A STUDY ON HIGH STRENGTH SELF COMPACTING CONCRETE ON EXPOSURE TO VARIOUS TEMPERATURES

57
International Journal of Research and Innovation (IJRI)
A STUDY ON HIGH STRENGTH SELF COMPACTING CON-
CRETE ON EXPOSURE TO VARIOUS TEMPERATURES
A.Swetha 1
, K. Mythili2
,
1 Research Scholar, Department Of Civil Engineering, Aurora's Scientific Technological & Research Academy, Hyderabad, India
2 Associate Professor, Department Of Civil Engineering, Aurora's Scientific Technological & Research Academy,Hyderabad, India
*Corresponding Author:
A.Swetha,
Research Scholar, Department of CIVIL Engineering,
Aurora's Scientific Technological & Research Academy,
Hyderabad, India
Published: October 27, 2014
Review Type: peer reviewed
Volume: I, Issue : II
Citation:A.Swetha , (2014) A Study On High Strength Self Com-
pacting Concrete On Exposure To Various Temperatures
INTRODUCTION
GENERAL
Concrete is one of the most extensively used con-
struction materials in the world, with about two
billion tons of utilization worldwide each year. It
is attractive in many applications because it offers
considerable strength at a relatively low cost. Con-
crete can generally be produced of locally available
constituents, can be cast in to wide variety of struc-
tural configurations and requires minimal mainte-
nance during service. However, environmental con-
cerns, stemming from high-energy expense and CO2
emission associated with cement manufacture, have
brought pressures to reduce consumption through
the use of supplementary materials.
In general, concrete is said to be a very durable one.
But when Reinforced Concrete structure is subject-
ed to severe environmental conditions, its properties
are affected adversely depending on the type of ex-
posure. Durability is one the most important prop-
erties to be considered in the design of Reinforced
Concrete structures exposed to aggressive environ-
ments which can be described by two stages: the
initiation and the propagation period.
Increasing the concrete strength is always one of the
main desires of Concrete Technology. Since more
than 20 years High Strength concretes with com-
pressive strength ranging from 50 N/mm2 to 130N/
mm2 have been used worldwide in tall buildings
and bridges with long spans or buildings in aggres-
sive environments. Building elements made of High
Strength concrete are usually densely reinforced.
The small distance between reinforcing bars may
lead to defects in concrete. If High Strength con-
crete is self-compacting, the production of dense-
ly reinforced building element from High Strength
concrete with high homogeneity would be an easy
work. Self-compacting concrete is a concrete that
flows and compacts only under gravity. It fills the
whole mould completely without any defects. The
usual self-compacting concretes have a compres-
sive strength in the range of 60-100N/mm2
.
Self Compacting Concrete (SCC):
Placement of concrete generally requires consolida-
Abstract
The extensive use of concrete as a structural material for the high rise buildings, storage tanks, nuclear reactors and
pressure vessels increase the risk of concrete being exposed to high temperatures. This has led to a demand to improve
the understanding of the effect of temperature on concrete. The behavior of concrete exposed to high temperature is a
result of many factors including the exposed environment and constituent materials.
Concrete structures are exposed to fire when a fire accident occurs. Damage in concrete structures due to fire depends
to a great extent on the intensity and duration of fire. The distress in concrete manifests in the form of cracking and
spalling of concrete surface.
The main aim of the present experiment investigation is to study the behavior of High Strength Self Compacting Con-
crete when subjected to elevated temperatures.
High Strength Self Compacting Concrete specimens made with Cement, Micro Silica, Quartz Sand, Quartz Power and
Basalt of size 2 to 5 mm and Chemical Admixtures.
In the present investigation, tests were conducted on Concrete Specimens by exposing them at different temperatures
like 2000 C, 4000 C and 6000 C at 4 hours, 8 hours and 12 hours duration. After 28 days curing the specimens are
tested for Compressive Strength, Split Tensile Strength, Percentage Weight Loss and Non Destructive Test to measure
velocity of Concrete.
Based on the study, conclusions were made that High Strength Self Compacting Concrete with the above materials not
able to resist temperature of 6000
C and above.
1401-1402

