a study on mechanical properties of high strength metacem...

International Journal of Engineering Technology, Management and Applied Sciences

www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476

338 Smt. B. Ajitha,

Neelam. Manjula

A Study on Mechanical Properties of High Strength Metacem

Admixtured Concrete

*

Smt. B. Ajitha, **

Neelam. Manjula

*Assistant Professor, Department of Civil Engineering ,

** Post Graduate Student in Structural Engineering,

JNTUA JNTUA

ABSTRACT: This paper presents the result of mix design developed for high strength concrete and with replacement of

cement by Metakaolin/Metacem 85-C a comparison is drawn to find optimum percentage of Metakaolin .It involves the

process of determining experimentally the most suitable concrete mixes in order to achieve the maximum compressive

strength and split tensile strength of concrete for various mix proportions. In this research work Mix design for M60

concrete has been designed with 53 grade Ordinary Portland Cement, the locally available river sand, 16 mm and 10

mm graded coarse aggregate with a combination of 60% and 40% were selected based on ASTM C 127 standard for

determining the relative quantities and for this replacements cement is replaced with metakaolin in various proportions

(0,5,10,15 and 20 %) by weight. The mechanical properties like compressive strength and split tensile strength values

increased at 10% of partial replacement of cement by MK. For this design IS 10262-2009 guidelines were followed by

trial and error method fixed the mix design without any mineral admixtures.

Keywords: High Strength Concrete, Metakaolin, compressive strength ,Split tensile strength, Water to cement Ratio.

I . INTRODUCTION

High Strength Concrete (HSC) may be defined as

concrete with characteristic cube strength between

60 and 100 N/mm2. High-Strength Concrete is used

more widely with each passing year . The

compressive strength of HSC with cement-

Metakaolin blend of 0 - 20% mass of Metakaolin

and water to Cementitious ratio of 0.32 from 3

days to 28 days is investigated. The compressive

and split tensile strength of High Strength Concrete

after 28 days is found and keeping workability

criteria in mind, the mechanical properties are

found. The appropriate replacement of

Metakaolin/Metacem 85-C, low w/c ratio are

beneficial to the compressive strength of the High

Strength concrete by blending with Metakaolin in

various percentages. Metakaolin is not a by-product.

It is obtained by the calcinations of pure or refined

Kaolinite clay at a temperature between 650°C and

850°C, followed by grinding to achieve a finesse of

700-900 m²/kg. It is a high quality pozzolonic

material, which is blended with cement in order to

improve the durability of concrete.

Although high-strength concrete is often considered

a relatively new material, its development has been

gradual over many years. As the development has

continued, the definition of high-strength concrete

has changed. In the1950s, concrete with a

compressive strength of 34 N/mm2 was considered

as high strength. In the 1960s, concrete with 41 and

52 N/mm2 compressive strengths were used

commercially. In the early 1970s, 62 N/mm²

concrete was being produced. More recently,

compressive strengths approaching 138 N/mm²

have been used in cast-in-place buildings. For many

years, concrete with compressive strength in excess

of 41 N/mm² was available at only a few locations.

However, in recent years, the applications of high-

strength concrete have increased, and high-strength

concrete has now been used in many parts of the

world. The growth has been possible as a result of

recent developments in material technology and a

demand for higher-strength concrete The

construction of Chicago‟s Water Tower Place and

311 South Wacker Drive concrete buildings would

not have been possible without the development of

high-strength concrete. The use of concrete

superstructures in long span cable-stayed bridges

such as East Huntington, W.V., and bridge over the

Ohio River would not have taken place without the

availability of high-strength concrete.

The composition of HSC usually consists of

cement, water, fine sand, superplasticizer.

Sometimes components as well for HSC having



339 Smt. B. Ajitha,

Neelam. Manjula

ultra-strength and ultra-ductility respectively. The

key elements of high strength concrete can be

summarized as follows:

Low water-to-cement ratio,

Large quantity of cement

Mineral admixtures(Metacem 85-C)

Coarse Aggregates(16 mm &10 mm) and

fine sand,

High dosage of Super plasticizers (1.2% )

METAKAOLIN AS A ADMIXTURE:

Metakaolin, used in this present experimental study

is obtained from ASTRRA Chemicals, Chennai.

Specification, physical and chemical properties of

the Metakaolin as given by the supplier are given in

the following Tables.

