a study on mechanical properties of high strength metacem...
TRANSCRIPT
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
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476
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
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476
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)
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476
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
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476
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
replacement of Metakaolin is done, here Metakaolin
content is 10 % and cement content is 90 % 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%.
S4: Sample four, the mix design of proportion the
replacement of Metakaolin is done, here Metakaolin
content is 15 % and cement content is 85 % 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%.
S5: Sample five, the mix design of proportion the
replacement of Metakaolin is done, here Metakaolin
content is 0 % and cement content is 80 % 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%.
Fig.6.Percentage replacement v/s slump
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476
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
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476
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
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476
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.,
International Journal of Engineering Technology, Management and Applied Sciences
www.ijetmas.com April 2017, Volume 5, Issue 4, ISSN 2349-4476
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.