58
tion by vibration in the forms. Self compacting Con-
crete (SCC) can be defined as the “highly flowable
concrete yet stable concrete that can spread readily
into place and fill the formwork without any con-
solidation and without undergoing any significant
separation”( Khayat, Hu and many, proceeding first
international RILEM symposium, SCC Stockholm
1999).An alternative specification suggest SCC as a
“flowing concrete without segregation and bleeding,
capable of filling spaces and dense reinforcement or
inaccessible voids without hindrance or blockage.
Self compacting concrete was first developed in
1986 in Japan to achieve durable concrete struc-
ture since then, various investigations have been
carried out this type of concrete has been used in
practical structures in Japan, mainly by large con-
struction companies.
The first usable self compacting concrete was com-
pleted in 1988 and was named “High performance
concrete” and later proposed as “Self compacting
high performance concrete’. This leads to develop-
ments of self compacting concrete. Self compacting
concrete has been described as “The most revolu-
tionary development in concrete construction for
several decades” originally developed to offset a
growing shortage of skilled labour, it has proved
beneficially economically.
Self compacting concrete a new kind of high perfor-
mance concrete (HPC) excellent deformability and
segregation resistance, it is a special kind concrete
than can flow through and fill the gaps of reinforce-
ment and corners of molds without any need for vi-
bration and compaction during the pacing process.
Through showing good performance, self compact-
ing concrete is different from the HPC developed in
North America and Europe, which emphasizes on
high and durability of concrete. In terms of work-
ability, HPC merely improved fluidity of concrete
to facilitate placing: however it cannot flow freely
by itself to pack every corner of molds and all gaps
among reinforcement. In other words HPC still re-
quires vibration and compaction in the construction
process. Comparatively self compacting concrete
has more favorable characteristics such as high flu-
idity, good segregation resistance and the distinc-
tive self compacting ability without any need for vi-
bration during the placing process.
BENEFITS AND ADVANTAGES OF SCC:
•Modern, presently self compacting concrete (self
compacted concrete) can be classified as an ad-
vanced construction material. The self compacting
concrete as the name suggests, does not require to
be vibrated to achieve full compaction. This many
benefits and advantages over conventional concrete.
•Improved quality of concrete and reduction of
onsite repairs.
•Faster construction times.
•Lower overall costs.
•Facilitation of introduction of automation into con-
crete construction.
•Better surface finishes.
•Easier placing.
•Thinner concrete sections.
•Greater freedom in design.
•Improved durability and reliability of concrete
structures.
•Easy of placement results in cost savings through
reduced equipment and labour requirement.
High Performance Concrete:
Long-term performance of structures has become
vital to the economies of all nations. Concrete has
been the major instrument for providing stable and
reliable infrastructure since the days of the Greek
and Roman civilization. Deterioration, long term
poor performance and inadequate resistance to
hostile environment coupled with greater demands
for more sophisticated architectural form, led to
the accelerated research into the microstructure of
cements and concretes and more elaborate codes
and standards. As a result, new materials and
composites have been developed and improved ce-
ments evolved. Today concrete structures with a
compressive strength exceeding138 Mpa are being
built world over. In research laboratories, concrete
strengths of even as high as 800 Mpa are being pro-
duced. One major remarkable quality in making
of High Performance Concrete (HPC) is the virtual
elimination of voids in the concrete matrix which
are mainly the cause of most of the ills that generate
deterioration.
Advantages of High Performance Concrete:
The advantages of using high strength high perfor-
mance concretes often balance the increase in ma-
terial cost. The following are the major advantages
that can be accomplished.
1.Reduction in member size, resulting in increase in
plinth area/useable area and direct savings in the
concrete volume.
2.Reduction in the self-weight and super-imposed
DL with the accompanying saving due to smaller
foundations.
3.Reduction in form-work area and cost with the ac-
companying reduction in shoring and stripping time
due to high early-age gain in strength.
4.Construction of High-rise buildings with the ac-
companying savings in real-estate costs in congest-
ed areas.
5.Longer spans and fewer beams for the same mag-
nitude of loading.
6.Reduced axial shortening of compression sup-
porting members.

