INTERNSHIP REPORT

A report submitted in partial fulfillment of the requirements of the award of degree

Of

BACHELOR OF TECHNOLOGY

IN

CIVIL ENGINEERING

Submitted by T V S GOWTHAMRegd. No.16A51A0185

DEPARTMENT OF CIVIL ENGINEERING

ADITYA INSTITUTE OF TECHNOLOGY AND MANAGEMENT

(An Autonomous Institute)

Approved by AICTE, Permanently affiliated to JNTU, Kakinada, Accredited by NBA

(AICTE) & NAAC (UGC), Recognized by UGC u/s 2(f) & 12(B), TEQIP (Phase II)

Funded College, Recognized as SIRO by DSIR, DST, New Delhi.

Tekkali, Andhra Pradesh

2016– 2020

DEPARTMENT OF CIVIL ENGINEERING

ADITYA INSTITUTE OF TECHNOLOGY AND MANAGEMENT

(An Autonomous Institute)

TEKKALI

CERTIFICATE

This is to certify that the “Internship report” submitted by T V S GOWTHAM (Regd. No.:

16A51A0185) is a bonafide record of work done by him and submitted during 2019 – 2020

academic year, in partial fulfilment of the requirements for the award of the degree of

BACHELOR OF TECHNOLOGY in CIVIL ENGINEERING.

College Internship Coordinator Department Internship Coordinator

Dr. B. Rajesh Mr. B. Govinda Rajulu, M.Tech

Asst. Prof.

Head of the Department

Sri. Dr. V. CHITTI BABU, Ph.D.

Department of Civil Engineering

ACKNOWLEDGEMENT

I am highly indebted to Director Prof. V. V. Nageswara Rao and Principal Dr. A. Srinivas

Rao, for the facilities provided to accomplish this internship.

I would like to thank our Head of the Department Dr. V. CHITTI BABU Ph.D. for his

constructive criticism throughout my internship.

I would like to thank Dr. B. Rajesh, College internship coordinator and Mr. B. Govinda Rajulu, Department internship coordinator for their support and advices to get a complete internship in above said organization.

I am extremely grateful to my department staff members and friends who helped me in

successful completion of this internship.

T V S GOWTHAM (16A51A0185)

A STUDY ON “VARIOUS CONSTRUCTION MATERIALS AND TESTS”

Submitted to

IVRCL LIMITED

MIHIR, H. No. 8-2-350/5/A/24/1B

Panchavati

Colony,

Road no. 2,

Banjara

Hills,

Hyderabad –

500 034.

Telangana, India

Submitted by

T V S GOWTHAM 16A51A0185

B AMRUTHA 16A51A0110

G SAI MANOHAR 16A51A0145

M SAI NIKHILA 16A51A0154

An internship report submitted as a part of the

training Taken at OLD MLA QUARTERS,

HYDERABAD.

DEPARTMENT OF CIVIL ENGINEERING

ADITYA INSTITUTE OF TECHNOLOGY AND MANAGEMENT

(An Autonomous Institute)

TEKKALI.

vi

ABSTRACT

This study presents the compendia of the observation made during the one month of our

study. This report mainly resolves around the materials used and the tests on each

building components. To understand the process of application, sustainable masonry

product development is discussed in detail. In order to evaluate the feasibility of the

material, the necessary test evaluation method is also learned. The developed end product

performance evaluation is also learned by desired tests as recommended by standards

(IS). In this report we estimate the quantities required for the construction of building.

iii

ACKNOWLEDGEMENT

Any endeavor cannot lead to result unless and until a proper platform is provided

for the same. We express our thanks to IVRCL LTD for giving us the opportunity to

undertake this summer internship program.

We sincerely thank Management for their constant guidance, valuable

suggestions and encouragement throughout the progress of summer internship program.

We would also like to take this opportunity to thank all projects team for their

precious guidance and administration staff for their help.

And last but not the least we would like to thank our parents and colleagues for

their motivational support.

