project reference no.: 39s be 1782€¦ · structural hollow sections made of steel make the most...

STUDIES ON THE STRENGTH AND ELASTIC BEHAVIOUR OF CONCRETE IN-FILLED STEEL

TUBULAR SECTIONS

PROJECT REFERENCE NO.: 39S_BE_1782

COLLEGE : BMS COLLEGE OF ENGINEERING, BASAVANAGUDI, BENGALURU BRANCH : DEPARTMENT OF CIVIL ENGINEERING

GUIDE : DR. RAGHUNATH S

STUDENTS : MR. B.N. POOJITH

MR. SAGAR POUDEL

MS. AASHIKA DUTT

MR. SHASHANK P

Studies on the Strength and Elastic Behaviour of Concrete In-filled Tubular Sections

2016

Department of Civil Engineering, B.M.S.C.E, Bangalore Page 5

ABSTRACT

Reinforced cement concrete is one of the most versatile and most commonly used construction

material and it's discovery has been a boon to mankind. It essentially consists of providing

reinforcement in the form of twisted steel bars of varying diameter in the concrete element to

enhance its tensile strength.

Structural hollow sections made of steel make the most efficient compression members, filling them

with concrete gives further advantages, some of which includes, higher load carrying capacity,

reduced sectional dimensions resulting in slender members etc.

These hollow sections have an added advantage of not needing of any formwork during the casting

and installation as well as there are no requirement of fabrication of the reinforcements which in

turn reduce the labor work and cost.

Another advantage of such sections is that concrete, which is susceptible to fire hazards is not

exposed to the environment but the drawback here is the exposure of steel to the environment can

result in corrosion which can be easily tackled by coating the steel member with suitable anti-rust or

anti-corrosive coatings.

In modern construction, especially in the housing sector use of precast elements has become

increasingly popular. These elements can also be used as precast members for repair purpose in case

of damage to the structure due to various reasons such as natural calamities like earthquakes, old

and dilapidated structures of archeological importance etc, popularly known as retrofitting and

rehabilitation of structures etc,.

In this project, we mainly aim in confining concrete into hollow steel tube, this confinement of

concrete in the steel tubes also provides lateral stability to the elements which in turn increases the

load carrying capacity, its flexural stiffness and rigidity. These specimen tubes are then compared

with hollow specimens of same dimensions in terms of their flexural strength, compressive strength,

finite element analysis is carried out and the corresponding graphs are plotted.


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CHAPTER 1

INTRODUCTION

1.1 General

Reinforced cement concrete is one of the most versatile and most commonly used

construction material and it's discovery has been a boon to mankind. It essentially

consists of providing reinforcements in the form of steel TMT or HYSD bars of

varying diameter ranging from 8mm to 32mm in the concrete element to enhance its

tensile strength, The steel reinforcement is provided as we know that concrete is

very poor in resisting tensile stresses.

1.1.1 Concrete

Concrete essentially consists of four main components. namely Ordinary Portland

Cement(OPC), fine aggregate(IS 4.75mm to 600 microns), coarse aggregates(IS

12.5mm to 4.75 mm), potable water and admixtures( mineral and chemical).

Self-compacting concrete, (herein after refers as SCC), a new composite material,

which has the ability to flow under its own weight over a long distance without

segregation and to achieve consolidation without the use of vibrators, seems to be

one of the solutions to solve all those construction related problems. The use of SCC

has potentially reduce the required labors by more than50%. [RILEM, 1999]

The advantages of SCC

Improved ability of concrete to flow into intricate spaces and between congested reinforcement.

Improved form surface finish and reduced need to repair defects such as bug holes and honeycombing.

Reduced construction costs due to reduced labour costs and reduced equipment purchase and maintenance costs.

The disadvantages of SCC

Increased material costs, especially for admixtures and cementitious materials.

Increased formwork costs due to possibly higher formwork pressures.

Increased technical expertise required to develop and control mixtures


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1.1.2 Steel Structural hollow sections made of steel make the most efficient compression

members, filling them with concrete may give further advantages, which may include

higher capacity, reduced section diameter etc.

These sections have the added advantage as there is no need of any formwork

during the casting as well as there are no requirement of fabrication of the

reinforcements which in turn reduce the labor work as well as cost.

One more advantage of such sections is that concrete is not exposed to the

environment but the drawback here is the exposure of steel to the environment

which can be tackled by coating the steel member with suitable coatings.

In modern construction, especially in the housing sector use of precast elements has

become increasingly popular, these elements can be used as precast members in

case of damage to the structure, repair maintenance works etc,.

In this project, we mainly aim in confining concrete into hollow steel tubes thereby

eliminating the conventional reinforcement. this confinement of concrete in the steel

tubes also provides lateral stability to the elements.

1.2 Need For This Study

This study and experimentation on Concrete in-filled tubular sections is mainly due to

the following reasons.

1. There is no formwork required during its casting

2. There is no need of fabrication of reinforcements

3. Concrete that is cast is not exposed to the environment

4. Concrete being susceptible to fire hazards is protected here, though the steel is

exposed, it offers better resistance when compared to concrete

5. This project has many application in precast works, repair and maintenance

works, rehabilitation and retrofitting applications etc.

1.3 Objective of The Study

Steel members have the advantages of high tensile strength and ductility, while

concrete members have the advantages of high compressive strength and stiffness.


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Composite members combine steel and concrete, resulting in a member that has the

beneficial qualities of both materials.

Here the strength and elastic properties of such beams will be studied.

The behavior of concrete in-filled tubular sections under shear, flexure as well as

compression will the studied.

The theoretical analysis of such beams will be carried out by the finite element

analysis method.

1.4 Scope of The Work

The scope is limited to the materials used for the experiments, which are

Hollow rectangular steel section of 1 gauge measure only.

One grade of SCC concrete of M20

Testing is restricted to only flexure and compression.

Comparison between the experimental results and the analytical

results

1.5 Review of Literature

1.5.1 General

This section deals with the literature relating various studies that have been carried

out previously on In-filled tubular sections, various shapes adopted, and and

methodologies adopted.

1.5.2

Strength of Concrete Filled Steel Box Columns Incorporating Local Buckling

Brian Uy, Sr. Lect. in Civ. Engrg., School of Civ. and Envir. Engrg., Univ. of New

South Wales, Sydney, NSW 2052

"Concrete filled steel box columns have recently experienced a renaissance in their

use throughout the world. This has occurred due to the significant advantages that

the construction method can provide. This paper deals with the strength behavior of

short columns under the combined actions of axial compression and bending

http://ascelibrary.org/author/Uy%2C+Brian


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moment. The paper addresses the effect of steel plate slenderness limits on this

behavior. An extensive set of experiments has been carried out and a numerical

model developed elsewhere is augmented and calibrated with these results. A simple

model for the determination of the strength-interaction diagram is also verified against

both the test results and the numerical model developed in this paper. This model,

based on the rigid plastic method of analysis, is existent in international codes of

practice, but does not account for the effects of local buckling, which are found to be

significant with large plate slenderness values, particularly for large values of axial

force. Thus some suggested modifications are proposed to allow for the inclusion of

slender plated columns in design."

1.5.3

Behavior of Centrally Loaded Concrete-Filled Steel-Tube Short Columns

Kenji Sakino1; Hiroyuki Nakahara2; Shosuke Morino3; and Isao Nishiyama

1Professor, Dept. of Architecture, Graduate School of Human Environmental Studies, Kyushu

Univ., 6-10-1 Hakozaki, Higashi-ku, Fukuoka-shi 812-8581, Japan.

2Research Associate, Dept. of Architecture, Faculty of Engineering, Kagoshima Univ., 1-21-

40 Korimoto, Kagoshima-shi 890-0065, Japan.

3Professor, Dept. of Architecture, Faculty of Engineering, Mie Univ., Kamihama-cho, Tsu-shi

514-8507, Japan.

4Advanced Research Engineer, Dept. of Production Engineering, Building Research Institute,

Tachihara-1, Tsukuba, Ibaraki 305-0802, Japan.