59
7.Reduction in the number of supports and the sup-
porting foundations due to the increase in spans.
8.Reduction in the thickness of floor slabs and sup-
porting beam sections which are a major component
of the weight and cost of majority of structures.
9.Superior long-term service performance under
static, dynamic and fatigue loading.
10.Low creep and shrinkage.
11.Greater stiffness as a result of a higher modulus
(Ec).
12.Higher resistance to freezing and thawing, chem-
ical attack, and significantly improved long-term
durability and crack propagation.
13.Reduced maintenance and repairs.
14.Smaller depreciation as a fixed cost.
Aim of the Present Study:
The Aim of the Present Study is to investigate the
Compressive Strength and Split Tensile Strength
of High Strength Self Compacting Concrete when
subjected to elevated temperatures. To investigate
the effect of temperature and to evaluate structural
safety, an attempt has been made to study the Com-
pressive Strength.The study concentrates mainly
on the properties of Compressive Strength of High
Strength Self Compacting Concrete for a particu-
lar water binder (w/b) ratio at 2000C, 4000C and
6000C.
In the present investigation, the tests were con-
ducted for a total of 180 specimens on a particular
w/b ratio by exposing them at different tempera-
tures like Room Temperature, 2000C, 4000C and
6000C for 4 Hours, 8 Hours and 12 Hours duration.
The results indicate that the High Performance Self
Compacting Concrete is effective in resisting the ef-
fect of temperature on the compressive strength.
The main aim of the present experiment investiga-
tion is to study the behavior of High Strength Self
Compacting Concrete when subjected to elevated
temperatures.
High Strength Self Compacting Concrete speci-
mens made with Cement, Micro Silica, Quartz sand,
Quartz Powder, Basalt of size 2 to 5 mm and Chemi-
cal Admixtures.
In the present investigation tests were conducted
on Concrete specimens by exploring that at differ-
ent temperatures like 2000C, 4000C and 6000C
for 4 Hours, 8 Hours and 12 Hours duration after
28 days curing. The specimens are tested for Com-
pressive Strength, Split Tensile Strength , % Weight
Loss and Non Destructive Test to measure Velocity
of Concrete.
Based on the study, conclusions were made that
High Strength Self Compacting Concrete with the
above materials was not able to resist temperature
of 6000
C and above.
EXPERMENTAL INVESTIGATION
GENERAL:
The present investigation is a study of the concrete
compressive strength, Split tensile strength and %
reduction in weight of concrete for High Strength
Self compacting concrete when subjected to elevat-
ed temperatures of 2000
C, 4000
C, and 6000
C. This
was planned to be carried out through an experi-
mental program on concrete specimens of size 100
x 100 x 100 mm cubes and 100 x 200 mm cylinders
for compressive strength and split tensile strength.
The test specimens were de-moulded 4 hrs of air
cooling and kept for water curing for 28 days.
The standard specimens after curing period were
placed in muffle furnace at requisite temperature of
2000
C, 4000
C and 6000
C at 4 hrs, 8 hrs and 12 hrs
duration.
After the specimen removed from the furnace, the
specimens were allowed to cool in air for 2 hrs.
Then the specimens were tested for NDT, compres-
sive strength, split tensile strength, the results were
tabulated & required comparative study was made.
The objective of the experimental study that was
conducted is given below.
1)To study the pulse velocity (m/sec) at 28 days at
Room, Temperature, 2000
C, 4000
C and 6000
C expo-
sure at 4hrs, 8 hrs and 12 hrs duration.
2)To study the percentage weight loss at 28 days at
Room Temperature, 2000
C, 4000
C and 6000
C expo-
sure at 4hrs, 8 hrs and 12 hrs duration.
3)To study the Compressive strength and Split ten-
sile strength ( Mpa) at 28 days at Room Tempera-
ture, 2000
C, 4000
C and 6000
C exposure at 4hrs, 8
hrs and 12 hrs duration.
Materials used:
The materials that are used in this study are:
•Cement
•Fine aggregate (Quartz sand)
•Quartz Powder
•Coarse aggregate (Crushed basalt)
•Super plasticizer
•VMA
•Water
Cement
Ordinary Portland cement of 53 grade available in
local market is used in the investigation. The ce-
ment used has been tested for various proportions
as per IS 4031 – 1988 and found to be confirming to
various specifications of IS 12269-1987. The specif-
ic gravity was 3.15 and fineness was 2800 cm2/gm.
In the experimental investigations ordinary Port-
land cement i.e., I.S Type cement of 53 grade is
used. Care to be taken that it is made from a single
source and fine grained and is stored in an airtight
container to prevent it from the atmospheric mois-
ture and humidity.

