when size of aggregate is less than 19 mm)
Tamping bar (40 cm long, weighing 2 kg and tamping section having size of 25 mm x 25 mm)
Flexural testmachine– The bed of the testing machine shall be provided with two steel
rollers, 38 mm in diameter, on which the specimen is to be supported, and these rollers shall be
so mounted that the distance from centre to centre is 60 cm for 15.0 cm specimens or 40 cm for
10.0 cm specimens. The load shall be applied through two similar rollers mounted at the third
points of the supporting span that is, spaced at 20 or 13.3 cm centre to centre. The load shall be
divided equally between the two loading rollers, and all rollers shall be mounted in such a
manner that the load is applied axially and without subjecting the specimen to any torsional
stresses or restraints.
Flexural Strength Test Arrangement

57. PROCEDURE
Prepare the test specimen by filling the concrete into the mould in 3 layers of approximately
equal thickness. Tamp each layer 35 times using the tamping bar as specified above. Tamping
should be distributed uniformly over the entire crossection of the beam mould and throughout the
depth of each layer.
bearing surfaces of the supporting and loading rollers , and remove any loose sand or other
material from the surfaces of the specimen where they are to make contact with the rollers.
Circular rollers manufactured out of steel having cross section with diameter 38 mm will be used
for providing support and loading points to the specimens. The length of the rollers shall be at
least 10 mm more than the width of the test specimen. A total of four rollers shall be used, three
out of which shall be capable of rotating along their own axes. The distance between the outer
rollers (i.e. span) shall be 3d and the distance between the inner rollers shall be d. The inner
rollers shall be equally spaced between the outer rollers, such that the entire system is systematic.
The specimen stored in water shall be tested immediately on removal from water; whilst they are
still wet. The test specimen shall be placed in the machine correctly centered with the
longitudinal axis of the specimen at right angles to the rollers. For moulded specimens, the
mould filling direction shall be normal to the direction of loading.
The load shall be applied at a rate of loading of 400 kg/min for the 15.0 cm specimens and at a
rate of 180 kg/min for the 10.0 cm specimens.
CALCULATION
The Flexural Strength or modulus of rupture (fb) is given by

58. fb = pl/bd2 (when a > 20.0cm for 15.0cm specimen or > 13.0cm for 10cm specimen)
or
fb = 3pa/bd2 (when a < 20.0cm but > 17.0 for 15.0cm specimen or < 13.3 cm but > 11.0cm for
10.0cm specimen.)
Where,a= the distance between the line of fracture and the nearer support, measured on the
center line of the tensile side of the specimen
b = width of specimen (cm)
d = failure point depth (cm)
l = supported length (cm)
p = max. Load (kg)
REPORTS
The Flexural strength of the concrete is reported to two significant figures.
SAFETY & PRECAUTIONS:
Use hand gloves while, safety shoes at the time of test.
After test switch off the machine.
Keep all the exposed metal parts greased.
Keep the guide rods firmly fixed to the base & top plate.
Equipment should be cleaned thoroughly before testing & after testing.

59. Results obtained from flexural strength test and the corresponding
bending strength
S. No Mix % hair Maximum
load (KN)
Bending
stress
(N/mm2)
1. M25 0% 46 4.09
2. M25 1% 47.3 4.21

60. Problems Encountered: It is well said that: “The taste of defeat has a richness
of,experience all its own.” During our research work we also faced the problem of uniform
distribution of hair in the concrete. So to overcome this problem we have adopted the manual
method of distribution of hair in the concrete.
Future Scope:
The use of waste human hair as a fibre reinforcement in concrete widens the door for further
research in the given field. They are as follows:
i. The distribution matrix of hair in concrete since the resultant matrix could affect the
properties.
ii. The study of admixtures and super plasticizer which could distribute the hairs without
affecting the properties of concrete.
iii. The use of animal hairs in concrete.

61. Conclusion
Crack formation and propagation are very much reduced showing that hair fibre reinforced
concrete can have various applications in seismic resistant and crack resistant constructions, road
pavement constructions etc. Future scope of this study can be as follows:
 During our research work we also faced the problem of uniform distribution of hair in
the concrete. So an efficient method of mixing of hair fibre to the concrete mix is to be
found out.
 A wide study on partial replacement of cement using fine hair fibre is to be carried out.
 The study of admixtures and super plasticizer which could distribute the hairs without
affecting the properties of concrete.
 The use of animal hairs in concrete.
 Applications fiber on other properties of composites such physical, thermal properties
and appearances.
 The total energy absorbed in fiber as measured by the area under the load deflection
curve is at least 10 to 40 times higher for fiber reinforced concrete than that of plain
concrete.
 Addition of hair fiber to conventionally reinforced beams increased the fatigue life and
decreased the cracks width under fatigue loading.
 At elevated temperature HFRC have more strength both in compression and tension.