T V S GOWTHAM (16A51A0185)

B AMRUTHA (16A51A0110)

M SAI NIKHILA (16A51A0154)

G SAI MANOHAR (16A51A0145)

iv

DECLARATION

We hereby declare that the summer Internship report titled “VARIOUS

CONSTRUCTION MATERIALS AND TESTS” is bonafide work carried out by us

under guidance of project team at IVRCL LTD. Further we declare that this report has

not previously formed the basis of award of any associate ship or other similar degrees or

diplomas, has not been submitted anywhere else.

DATE:

T V S GOWTHAM (16A51A0185)

B AMRUTHA (16A51A0110)

M SAI NIKHILA (16A51A0154)

G SAI MANOHAR (16A51A0145)

v

OBJECTIVES OF SUMMER INTERNSHIP PROGRAM

1. To familiarize with proper planning, design and field operations.

2. Plan should include construction methods to be adopted for different

construction activities.

3. To get exposure with the management and communication functions

performed with in a construction project.

4. Construction projects are executed based on the drawing and specifications.

vi

CONTENTS

1. COMPANY PROFILE (1-3)

History 1

Projects 2

Awards 3

2. MATERIALS AND TESTS (4-23)

SAND 5

I. Bulking of sand 6

II. Sieve analysis 7

III. Fineness modulus 8

COARSE AGGREGATE 9

I. Specific gravity 10

II. Water absorption 11

CEMENT 11

I. Fineness test 12

II. Strength test 12

III. Specific gravity test 13

BRICK 13

I. Compressive strength 13

II. Water absorption test 13

III. Efflorescence 13

STONE 14

CONCRETE 16

I. Slump cone test 20

II. Compressive strength 21

III. Water permeability 21

IV. Rapid penetration test 21

V. Water absorption test 21

VI. Modulus of elasticity & Setting time 21

EQUIPMENT USED 22

CONCLUSION 23

1

COMPANY PROFILE

HISTORY

IVRCL infrastructure & projects limited was established in the year 1987. Commercial

operations of the company were started in the year 1990. In the same year, IVRCL established

itself as a premier EPC & LSTK Service Provider with front-end engineering capabilities.

Company is in leading EPC and Infrastructure public limited company listed on NSE and BSE

Stock Exchanges in India. Company strongly entrenched with proven domain knowledge,

experience and credentials. It is the largest water company in India and we take pride in building

& owning India’s 1st and largest desalination plant at Minjur (near Chennai) with 100MLD

capacity. We are present across the length and breadth of India with our major offices in metro

cities such as New Delhi (NCR), Mumbai, Chennai, Kolkata, Hyderabad, Pune, Bangalore,

Ahmadabad and Guwahati. We have also made our global footprints with operations in Sri

Lanka, Africa and the Middle East.

They are a diversified group and their core work of areas include various sectors such as

o Water and Environment

o Irrigation

o Transportation

o Building & Industrial Structures

o Power Distribution & Transmission

o Operations & Maintenance

o Mining

2

PROJECTS

1. Water & environment projects

Project: Chambal - Dholpur - Bharatpur - water supply project

2. Transportation

Project: Design, construction, development, finance, operation &

maintenance of Indore-Gujarat border on NH-59, in the state of Madhya

Pradesh.

3. Building & Industrial Structure

Project: Infrastructure Development for the Dahej Petrochemical

Complex on Lump sum Turkey (LSTK) basis at Dahej, Gujarat.

4. Power Distribution & Transmission

Project: 765KV S/C (Quad) Transmission Line from Seoni to Nandanwadi in

Madhya Pradesh.

5. Mining

Project: Malanjkhand Open Cast Project, Balaghat, Madhya Pradesh

3

AWARDS

1. 11th Annual Greentech Safety Award 2012: Rihand Super Thermal Power Plant.

2. 12th Global Greentech Environment Excellence Awards 2011: Secretarial Complex for

NRDA, Raipur.

3. 10th Annual Greentech Safety Award 2011: Make-up Water Pumphouse Project, Tiroda.