"A 5 year research on concrete-filled steel tubular (CFT) column system was carried

out as a part of the fifth phase of the U.S.–Japan Cooperative Earthquake Research

Program, and the tests of centrally loaded short columns were finished. The

objectives of these tests were to clarify the synergistic interaction between steel tube

and filled concrete, and to derive methods to characterize the load–deformation

relationship of CFT columns. A total of 114 specimens was fabricated and tested in

the experimental phase of investigations on centrally loaded hollow and CFT short

columns. Parameters for the tests are as follows: (1) tube shape, (2) tube tensile

strength, (3) tube diameter-to-thickness ratio, and (4) concrete strength. In

http://ascelibrary.org/author/Sakino%2C+Kenjihttp://ascelibrary.org/author/Nakahara%2C+Hiroyukihttp://ascelibrary.org/author/Morino%2C+Shosukehttp://ascelibrary.org/author/Nishiyama%2C+Isao


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determining the range of parameters, the emphasis was placed on obtaining a wide

range of test data for establishing a generally applicable design method of CFT

column systems. Design formulas to estimate the ultimate axial compressive load

capacities are proposed for CFT columns with both circular and square sections

based on tests results described in this paper."

1.5.4

Analysis of concrete-filled steel tubular Beam-columns

W. F. Chen 1 and C. H. Chen 2

1Associate Professor of Civil Engineering, Lehigh University, Bethlehem,

Pennsylvania.

2Teaching Assistant, Department of Civil Engineering, CarnegieMellon University,

Pittsburgh, Pennsylvania; formerly, Research Assistant, Fritz Lab., Department of

Civil Engineering, Lehigh University, Bethlehem, Pennsylvania.

"The elastic-plastic behavior of pin-ended, concrete-filled steel tubular columns,

loaded either symmetrically or unsymmetrical about either of the two axes is studied

using the Column Curvature Curve method. Two types of cross section are

considered: circular shapes and square shapes. Three types of stress-strain

relationship for concrete are studied: (a) uni-axial state of stress; (b) tri-axial state of

stress, the. effect being assumed to increase the ductility only; not the strength; (c)

tri-axial state of stress, the effect being assumed to increase both the ductility and

strength. Using the corresponding stress-strain curves for concrete, interaction

curves relating axial force, end moment, and slenderness ratio are presented for the

maximum load carrying capacity of the beam columns. The results obtained are

corn~ pared with those from tests reported elsewhere, and good agreement is

observed."

1.5.5

Flexural and Cyclic Behaviour of Hollow and Concrete-filled Steel Tubes

Arivalagan .S1, Kandasamy.S2


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1Dept.of Civil Engg., Dr M.G.R.Educational and Research Institute, Dept. of Civil Engg., Dr

M.G.R.Educational and Research Institute, Dr M.G.R.University, Chennai, TamilNadu, India. . 2Dean, Anna University-Trichirappali,Ariyallur Campus, Ariyallur,TamilNadu,

"This paper presents a study on the flexural and cyclic behaviour of concrete filled

steel hollow beam sections. The specimens in-filled with normal mix concrete, fly ash

concrete, quarry waste concrete and low strength concrete (Brick-bat-lime concrete)

and hollow steel sections were tested. Measurements of strains and deflections were

made under two-point loading. A theoretical model was also developed to predict the

moment carrying capacity. The capacities of the beams were compared with the

ultimate capacity obtained using the international standards EC4-1994, ACI-2002

and AISC-LRFD-1999. The result of the experimental investigation showed that the

moment carrying capacity increases based on the compressive strength of the filler

materials. Energy absorption capacity also increase due to in filled materials.

Analytical results show good agreements with experimental results."

1.5.6

Numerical Analysis of Concrete-Filled Circular Steel Tubes

Yaohua Deng, University of Nebraska-Lincoln

Terri R. Norton, University of Nebraska-Lincoln

Christopher Y. Tuan, University of Nebraska-Lincoln,

"Concrete-filled steel tubes (CFTs) are composite members possessing the best

attributes of both concrete and steel. The flexural behaviour of CFTs and post-

tensioned CFTs was investigated analytically. Finite-element analysis (FEA) was

performed using the elastic - perfectly plastic uniaxial material model for steel and

the Drucker-Prager (DP) plasticity model for concrete. Theoretical sectional analysis

(TSA) was carried out by dividing the cross-section of a circular CFT member into a

large number of horizontal layers parallel to the axis of bending. The elastic perfectly

plastic uniaxial material model was also used for the steel tube and confined

concrete theory was applied to the concrete core."


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CHAPTER 2 Part A

EXPERIMENTAL DETAILS

3.1 Introduction

This chapter deals with the materials used, procedure adopted in this study.

3.2 Materials

Cement:

All types of cement complying with Indian Standards are suitable for making

concrete. The choice of the type of cement and content depends on the strength

requirements, the exposure class for the durability and the minimum amount of fines

required for the mix.

Fine Aggregates:

Sand plays a very important role in concrete. It manages to fill the voids between the

powders and coarse aggregates. That is why sand must be well graded from a

particle size point of view, in order to guarantee the filling between the various

aggregates as much as possible, sand can be finer than normal, as the material less

than 150 micron may help increase cohesion, thereby resisting segregation.

Coarse aggregates:

Concrete can be made from most normal concreting aggregates. Coarse aggregates

differ in nature and shape depending on their extraction and production. SCC has

been produced successfully with coarse aggregate up to 40mm. The maximum size

depends on reinforcement layout and formwork dimensions in the same way as

traditional vibrated concrete. Natural aggregates require less water than crushed

aggregates in SCC. However, elongated aggregates are not suitable. Here due to

specimen size constraints, the maximum size of aggregates is restricted to 12.5mm

downsize.


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Water

Potable water as obtained from Bore well was used for the preparation of concrete

mix and for curing as per Indian Standards.

Admixtures:

Admixtures are essential in determining flow characteristics and workability

retention. Super plasticizers are an essential components SCC to provide the

necessary workability. Other types may be incorporated as necessary, such as

Viscosity Modifying Agents (VMA) for stability, Air Entraining Admixtures (AEA) to

improve freeze-thaw resistance, retarders to control of setting, etc. Other materials

may indicate the requirement for additional segregation control admixtures such as

ultra fine silica, polysaccharide gum, modifying polyether or even simple air-

entrainers.

Role of Super plasticizers:

When the slump is over 175mm the bleeding increases too much. With the advent of

super plasticizer, flowing concretes with slump level up to 250mm were

manufactured with no or negligible bleeding, provided that an adequate cement

factor was used. In the middle of 1970’s, it was suggested to define rheoplastic a

concrete that, besides being very flowable, is also very cohesive and therefore has a

low tendency for segregation and bleeding. The most important basic principle for

flowing and unseggregable concretes including SCC’s, is the use of super plasticizer

combined with a relatively high content of powder materials in terms of Portland

cement, mineral additions, ground filler and very fine sand. A partial replacement of

cement by fly ash was soon realized to be the best compromise in terms of

rheological properties, resistance to segregation, strength, and crack freedom

particularly in mass concrete structures exposed to restrained thermal stresses

produced by cement hydration.

Special attention was used in selecting coarse aggregate with maximum size smaller

than 20mm (preferably smaller than 15mm), in order to enhance the mobility of all

the concrete ingredients without any significant segregation affects. It was decided to

use poker vibrators initially, to ensure the concrete was adequately under and


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around the bottom mat of reinforcement. At the end it was considered unnecessary

to continue the vibrating of concrete, as the super plasticizer produced flowing

concrete that was self-compacting in nature. The apparently large volume of

displaced water showed the self-compacting property during the pour that finally had

to pump away to allow surface finishing- off to proceed.

Conventional SP such as those sulphonated melamine and naphthalene

formaldehyde condensates, at the time of mixing becomes absorbed onto the

surface of cement particles. This absorption takes place at a very early stage in the

hydration process. The sulphonic groups of the polymer chains increase the

negative charge on the surface of the cement particles and dispersion of cement

occurs by electrostatic repulsion.

Polycarboxylic ether based super plasticizer has long lateral chains. This greatly

improves cement dispersion. At the start of the mixing process the same

electrostatic dispersion occurs as described previously, but presence of laterals

chains, linked to the polymer backbone, generate a steric hindrance, which stabilizes

the cement particles capacity to separate, and disperse.

