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A Summer Training Report On Overhead Bridge

Completed by,

U.P. STATE BRIDGE CORPORATION

Ltd.

Project Name

Construction of overhead bridge over existing railway crossing

NO.94-C Hathras Jn. Ladpur Tundla-Ghaziabad rail section (94-C)

Duration

20 June to 30 July, 2016

Submitted by

Ankit Gautam 1334000007

B.Tech- 3rd Year

Department Of Civil Engineering

Vivekananda College of Technology & Management

ALIGARH (U.P) India -202002

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Contents

1. Site location

2. Introduction to UPSBC

3. Some important things

4. Acknowledgement

5. Features of project

6. Machines and equipment used

Hydraulic crane

Portable concrete mixer

Auto level

Pre-stressing jacks

Pressure grouting machine

Needle vibrator

7. Component of bridge

Reinforced earth wall panels

Geomats

Geotextile

Pier

Bearing

Bridge deck

Abutment

Pre-stressing

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Sheathing or ducts

Strands

Pre-stressed concrete

Production of concrete

8. Quality control of concrete

Cube strength of concrete

Aggregate impact value

Sieve analysis

Flakiness and elongation index

Slump cone test

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About U.P State Bridge Corporation Ltd.

U.P. State Bridge Corporation Ltd. started functioning on 1st March

1973 as a company under U.P. State Government to accelerate the

activities of design and construction of Bridges in the state.

U.P. State is rich in Geographical and topographical diversities like

small and big rivers, varying terrain all through the state. For the speedy

development of the state it was necessary to connect all part of the state

by roads and bridges. Simultaneously it also required provision of best

technical support for economic & quality execution, commensurate to

Infrastructural facilities in the form of Bridge engineers and technical

staff available in the State. Initially in U.P.P.W.D. departmental

construction units were established for the purpose of Quality and

Speedy construction. With great success the bridge engineers and

technical staff of U.P.P.W.D. were ready to complete the Bridges

departmentally within stipulated time with desired workmanship. This

encouraged the engineers and U.P. Govt. to establish a separate body

for design and construction of bridge and this gave birth to U.P state

bridge corporation (UPSBC).After successful completion of several

bridges, the Board of Director of UPSBC felt that the technical experts

of the State in the field of Bridge Construction & Design should be

utilized in enhancing the similar activities in other States of the country

and abroad. To achieve this UPSBC started competing in tender

process for obtaining the work in open market competition. If proved

to be of great success day by day. Incidentally due to liberalization of

economic environment, the consultants and contractors have come to

occupy a crucial role in Indian economy. They not only provide the

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needed expertise to plan, build and manage the projects within the

country, but also bring the foreign currency from assignments abroad,

besides promoting transfer of technologies more effectively and

providing professional inputs for industrial & technological

developments. Due to the liberalization policy Indian consultants and

contractors need considerable impulse to expand and grow, and realize

its high potential at home and aboard.

The main theme and activities of UPSBC always remain to provide a

strong support in the field of Bridge and highways construction and

Consultancy in design, planning and maintenance which has a large

scope not only in our country but also aboard. UPSBC has successfully

constructed a number of bridges and roads in Iraq, Yemen and Nepal

also in addition to U.P. along with other States of India and earned

reputation and foreign currency for the country. Since UPSBC is a

Govt. undertaking, therefore all the profit earned by UPSBC ultimately

adds to State Govt.

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Some important things!!

Always wear good quality helmet on the site.

Always wear shoes on site.

Wear safety belt, if required.

Safety nets should be provided wherever it is

necessary.

Do not should wires at construction site

Always follow the instruction of higher

authority.

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ACKNOWLEDGEMENT

The internship opportunity I had with UPSBC was a great chance for learning and

professional development. Therefore, I consider myself as a very lucky individual as I was

provided with an opportunity to be a part of it. I am also grateful for having a chance to meet

so many wonderful people and professionals who led me though this internship period.