4. CIDC 3rd Vishwakarma Awards 2011 for Best Project – Roads & Highways.

5. 11th Global Greentech Environment Excellence Awards 2010: Construction Sector (Silver)

for CIDCO Exhibition Centre.

6. EPC World Awards 2010: Outstanding Company in Roads & Highways Sector.

4

VARIOUS CONSTRUCTION MATERIALS AND TESTS

Building construction methods and materials have an enormous impact on fire behavior and

firefighter safety. In this course, you will learn about various types of building construction, the

importance of the fire resistance for structural support elements, and the risks associated with

performing fire- suppression activities inside and around buildings involved in fire. You will

also learn about the importance of teamwork among fire protection and design professionals.

Upon completion of this course, you will be able to:

Describe the benefits of cross-disciplinary cooperation among fire protection and

design professionals.

Explain the elements of building construction as they apply to construction

codes.

Describe the elements of building construction as they apply to firefighter

safety.

Anticipate fire behavior based on structural elements and thermal effects on

each of the following types of construction:

Protected noncombustible building construction

Unprotected noncombustible building construction

Masonry construction

Heavy timber construction

Wood frame construction

5

VARIOUS BUILDING MATERIALS FOR CONSTRUCTIONS:

1. INE AGGREGATE

2. COARSE AGGREGATE

3. FCEMENT

4. BRICK

5. STONE

6

1) SAND:

Sand is a naturally occurring granular material composed of finely divided rock and mineral

particles. It is defined by size, being finer than gravel and coarser than silt. Sand can also refer to

a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized

particles by mass.

The composition of sand varies, depending on the local rock sources and conditions, but the most

common constituent of sand in inland continental settings and non-tropical coastal settings is

silica, usually in the form of quartz. The second most common type of sand is calcium carbonate,

for example, aragonite,

Sand is a non-renewable resource over human timescales, and sand suitable for making concrete is in

high demand.

7

COMPOSITION

The exact definition of sand varies. The scientific Unified Soil Classification System used in

engineering and geology corresponds to US Standard Sieves and defines sand as particles with a

diameter of between 0.074 and

4.75 millimeters. By another definition, in terms of particle size as used by geologists, sand

particles range in diameter from 0.0625 mm (or 1/16 mm) to 2 mm. An individual particle in this

range size is termed a sand grain. Sand grains are between gravel (with particles ranging from 2

mm up to 64 mm by the latter system, and from 4.75 mm up to 75 mm in the former) and silt

(particles smaller than 0.0625 mm down to 0.004 mm).

TESTS ON FINE AGGREGATE

1. BULKING OF SANDWhen sand is damp, the water coating on the surface of each sand particle causes separation of

particles from one another due to surface tension. This causes sand to bulk. Bulked sand occupies

more volume and hence if volumetric measuring is done while proportioning it, bulking

correction is necessary.

The bulking test is done as follows:

1. The sand is filled, in loose condition in a box of measured height (H cm).

2. The box is then flooded with water and Roding is done to make the sand settle and

consolidate. Care should be taken that sand does not overflow during the flooding and

compaction.

3. The sand is then leveled in the box and the drop in height is measured (h cm).

4. Bulking is calculated as: Bulking % = h/H x 100%

Dry sand occupies the same volume as fully saturated sand. The bulking will vary from load to

load and day to day depending on the fineness of sand and its surface moisture content. It is

there-fore, very essential to make bulking corrections by checking the actual bulking of sand

proposed to be used by volumetric batching for mortar or concrete.

8

Moisture contents%age by wt.

Bulking% by volume

2 15

3 20

4 25

5 30

2. SIEVE ANALYSIS

Sieve analysis is done to check the gradation of aggregate. The test is done as follow.

1. Take required amount of aggregate sample (for coarse aggregate take approx.

2.5 kg and for fine aggregate take 0.5 kg)

2. Arrange the required no of sieves as per the contract or job requirement in a descending

manner.

3. Shake vigorously the sieve set for at least 2 minute.

4. Then measure the weight of aggregate on each sieve and express it as the percentage of

passing.

Grading limit of coarse aggregate and fine aggregate is given below for reference.