3.3 Preparation of Steel specimens - Hollow

Stainless steel rectangular hollow tubes having the following characteristics is used

for the all the experiments:

Grade of steel : 202

Tensile strength : 515Mpa

Elastic modulus : 207GPa

Poisson’s ratio : 0.27

The specimen was 6.5m factory made. This was later cut into four specimens of

1.2m length for flexure tests and 0.2m for compression tests.

Compression specimens

Two hollow specimens were prepared for compression test.

The gross length of the specimens was 0.2m and the gauge length was fixed

to 0.1m to accommodate the dial gauge(Fig. 1) Indents were made into the


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specimens to enable for the fixing of the De-mech gauge(Demountable

Mechanical gauge). This gauge is used for getting the deflection of the

specimen under loading.

Flexure specimens

Two hollow specimens were prepared for flexural testing.

The gross length of the specimens was 1.2m and had an effective length of

0.9m(Fig. 2)

A thin metal strip was attached at the mid span to facilitate for fixing of the dial

gauge required to record deflections during the load application.

Fig. 1


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Fig 2

3.4 Concrete Mix Design

SCC Mix design adopted is based on Volume Fraction method.

Notations used:

V - Volume of concrete

Vp - Volume of paste(cement + flyash + water)

Vag - volume of aggregates( fine + coarse)

w.k.t.:

V = Vp + Vag

and

Vp = Vc + Vfly + Vw

taking

Water = 190 l/cu.m,

Cement content = 250 kg/cu.m and

Vp = 0.37


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0.37 = Vc +Vfly + Vw

0.37 =

+ Vfly + 0.190

Vfly = 0.4 -

- 0.190

Vfly = 0.10

Weight = 0.2 * 2.1 * 1000 = 211 kg/cu.m

Vag = 1.00 - 0.37 = 0.63

Taking the fine aggregate to coarse aggregate ratio as 55:45

Vfa = 0.55 * .63 * 2.68 * 1000 = 928.62 kg/cu.m

Vca = 0.45 * 0.63 * 2.68 * 1000 = 760.0 kg/cu.m

Dosage of Superplastisizer = 0.9% by weight of Cement.

The mix proportion works out to:

Ordinary Portland Cement - 250 kg/m3

Fly Ash - 211 kg/m3

Water - 190 lt/m3

Fine aggregate - 928 kg/m3

Coarse aggregate - 760 kg/m3

Mix Proportion ratio works out to be = 1 : 0.84 : 3.7 : 3.0

(Cement : Flyash : Fine aggregate : Coarse aggregate)

Average slump flow obtained from the above mix = 615mm which is found to be

satisfactory as explained in the following pages.


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3.5 Preparation of In-filled Specimens

Stainless steel rectangular hollow tubes having the following characteristics is used

for the all the experiments:

Grade of steel : 202

Tensile strength : 515Mpa

Elastic modulus : 207GPa

Poisson’s ratio : 0.27

The specimen was 6.5m factory made. This was later cut into four specimens of

1.2m length for flexure tests and 0.2m for compression tests.

Compression specimens

Two hollow specimens were prepared for compression test.

The gross length of the specimens was 0.2m and the gauge length was fixed

to 0.1m to accommodate the dial gauge(Fig. 3)

Indents were made into the specimens to enable for the fixing of the De-mech

gauge(Demountable Mechanical gauge). This gauge is used for getting the

deflection of the specimen under loading.

These specimens were levelled and filled with SCC concrete mixed as per the

above design and were left to cure for 28 days.

The ends of the tubes were sealed using polyurethane membrane and cello

tape thereby ensuring that there is no evaporation of water.


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Fig. 3

Flexure specimens

Two hollow specimens were prepared for flexural testing.

The gross length of the specimens was 1.2m and had an effective length of

0.9m.

A thin metal strip was attached at the mid span to facilitate for fixing of the dial

gauge required to record deflections during the load application.

These specimens were levelled and filled with SCC concrete mixed as per the

above design and were left to cure for 28 days.

The ends of the tubes were sealed using polyurethane membrane and cello

tape thereby ensuring that there is no evaporation of water.

3.6 Tests on Self-Compacting Concrete

3.6.1. Introduction

Many different tests methods have been in attempt to characterize the properties of

SCC so far no single method or combination of methods has achieved universal

approval and most of them have their adherents. Similarly no single methods has

been found which characterizes all the relevant workability aspects so each mix

design should be tested by more than one test method for different workability


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parameters. Typical acceptance criteria for SCC with a maximum aggregate size up

to 20mm are shown in Table.3.1

TABLE 3.1: List of Test Methods for Workability Properties of SCC.

SL.NO METHOD PROPERTY

1 SLUMP FLOW BY ABRAMS CONE FILLING ABILITY

2 T50 cm SLUMP FLOW FILLING ABILITY

3 J-RING PASSING ABILITY

4 V-FUNNEL FILLING ABILITY

5 V-FUNNEL AT 5 MINUTES SEGGREGATION RESISTANCE

6 L-BOX PASSING ABILITY

7 U-BOX PASSING ABILITY

8 FILL-BOX PASSING ABILITY

9 GTM SCREEN STABILITY TEST SEGGREGATION RESISTANCE

10 ORIMET TEST FILLING ABILITY

TABLE 3.2: Acceptance Criteria for SCC

SL.NO

METHOD

UNIT

MINIMUM VALUE

MAXIMUM

VALUE

1 Slump Flow by Abrams Cone mm 650 800

2 T50 cm Slump Flow Sec 2 5

3 J-RING mm 0 10

4 V-FUNNEL Sec 6 12

5 V-FUNNEL AT 5 MINUTES Sec 0 +3

6 L-BOX h2/h1 0.8 1.0

7 FILL-BOX % 90 100

1. Slump Flow Test and T50cm Test:

The slump flow is used to assess the horizontal free flow of SCC in the absence of

obstructions. It was first developed in Japan for use in assessment of underwater


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concrete. The test method is based on the test method for determining the slump.

The diameter of the concrete circle is a measure for the filling ability of the concrete.

Assessment of Test: This is a simple, rapid test procedure, though two people are needed if the T50 time

is to be measured. It can be used on site, though the size of the base plate is

somewhat unwieldy and leveled ground is essential. It is the most commonly used

test, and gives a good assessment of filling ability. It gives no indication of the ability

of the concrete to pass between reinforcement without blocking, but may give some

indication of resistance to segregation. It can be argued that the completely free

flow, unrestrained by any boundaries, is not representative of what happens in

practice in concrete construction, but the test can be profitably be used to assess the

consistency of supply of ready-mix concrete to a site from load to load.

Equipment:

Fig. 4: Slump Flow and T50cm Test

Mould in the shape of a truncated cone with an internal dimensions 200mm

diameter at the base, 100mm diameter at the top and a height 300mm,

confirming to EN 12350-2.


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Base plate of a stiff non-absorbing material, at least 700mm square, marked with

a circle marking the central location for the slump cone,.

Trowel.

Scoop.

Ruler.

Stop watch (optional).

Procedure:

About 6 liters of concrete is needed to perform the test, sampled normally.

Moisten the base plate and inside the slump cone.

Place base plate on a level stable ground and the slump cone centrally on the

base plate and hold down firmly.

Fill the cone using the scoop. Do not tamp, simply strike off the concrete level

with the top of the cone with the trowel.

Remove any surplus concrete from around the base of the cone.

Raise the cone vertically and allow the concrete to flow out freely.

Simultaneously, start the stopwatch and record the time taken for the concrete to

reach the 500mm-spread circle (this is the T50 time).

Measure the final diameter of the concrete in two perpendicular directions.

Calculate the average of the two measured diameters (this is the slump flow in

mm).

Note any border of mortar or cement paste without coarse aggregate at the edge

of the pool of concrete.

Interpretation of Results:

The higher the slump flow (SF) value, the greater is its ability to fill formwork under

its own weight. A value of at least 650mm is required for SCC. There is no generally

accepted advice as to whatever the reasonable tolerances about a specified value

are, though 50mm, as with the related flow table test, might be appropriate.