Bearing in mind previous I am using this opportunity to express my deepest gratitude and

special thanks to the Mr.R.K Singh, Project Manager of this project who in spite of being

extraordinarily busy with his duties, took time out to hear, guide and keep me on the correct

path and allowing me to carry out my project at their esteemed organization and extending

during the training.

I express my deepest thanks to Mr.Satyendra Singh, Assistant engineer for taking part in

useful decision & giving necessary advices and guidance and arranged all facilities to make

training easier. I choose this moment to acknowledge his contribution gratefully.

It is my radiant sentiment to place on record my best regards, deepest sense of gratitude to

Mr.Sarvesh Kumar Pal, Junior Engineer and Mr.Pawan Singh, Site Engineer for their

careful and precious guidance which were extremely valuable for my study both theoretically

and practically.

I perceive as this opportunity as a big milestone in my career development. I will strive to use

gained skills and knowledge in the best possible way, and I will continue to work on their

improvement, in order to attain desired career objectives. Hope to continue cooperation with

all of you in the future,

Sincerely,

Mr.R.K Singh, Project Manager

Mr.Satyendra Singh, Assistant engineer

Mr.Sarvesh Kumar Pal, Junior Engineer

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Salient Features

Project cost : Rs. 2972.40 lac

Agency : UPSBC

Date of commencement : May, 2015

Target date of completion : March, 2017

Physical features

1. Total length of bridge 729.550m

2. No. of piers 16

3. Diameter of each pier 2.5m

4. No. of decks 17+1(RLWY)

5. Type of superstructure PSC

GIRDERS

6. Width of each Deck 8.5m

7. Slope along bridge length 1 in 30

8. Slope across bridge length 0.25 in 1

9. Length of underpass girder 37.5m

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MACHINES AND EQUIPMENTS USED

HYDRAULIC CRANE

A Hydraulic crane is a cable-controlled crane mounted on crawlers or rubber-

tired carriers or a hydraulic-powered crane with a telescoping boom mounted

on truck-type carriers or as self-propelled models. They are designed to easily

transport to a site and use with different types of load and cargo with little or no

setup or assembly. A mobile crane is a cable-controlled crane mounted

on crawlers or rubber-tired carriers or a hydraulic-powered crane with a

telescoping boom mounted on truck-type carriers or as self-propelled models.

They are designed to easily transport to a site and use with different types of load

and cargo with little or no setup or assembly.

Fig.(a) Hydraulic Crane On Site

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ON SITE AND PORTABLE CONCRETE MIXER

A concrete mixer is a device that homogeneously

combines cement, aggregate such as sand or gravel, and water to form concrete.

A typical concrete mixer uses a revolving drum to mix the components. For

smaller volume works portable concrete mixers are often used so that the concrete

can be made at the construction site, giving the workers ample time to use the

concrete before it hardens. An alternative to a machine is mixing concrete by

hand.

A typical portable concrete mixer uses a small revolving drum to mix the

components. For smaller jobs the concrete made at the construction site has no

time lost in transport, giving the workers ample time to use the concrete before it

hardens.

These concrete mixers are further divided based on their loading mechanism.

Cement, sand and other aggregates are loaded in a hydraulically operated hopper

and then poured in the mixing drum for final mixing and then can be unloaded by

tilting the drum. While in Hand Feed Concrete Mixers, cement, sand and other

aggregates are directly added to the mixing drum manually. These both type of

concrete mixers are highly popular and used in regular construction activities in

Africa, some Middle Eastern Countries and in the Indian subcontinent.

Fig.(b) Portable Concrete Mixer

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AUTO LEVEL

An automatic level, builder's auto level, levelling instrument or dumpy level is a

professional levelling tool that is used by land surveyors, builders, contractors

and engineers. The automatic level is known for providing users with consistent

levelling accuracy every time while also being fast, low cost and easy to use.

The automatic level is most commonly used in measuring, surveying, and setting

horizontal and vertical levels. The instrument is normally situated on a tripod and

then calibrated to a levelled position using levelling screws. The operator of the

automatic level then looks through the telescope attached to the instrument, while

a second person holds a graduated staff or tape measure at the position under

measurement.