9

3. FINENESS MODULUS

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.

1. Sieve the aggregate using the appropriate sieves (80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm,

2.36 mm, 1.18 mm, 600 micron, 300 micron & 150 micron)

2. Record the weight of aggregate retained on each sieve.

3. Calculate the cumulative weight of aggregate retained on each sieve.

4. Calculate the cumulative percentage of aggregate retained.

5. Add the cumulative weight of aggregate retained and divide the sum by 100. This value is

termed as fineness modulus

Compare the test value with the values given in the following table and you can get an idea about how

coarse or fine the sand is.

Only sand between FM 2.6 to 2.9 is considered suitable for nominal mix proportion

Type of Sand Fineness Modulus Value

Very fine sand Below 2.2

Fine sand 2.2 to 2.6Medium sand 2.6 to 2.9Coarse sand 2.9 to 3.2

Very coarse sand Above 3.2

10

2) COARSE AGGREGATE:

AGGREGATE CLASSIFICATION [BASED ON SHAPE]

According to shape the aggregate is classified as

Rounded aggregate

Irregular or partly rounded aggregate

Angular aggregate

Flaky aggregate

Elongated aggregate

Flaky and elongated aggregate

1. ROUNDED AGGREGATEThe aggregate with rounded shape has the minimum percentage of voids ranging from 32 to 33%. It

gives minimum ratio of surface area to given volume and hence requires minimum water for

lubrication. It gives good workability for the given amount of water and hence needs less cement for a

given water cement ratio. The only disadvantages is that the interlocking between its particles is less

and hence the development of bond is poor. This is why rounded aggregate is not suitable for high

strength concrete and for pavements subjected to tension.

2. IRREGULAR OR PARTLY ROUNDED AGGREGATEThe aggregate with irregular shape has higher percentage of voids ranging from 35 to 37%. It

gives lesser workability than rounded aggregate for the given water content. Water requirement

is higher and hence more cement is needed for constant water cement ratio. The interlocking

11

between aggregate particles is better than rounded aggregate but not adequate to be used for high

strength concrete and pavements subjected to tension.

3. ANGULAR AGGREGATEThe aggregate with angular shape has the maximum percentage of void ranging from 38 to 45%.

It requires more water for lubrication and hence it gives least workability for the given water

cement ratio. For constant water cement ratio and workability the requirement of cement

increase. The interlocking between the aggregate particles is the best and hence the development

of bond is very good. This is why angular aggregate is very suitable for high strength concrete

and for pavements subjected to tension.

4. FLAKY AGGREGATEThe aggregate is said to be flaky when its least dimension is less than 3/5th (or 60%) of its mean

dimension. Mean dimension is the average size through which the particles pass and the sieve

size on which these are retained. For example, mean size of the particles passing through 25 mm

sieve and retained on 20 mm sieve is (20+25)/2 = 22.5 mm. if the least dimension is less than 3/5

x (22.5) = 13.5mm, then the material is classified as flaky. Flaky aggregate tends to be oriented

in one plane which affects the durability.

TESTS ON AGGREGATEAggregate plays an important role in pavement construction. Aggregates influence, to a great

extent, the load transfer capability of pavements. Hence it is essential that they should be

thoroughly tested before using for construction. Not only that aggregates should be strong and

durable, they

Should also possess proper shape and size to make the pavement act monolithically. Aggregates

are tested for strength, toughness, hardness, shape, and water absorption.

In order to decide the suitability of the aggregate for use in pavement construction, following

tests are carried out:

1. SPECIFIC GRAVITY AND WATER ABSORPTION TESTThe specific gravity and water absorption of aggregates are important properties that are required

for the design of concrete and bituminous mixes. The specific gravity of a solid is the ratio of its

mass to that of an equal volume of distilled water at a specified temperature. Because the

aggregates may contain water-permeable voids, so two measures of specific gravity of

12

aggregates are used:

1. Apparent specific gravity2. Bulk specific gravity.

Apparent Specific Gravity

Gapp, is computed on the basis of the net volume of aggregates i.e. the volume excluding water-

permeable voids. Thus

Gapp = [(MD/VN)]/W

Where,

MD is the dry mass of the aggregate,

VN is the net volume of the aggregates excluding the volume of the absorbed matter,

W is the density of water.