The T50 time is secondary indication of flow. A lower time indicates greater

flowability. The BriteEuRam research suggested that a time of 3 to 7 seconds is

acceptable for civil engineering applications, and 2 to 5 seconds for housing


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applications. In case of severe segregation most coarse aggregate will remain in the

center of pool of concrete and mortar and cement paste at the concrete periphery. In

case of minor segregation a border of mortar without coarse aggregate can occur at

the edge of the pool of the concrete.

2.0. J-RING TEST

The principle of J ring test may be from the Japanese, but no references are known.

The J ring test itself has been developed at the University of Paisley. The test is

used to develop the passing ability of the concrete. The equipment consists of a

rectangular section (30mm x 25mm) open steel ring, drilled vertically with holes to

accept threaded sections of reinforcement bars. These sections of bars can be of

different diameters and spaced at different intervals; in accordance with the normal

reinforcement considerations, three times the maximum aggregate size may be

appropriate. The diameter of the ring of the vertical bars is 300mm, and the height is

100mm.

The J ring test can be used in conjunction with the slump flow test, the Orimet test,

or eventually even the V-Funnel test. These combinations test the flowing ability (the

contribution of the J ring) and the passing ability of the concrete. The Orimet time

and or slump flow spread is measured as usual to assess the flow characteristics.

The J ring bars can principally be set at any spacing to impose a more or less severe

test on the passing ability of the concrete. After the test, the difference in height

between the concrete inside and that just outside the J ring is measured. This is an

indication of the passing ability or the degree to which the passage of concrete

through the reinforcement bars is restricted.


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Fig.5 J-RING Apparatus

Assessment of the Test:

These combinations of the tests are considered to have great potentials, though

there is no general view on how the results of the tests should be interpreted. There

are a number of options; for instance it may be instructive to compare the slump-

flow/Jring spread with the unrestricted slump-flow: as to what extent it has reduced?

Like the slump flow test, these combinations have the disadvantage of being

unconfined, and therefore do not reflect the way concrete is placed and moves in

practice. The Orimet option has the advantage of being a dynamic test, also

reflecting placement in practice, though it suffers from requiring two operators.

Equipment:

Mould, WITHOUT foot pieces, in the shape of a truncated cone with the internal

dimensions 200mm diameter at the base, 100mm diameter at the top and a

height of 300mm.

Base plate of a stiff non-absorbing material, at least 700mm square, marked with

a circle.

Showing the central location for the slump cone, and a further concentric circle of

500mm diameter.

Trowel.

Scoop.

Ruler.


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J ring, a rectangular section (30mm x 25mm) open steel ring, drilled vertically

with holes.

In the holes can be screwed threaded sections of reinforcement bars (length

100mm, diameter 10mm, spacing 482mm).

Procedure:


Moisten the base plate and inside of the slump cone.

Place the J ring centrally on the base-plate and the slump cone centrally inside it

and hold down firmly.

Fill the cone using the scoop. Do not tamp, simply strike off the concrete level

with the top of the cone with the trowel.

Remove any surplus concrete from around the base of the cone.

Raise the cone vertically and allow the concrete to flow out freely.

Measure the final diameter of the concrete in two perpendicular directions.

Calculate the average of the two measured diameters (in mm).

Measure the difference in height between the concrete just inside the bars and

that just outside the bars.

Calculate the average of the difference in the heights at four locations (in mm).

Note any border of mortar or cement paste without coarse aggregate at the edge

of the pool of concrete.


It should be appreciated that although these combinations of tests measure the flow

and passing ability, the results are not independent. The measured flow is certainly

affected by the degree to which the concrete movement is blocked by the reinforcing

bars. The extent of the blocking is much less affected by the flow characteristics, and

we can say that clearly, the greater the difference in height, the less the passing

ability of the concrete. Blocking and/or segregation can also be detected visually,

often more reliably, than by calculation.


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Note: The results of the J ring are influenced by the combination method selected

and results obtained from different combinations will not be comparable.

3.0. V-FUNNEL TEST AND V-FUNNEL TEST AT 5 MINUTES

The test was developed in Japan and used by Ozawa Et Al (5). The equipment

consists of a V-shaped funnel, shown in figure. An alternative type of V-funnel, the O

funnel, with a circular section is also used in Japan.

The described V-funnel test is used to determine the filling ability (flowability) of the

concrete with a maximum aggregate size of 20mm. The funnel is filled with about 12

liters of concrete and the time taken for it to flow through the apparatus measured.

After this the funnel can be refilled with concrete and left for 5 minutes to settle. If the

concrete shows segregation then the flow time will increase significantly.

Assessment of the Test:

Though the test is designed to measure flowability, the result is affected by concrete

properties other than flow. The inverted cone shape will cause any liability of the

concrete to block to be reflected in the result –if, for example there is too much

aggregate. High flow time can also be associated with low deformability due to a

high paste viscosity, and with high inter-particle friction.

While the apparatus is simple, the effect of the angle of the funnel and the wall effect

on the flow of concrete are not clear.


2016


Fig.6. V-Funnel Test Apparatus

Equipment:

V-Funnel.

Bucket (12 liters).

Scoop.

Stopwatch.

Procedure:

About 12 liters of concrete is needed for perform the test, sampled normally.

Set the V-Funnel firm on the ground.

Moisten the inside surfaces of the funnel.

Keep the trap door open to allow any surplus water to drain.

Close the trap door and place a bucket underneath.

Fill the apparatus completely with concrete without compacting or tamping,

simply strike off the concrete level with the top with the trowel.

Open within 10 seconds after filling the trap door and allow the concrete to flow

out under gravity.

Start the stopwatch when the trap door is opened and record the time for the

discharge to complete (the flow time). This is taken to be when light is seen from

the above through the funnel.

The whole test has to be performed within 5 minutes.


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Procedure for Flow Time at T5Minutes:

Do not clean or moisten the inside surface of the funnel again

Close the trap and refill the funnel immediately after measuring the flow time.

Place a bucket underneath

Fill the apparatus completely with concrete without compacting or tapping,

simply strike off the concrete

Level with a trowel

Open the trap door 5 minutes after the second fill of the funnel and allow the

concrete to flow out under gravity

Simultaneously start the stopwatch when the trap door is opened, and record

the time for the discharge to complete (the flow time at T5 minutes). This is

taken to be when light is seen from above through the funnel.


This test measures the ease of flow of the concrete; shorter flow times indicate

greater flowability. For SCC, a flow time of 10 seconds is considered appropriate.

The inverted cone shape restricts flow, and prolonged flow times may give some

indication of the susceptibility of the mix to blocking.

After 5 minutes of settling, segregation of concrete will show a less continuous flow

with an increase in flow time.

4.0.L-BOX TEST

This test, based on a Japanese design for underwater concrete, has been described

by Petersson [28]. The test assesses the flow of concrete, and also the extent to

which it is subjected to blocking by reinforcements. The apparatus is as shown in

figure.

The apparatus consists of a rectangular section box in the shape of an “L”, with a

vertical and horizontal section, separated by a movable gate, in front of which

vertical lengths of reinforcement bars are fitted. The vertical section is filled with

concrete, and then the gate is lifted to let the concrete flow into the horizontal

section. When the flow has stopped, the height of the concrete at the end of the

horizontal section is expressed as a proportion of that remaining in the vertical

section (H2/H1 in the diagram). It indicates the “slope” of the concrete when at rest.


2016


This is an indication of the passing ability, or the degree to which the passage of

concrete through the bars is restricted.

The horizontal section of the box is marked at 200mm and 400mm from the gate and

the times taken to reach these points are measured. These are known as the T20

ansT40 times and are the indication for the filling ability.

The sections of the bar can be of different diameters and spaced at different

intervals; in accordance with normal reinforcement considerations, three times the

maximum aggregate size might be appropriate. The bars can principally be set at

any spacing to impose a more or less severe test of the passing ability of the

concrete.

Assessment of Test:

This is a widely used test, suitable for laboratory, and perhaps site use. It assesses

filling and passing ability of SCC, and serious lack of stability (segregation) can be

detected visually. Subsequently sawing and inspecting sections of the concrete in

the horizontal section may also detect segregation.