Table 1: Properties of Metakaolin

PHYSICAL

PROPERTIES

VALUES

PHYSICAL FORM Powder

PARTICLE SHAPE Spherical

COLOUR Half- White

SPECIFIC

GFRAVITY

2.5

DENSITY (gm/cm³) 2.17

BULK DENSITY

(gm/cm³)

1.26

CHEMICAL

PROPERTIES

VALUES

SILICA (SiO₂) 53%

ALUMINA (Al₂O₃) 43%

FERRIC OXIDE

(Fe₂O₃) 0.5%

SULPHURIC

ANHYDRIDE (SO4)

0. 1%

CALCIUM OXIDE

(CaO)

0. 1%

SODIUM OXIDE

(Na₂O)

0.05%

POTTASIUM OXIDE

((K2O)

0.4%

LOSS ON IGNITION 0.11%

Fig. 1. Formation of Metakaolin

Fig. 2. Appearance of Metacem 85-C

Scope of the project:

According to the codal procedure, we have to

perform the tests to know about the fresh and

hardened properties of High strength concrete made

with Metakaolin replacement. The experimental

work was conducted on cubes and beams so that it

leads to evaluate the compression and flexural

strengths of concrete.

The details and properties of materials that were

used in this study are discussed High strength

Concrete (HSC) can be used in high-rise buildings,

tall structures and both in super and substructure of

bridges and many more. The mix design developed

for high strength concrete with metakaolin. Here

five mixes proportions were designed with

Metakaolin quantities varied from 0 to 20 percent

weight of Cementitious materials. Each mix 9

numbers of specimens cube, were casted then kept

in curing tank after 24 hours of time period. For

M60 grade of concrete, the Cementitious materials

are replaced with metakaolin in the proportion of

0%, 5%, 10%, 15% and 20% (by weight) in all

mixes. Here an attempt made on concrete blended

with Metakaolin of various proportions in concrete



340 Smt. B. Ajitha,

Neelam. Manjula

to evaluate the Compressive strength ,workability,

compaction factor, slump is calculated.

II. LITERATURE REVIEW

In recent years, the applications of high-

strength concrete have increased, and high-strength

concrete has now been used in many parts of the

world.

Beulah et al. (2012) [1] this paper presents an

experimental investigation on the effect of partial

replacement of cement by metakaolin by various

percentages, viz., 0%, 10%, 20%, and 30% on the

properties of high performance concrete, when it is

subjected to hydrochloric acid attack.

Vikas Srivastava et al. (2012) [2]this study deals

with the addition of some pozzolanic materials, the

various properties of concrete, viz., workability,

durability, strength, resistance to cracks and

permeability can be improved. In this present work

is to find the mechanical

properties of partially replaced cement with

Metakaolin at 0%, 10%, 15%, 20%, 25% and 30%

for M70 grade of concrete. To evaluate compressive

strength, split tensile strength, Flexural strength and

stress-strain curve of MKC.

A.V.S.Sai. Kumar et.al [3] investigated the effect

of strength of concrete with partial replacement as

Metakaolin. Different replacement using 2.5%,

5.0%, 7.5%, 10.0%, 12.5% metakaolin was carried

out with cement and they had reported that

metakaolin can be used as a partial replacement of

cement.

Nova John (2013) [4] investigated the cement

replacement levels were 5%,10%,15%,20% by

weight for metakaolin. The strength of all

metakaolin admixed concrete mixes over shoot the

strength development of concrete. Mix with 15%

metakaolin is superior to all other mixes. The

increase in metakaolin content improves the

compressive strength, split tensile strength and

flexural strength upto 15% replacement. The result

encourages the use of metakaolin, as pozzolanic

material for partial cement replacement in

producing high strength concrete. The inclusion of

metakaolin results in faster early age strength

development of concrete. The utilization of

supplementary cementitious material like

metakaolin concrete can compensate for

environmental, technical and economic issues

caused by cement production.