Bulk Specific Gravity

Gbulk is computed on the basis of the total volume of aggregates including water permeable voids. Thus

Gbulk = [(MD/VB)]/W

Where,

VB is the total volume of the aggregates including the volume of absorbed water.

Water Absorption:The difference between the apparent and bulk specific gravities is nothing but the water

permeable voids of the aggregates. We can measure the volume of such voids by weighing the

aggregates dry and in a saturated surface dry condition, with all permeable voids filled with

water. The difference of the above two is MW.

MW is the weight of dry aggregates minus weight of aggregates saturated surface dry condition.

Thus,

Water Absorption = (MW/MD) x 100The specific gravity of aggregates normally used in road construction ranges from about 2.5 to

2.9. Water absorption values ranges from 0.1 to about 2.0 percent for aggregates normally used

in road surfacing.

2) CEMENT

13

Types of Cement:

Rapid Hardening Cement:

Definition:

It is also known as High-Early-Strength cement. It is manufactured with such adjustments in the

proportion of raw materials so that the cement produced attains maximum strength with-in 24-72

hours.

Properties:

Two essential properties of Rapid Hardening Cement are following.

(i) It contains relatively more tri-calcium silicate. This is done by adding a greater

proportion of limestone in the raw materials compared to that required for ordinary

cement.

(ii) It is more fine-grained (Air permeability 3250 cm2/gm) than the ordinary cement. This

factor helps in quicker and complete hydration of cement particles during setting and

helps in gaining early strength.

However, the setting time and ultimate strength of Rapid Hardening Cement is same as of

Ordinary Cement.

TESTS ON CEMENT

The physical tests which are generally performed to determine the acceptability of cements are:

1. Fineness Test2. Strength Test3. Specific Gravity Test4. Setting test

1. Fineness Test

Fineness is the mean size of cement grain. Fineness test is done to measure the mean size of cement

grain.

The finer the cement the surface area for hydration will be large and it increases the strength of

cement. But the fineness varies in different types of cement.

14

Following three methods are applied to test the fineness of cement

Sieve method

Air Permeability method

Sedimentation method

2. Strength Test

Cement has two types of strength – compressive strength and tensile strength.

To know the compressive strength and tensile strength of cement following tests are performed –

Cement mortar cube test (for compressive strength)

Briquette test (for tensile strength)

Split tensile test (for tensile strength)

3. Specific Gravity Test

Specific gravity of cement is a comparison of weight of a cement volume to the weight of

same volume of water.

4. Setting Test

A thick paste of cement with water is made on a piece of glass plate and it is kept under water

for 24 hours. It should set and not crack.

15

3) BRICK

Classification and Characteristics of Bricks as per IS 1077-1973

Tests for the acceptance of bricks for building construction are:

1. Compressive strength test

2. Water absorption test

3. Efflorescence test

1. Compressive Strength Test on BricksThe compressive strength of a common brick should be 50 kg/sq.cm

2 . Water Absorption Test on BricksIf the water absorption capacity of a brick is more, its strength will be comparatively low. For first class

bricks, the water absorption capacity should not be more than 20% by weight.

3 . Efflorescence Test on BricksThis test is performed to know the presence of any alkaline matter in the bricks.

16

4) STONEStone is a ‘naturally available building material’ which has been used from the early age of

civilization. It is available in the form of rocks, which is cut to required size and shape and used

as building block.

Properties of Stones

The following properties of the stones should be looked into before selecting them for

engineering works:

a. Structure: The structure of the stone may be stratified (layered) or uncertified.