Unfortunately, there is no agreement on the materials, dimensions, or reinforcing bar

arrangement, so it is difficult to compare the test results. There is no evidence of

what effect the wall of the apparatus and the consequent “wall effect” might have on

the concrete flow, but this arrangement does to some extent, replicate what happens

to concrete on site when it is confined with the formwork.

Two operators are required if times are measured, and a degree of operator error is

inevitable.

Equipment:

L box of a stiff and non-absorbing material.

Trowel.

Scoop.

Stopwatch.


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Fig.7: L-BOX Test Apparatus

Procedure:


Set the apparatus level on the ground firmly, and ensure that the sliding gate can

open freely and then close the gate.

Moisten the inside surfaces of the apparatus and remove any surplus water.

Fill the vertical section of the apparatus with the concrete sample.

Leave it to stand for 1 minute.

Lift the sliding gate and allow the concrete to flow out into the horizontal section.

Simultaneously, start the stopwatch and record the times taken for the concrete

to reach the 200mm and 400mm marks.

When the concrete stops flowing, the distances H1 and H2 are measured.

Calculate H1/H2, the blocking ratio.

The whole test has to be performed within 5 minutes.


If the concrete flows freely as water, at rest it will be horizontal, so H2/H1 = 1.

Therefore the nearer this test value, the “blocking ratio”, is to unity, the better the

flow of the concrete. The EU research team suggested a minimum acceptable value

of 0.8. T20 and T40 times can give some indication of the ease of flow, but no

suitable values have been generally agreed. Obvious blocking of coarse aggregate

behind the reinforcing bars can be detected visually.


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CHAPTER 2 Part B

EXPERIMENTAL PROCEEDINGS

4.1 Introduction

This chapter deals with the methodology adopted, and various tests conducted.

4.2 Preparation of Experimental Set-up - FLEXURE TEST

Fig. 8

Fig. 8 shows the schematic diagram for setting up the specimens for flexure

test.

Two point loading configuration is used for flexure testing as in this case pure

bending theory can be easily applied for simplified calculations

SS tubes of length 1.2m were prepared to be tested for flexural strength.

Four specimens, two hollow and two filled with SCC of grade M20 were

prepared.

These specimens were then tested by a 2-point load configuration as shown

in Fig. 8 and following graphs were plotted:

Stress-Strain Curve

Moment-Curvature Curve


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Load Deflection Curve

Fig. 9: Flexure test set-up

4.2.1 Test Results

Specimen Ultimate

Load Ultimate Stress

Ultimate Moment

Hollow specimens

1. 25.05 kN 118.75 N/mm2 3757.5 N-m

2. 27.05 kN 156.25 N/mm2 4057.5 N-m

3. 22.18 kN 138.63 N/mm2 3327 N-m

4. 26.97 kN 168.58 N/mm2 4046 N-m

In-filled specimens

1. 32.93 kN 205.81 N/mm2 4939 N-m

2. 34.37 kN 212.5 N/mm2 5155 N-m

3. 32.07 kN 200.42 N/mm2 4810 N-m

4. 33.00 kN 206.26 N/mm2 4950 N-m


2016


Test results show that there is a consistency in the failure loads taken up

by the specimens.

It can also be seen that there is an increase in the load carrying capacity

of the tubular sections when filled with concrete.

4.2.2 Failure Pattern

Hollow steel tubes –Local buckling of the specimen at points of load

application.

Concrete in-filled steel tubes -Pure flexural failure with development of cracks

on the tensile face of the specimen.

It can therefore be concluded that there is bonding between the steel and

concrete and the inner surface is not smooth as opposed to the outer polished

surface.

Fig. 10: View of the test set-up


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Fig. 11: Bending of the specimen.

Fig. 12: Specimen after removal of load.


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Fig. 13: Bending of hollow specimen with slight crimping at points

of application of load.

Fig. 14: Bending at mid span in In-filled specimen. Note: No crimping near

points of load application.


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Fig 15: Local buckling of hollow specimen

Fig. 16: Failure crack in In-filled Specimen


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4.2.3 Plot of the results

The specimens, both, hollow and In-filled were subjected to flexure testing as

explained above and corresponding loads and deflections were

recorded(Appendix A).

Using the obtained loads and deflections, the following plots of moment-

curvature, stress strain and load-deflection curves are plotted after

calculations of the required parameters.

4.2.3.a Moment vs. Curvature plots

Graph 1: Plot of moment vs. Curvature for hollow specimens subjected

to flexure loading

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 0.05 0.1 0.15 0.2

Mo

me

nt

(N-m

)

Curvature (per m)

Moment vs Curvature - Hollow Specimens

Specimen 1

Specimen 2

Specimen 3

Specimen 4


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Graph 2: Plot of moment vs. Curvature for in-filled specimens subjected

to flexure loading.

Graph 4: Plot of normalized moment vs. Curvature to flexure loading. The equation

gives the flexural rigidity of the composite specimen.

0

500

1000

1500

2000

2500

3000

0 0.05 0.1 0.15 0.2 0.25

Mo

me

nt

(N-m

)

Curvature (per m)

Moment vs Curvature - In-fill Specimens

Specimen 1

Specimen 2

Specimen 3

Specimen 4


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4.2.3.b Stress vs. Strain graphs

Graph 5: Plot of Stress Strain curve for hollow specimens

subjected to flexure loading

Graph 6: Plot of stress strain curve for in-filled specimens subjected to flexure

loading


2016


Graph 7: Comparison of plots of stress strain for all specimens subjected to flexure

loading

Graph 8: Normalized plot of Stress vs. Strain for the specimens subjected to flexure

loading. The equation to the trend line gives the equivalent modulus of elasticity for

the composite specimen.


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4.2.3.c Load vs. Deflection plots

Graph 9: Plot of Load vs. Deflection for hollow specimens subjected to flexure loading

Graph 10: Plot of load vs. deflection for in-filled specimens subjected to flexure

loading

0

5000

10000

15000

20000

25000

30000

0 0.005 0.01 0.015 0.02

Load

(N

)

Deflection (m)

Load vs Deflection - Hollow specimens

Specimen 1

Specimen 2

Specimen 3

Specimen 4

0

5000

10000

15000

20000

25000

30000

35000

0 0.005 0.01 0.015 0.02 0.025 0.03

Load

(N

)

Deflection (m)

Load vs Deflection - In-filled Specimens

Specimen 1

Specimen 2

Specimen 3

Specimen 4


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Graph 11: Plot of load vs. deflection for all specimens subjected to flexure loading

Graph 12: Plot of Load vs. Deflection for all the specimens subjected to flexure

loading. The equation to the plotted trend line gives the stiffness of the specimen.

4.3 Preparation of Experimental Set-up - COMPRESSION TEST


2016


Fig.18 shows the experimental set-up adopted for conducting compression

test to ascertain the compressive strength as well as other parameters which

is explained below.

The set-up or preparations involved levelling of the specimens to the true

plane so as to ensure that loading is along its axis or in other words to ensure

that only axial loading is applied.

Two indents were made on one face of the specimen to facilitate for fixing of

the De-mech dial gauge as shown in Fig. 18.

The loads and corresponding deflection were recorded and various

parameters such as stress, strain is calculated (Appendix B) and the following

graphs are plotted.

Stress vs. Strain graphs

Load vs. Deflection graphs.

Fig. 18: Experimental set-up for compression testing.


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4.3.1 Test results

Specimen Ultimate Load Ultimate Stress

Hollow Specimen

1. 120.00 kN 50.00 N/mm2

2. 123.43 kN 51.43 N/mm2

3. 147.50 kN 61.46 N/mm2

4. 156.00 kN 65.00 N/mm2

In-Filled Specimen

1. 237.00 kN 98.75 N/mm2

2. 227.00 kN 94.58 N/mm2

3. 228.00 kN 95.00 N/mm2

4. 235.50 kN 98.13 N/mm2

4.3.2 Failure pattern

Fig. 19: Failure in in-filled specimen.


2016


Fig. 20 Top view of failure of in-filled specimen, buckling near the top surface.