60
Properties of Quartz powder and Quartz sand:
Name SiO2 TiO2 Fe2O3 Al2O3 CaO MgO
Loss on Igni-
tion
Per-
centage
99.24 Absent 0.04 0.12 0.28 Absent 0.06

Pictures of Quartz sand and Quartz powder
Coarse aggregate (Crushed basalt 2 to 5mm)
Basalt comes from extensive lava flows. Basalt is
a very common igneous rock and the most com-
mon rock in the Earth's crust. Almost all oceanic
crust is made of Basalt and it is a common extru-
sion from many volcanic regions around the world.
It forms from the melting of the upper mantle and
its chemistry closely resembles the upper mantle's
composition. It is generally Silica poor and Iron and
Magnesium rich. Basalt originates from "hot spot"
volcanoes, massive basalt flows and mid oceanic
ridges.
In present investigations crushed basalt is used
with size varying from 2 - 5 mm.
V-Funnel Test Apparatus
The average flow through speed, Vm, is calculated in terms of the
flow through time, t0;
To quantify segregation resistance, the flow-
through index, Sf, is calculated in terms of
initial flow through time, t0, and the flow
through time after 5 minutes, t5:
Slump Flow Test:
The simplest and most widely used test method
for self-compacting concrete is the slump flow test
(Kuroiwa et al. 1993; EFNARC 2002; Bartos, Sonebi,
and Tamimi 2002). The test, which was developed in
Japan, was originally used to measure underwater
concrete and has also been used to measure highly
flowable concretes. To perform the test, a conven-
tional slump cone is placed on a rigid, non-absor-
bent plate and filled with concrete without tamping.
The plate must be placed on a firm, level surface.
The slump cone is lifted and the horizontal spread of
the concrete is measured. For an additional meas-
ure of flowability, the time required for the concrete
to spread to a diameter of 50 cm can be measured.
The slump flow was used to assess the horizontal
free flow and the falling ability in the absence of ob-
structions. The recommended slump range was 650
to 800 mm. This value of T50 generally ranges from
2-7 seconds. It is possible to assess the stability of
concrete qualitatively after performing the slump
flow test. A visual stability index(VSI) has been de-
veloped as a standard means of determining stabil-
ity. A numerical score on a scale of 0 to 3 is assigned
based on a visual evaluation of the segregation and
bleeding in the concrete sample. Self-compacting
concrete should exhibit a rating of 0 or 1 to be con-
sidered acceptable.
L-Box Test:
The L-box test (EFNARC 2002; Bartos, Sonebi, and
Tamimi 2002) measures the filling and passing abil-
ity of self-compacting concrete. Originally devel-
oped in Japan for underwater concrete, the test is
also applicable for highly flowable concrete. As the
test name implies, the apparatus consists of an L-
shaped box.
L-Box Test Apparatus
Casting
For casting the cube and cylinder specimens, stand-
ard cast iron metal moulds of size 100 x 100 x 100
mm and 100 x 200 mm were used. The moulds were
cleaned from adhering dust particle and oiled on all
sides, before concrete is poured into. Thoroughly
mixed concrete was filled in moulds.
Curing
After casting, the specimens were stored in the labo-
ratory free of vibrations in moist air at room tem-
Sf = ts t0
t0
Vm
0.01
(0.065x0.075)xt0
= = 2.05
t0
(m/s)

61
perature for 24 hrs. After this period, the specimens
were removed from the mould and immediately im-
mersed in clean, fresh water curing tank. The above
climate was maintained for 28 days.
Testing of Specimens:
A time schedule for testing of specimens is main-
tained to ensure their proper testing on the due
date and time. The cast specimens are tested as per
standard procedures, immediately after they are re-
moved from curing pond and wiped off the surface
water. The test results are tabulated carefully
Description of Compression Testing Machine
The compression testing machine (Microproces-
sor based) used for testing the cube specimens is
of standard make. The capacity of the testing ma-
chine is 200 Tonnes or 2000 KN. The machine has
an ideal gauge on which the load applied can be
read directly. The oil level is checked, the MS plates
are cleaned and the machine is kept ready for test-
ing specimens.
Ultra Pulse Velocity apparatus
This determines the velocity of longitudinal waves.
The determination consists of measurement of the
time taken by a pulse, hence the name of the meth-
od to travel a measured distance. The apparatus in-
clude transducers which are placed in contact with
the concrete, a pulse generator with a frequency of
between 10 and 150 Hz, an amplifier a time meas-
uring circuit and a digital display of the time taken
by the pulse of longitudinal waves to travel between
the transducers. The test method is prescribed by
ASTM C 597 – 83 and by BS 1881:203:1986.
EXPERIMENTAL RESULTS
GENERAL:
In the present study, investigations are carried out
to study the effect of elevated temperatures on High
strength self compacting concrete.
Properties of Micro Silica
Typical Oxide Composition of Micro Silica (Oriental
Trexim Pvt Ltd)
Sl. No: Constituents Percentage
1 Silica, Sio2 92.00
2 Alumina, A12O3 0.46
3 Iron Oxide, Fe2O3 1.60
4 Lime, CaO 0.36
5 Magnesia, MgO 0.74
6 Sulphur Trioxide, SO3 0.35
7 Loss on ignition 2.50
8 Na2O 0.70
9 K2O 0.90
10 pH 7.60
11
Accelerated Pozzolonic
Acidity index in 7 days
104.00
12
Accelerated Pozzolonic
Acidity index in 28 days
117.00
13 Surface Area m2/kg 1890
14 Moisture Content 1.00
15 Bulk Density 450-650
Quantities of Materials required per 1m3 of High
Strength Self Compacting Concrete
Sl. No: Material Weight (Kg)
1 Crushed basalt-2 to 5mm 1022
2 Quartz Sand (3 to 8 μm) 437
3 Quartz Powder (0 to 10 μm) 202
4 Micro Silica 142
5 Cement 472
6 Water 175 lt
7 Super Plasticizer 14688 ml
8 VMA 816 ml
9
Water /(cement + Micro
Silica + Quartz Powder) 0.215
Workability of High Strength Self Compacting
Concrete
Test method Mix
Permissible limits as per EFNARC
Guidelines
Min Max
V-Funnel 9.7 sec 6 sec 12 sec
V-Funnel at T5
min
13.85 sec 11 sec 15 sec
Abrams slump
flow
690 mm 650 mm 800 mm
T 50cm slump
flow
4 sec 2 sec 5 sec
L- Box
0.9 0.82 1.0
1 sec 1 sec 2 sec
2 sec 2 sec 3 sec
Details of specimens to be tested for elevated tem-
perature of HPSCC