Structured stones should be easily dressed and suitable for super structure. Uncertified

stones are hard and difficult to dress. They are preferred for the foundation works.

b. Texture: Fine grained stones with homogeneous distribution look attractive and hence

they are used for carving. Such stones are usually strong and durable.

c. Density: Denser stones are stronger. Light weight stones are weak. Hence stones with

specific gravity less than 2.4 are considered unsuitable for buildings.

d. Strength: Strength is an important property to be looked into before selecting stone as

building block. Indian standard code recommends, a minimum crushing strength of 3.5

N/mm2 for any building block. Table shows the crushing strength of various stones.

Due to non-uniformity of the material, usually a factor of safety of 10 is used to find the

permissible stress in a stone. Hence even laterite can be used safely for a single storey

building, because in such structures expected load can hardly give a stress of 0.15

N/mm2. However in stone masonry buildings care should be taken to check the stresses

when the beams (Concentrated Loads) are placed on lateral wall.

e. Hardness: It is an important property to be considered when stone is used for flooring

and pavement. Coefficient of hardness is to be found by conducting test on standard

specimen in Dory’s testing machine. For road works coefficient of hardness should be

17

at least 17. For building works stones with coefficient of hardness less than 14 should

not be used.

f. Porosity and Absorption: All stones have pores and hence absorb water. The reaction

of water with material of stone causes disintegration. Absorption test is specified as

percentage of water absorbed by the stone when it is immersed under water for 24

hours. For a good stone it should be as small as possible and in no case more than 5.

g. Toughness: The resistance to impact is called toughness. It is determined by impact test.

Stones with toughness index more than 19 are preferred for road works. Toughness

indexes 13 to 19 are considered as medium tough and stones with toughness index less

than 13 are poor stones.

h. Resistance to Fire: Sand stones resist fire better. Argillaceous materials, though poor in

strength, are good in resisting fire.

CONCRETE:

Concrete is a construction material composed of cement, fine aggregates (sand) and coarse

aggregates mixed with water which hardens with time. Portland cement is the mostly used type

of cement for production of concrete.

There are different types of binding material is used other than cement such as lime for lime

concrete and bitumen for asphalt concrete which is used for road construction.

Various types of cements are used for concrete works which have different properties and

applications. Some of the type of cement is Portland Pozzolana Cement (PPC), rapid hardening

cement, Sulphate resistant cement etc.

18

Table of Contents:

Materials are mixed in specific proportions to obtain the required strength.

Strength of mix is specified as M5, M10, M15, M20, M25, M30 etc., where M signifies Mix and

5, 10, 15 etc. as their strength in kN/m2. In United States, concrete strength is specified in PSI

which is Pounds per Square Inch.

Water cement ratio plays an important role which influences various properties such as

workability, strength and durability. Adequate water cement ratio is required for production of

workable concrete.

When water is mixed with materials, cement reacts with water and hydration reaction starts. This

reaction helps ingredients to form a hard matrix that binds the materials together into a durable

stone-like material. Concrete can be casted in any shape. Since it is a plastic material in fresh

state, various shapes and sizes of forms or formworks are used to provide different shapes such

as rectangular, circular etc.

Various structural members such as beams, slabs, footings, columns, lintels etc. are constructed

with concrete.

ACI 318 Building code requirements for structural concrete and ACI 301 Specifications for

Structural Concrete are used in United States as standard code of practice for concrete

construction.

There are different types of admixtures which are used to provide certain properties. Admixtures

or additives such as pozzolans or super plasticizers are included in the mixture to improve the

physical properties of the wet mix or the finished material.

Various types of concrete are manufactured these days for construction of buildings and

structures. These have special properties and features which improve quality of construction as

per requirement.

Components of Concrete:

Components of concrete are cement, sand, aggregates and water. Mixture of Portland cement

and water is called as paste. So, concrete can be called as a mixture of paste, sand and

aggregates. Sometimes rocks are used instead of aggregates.

19

The cement paste coat the surface of the fine and coarse aggregates when mixed thoroughly and

binds them. Soon after mixing the Components, hydration reaction start which provides strength

and a rock solid concrete is obtained.

What is Grade of Concrete?

Grade of concrete denotes its strength required for construction. For example, M30 grade

signifies that compressive strength required for construction is 30MPa. The first letter in grade

“M” is the mix and 30 is the required strength in MPa. .