III. MATERIAL AND EXPERIMENTAL

INFORMATION

3.1. Properties of cement

Ordinary Portland cement of grade 53 ACC was

used in this experimental work. The properties of

cement are as follows

i. Specific gravity :3.15

ii. Normal Consistency: 26.5%

iii. Fineness of cement (m2/kg) :289

iv. Fineness :3%

v. Setting time (minutes)

a. Initial setting :39

b. Final setting :185

vi. Soundness of cement :1.0

Fig. 3 cement

3.2. Fine aggregate:

Locally available river sand is used as fine

aggregate which is passed through 4.75mm I.S.

sieve. The specific gravity of the sand is found to be

2.343. The sand used for the experimental program

was locally procured and conformed to Indian

Standard Specifications IS: 383-1970.

i. Specific gravity : 2.45

ii. Fineness modulus : 3.015

iii. Bulk density :16.70 KN/m3

iv. Bulking of Sand : 27.53%

v. Grading of Sand : Zone – II

Fig. 4 fine aggregate (sand)



341 Smt. B. Ajitha,

Neelam. Manjula

3.3 Coarse aggregate:

The local available natural granite aggregate is

used in this study. The all in all size coarse

aggregate which passes through IS 20mm sieve and

retained on IS 10mm sieve has been used in this

study. The all in all size aggregate is preferred for

effective utilization and good placing of aggregates.

The properties of granite aggregate are shown in the

following tables. Locally available coarse aggregate

having a maximum size of 16mm, 10mm were used

for work. The aggregates were tested as per Indian

Standards Specification IS: 383-1970.

i. Specific gravity

a.16 mm&10 mm = 2.658

ii. Fineness modulus : 2.08

iii. Flakiness Index : 18.96 %

iv. Elongation Index : 24.64%

v. Crushing Value: 20 %

vi. Impact Value : 20.36 %

vii. Water Absorption : 0.50 %

Fig. 5 Coarse aggregate (kankar)

3.4 Advantages of HSC with MK as

admixture:

High Strength Concrete with Metakaolin as

admixtures offers many advantages. Some of these

are as follows –

a) Facilitate finishing concrete surfaces by rubbing

and smoothing due to the lack of stickiness of

concrete to the tool and good thixotropy.

b) It reduces the amount of cement in the formation

of concrete, especially in concrete with high

requirements for water resistance.

c) The strength and durability of concrete increases.

d) Use of Metakaolin accelerates the initial set time

of concrete.

e) The cross sectional areas of structural members

can be reduced safely, so saving in concrete and can

be economically used for high rise buildings, dams,

bridges etc.

f) It Imparts improved water-tightness, so safely

used for water retaining structure, off shore

structure etc.

g) Confers high early strength, allows a quicker

reuse of formwork, and thus enhances the

production rate.

h) Ecofriendly.

i) Metakaolin reduces heat of hydration leading to

better shrinkage and crack control.

3.4.1 Applications of HSC with MK as

admixture:

High Strength Concrete with Metakaolin as

admixtures offers many advantages as mentioned

above. So it can be used for – a)Dams, b) Bridges c)

Water retaining structures d) High rise buildings e)

Off shore structures f) industrial flooring g)

Warehouses h) Container Depots i) Roads j) Lining

k) Mass concreting l)aqueducts m) Nuclear power

stations n) structural members where cross section

required to be small etc.

3.4.2Cementitious application of Metakaolin

1. It enhances the mechanical properties,

durability and constructability in concrete.

2. It is used in the production of high strength

& high performance concrete.

3. It is used in the production of high

performance concrete structures like bridge’s where

the strength and durability properties of the concrete

are required.

4. It can be used to build marine structures as

it reduces the damage caused due to the reaction of

chloride and various chemicals, it helps in

protection of steel from rust and corrosion and

increases the life of the structure.

5. The recommended dosage is 7 – 10 % of

the cementitious weight added to the concrete.

3.5 Use of Metakaolin in HSC:

Metakaolin reduces the size of pores in

cement paste and transforms many finer particles

into discontinuous pores, therefore decreasing the

permeability of concrete substantially. Metakaolin

increases compressive and flexural strengths. It

reduces water permeability and efflorescence. Also

it reduces heat of hydration leading to better



342 Smt. B. Ajitha,

Neelam. Manjula

shrinkage and crack control. So use of Metakaolin

has wide scope in its use in HSC.

3.6 Water:

The locally available potable fresh water was

used for mixing and curing of specimens. Clean

portable water was used for mixing motor, concrete

and curing. Water must be free from injurious

amounts of oils, acids, alkalis, salts, sugar, organic

materials or other substances that may be

deleterious to concrete or steel. Portable water is

generally considered satisfactory for mixing

concrete.