Fig. 21 Failing of the hollow specimen under loading.


2016


Fig. 22 Failure pattern - buckling - in hollow specimen, implies that the specimen

has behaved as a long column .

Fig. 23 Failure of in-filled specimen. In-filled specimens develop lateral stress causing

splitting of specimen. Also no crushing of concrete is seen.


2016


4.3.3 Plot of the results

4.3.3.a Stress vs. Strain Curves

Graph 13: Plot of Stress vs. Strain curve for hollow specimens subjected to axial

compression loading.

Graph 14: Plot of Stress vs. Strain curve for in-filled specimens subjected to axial



2016


Graph 15: Comparison of plots of Stress vs. Strain curve for specimens subjected to axial


Graph 16: Normalized plot of Stress vs. Strain curve for all specimens subjected to axial

compression loading. The equation gives the equivalent modulus of elasticity for the

composite section.


2016


4.3.3.b Load vs. Deflection plots

Graph 17: Plot of Load vs. Deflection for hollow specimens subjected to axial compression.

Graph 18: Plot of Load vs. Deflection for in-filled specimens subjected to axial compression


2016


Graph 19: Comparison of plots of Load vs. Deflection for all specimens subjected to axial

compression


2016


CHAPTER 3

FREE VIBRATION TEST

3.1 Experimental Set-up

The main objective of this test is to determine the natural frequency of the

specimens which in turn is required to calculate the effective flexural rigidity

and effective modulus of elasticity.

It may be calculated as elaborated as follows:

The formula used to calculate flexural rigidity for continuous systems is given

by:

Where,

– natural frequency of system = 2πf (where f is frequency in Hertz)

EI – flexural rigidity

m – mass per unit length

L – length of specimen

– 3.516 for fundamental mode


2016


Fig. 24 Experimental set-up for conduction of free vibration test. Two accelerometers were mounted as shown and the vibration response

was recorded through the data acquisition system.

Fig. 25 Fig. 26

The accelerometers were mounted in such a way that they were able to record the vibrations at the edge as well as in the mid span of the element.

The element was subjected to cantilever boundary conditions as shown in the figures.

This type of boundary condition enables the element to behave as a cantilever beam, and hence the vibrations can be stimulated as depicted in Fig. 27


2016


Fig. 27

Fig. 28 Fig. 29

It can observed in Fig. 29 that the element is clamped by fixing it to the Universal testing machine by applying just enough load sufficient to hold it firmly.

At the same time, precautions were taken to ensure that this clamping conditions did not prohibit or affect the element from freely vibrating on application of initial conditions.

3.2 Results

The following plots were obtained through a platform called EZ-Analyst and the

Fourier amplitude was determined.


2016


Fig. 30 Plot of time history data for hollow specimens.

From the figure it can be observed that when the beam element is subjected to free

vibrations by applying initial conditions, the fundamental mode of frequency is

excited throughout the element.

The plot shown in Blue colour is from the accelerometer mounted at the edge and

that shown in Red is from the accelerometer mounted at the mid span.

Fig. 31 Plot of Fourier amplitude.


2016


Fundamental Frequency = 21.25Hz

Using this frequency, we can calculate the flexural rigidity and in turn we can determine the

equivalent modulus of elasticity, using the formula stated above.

Fig. 32 Plot of time history data for in-filled specimen

It can be observed from Fig. 32 that apart from the fundamental modes, other modes have

been excited as well, but the fundamental mode is distinguished from the peaks.

Fig. 33 Plot of Fourier amplitude for in-filled specimens.


2016


From this plot it is established that the fundamental frequency of in-filled specimens is

20.0Hz.

It is seen that the frequency of the in-filled specimen is less than that of the hollow specimen.

It is due to the reason that, mass of the specimen increases with addition of concrete to the

tubular specimen. As we know that frequency is inversely proportional to the mass of the

object by the formula

where = natural frequency of the object,

K = Stiffness of the material and

M = Mass of the object.


2016


CHAPTER 4

FINITE ELEMENT ANALYSIS

4.1 Introduction

The finite element analysis is a numerical technique. In this method all the

complexities of the problems, like varying shape, boundary conditions and

loads are maintained as they are.

Because of its diversity and flexibility as an analysis tool, it is receiving much

attention in engineering. Some of the popular packages are Staad-Pro, Gt-

Strudel, NISA .

Civil engineers use this method extensively for the analysis of beams, space

frames, plates, shells, folded plates, foundations, rock mechanics problems

and seepage analysis of fluid through porous media.

Both static and dynamic problems can be handled by finite element analysis.

Free vibrations were simulated to the specimens by modelling them on a

Finite Element Analysis software, NISA – Display IV.

Natural frequency of the specimens, total mass and Eigen value analysis

were obtained and results are shown in following slides


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4.2 Results

4.2.1 Hollow Specimen

Fig. 34 Free vibration simulation of hollow tubular section.

Fig. 35 Various properties of the specimen as obtained in NISA Display IV


2016


Fig. 36 The frequencies of 10 modes obtained in NISA Display IV

4.2.2 In-filled specimen

Fig. 37 Free vibration simulation of in-filled tubular section.


2016


Fig. 38 Mass characteristic of in-filled specimen

Fig 39. Frequency table of 10 modes obtained from NISA Display IV

It can be noticed that the frequency obtained in the free vibration test and that obtained in

the finite element analysis is almost similar.

The minor variations in the results may be due to various conditions such as:

Laboratory conditions

Boundary conditions, and so on.


2016


CHAPTER 5

RESULTS AND CONCLUSION

5.1 FLEXURAL TEST RESULTS:

5.1.1 Moment vs. Curvature Plot

The slope of Moment vs. Curvature gives the of the composite element in flexure

and it can be calculated by using the equation of the trend line plotted.

Therefore, by differentiating the equation

y = -303230x2 + 75096x

we get,

, which is nothing but the at any given point on the trend line.

5.1.2 Stress vs. Strain Plot

The slope of the Stress vs. Strain plot gives the modulus of elasticity of the specimen

in flexure and this can be calculated by using the equation obtained from the trend

line plotted for the normalised stress vs. strain graph.

y = -9E+11x2 + 7E+09x

Differentiating this equation, we get

, which gives the equivalent modulus of

elasticity of the specimen.

5.1.3 Load vs. Deflection plot

Load vs. defection is plotted with load on Y-axis and deflection on X-axis for the

specimen subjected to flexural loading.

A trend line is fitted to the normalised graph and the following equation is obtained:

y = -6E+07x2 + 3E+06x

Differentiation of the above equation gives

which is the Stiffness of the composite

member along any point on the graph.


2016


5.2 COMPRESSION TEST RESULTS:

5.2.1 Stress vs. Strain Plot

The slope of the Stress vs. Strain plot gives the modulus of elasticity of the specimen

in compression and this can be calculated by using the equation obtained from the

trend line plotted for the normalised stress vs. strain graph.

y = -3E+10x2 + 1E+08x

This equation, on differentiating, gives the flexural rigidity of the specimen in

compression.

5.2.2 Load vs. Deflection plot

Load vs. defection is plotted with load on Y-axis and deflection on X-axis for the

specimen subjected to compression loading.

A trend line is fitted to the normalised graph and the following equation is obtained:

y = -6128.5x2 + 2315.3x

Differentiation of the above equation gives

which is the Stiffness of the composite

member along any point on the graph.

5.3 CONCLUSION

It is found out that both hollow as well as in-filled specimens have their own

merits as well as demerits.

It can however be noted In-Filled specimens displayed higher load carrying

capacity when compared to hollow specimens.

Similarly In-Filled specimens has a higher Strain Energy capacity when

compared to Hollow specimens.

In-Filled specimens failed by cracking off of the tensile face when subjected to

flexure testing, when compared to hollow specimens which failed due to local

buckling at the points of loading as evident from the photographs taken during

the testing process.