62
Strength point of view no”.of cubes required
Sl.
No
Size of the
cube
No. of days (all 28 days)
No.of
cubesRoom
temp
4
hrs
8
hrs
12
hrs
1(a)
100 x 100
x 100 mm
cubes
(Compressive
strength) –
2000
C
3 3 3 3 12
1(b)
100 x 100
x 100 mm
cubes
(Compressive
strength) -
4000
C
- 3 3 3 9
1(c)
100 x 100
x 100 mm
cubes
(Compressive
strength) -
6000
C
- 3 3 3 9
2(a)
150 x 300
mm cylinders
(Split tensile
strength) -
2000
C
3 3 3 3 12
2(b)
150 x 300
mm cylinders
(Split tensile
strength) -
4000
C
- 3 3 3 9
2(c)
150 x 300
mm cylinders
(Split tensile
strength) -
6000
C
- 3 3 3 9
Compressive Strength of High Strength Self Com-
pacting Concrete for 28 days at Room Temperature
and 2000
C at 4, 8, 12 hours duration.
S.no:
Water /
Binder
Ratio
Compressive Strength (N/mm2
)
Duration
Room
Tempera-
ture
4
Hours
8
Hours
12
Hours
1
0.215
82.57 77.68 74.68 72.58
2 84.69 80.59 76.59 74.55
3 83.59 76.62 73.62 71.68
and 4000
S.no:
Water /
Binder
Ratio
)
Duration
Room
Tempera-
ture
4
Hours
8
Hours
12
Hours
1
0.215
82.57 68.68 66.58 61.95
2 84.69 71.68 67.02 64.65
3 83.59 68.02 66.02 63.52
pacting Concrete for 28 days at Room Tem-
perature and 6000 C at 4, 8, 12 hours duration.
S.
no:
Water /
Binder
Ratio
)
Duration
Room
Tem-
pera-
ture
4 Hours 8 Hours
12
Hours
1
0.215
82.57 Crushed Crushed Crushed
2 84.69 Crushed Crushed Crushed
3 83.59 Crushed Crushed Crushed
Percentage Decrease of Compressive Strength of
High Strength Self Compacting Concrete at 2000
C
at 4, 8, 12 hours duration with respect to 28 days
compressive strength
S.
no:
Water /
Binder
Ratio
Percentage Decrease of Compressive
Strength
Duration
4 Hours 8 Hours 12 Hours
1
0.215
5.92 9.56 12.10
2 4.84 9.56 12.00
3 8.34 11.90 14.20
C
S.
no:
Water /
Binder
Ratio
Strength
Duration
1
0.215
16.80 19.40 25.00
2 15.40 20.90 23.70
3 18.60 21.00 24.00
C