Fig.(c) An Auto Level

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PRE-STRESSING JACKS

The tensioning of the steel strand (or individual wires) is usually by means of

hydraulic jacks. In pre-tensioning, single strand jacks may be used. In post-

tensioning the strands are often grouped to form tendons. These may be stressed

by large, multi-strand jacks. The load induced into the strand is determined from

the pressure in the hydraulic oil supplied to the jack or from the extension of the

strand. Wedge grips are used to grip each strand during stressing and to hold the

strand permanently in the tendon anchor after stressing. The jack is removed after

stressing and anchoring. In post-tensioning the pre-stressing force is applied

directly to the concrete. In the case of pre-tensioning the anchor holds the strands

until after the concrete has gained sufficient strength; the strands are then

released, transferring the pre-stressing force to the concrete.

Fig.(d) Pre-Stressing Jack And Machine

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PRESSURE GROUTING MACHINE

Pressure grouting involves injecting a grout material into generally isolated pore

or void space of which either the configuration or volume are known, and is often

referred to simply as grouting. The grout may be a cementious, resinous,

or solution chemical mixture. The greatest use of pressure grouting is to improve

geo materials (soil and rock). The purpose of grouting can be either to strengthen

or reduce water flow through a formation. It is also used to correct faults

in concrete and masonry structures. Since first usage in the 19th century, grouting

has been performed on the foundation of virtually every one of the world’s

large dams, in order to reduce the amount of leakage through the rock, and

sometimes to strengthen the foundation to support the weight of the overlying

structure, be it of concrete, earth, or rock fill. Although very specialized, pressure

grouting is an essential construction procedure that is practiced by specialist

contractors and engineers around the world.

Fig.(e) Grouting System

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NEEDLE VIBRATORS

These are also known as immersion vibrators. It has a steel tube, called a poker,

with one end being closed and rounded. There is an eccentric vibrating element

inside it. The poker is connected to an electric motor, sometimes a diesel motor,

through a flex tube.

These needle vibrators come in a variety of sizes from 40 to 100 mm in diameter.

The poker’s diameter is determined by the spacing between the reinforcing bars

in the form work. The general range of vibrations for a needle vibrator is between

3000 to 6000 rpm. The period of vibration necessary can be from 30 seconds to

2 minutes and the concrete should be placed in layers no more than 600mm high.

fig.(f) Needle Vibrator

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COMPONENTS OF BRIDGE

REINFORCED EARTH WALL PANELS

Reinforced Earth retaining wall panels are coherent gravity structures engineered

to resist specific loading requirements. The primary components of a Reinforced

Earth wall consist of alternating layers of granular backfill, and linear metallic,

high-adherence soil reinforcing strips or ladders to which a modular precast

concrete facing is attached. Its strength and stability are derived from the

frictional interaction between the granular backfill and the reinforcements,

resulting in a permanent and predictable bond that creates a unique composite

construction material.

Reinforced Earth retaining walls are an economical way to meet every-day earth

retention needs for highway and bridge grade separations, railroads and mass

transit systems, waterfronts, airports, loading docks, industrial facilities and

commercial and residential developments. They are also used in response to

difficult design conditions such as very high structures, restricted space, where

obstructions within the soil mass are present and poor foundation soils. The

inherent strength and flexibility of the overall wall system gives designers a

powerful way to economically solve difficult stability issues for structures subject

to flooding or other hydrodynamic forces, or those in seismically active areas.

Benefits include:

Considerable advantages over cast-in-place, both in construction time and

quantity of materials

Flexibility, making it possible to build directly upon compressible soils

High load-carrying capabilities, both to static and dynamic loads

Ease of installation since construction using prefabricated components is

rapid and predictable

Superior appearance since the facing is highly suited for architectural finishes

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Fig.(g) Reinforced Earth Wall Panel

Fig.(h) Geotextile And Geomats

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GEOMATS

The geomats are used to tie the reinforced earth wall panels of both sides.