Water content: 148.8 kg/m3

3.7 Superplasticizer:

SP430 is a chloride free,

superplasticising admixture based on selected

sulphonated napthalene polymers. It is supplied as a

brown solution which instantly disperses in water. It

has been specially formulated to give high water

reductions up to 25% without loss of workability or

to produce high quality concrete of reduced

permeability.

Specific gravity : 1.145

IV RESULTS AND DISCUSSION

4.1 Preliminary results on concrete:

Table 2: Workability results

NO TEST RESULT INFERENCE

1 Slump cone 4-14 mm Low

workability

2 Compaction

factor

0.84-0.888 Low

workability

3 Vee –Bee T=13-5

sec

Low

workability

4.2 Mix design proportions:

Table 3: Proportions of Mix design

Specimen Mix proportions

Cement Fine

aggregate

Coarse

aggregate

S1

(nominal mix)

1 1.34 2.54

S2 1 1.250 2.370

S3 1 1.316 2.494

S4 1 1.389 2.632

S5 1 1.471 2.788

S1: Sample one of mix design of proportion

(nominal mix M60 ) Here Metakaolin content is 0%

and cement content is 100% and SP 430 of 1.2% of

cement content and here coarse aggregate of 16

mm and 10 mm in combination is used in 60 and

40%.

S2: Sample two, the mix design of proportion the

replacement of Metakaolin is done, here Metakaolin

content is 5 % and cement content is 95 % and SP

430 of 1.2% of cement content and here coarse

aggregate of 16 mm and 10 mm in combination is

used in 60 and 40%.

S3: Sample three, the mix design of proportion the





used in 60 and 40%.

S4: Sample four, the mix design of proportion the





used in 60 and 40%.

S5: Sample five, the mix design of proportion the





used in 60 and 40%.

Fig.6.Percentage replacement v/s slump



343 Smt. B. Ajitha,

Neelam. Manjula

Fig.7.Percentage replacement v/s

compaction factor

Fig. 8. Percentage replacement v/s VEE-

BEE value

4.3 Cube compressive strength test

Fig. 9 Apparatus of Compressive strength test

Table 4: Compressive Strength values for High

strength Concrete Mix M60

Replacement

of Metakaolin

(%)

Compressive Strength in

N/mm2

3 days 7 days 28 days

S1 (0%) 34.47 46.25 64.93

S2 (5%) 37.40 50.12 71.43

S3 (10%) 38.27 55.20 76.58

S4 (15%) 42.75 51.39 68.23

S5 (20%) 41.55 47.88 67.35

The table 4: shows the average compressive

strength values recorded at the time of testing for 3,

7 and 28 days of curing and the percentage

difference of compressive strength for all batch

mixes. The variation of compressive strength at 3, 7

and 28 days to the percentage replacement of

Metakaolin is shown in the figure . The figure

shows that the compressive strength value increased

when we replace the Metakaolin up to 10% after

that it gradually declined up to 20%. At the same

time, As a result the percentage difference for 0%

and 10% Metakaolin replacement is 17.94.

Surprisingly in this analysis the replaced

Metakaolin in High- Strength concrete got more

compressive strength value and satisfied the

nominal mix i.e. 0% replacement of Metakaolin

with 100% cement content.

Fig. 10 Curing periods v/s Compressive Strength



344 Smt. B. Ajitha,

Neelam. Manjula

Fig. 11 Percentage replacement v/s Compressive

Strength

Fig. 12 Percentage replacement v/s Compressive

Strength (28 days)

4.4 Split tensile strength test:

Fig. 13 Split tensile strength test

Table 5: Split tensile Strength values for High

strength Concrete Mix M60

Replacement

of Metakaolin

(%)

Split tensile Strength in

N/mm2

3 days 7 days 28 days

S1 (0%) 3.09 3.54 4.39

S2 (5%) 3.36 3.58 4.43

S3 (10%) 3.43 4.64 5.56

S4 (15%) 3.29 3.52 4.03

S5 (20%) 3.18 3.41 3.98

The table 5: shows the average split tensile strength

values recorded at the time of testing for 3, 7 and 28

days of curing and the percentage difference of split

tensile strength for all batch mixes. The variation of

compressive strength at 3, 7 and 28 days to the

percentage replacement of Metakaolin is shown in

the figure . The figures shows that the split tensile

strength values increased when we replace the

Metakaolin up to 10% after that it gradually

declined up to 20%. and satisfied the nominal mix

i.e. 0% replacement of Metakaolin with 100%

cement content.