63
S.
no:
Water /
Binder
Ratio
Strength
Duration
1
0.215
Crushed Crushed Crushed
2 Crushed Crushed Crushed
Percentage Weight Loss of High Strength Self Com-
pacting Concrete at 2000
C at 4, 8, 12 hours dura-
tion with respect to 28 days compressive strength
S.
no:
Water /
Binder
Ratio
Percentage Weight Loss
Duration
1
0.215
1.58 2.29 3.27
2 1.60 1.96 3.29
3 0.79 2.43 4.07
tion with respect to 28 days compressive strength.
S.
no:
Water /
Binder
Ratio
Duration
1
0.215
4.86 7.31 7.98
2 3.92 8.16 9.96
3 6.35 5.91 8.30
tion with respect to 28 days compressive strength.
S.
no:
Water /
Binder
Ratio
Duration
1
0.215
Crushed Crushed Crushed
Pulse Velocity of High Strength Self Compacting
Concrete for 28 days at Room Temperature and
2000
S.
no:
Water /
Binder
Ratio
Pulse Velocity (m/sec)
Duration
Room
Tem-
pera-
ture
4 Hours 8 Hours
12
Hours
1
0.215
4430 4270 4220 4200
2 4370 4290 4130 4200
3 4430 4390 4200 4290
4000 C at 4, 8, 12 hours duration.
S.
no:
Water /
Binder
Ratio
Duration
Room
Tem-
pera-
ture
4 Hours 8 Hours
12
Hours
1
0.215
4430 3900 3800 3470
2 4370 4090 3690 3390
3 4430 4050 3500 3250
EXPERIMENTAL PHOTOGRAPHS
Quartz Sand Quartz Powder

64
Basalt Pan Mixer
V-Funnel Test Testing of Split Tensile Strength Specimen
specimen of Split Tensile Strength after Test Strength Concrete Specimen in Compression Testing
Machine

65
6000
S.
no:
Water /
Binder
Ratio
Duration
Room
Tem-
pera-
ture
4 Hours 8 Hours
12
Hours
1
0.215
2 4370 Crushed Crushed Crushed
3 4430 Crushed Crushed Crushed
DISCUSSION OF TEST RESULTS
pacting Concrete exposure to 2000
C for 4, 8 & 12
hours duration.
Table 4.4.13 and Graph 1 show the compressive
strength of High Strength Self Compacting Concrete
for water binder ratio 0.215 after exposure to 4, 8
and 12 hours duration at 2000
C.
The Compressive Strength of High Strength Self
Compacting Concrete for 4 hours exposure are
77.68, 80.59 and 76.62 N/mm2 ; 8 hours exposure
are 74.68, 76.59 and 73.62 N/mm2 and 12 hours
exposure are 72.58, 74.55 and 71.68 N/mm2.
C for 4, 8 & 12
hours duration.
C.
exposure are 61.95, 64.65 and 63.52 N/mm2.
C for 4, 8 & 12
hours duration.
C.
All the specimens are exposed to 6000
C at 4, 8 & 12
hours duration. All the specimens are crushed and
entire concrete became powder material. Hence the
concrete is not able to take 6000
C temperature.
Percentage decrease of Compressive
Strength of High Strength Self Compacting
Concrete exposure to 2000
C for 4, 8 & 12 hours
duration.
Table 4.4.14 and Graph 2 show the Percentage de-
crease of compressive strength of High Strength Self
Compacting Concrete for water binder ratio 0.215
after exposure to 4, 8 and 12 hours duration at 2000
C.
Compacting Concrete for 4 hours exposure are 5.92,
4.84 and 8.34 N/mm2 ; 8 hours exposure are 9.56,
9.56 and 11.90 N/mm2 and 12 hours exposure are
12.10, 12.00 and 14.20 N/mm2
.
Percentage decrease of Compressive Strength of
High Strength Self Compacting Concrete exposure
to 4000
C for 4, 8 & 12 hours duration.
C.
exposure are 25.00, 23.70 and 24.00 N/mm2
Percentage decrease of Compressive Strength of
to 6000
C.
C at 4, 8 & 12
C temperature.
Percentage Weight Loss of Compressive Strength of
to 2000
Table 4.4.15 and Graph 3 show the Percent-
age Weight Loss of Compressive Strength of High
Strength Self Compacting Concrete for water binder
ratio 0.215 after exposure to 4, 8 and 12 hours du-
ration at 2000
C.
1.58, 1.60 and 0.79 N/mm2 ; 8 hours exposure are
2.29, 1.96 and 2.43 N/mm2 and 12 hours exposure
are 3.27, 3.29 and 4.07 N/mm2
.
to 4000
ration at 4000
C.