These geomats resists the horizontal pressure coming over the reinforced

earth wall panels.

Geomats are three-dimensional water permeable polymer or other

synthetically materials’ structures, thermally jointed with each other.

Geomats are three-dimensional water permeable polymer or other

synthetically materials’ structures, thermally jointed with each other.

Geomats are three-dimensional water permeable polymer or other

synthetically materials’ structures, thermally jointed with each other.

GEOTEXTILES

Geotextiles are permeable fabrics which, when used in association

with soil, have the ability to separate, filter, reinforce, protect, or drain.

Geotextiles are typically made from polypropylene or polyester.

Gaps between the reinforced earth wall panels are covered with geotextiles

by pasting over them using any sticky material.

A filter pipe placed parallel to reinforced earth wall is also covered with

the geotextile.

PIER OR PIER FOUNDATION

A pier is a raised structure typically supported by well-spaced piles or pillars.

Bridges, buildings, and walkways may all be supported by piers. Their open

structure allows tides and currents to flow relatively unhindered, whereas the

more solid foundations of a quay or the closely spaced piles of a wharf can act as

a breakwater, and are consequently more liable to silting. Piers can range in size

and complexity from a simple lightweight wooden structure to major structures

extended over 1600 metres. In American English, pier may be synonymous

with dock.

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Fig.(i) Section At And Top Plan Of A Pier

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Materials for piers and abutments:

The following types of materials are generally used for the construction of piers

and abutments:

a) Mass concrete of M-10 grade corresponding to mix proportion of 1:3:6 with

40 mm maximum size of aggregates.

b) Reinforced concrete of M-15 grade corresponding to mix proportion of 1:2:4.

c.) Coursed rubble masonry in cement mortar of proportions 1:4

d) Brick masonry in cement mortar of proportions 1:6

e)Prestressed concrete for the piers particularly in viaducts with tall piers.

Concrete of M-30 to M-40 grade is the minimum requirement for Prestressed

concrete piers.

The maximum permissible compressive and tensile stresses in the various types

of the materials in the substructure are compiled and written in the form of

tables before the design.

Forces to be considered on a pier: Design of the piers involves the consideration of various forces acting on the

pier. Forces that are considered to be acting on the piers are:

1. Dead load of superstructure and pier

2. Live load of vehicles moving on the bridge

3. Effect of eccentric live loads

4. Impact effect for different classes of loads

5. Effect of buoyancy on the submerged part of the pier

6. Effect of wind loads acting on the moving vehicles and superstructure

7. Forces due to water current

8. Longitudinal forces due to tractive effort of vehicles

9. Longitudinal forces due to braking of vehicles

10. Longitudinal forces due to resistance in bearings

11. Effect of earthquake forces

12. Forces due to the collision for piers in navigable rivers.

Stability analysis for piers is generally made by considering some of the critical

forces which will have significant effect on the stresses developed in the piers.

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BEARING

A bridge bearing is a component of a bridge which typically provides a resting

surface between bridge piers and the bridge deck. The purpose of a bearing is

to allow controlled movement and thereby reduce the stresses involved.

Movement could be thermal expansion or contraction, or movement from

other sources such as seismic activity. The bearings used consisted of

following types:

1. Pin

2. Roller

3. Rocker

4. Metal sliding bearings

Fig.(j) Bearing Before Installation And After Installation

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BRIDGE DECK

A bridge deck or road bed is the roadway, or the pedestrian walkway, surface of

a bridge, and is one structural element of the superstructure of a bridge. It is not

to be confused with any deck of a ship. The deck may be constructed

of concrete, steel, open grating, or wood. Sometimes the deck is covered

with asphalt concrete or other pavement. The concrete deck may be an integral

part of the bridge structure (T-beam or double tee structure) or it may be

supported with I-beams or steel girders.

When a bridge deck is installed in a through truss, it is sometimes called a floor

system. A suspended bridge deck will be suspended from the main structural

elements on a suspension or arch bridge. On some bridges, such as a tied-

arch or a cable-stayed, the deck is a primary structural element, carrying tension

or compression to support the span.