Fig. 14 Curing periods v/s Split tensile Strength

Fig. 15 Percentage replacement v/s split tensile

Strength



345 Smt. B. Ajitha,

Neelam. Manjula

The above figures shows the various percentages of

replacement of Metakaolin like 0%,5%,10%,15%

and 20% and their curing periods v/s compressive

and split tensile strength and replacement

percentages represented in line diagrams and bar

charts. In this study, compressive and split tensile

strength was increased from 0% replacement of

Metakaolin to 10% replacement later it is slightly

declined to 20%.

Fig. 16. Casting of Specimens

Fig. 17. Curing of Specimens

5. CONCLUSIONS:

Based on the Investigation conducted on the Mix

design of high strength concrete by using

Metakaolin, the following conclusions were made.

Increase in the percentage of Metakaolin requires

more demand of water because of the Greater

fineness. To maintain the workability of the

concrete use of super plasticizer is necessary.

Increase in Percentage of Metakaolin the slump of

the concrete was reduced, to maintain the require

slump addition of super plasticizer is necessary. In

this study Metakaolin added from 0 to 20%, the

observation was Increase in Metakaolin

compressive and split tensile strength also increased

up to 10% but the slump value was reduced.

Replacement of cement with Metakaolin 10%, gave

the maximum compressive strength, so 10%

replacement of Metakaolin is optimum

The following are the key points that are concluded

from the present experimental work.

1. The compressive and split tensile strengths

for HSC has increased for 5% and 10% replacement

of Metakaolin and decreased in 15% and 20%

replacements. So, optimum percentage of

replacement of Metakaolin is 10%.

2. Success of HSC requires more attention on

proper mix design, production, placing and curing

of concrete. For each of these operations controlling

parameters should be achieved by concrete producer

for an environment that a structure has to face.

3. Even though the initial cost of HSC is

comparatively higher than conventional concrete,

considering the long service life of the structures

and the minimum maintenance required, the benefit

cost ratio is very much in favor.

4. The higher strength concrete permits use of

reduced sizes of structural members and increases

available usable space in building, which is an

important factor in congested urban locations.

5. HSC can be advantageously used for the

production of precast products which can be mass

produced and which utilize effectively the high

durability and strength characteristics such as

electric poles in coastal areas, pipes for

transportation of corrosive liquids such as sewage,

effluents etc.

6. The workability for HSC with replacing of

Metakaolin decreases.

5.1 Recommendations for future

investigations:

1. The study on high strength concrete with

replacing of Metakaolin in various percentages can

be further extended for research purpose.

2. We can increase the strength of concrete by

replacing mineral admixtures and also have wide

scope in tall structures.

3. Studies can be conducted by incorporation

of variation of other percentages of Metakaolin

replacement.

4. Studies can be conducted on HSC with

percentages of Metakaolin replacement such as

sulphate attack, acid resistance , performance under

impact, torsion etc.,



346 Smt. B. Ajitha,

Neelam. Manjula

5. In metro projects HSC can be useful and

also piers and abutments and to build high rise

buildings by reducing column sizes and increasing

available space.

5.2 References: [1] Indian Standard Recommended guidelines for

Concrete Mix Design, IS 10262: 1982, Bureau of Indian

Standard, New Delhi.

[2] Santhakumar, A.R. (2009). ―Concrete Technology‖,

Oxford University Press Publication, India, pp. 939-311.

[3] Wild, S., Khatib, J.M. and Jones, A. 1996. Relative

strength, pozzolanic activity and cement hydration in

superplasticized Metakaolin concrete. Cement Concr.

Res.26(10): 1537- 1544.

[4] Basu, Prabir C, et al, High Reactivity metakaolin: a

new pozzolan, Proceedings of the national seminar on

Innovative construction materials, VJTI, Mumbai, Jan

21-22, 2001.

[5] Caldarone, M.A. et al “High reactivity metakaolin:

anew generation mineral admixture”.Concrete Int,

vol.34,November 1994, pp: 37-40.

a study on mechanical properties of high strength metacem...

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