66
7.31, 8.16 and 5.91 N/mm2
and 12 hours exposure
are 7.98, 9.96 and 8.30 N/mm2
.
to 6000
ration at 6000
C.
C at 4, 8 & 12
C temperature.
Pulse Velocity (m/sec) of High Strength Self Com-
and 2000
C at 4, 8, 12 hours duration
Table 4.4.16 and Graph 4 show the Pulse Velocity
(m/sec) of High Strength Self Compacting Concrete
C.
The Pulse Velocity of High Strength Self Compacting
Concrete for 4 hours exposure are 4270, 4290 and
4390 m/sec ; 8 hours exposure are 4220, 4130 and
4200 m/sec and 12 hours exposure are 4200, 4200
and 4290 m/sec.
and 4000
C.
and 3250 m/sec.
and 6000
C.
C at 4, 8 & 12
C temperature.
Split Tensile Strength of High Strength Self Com-
C for 4, 8 & 12
hours duration.
Table 4.5.12 and Graph 5 show the Split Tensile
Strength of High Strength Self Compacting Con-
crete for water binder ratio 0.215 after exposure to
4, 8 and 12 hours duration at 2000
C.
The Split Tensile Strength of High Strength Self
6.99, 7.22 and 7.32 N/mm2
are 6.87, 7.08 and 7.07 N/mm2
.
C for 4, 8 & 12
hours duration.
C.
6.80, 6.99 and 6.95 N/mm2
; 8 hours exposure are
6.69, 6.87 and 6.82 N/mm2 and 12 hours exposure
are 6.24, 6.49 and 6.49 N/mm2
.
pacting Concrete exposure to 6000 C for 4, 8 & 12
hours duration.
C.
C at 4, 8 & 12
C temperature.
Percentage decrease of Split Tensile Strength of
to 2000
crease of Split Tensile strength of High Strength Self
C.
4.51, 7.08 and 5.43 N/mm2
are 6.15, 8.88 and 8.66 N/mm2
.
to 4000

67
crease of Split Tensile Strength of High Strength
Self Compacting Concrete for water binder ratio
0.215 after exposure to 4, 8 and 12 hours duration
at 4000
C.
7.10, 10.04 and 10.21 N/mm2
; 8 hours exposure
are 8.61, 11.58 and 11.89 N/mm2
and 12 hours ex-
posure are 14.75, 16.47 and 16.15 N/mm2
.
to 6000
crease of Split Tensile Strength of High Strength
Self Compacting Concrete for water binder ratio
0.215 after exposure to 4, 8 and 12 hours duration
at 6000
C.
C at 4, 8 & 12
C temperature.
Percentage Weight Loss of Split Tensile Strength of
to 2000
age Weight Loss of Split Tensile Strength of High
ration at 2000
C.
0.57, 0.45 and 0.97 N/mm2
0.63, 1.00 and 1.18 N/mm2
are 2.03, 3.40 and 2.34 N/mm2
.
Percentage weight loss of High Strength Self Com-
pacting Concrete Specimen of Split Tensile Strength
exposure to 4000
ration at 4000
C.
3.37, 3.62 and 3.42 N/mm2
4.62, 4.07 and 4.14 N/mm2
are 6.07, 6.50 and 6.46 N/mm2
.
exposure to 6000
ration at 6000
C.
C at 4, 8 & 12
C temperature.
for 28 days at Room Temperature and 2000
C at 4,
8, 12 hours duration
C.
and 4450 m/sec.
for 28 days at Room Temperature and 4000 C at 4,
C.
and 3060 m/sec.
for 28 days at Room Temperature and 6000
C at 4,
C.
C at 4, 8 & 12
C temperature.
CONCLUSIONS
The following conclusions are drawn from the Ex-
perimental Investigation in present Thesis:
1)The percentage decrease of compressive strength
was found higher for higher exposure time.