Based on various lab tests, grade of concrete is presented in Mix Proportions. For example, for

M30 grade, the mix proportion can be 1:1:2, where 1 is the ratio of cement, 1 is the ratio of sand

and 2 is the ratio of coarse aggregate based on volume or weight of materials.

The strength is measured with concrete cube or cylinders by civil engineers at construction site.

Cube or cylinders are made during casting of structural member and after hardening it is cured

for 28 days. Then compressive strength test is conducted to find the strength.

20

Regular grades of concrete are M15, M20, M25 etc. For plain cement concrete works, generally

M15 is used. For reinforced concrete construction minimum M20 grade of concrete are used.

Concrete Grade Mix RatioCompressive Strength

MPa (N/mm2) Psi

Normal Grade of Concrete

M5 1 : 5 : 10 5 MPa 725 psi

M7.5 1 : 4 : 8 7.5 MPa 1087 psi

M10 1 : 3 : 6 10 MPa 1450 psi

M15 1 : 2 : 4 15 MPa 2175 psi

M20 1 : 1.5 : 3 20 MPa 2900 psi

Standard Grade of Concrete

M25 1 : 1 : 2 25 MPa 3625 psi

M30 Design Mix 30 MPa 4350 psi

M35 Design Mix 35 MPa 5075 psi

M40 Design Mix 40 MPa 5800 psi

M45 Design Mix 45 MPa 6525 psi

M50 Design Mix 50 MPa 7250 psi

21

M55 Design Mix 55 MPa 7975 psi

M60 Design Mix 60 MPa 8700 psi

M65 Design Mix 65 MPa 9425 psi

M70 Design Mix 70 MPa 10150 psi

How to Make Concrete

Concrete is manufactured or mixed in proportions w.r.t. cement quantity. There are two

types of concrete mixes, i.e. nominal mix and design mix. Nominal mix is used for normal

construction works such as small residential buildings. Most popular nominal mix are in the

proportion of 1:2:4.

Design mixed concrete are those for which mix proportions are finalized based on various

lab tests on cylinder or cube for its compressive strength. This process is also called as mix

design. These tests are conducted to find suitable mix based on locally available material to

obtain strength required as per structural design. A design mixed offers economy on use of

ingredients.

Once suitable mix proportions are known, then its ingredients are mixed in the ratio as selected.

Two methods are used for mixing, i.e. Hand mixing or Machine Mixing.

Based on quantity and quality required, the suitable method of mixing is selected. In the

hand mixing, each ingredients are placed on a flat surface and water is added and mixed with

hand tools. In machine mixing, different types of machines are used. In this case, the ingredients

are added in required quantity to mix and produce fresh concrete. Once it is mixed adequately it

is transported to casting location and poured in formworks. Various types of formworks are

available which as selected based on usage. Poured concrete is allowed to set in formworks for

specified time based on type of structural member to gain sufficient strength. After removal of

formwork, curing is done by various methods to make up the moisture loss due to evaporation.

Hydration reaction requires moisture which is responsible for setting and strength gain. So,

22

curing is generally continued for minimum 7 days after removal of formwork.

23

Types of Concrete Construction:

Concrete is generally used in two types of construction, i.e. plain concrete construction

and reinforced concrete construction. In PCC, it is poured and casted without use of any

reinforcement. This is used when the structural member is subjected only to the compressive

forces and not bending. When a structural member is subjected to bending, reinforcements are

required to withstand tension forces structural member as it is very weak in tension compared to

compression. Generally, strength of concrete in tension is only 10% of its strength in

compression. It is used as a construction material for almost all types of structures such as

residential concrete buildings, industrial structures, dams, roads, tunnels, multi storey buildings,

skyscrapers, bridges, sidewalks and superhighways etc.

Example of famous and large structures made with concrete are Hoover Dam, Panama Canal and

Roman Pantheon. It is the largest human made building materials used for construction.