62. Crack ResistantStructures
According to Grimm, 1988, a crack may be defined as a “break, split, fracture, fissure,
separation, cleavage or elongated narrow opening visible to the normal human eye and
extending from the surface and into a masonry unit, mortar joint, interface between a
masonry unit and adjacent mortar joint”. The cracks are classified according to its
damage level for load bearing masonry. In order to repair cracks up to a width of 5mm,
either cement grouting can be used or steel wire meshes can be inserted into the cracks.
But it is found that when fibre reinforced concrete is used, crack formation and
propagation is very much reduced since fibres can form a strong bond with the concrete
mix and can bridge the cracks to some extent. Examining the concrete specimens after
the tests, it is found that only hair line cracks were formed after the compressive strength
tests cracks in specimens with hair fibre when compared with concrete specimens without
hair fibre content. When fibres are added to concrete, it becomes homogeneous, isotropic
and transforms it to a ductile material. These fibres will act as secondary reinforcement in
concrete and reduces crack formation and propagation. the bridging effect by this fibre
leads to the improvement in the tensile and flexural strength.
Seismic ResistantStructures
Safety against seismic forces is a combination of both structural stability and adoption of
suitable construction techniques. It is well known that it is not the earthquake that kills
people but the collapse of structures that causes the havoc. Light weight construction
techniques have its application in this context. If the structure is light in weight at the
same time stable in structural integrity, the problems caused by the collapse of buildings
can be reduced. The possibility of hair fibre reinforced concrete can be discussed here.
From the experimental results it is obvious that hair fibre reinforced concrete can be used
for ordinary concreting works as such. For reinforced cement concrete, amount of steel
reinforcement can be reduced by adopting required percentage of hair fibre reinforcement
which makes the section light in weight. Reduction in crack formation under service
loads gives better life time for the steel reinforcement as it will resist corrosion of
steel through the cracks. Studies have been put forward the possibility of partial
replacement of cement with fibres in fibre reinforced concrete. If it is feasible, the section
will be economical without compromising the strength.

63. Roadand PavementConstruction
Various studies have been conducted to find the effects of human hair additives in
compressive strength of asphalt cement mixture as potential binder in road pavement and
those prove that adding cement and human hair to asphalt mixture greatly increase the
strength of the mixture thus making it a good material for the construction of road
pavement. Adding of both cement and human hair to asphalt mixture improves the
load bearing capacity of the mixture. Hence hair fibre reinforced concret has its
application in construction of pavements also.
WaterProof Constructions
By adopting hair fibre reinforced concrete the formation of minute cracks can be limited
which reduces the leakage problems, making it suitable for water proof constructions.
Acknowledgement With the deepest sense of gratitude we realize the valuable helps and
encouragement rendered by many individuals during the preparation of this report. We
are deeply grateful to the management and authority of Sahrdaya College of Engineering
And Technology to carry out this work. We also acknowledge with deep gratitude the
help and guidance rendered by the faculty members of civil engineering department who
have always been kind to offer their help in the hours of need. We appreciate the support
given by our friends during this work. Last but not the least, we extent our deep thanks to
our dear parents and God Almighty for guiding us through all difficulties and showering
blessings to fulfil our work.

64. References
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Establishment, (1975)
2. Johnston C.D., Definition and measurement of flexural toughness parameters for fibre
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3. Balaguru Perumalsamy N., Shah Sarendra P., Fiber reinforced cement composites, McGraw
Hill International Editions (1992)
4. Maidl B.R., Steel fibre reinforced concrete, Berlin: Ernst & Sohn, (1995)
5. Johnston Colin D., Fiber reinforced cements and concretes, Advances in concrete technology
volume 3– Gordon and Breach Science publishes (2001)
6. Neville A.M., Properties of Concrete, (2005)
7. Gambhir M.L., Concrete Technology, (2009)
8. Shetty M.S., Concrete Technology, (2009)
9. Ahmed S., Ghani F. and Hasan M., Use of Waste Human Hair as Fibre Reinforcement in
Concrete, IEI Journal, Volume 91 FEB, Page no 43, (2011)
10. Banthia N., Fibre Reinfoeced Concrete