68
2)A gradual reduction in strength was found with
increase in temperature from 200 to 6000
C for all
exposure duration of 4, 8 and 12 hours.
3)The percentage decrease of weight loss was found
higher for higher exposure times.
4)The pulse velocity of High Strength Self Compact-
ing Concrete was found lower for higher exposure
time.
5)The specimens when exposed to 6000
C for 4, 8, 12
hours duration, all the specimens got totally pow-
dered at this temperature.
6)High Strength Self Compacting Concrete speci-
mens exhibited maximum percentage decrease of
compressive strength of nearly 24% at 4000
C for 12
hours duration.
mens exhibited maximum percentage weight loss of
9% at 4000
C for 12 hours duration.
mens exhibited maximum percentage decrease of
split tensile strength of nearly 15% at 4000
C for 12
hours duration.
9)The Pulse Velocity of High Strength Self Compact-
ing Concrete specimens after exposure at 4000
C for
12 hours duration is 3470 m/Sec to 3290m/Sec
SCOPE OF FUTURE STUDIES
1.Investigation can be made with the addition of
Glass Fibres to know Residual Strength of High
Strength Self Compacting Concrete.
2.Study can be made on High Strength Self Com-
pacting Concrete specimens by exposing concrete to
longer duration.
3.A time dependent study can be made to know
about the long term behavior of High Strength Self
Compacting Concrete.
REFERENCES
1.Castilo, C and Durrani A J (1990) Effect of transient high tem-
perature on High strength Concrete, ACI Materials Journal, Jan-
February 1990, pp 47-53.
2.Chakrabarti. S.C., Sharma. K.N., AND Abha Mittal., “Residual
Strength in Concrete after exposure to elevated temperature”.
The Indian Concrete Journal, December 1994 PP 713-717.
3.EFNARC, “Specifications and guidelines for self compacting
concrete”, www.efnarc.org.
4.George C. Hoff etal (2000) elevated temperature effects HSC
residual strength, Concrete International, April 2000, pp 41-47.
5.Hajime Okamura and Masahiro Ouchi (2003) “Self-Compact-
ing Concrete”, Journal of Advanced Concrete Technology, Japan
Concrete Institute, Vol.1, pp. 5-15.
6.Janotka, Nurnbergurora T (1990), Thermo-Mechanical proper-
ties of PENLY reactor envelop at temperatures up to 200oC, Ma-
terials and structures Vol.32, December 1999, pp 719-726.
7.Klaus Holschemacher and Y Vette Klug, Leipzig “A Database
for the Evaluation of Hardened properties of SCC” (Pages from
123-134).
8,Long T. Phan and Nicholas J.Carino “Effects of test Conditions
and Mixture proportions on Behavior of High Strength concrete
Exposed to High Temperatures”, ACI Materials Journal, January-
February 2002 PP 54-62.
9.Manu Santhanam and Subramaniam S. (2004) “current devel-
opments in Self Compacting Concrete”, Indian Concrete Journal,
June, Vol., pp 11-22.
10.Mohammed Bhai, G.T.G., “The residual strength of Concrete
subjected to elevated temperature”, Concrete Journal, Vol.17,
No.12, 1983, PP 22-27.
11.“Self Compacting Concrete”, Indian Concrete Journal, Au-
gust, pp. 1261-1266.
12.Srinivasa Rao K, Potha Raju M. & Raju P.S.N “Effect of age on
HSC on Residual Compressive Strength under Elevated temper-
atures”, International conference on Advances in Concrete and
Construction, December 2004, PP 733-741.
13.Srinivasa Rao K, Potha Raju M. & Raju P.S.N “Effect of Elevat-
ed temperature on compressive strength on HSC made with OPC
& PPC”, The Indian Concrete Journal, August 2006, PP 43-48.
14.Srinivasa Rao. P, Sravana. P and Seshagiri Rao. M.V. “Effect
of Thermal cycles on Strength Properties of OPC and fly ash con-
cretes”, the Indian Concrete Journal, March, 2006, PP 49-52.
Timo Wusthloz “Fresh properties of SCC” (Pages from 179-188)
Author
A.Swetha,
Research Scholar, Department of CIVIL Engineering,
Hyderabad, India
K. Mythili,
AssociateProfessor,Department of CIVIL Engineering,
Hyderabad, India

A STUDY ON HIGH STRENGTH SELF COMPACTING CONCRETE ON EXPOSURE TO VARIOUS TEMPERATURES

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

Ähnlich wie A STUDY ON HIGH STRENGTH SELF COMPACTING CONCRETE ON EXPOSURE TO VARIOUS TEMPERATURES

Ähnlich wie A STUDY ON HIGH STRENGTH SELF COMPACTING CONCRETE ON EXPOSURE TO VARIOUS TEMPERATURES (20)

Mehr von Ijripublishers Ijri

Mehr von Ijripublishers Ijri (20)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

A STUDY ON HIGH STRENGTH SELF COMPACTING CONCRETE ON EXPOSURE TO VARIOUS TEMPERATURES