Steps of Concrete Construction

The construction steps are:

1. Selecting quantities of materials for selected mix proportion

2. Mixing

3. Checking of workability

4. Transportation

5. Pouring in formwork for casting

6. Vibrating for proper compaction

7. Removal of formwork after suitable time

8. Curing member with suitable methods and required time.

TESTS1. Slump test before leaving the batching plant and on arrival on site

This is to determine the workability of concrete in terms of slump test. After batching the

concrete, a sample of fresh concrete shall be taken to test for slump tests and the samples for

compressive strength test be taken too. This is to make sure that the batched concrete is

complying with the mix design before it’s released from the batching plan

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Upon arrival on site, a sample of fresh concrete shall be tested with slump test again, but

temperature shall be checked with the calibrated thermometer beforehand. Three cubes or

cylinders of samples shall be taken for compressive strength tests, these will be the samples from

the site.

The plus or minus sign is the symbol of tolerance of slump. Let say for example the slump of

approved concrete design mix for your suspended slab is 150 mm +/- 25.

2. Compressive strength test

Three samples of cubes or cylinders shall be taken for compressive strength test, but it is not

commonly three samples, sometimes it is two depend on the specification. You might ask why

sometimes there is extra of one sample? Good that you asked. This one sample extra shall be

tested “if!” the two cubes or cylinders samples are tested from the three and if it is failed and the

remaining sample is passed. If the consultant is not satisfied with the result (definitely not!) and

he wishes to test the extra one. It shall be tested in 60 days.

3. Water Permeability test

A water permeability test is one of the tests to determine the durability of concrete. Three

cubes shall be taken from fresh concrete and tested in accordance to the German Standard DIN

1048 at 28 days age. This kind of test shall be taken from substructures concrete elements like

foundations, concrete water tank, retaining wall etc. The frequency of the water permeability test

can be found in this article The Frequency of Various Tests.

4. Rapid Chloride Ion Penetration TestLike water permeability test, this is also one of the tests to determine the durability of

concrete. Three cubes shall be taken from fresh concrete delivered on site and tested at 28 days

age. The test shall be done in accordance to ASTM C1202-97

5. Water Absorption TestHere is the other test that would determine the durability of concrete. The three cube sample

shall be taken from the delivered fresh concrete and kept it in the curing tank for 28 days or after

24 hours the concrete sample would be remolded and it will be sent directly to the approved third

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party laboratory to ensure its curing. The size of cube sample is 150 mm and tested in accordance

to BS 1881-122.

6. Modulus of elasticityModulus of elasticity of concrete is defined as the ratio of stress applied on the concrete to the

respective strain caused. The accurate value of modulus of elasticity of concrete can be determined by

conducting a laboratory test called compression test on a cylindrical concrete specimen. In the test, the

deformation of the specimen with respect to different load variation is analyzed. These observations

produce Stress-Strain graph (load-deflection graph) from which the modulus of elasticity of concrete is

determined.

7. Setting timeThe action of changing mixed cement from a fluid state to a solid state is called “Setting of Cement”.

Initial Setting Time is defined as the period elapsing between the time when water is added to the cement

and the time at which the needle of 1 mm square section fails to pierce the test block to a depth of about 5

mm from the bottom of the mold.

Final Setting Time is defined as the period elapsing between the time when water is added to cement

and the time at which the needle of 1 mm square section with 5 mm diameter attachment makes an

impression on the test block.

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EQUIPMENTS USED

Vi Cat apparatus Compression Testing Machine

Slump Cone Fineness modulus

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CONCLUSION

As an undergraduate of the AITAM College, we would like to say this training program is

an Excellent opportunity for us to get to ground level and experience the things that we would have

never gained through going straight into a job we are grateful to the AITAM and IVRCL LIMITED

(Hyderabad) for giving us this wonderful opportunity.

The main objective of the internship is to provide an opportunity to undergraduate to

identify, observe and practice how civil engineering is applicable and the real site it is not only to get

experience on technical practices but also to observe management practices and to interact with the field

workers. The only chance that an undergraduate has to have this experience in the industrial training

period.