ABUTMENT

In engineering, abutment refers to the substructure at the ends of a

bridge span or dam whereon the structure's superstructure rests or contacts.

The following are the uses of abutment in construction:-

To transfer loads from a superstructure to its foundation elements.

To resist and/or transfer self-weight, lateral loads (such as the earth pressure)

and wind loads.

To support one end of an approach slab.

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PRESTRESSING

Prestressed concrete is a method for overcoming concrete's natural

weakness in tension. It is a material that has the characteristics of high

strength concrete in compression and high ductile strength steel for tension.

The loss in material strength due to stressing can be computed and lies at

the stressed concrete shape. The bending shape should be opposite of the

applied force it will service. It can be used to

produce beams, floors or bridges with a longer span than is practical with

ordinary reinforced concrete. It is often used in commercial and residential

construction as a foundation slab. Prestressing tendons (generally of

high tensile strength steel cable or rods) are used to provide a clamping load

which produces a compressive stress that balances the tensile stress that the

concrete compression member would otherwise experience due to a

bending load. Traditional reinforced concrete is based on the use

of steel reinforcement bars, rebars, inside poured concrete. Prestressing can

be accomplished in three ways: pre-tensioned concrete, and bonded or

unbonded post-tensioned concrete.

METHOD OF PRE-STRESSING:

POST-TENSIONING VIA HYDRAULIC JACK

The wires are stretched after the concrete has hardened: which are either

encased in pipes or sheaths or holes are left in the concrete through which

wires are subsequently threaded. The wires in this method have to be held

stretched permanently by mechanical mean i.e. Anchors. There is no

bond b/w wires and concrete. The reinforcement in the former method

consist of the few large or several small cables made of high tensile steel

wires laid in one or more rings around a core.

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SHEATHING OR DUCTS

These are provided for avoiding the bonding b/w concrete and

tendon wires.

These may be of either steel, aluminium or PVC.

Fig.(k) Steel Ducts Along With Reinforcement

STRANDS

Wires are bound to form strands.

These are made up of high grade tensile steel.

Fig.(l) Tendon

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PRE-STRESSED CONCRETE

The technique of pre stressing eliminates tracking of concrete under all stages of

loading and enables the entire section to take part in resisting moments.as dead

load moments are neutralised and the shear stresses are reduced, the section

required are much smaller than in reinforced concrete.

Advantages

Large reduction in traditional reinforcement requirements as tendons

cannot destress in accidents.

Tendons can be easily weaved allowing a more efficient design approach.

Higher ultimate strength due to bond generated between the strands and

concrete.

No long term issues with maintaining the integrity of the anchor/dead end.

Problems likely to cause during or after concreting

Segregation

Segregation of concrete can be defined as separation of coarse aggregate from

mortar, resulting in their non-uniform distribution. Improper mix proportion

resulting in large proportion of coarse particles as compared to small

proportion of fine particles caused the separation of coarse particles from

mortar.

Honeycombing

The separation of coarse aggregate from mortar leaves voids in coarse aggregate

unfilled and this phenomenon is called honeycombing. Honeycombing decreases

density of concrete and hence reduction in strength of concrete.

Bleeding

Bleeding is the form of segregation in which water in a concrete mix rises to the

surface during placing it. It is because more water is present than is necessary for

the cement paste to lubricate the aggregate particles and the solid constituents of

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the mix are able to hold all the mixing water when they are settled down. Thus

the water rises up and appears on the surface of compacted concrete.

Precautions to be taken during placing of concrete

Under no circumstances, the water should be added to the concrete during

its passage from mixer to the formwork.

The formwork or the surface which has to receive the fresh concrete should

be properly cleaned, prepared, and well watered.

The concrete should be thoroughly worked around the reinforcement and

trapped in such a way that no honeycomb surface appears on the removal

formwork.

The concrete should be placed on the formwork as soon as possible.

During placing it should be seen that all edges and corners of the concrete

surface remain unbroken, sharp, and straight in line.