2016


BIBLIOGRAPHY

SEISMIC BEHAVIOUR OF CONCRETE FILLED STEEL TUBULAR BEAMS

E K Mohan raj*, Kongu Engineering College, India, S Kandasamy, Anna

University Tiruchirappalli, India, A Rajaraman, Indian Institute of Technology

Madras, India

BEHAVIOR OF CONCRETE IN FILLED DUPLEX STAINLESS STEEL

CIRCULAR COLUMNS AND BEAMS

Sunusi Aminu Yunusa, Thesis for: M. Tech structural engineering,

Department of Structural Engineering, SRM University, Chennai.

CONCRETE-FILLED CIRCULAR STEEL TUBES SUBJECTED TO PURE

BENDING

M. Elchalakani, X.L. Zhao, R.H. Grzebieta

ANALYSIS OF CONCRETE FILLED STEEL TUBULAR BEAM-COLUMNS

W. F. Chen, C. H. Chen

STRENGTH OF CONCRETE FILLED STEEL BOX COLUMNS

INCORPORATING LOCAL BUCKLING

Brian Uy, Sr. Lect. in Civ. Engrg., School of Civ. and Envir. Engrg., Univ. of

New South Wales, Sydney, NSW 2052

http://ascelibrary.org/author/Uy%2C+Brian


2016


APPENDIX A

FLEXURE TEST OBSERVATIONS

Load Deflection Moment radius Curvature Strain Stress

kN N mm m Nm m per m N/m

0 0 0 0 0 0 0 0 0

1 1000 0.65 0.00065 150 276.9234 0.003611107 0.000108333 416666.6667

2 2000 1.25 0.00125 300 144.0006 0.006944414 0.000208332 833333.3333

3 3000 1.72 0.00172 450 104.652 0.009555477 0.000286664 1250000

4 4000 2.35 0.00235 600 76.59692 0.013055355 0.000391661 1666666.667

5 5000 2.96 0.00296 750 60.81229 0.016444044 0.000493321 2083333.333

6 6000 3.53 0.00353 900 50.99327 0.019610432 0.000588313 2500000

7 7000 4 0.004 1050 45.002 0.022221235 0.000666637 2916666.667

8 8000 4.51 0.00451 1200 39.91356 0.02505414 0.000751624 3333333.333

9 9000 5.12 0.00512 1350 35.15881 0.028442373 0.000853271 3750000

10 10000 5.73 0.00573 1500 31.41648 0.03183043 0.000954913 4166666.667

11 11000 6.4 0.0064 1650 28.1282 0.035551511 0.001066545 4583333.333

12 12000 6.93 0.00693 1800 25.97749 0.038494865 0.001154846 5000000

13 13000 7.71 0.00771 1950 23.35016 0.042826262 0.001284788 5416666.667

14 14000 8.5 0.0085 2100 21.18072 0.047212747 0.001416382 5833333.333

15 15000 9.24 0.00924 2250 19.48514 0.051321162 0.001539635 6250000

16 16000 10.11 0.01011 2400 17.80921 0.056150724 0.001684522 6666666.667

17 17000 10.95 0.01095 2550 16.44383 0.060813079 0.001824392 7083333.333

18 18000 11.96 0.01196 2700 15.05615 0.066418054 0.001992542 7500000

19 19000 13.15 0.01315 2850 13.69479 0.073020481 0.002190614 7916666.667

Ultimate 25.05 25050 10437500

H-Tube-S1



0 0 0 0 0 0 0 0 0

5 5000 1.95 0.00195 750 92.30867 0.010833219 0.000324997 2083333.333

10 10000 4.24 0.00424 1500 42.45495 0.023554379 0.000706631 4166666.667

15 15000 6.38 0.00638 2250 28.21636 0.035440437 0.001063213 6250000

20 20000 9.03 0.00903 3000 19.93807 0.050155306 0.001504659 8333333.333

25 25000 15 0.015 3750 12.0075 0.083281283 0.002498438 10416666.67

Ultimate 27.05 27050 11270833.33

H-Tube-S2


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APPENDIX A (contd.)

Load Deflection Moment Radius Curvature Strain Stress


0 0 0 0 0 0 0 0 0

1 1000 0.28 0.00028 150 642.8573 0.001555555 4.66667E-05 416666.6667

2 2000 0.53 0.00053 300 339.6229 0.002944442 8.83333E-05 833333.3333

3 3000 0.82 0.00082 450 219.5126 0.004555547 0.000136666 1250000

4 4000 1.12 0.00112 600 160.7148 0.006222201 0.000186666 1666666.667

5 5000 1.42 0.00142 750 126.7613 0.007888845 0.000236665 2083333.333

6 6000 1.72 0.00172 900 104.652 0.009555477 0.000286664 2500000

7 7000 2.03 0.00203 1050 88.67097 0.011277649 0.000338329 2916666.667

8 8000 2.33 0.00233 1200 77.25438 0.012944249 0.000388327 3333333.333

9 9000 2.64 0.00264 1350 68.18314 0.014666383 0.000439991 3750000

10 10000 2.98 0.00298 1500 60.40417 0.016555147 0.000496654 4166666.667

11 11000 3.35 0.00335 1650 53.73302 0.018610531 0.000558316 4583333.333

12 12000 3.75 0.00375 1800 48.00188 0.02083252 0.000624976 5000000

13 13000 4.16 0.00416 1950 43.27131 0.02311 0.0006933 5416666.667

14 14000 4.58 0.00458 2100 39.3036 0.025442962 0.000763289 5833333.333

15 15000 5.02 0.00502 2250 35.85908 0.027886937 0.000836608 6250000

16 16000 5.47 0.00547 2400 32.9095 0.030386363 0.000911591 6666666.667

17 17000 5.93 0.00593 2550 30.3571 0.032941227 0.000988237 7083333.333

18 18000 6.43 0.00643 2700 27.99699 0.03571812 0.001071544 7500000

19 19000 6.94 0.00694 2850 25.94007 0.038550398 0.001156512 7916666.667

20 20000 7.46 0.00746 3000 24.13242 0.041438039 0.001243141 8333333.333

21 21000 8.02 0.00802 3150 22.4479 0.044547596 0.001336428 8750000

22 22000 8.62 0.00862 3300 20.88598 0.047879007 0.00143637 9166666.667

23 23000 9.29 0.00929 3450 19.38032 0.051598741 0.001547962 9583333.333

24 24000 9.65 0.00965 3600 18.65767 0.053597247 0.001607917 10000000

ultimate 32.93 32930 13720833.33

S-Tube-S1


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APPENDIX A (contd.)


kN n mm m Nm per m N/m

0 0 0 0 0 0 0 0 0

1 1000 0.32 0.00032 150 562.5002 0.001777777 5.33333E-05 416666.6667

2 2000 0.66 0.00066 300 272.7276 0.003666662 0.00011 833333.3333

3 3000 0.87 0.00087 450 206.897 0.004833323 0.000145 1250000

4 4000 1.11 0.00111 600 162.1627 0.006166646 0.000184999 1666666.667

5 5000 1.43 0.00143 750 125.8748 0.007944399 0.000238332 2083333.333

6 6000 1.74 0.00174 900 103.4491 0.009666585 0.000289998 2500000

7 7000 2.05 0.00205 1050 87.8059 0.011388756 0.000341663 2916666.667

8 8000 2.36 0.00236 1200 76.27237 0.013110908 0.000393327 3333333.333

9 9000 2.69 0.00269 1350 66.91584 0.014944144 0.000448324 3750000

10 10000 3.1 0.0031 1500 58.06607 0.017221762 0.000516653 4166666.667

11 11000 3.5 0.0035 1650 51.43032 0.019443783 0.000583313 4583333.333

12 12000 3.93 0.00393 1800 45.80349 0.021832397 0.000654972 5000000

13 13000 4.37 0.00437 1950 41.19212 0.02427649 0.000728295 5416666.667

14 14000 4.8 0.0048 2100 37.5024 0.02666496 0.000799949 5833333.333

15 15000 5.26 0.00526 2250 34.22316 0.029219977 0.000876599 6250000

16 16000 5.73 0.00573 2400 31.41648 0.03183043 0.000954913 6666666.667

17 17000 6.23 0.00623 2550 28.89557 0.03460738 0.001038221 7083333.333

18 18000 6.76 0.00676 2700 26.6306 0.037550789 0.001126524 7500000

19 19000 7.27 0.00727 2850 24.76292 0.04038296 0.001211489 7916666.667

20 20000 7.88 0.00788 3000 22.84658 0.043770228 0.001313107 8333333.333

21 21000 8.48 0.00848 3150 21.23066 0.047101702 0.001413051 8750000

22 22000 9.14 0.00914 3300 19.69822 0.050765997 0.00152298 9166666.667

23 23000 9.85 0.00985 3450 18.27904 0.054707478 0.001641224 9583333.333

24 24000 10.65 0.01065 3600 16.90673 0.059148031 0.001774441 10000000

25 25000 11.46 0.01146 3750 15.71254 0.063643449 0.001909303 10416666.67

26 26000 12.4 0.0124 3900 14.52233 0.068859478 0.002065784 10833333.33

27 27000 13.47 0.01347 4050 13.36976 0.074795636 0.002243869 11250000

28 28000 14.66 0.01466 4200 12.28564 0.081395852 0.002441876 11666666.67

29 29000 15.98 0.01598 4350 11.27207 0.088714849 0.002661445 12083333.33

30 30000 17.55 0.01755 4500 10.26519 0.097416654 0.0029225 12500000

31 31000 19.51 0.01951 4650 9.235793 0.108274407 0.003248232 12916666.67

32 32000 21.8 0.0218 4800 8.267781 0.120951442 0.003628543 13333333.33

33 33000 24.12 0.02412 4950 7.474747 0.1337838 0.004013514 13750000

ultimate 34.37 34370 14320833.33

S-Tube-S2


2016


APPENDIX B

COMPRESSION TEST OBSERVATIONS

Specimen 1 - hollowSl. No. Load(kN) Dial gauge Reading Deflection(mm) Strain Stress(kN/sqm)

1 0 0 0 0.000000 0

2 1 1 0.002 0.000020 416.6666667

3 2 1 0.002 0.000020 833.3333333

4 4 2 0.004 0.000040 1666.666667

5 8 4 0.008 0.000080 3333.333333

6 12.5 5.5 0.011 0.000110 5208.333333

7 15 7 0.014 0.000140 6250

8 20 11 0.022 0.000220 8333.333333

9 22.5 13 0.026 0.000260 9375

10 25 15 0.03 0.000300 10416.66667

11 27.5 18 0.036 0.000360 11458.33333

12 30 20 0.04 0.000400 12500

13 120 50000

Specimen 2-hollow

Sl. No. Load (kN) Dial Gauge Reading Deflection (mm) Strain Stress (kN/sqm)1 0 0 0 0.00000 0

2 2.5 0 0 0.00000 1041.666667

3 5 1.5 0.003 0.00003 2083.333333

4 7.5 2 0.004 0.00004 3125

5 10 3 0.006 0.00006 4166.666667

6 12.5 5 0.01 0.00010 5208.333333

7 15 6 0.012 0.00012 6250

8 17.5 6.5 0.013 0.00013 7291.666667

9 22.5 9.5 0.019 0.00019 9375

10 25 11.5 0.023 0.00023 10416.66667

11 37.5 22 0.044 0.00044 15625

12 50 32.5 0.065 0.00065 20833.33333

13 67.5 41.5 0.083 0.00083 28125

14 75 48 0.096 0.00096 31250

15 123.23 51345.83333


2016


APPENDIX B (cont.)

Sl. No. Load(kN) Dial gauge Reading Deflection(mm) strain Stress

1 0 0 0 0 0

2 5 0 0 0 2083.333333

3 10 0 0 0 4166.666667

4 15 0 0 0 6250

5 20 0 0 0 8333.333333

6 25 0 0 0 10416.66667

7 30 0 0 0 12500

8 35 0 0 0 14583.33333

9 40 0 0 0 16666.66667

10 45 0 0 0 18750

11 50 0 0 0 20833.33333

12 55 2.5 0.005 0.00005 22916.66667

13 60 6 0.012 0.00012 25000

14 65 7 0.014 0.00014 27083.33333

15 70 8 0.016 0.00016 29166.66667

16 75 10 0.02 0.0002 31250

17 80 11 0.022 0.00022 33333.33333

18 85 13 0.026 0.00026 35416.66667

19 90 15 0.03 0.0003 37500

20 95 17 0.034 0.00034 39583.33333

21 100 18.5 0.037 0.00037 41666.66667

22 105 20.5 0.041 0.00041 43750

23 110 23 0.046 0.00046 45833.33333

24 115 25 0.05 0.0005 47916.66667

25 120 27.5 0.055 0.00055 50000

26 125 30 0.06 0.0006 52083.33333

27 130 33 0.066 0.00066 54166.66667

28 135 35 0.07 0.0007 56250

29 140 38 0.076 0.00076 58333.33333

30 145 40 0.08 0.0008 60416.66667

31 150 42.5 0.085 0.00085 62500

32 155 45.5 0.091 0.00091 64583.33333

33 160 48 0.096 0.00096 66666.66667

34 165 51 0.102 0.00102 68750

35 170 54 0.108 0.00108 70833.33333

36 175 57 0.114 0.00114 72916.66667

37 180 61 0.122 0.00122 75000

38 185 61.5 0.123 0.00123 77083.33333

39 190 70 0.14 0.0014 79166.66667

40 195 75 0.15 0.0015 81250

41 200 80 0.16 0.0016 83333.33333

42 205 87 0.174 0.00174 85416.66667

43 210 94 0.188 0.00188 87500

44 215 104 0.208 0.00208 89583.33333

45 220 112 0.224 0.00224 91666.66667

46 225 122 0.244 0.00244 93750

47 237 98750

specimen 3 - solid


2016


APPENDIX B (cont.)

Sl. No. Load(kN) Dial gauge Reading Deflection(mm) strain Stress

1 0 0 0 0 0

2 5 0 0 0 2083.333

3 10 0 0 0 4166.667

4 15 0 0 0 6250

5 20 0 0 0 8333.333

6 25 2 0.004 0.00004 10416.67

7 30 3.5 0.007 0.00007 12500

8 35 4 0.008 0.00008 14583.33

9 40 5 0.01 0.0001 16666.67

10 45 5 0.01 0.0001 18750

11 50 7 0.014 0.00014 20833.33

12 55 7.5 0.015 0.00015 22916.67

13 60 8 0.016 0.00016 25000

14 65 8.5 0.017 0.00017 27083.33

15 70 10 0.02 0.0002 29166.67

16 75 11 0.022 0.00022 31250

17 80 12 0.024 0.00024 33333.33

18 85 13 0.026 0.00026 35416.67

19 90 14.5 0.029 0.00029 37500

20 95 16 0.032 0.00032 39583.33

21 100 17.5 0.035 0.00035 41666.67

22 105 19 0.038 0.00038 43750

23 110 20.5 0.041 0.00041 45833.33

24 115 22 0.044 0.00044 47916.67

25 120 24 0.048 0.00048 50000

26 125 26 0.052 0.00052 52083.33

27 130 28 0.056 0.00056 54166.67

28 135 30 0.06 0.0006 56250

29 140 32 0.064 0.00064 58333.33

30 145 34.5 0.069 0.00069 60416.67

31 150 36.5 0.073 0.00073 62500

32 155 38 0.076 0.00076 64583.33

33 160 40 0.08 0.0008 66666.67

34 165 42 0.084 0.00084 68750

35 170 43 0.086 0.00086 70833.33

specimen 4 (solid)


2016


APPENDIX B (cont.)

36 175 45 0.09 0.0009 72916.67

37 180 49 0.098 0.00098 75000

38 185 53 0.106 0.00106 77083.33

39 190 57 0.114 0.00114 79166.67

40 195 62 0.124 0.00124 81250

41 200 67 0.134 0.00134 83333.33

42 205 74 0.148 0.00148 85416.67

43 210 77 0.154 0.00154 87500

44 215 80 0.16 0.0016 89583.33

45 220 90 0.18 0.0018 91666.67

46 225 110 0.22 0.0022 93750

47 227 94583.33

1782.pdf39S_BE_1782.pdf

project reference no.: 39s be 1782€¦ · structural hollow sections made of steel make the most...

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