The placing of concrete should be carried out uninterrupted between pre-

determined construction joints.

Production of concrete:

The design of concrete mix involves the determination of the most rational

proportions of ingredients of concrete to achieve a concrete which is workable in

its plastic state and will develop the required qualities when hardened.

Concrete is graded according to its compressive strength. The various grades of

concrete as stipulated in IS: 456-2000 and IS: 1343-1980 are shown in table

below-

GROUP DESIGNATION CHARACTERSTIC COMP.

STRENGTH(N/mm2)

Ordinary concrete M 10

M 15

M 20

10

15

20

Standard concrete M 25 25

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M 30

M 35

M 40

M 45

M 50

M 55

30

35

40

45

50

55

High strength concrete M 60

M 65

M 70

M 75

M 80

60

65

70

75

80

Table (1) Showing Characteristic Compressive Strength For Different Mix

Of Concrete

The proportion of cement, sand and coarse aggregate for a desired strength can

be either adopted or rationally designed.

A concrete mix in which the proportions are adopted is referred to as nominal mix

GRADE CEMENT COARSE

SAND

AGGREGATE

(10 mm)

AGGREGATE

(20mm)

M 30 1 1.380 1.112 1.668

M 35 1 1.300 1.152 1.728

M 40 1 1.220 1.120 1.680

M 45 1 1.020 1.080 1.620

Table(2) Showing Proportions Of Constituents For Nominal mix

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QUALITY CONTROL OF CONCRETE

Cube strength of concrete Compressive strength test on 150mm cube of concrete is tested under

destructive load and it can’t be reused once the test is over

The compressive strength of a cube is an indication of the strength of

concrete it is possible to co-relate the flexural compressive and flexural

tensile strength of concrete.

It helps in determining whether the mix proportion are satisfactory or

need some changes

If concrete cubes from the same mix are tested at different period of time,

it helps in determining the rate of gain of strength, which in turn, helps in

determining the time of removal of formwork.

Fig.(m) Universal Testing Machine (UTM)

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Aggregate impact value

This test is done to determine the aggregate impact value of coarse

aggregates as per IS: 2386 (Part IV) – 1963. The apparatus used for

determining aggregate impact value of coarse aggregates is

Impact testing machine conforming to IS: 2386 (Part IV)- 1963,IS Sieves of

sizes – 12.5mm, 10mm and 2.36mm, A cylindrical metal measure of 75mm

dia. and 50mm depth, A tamping rod of 10mm circular cross section and

230mm length, rounded at one end and Oven.

Fig.(n) Impact Value Testing Machine

Sieve analysis

Sieve analysis helps to determine the particle size distribution of the coarse

and fine aggregates. This is done by sieving the aggregates as per IS: 2386

(Part I) – 1963. In this we use different sieves as standardized by the IS code

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and then pass aggregates through them and thus collect different sized

particles left over different sieves.

Fig.(o) Sieves Along With Vibrator

Flakiness and elongation index

FLAKINESS INDEX Aggregate particles are classified as flaky when they have a thickness (smallest

dimension) of less than 0.6 of their mean sieve size. The flakiness index of an

aggregate sample is found by separating the flaky particles and expressing their

mass as a percentage of the mass of the sample tested. This test is not applicable

to aggregate passing 6.30mm sieve and retained as 63.0mm sieve.

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ELONGATION INDEX Aggregate particles are classified as elongation when they have a length

(greatest dimension) of more than 1.8 of their mean sieve size. The elongation

index is found by separating the elongation particles and expressing their mess

as a percentage of the mass of sample tested. The test is not applicable to

material passing 6.30 mm sieve or retained on 50 mm sieve.

Slump cone test

The concrete slump test is an empirical test that measures workability of

fresh concrete. The test measures consistency of concrete in that specific

batch. It is performed to check consistency of freshly made concrete.

Consistency refers to the ease with which concrete flows. It is used to

indicate degree of wetness.

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Fig.(q) Slump Cone Test Apparatus