International Journal of Civil Engineering and Technology (IJCIET)
Volume 10, Issue 04, April 2019, pp. 250–258, Article ID: IJCIET_10_04_027
Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJCIET&VType=10&IType=4
ISSN Print: 0976-6308 and ISSN Online: 0976-6316
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EFFECTS OF GGBFS TO THE COMPRESSIVE
STRENGTH, WORKABILITY AND TIME SPAN
BETWEEN MIXING AND COMPACTING OF
CONCRETE PASTE
Sri Murni Dewi, Lilya Susanti, Hendro Suseno
Civil Engineering Department, Brawijaya University, MT. Haryono Street 167 Malang 65145
East Java, Indonesia
ABSTRACT
This paper investigated the effect of GGBFS to the concrete compressive strength,
workability and also time span between mixing and compacting of concrete paste. It
used 480 concrete cylinder specimens consist of 240 specimens for normal concrete
and 240 specimens of 2 hours mixing concrete varied in the percentage of GGBFS
replacing levels, concrete grades, ages and also water-cement ratio. Results found
that the optimum replacement level of GGBFS is 40% indicated by the highest
compressive strength of both normal and two hours mixing time. The workability of
concrete paste increases by the increasing replacement level of GGBFS. However this
workability values have to be checked using the Standard.
Key words: Concrete material, GGBFS, Compressive strength, Workability, Time
span of mixing and compacting.
Cite this Article: Sri Murni Dewi, Lilya Susanti, Hendro Suseno Effects of GGBFS to
the Compressive Strength, Workability and Time Span Between Mixing and
Compacting of Concrete Paste, International Journal of Civil Engineering and
Technology 10(4), 2019, pp. 250–258.
http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=10&IType=4
1. INTRODUCTION
Ground Granulated Blast-Furnace Slag (GGBFS) is obtained by quenching molten iron slag
(a by-product of iron and steel making) from a blast furnace in water or steam to produce a
glassy granular product that is then dried and ground into a fine powder. Recently GGBFS has
been widely used in some countries to partially replace the ordinary Portland cement or other
pozzolanic material because its composition which is almost similar to cement materials.
GGBFS cement is routinely specified in concrete and mortar materials. Some advantages in
using GGBFS are increasing concrete durability by providing a protection against both
sulphate attack and cloride attack and inflating the appearance of structure because its nearwhite color permits architects to achieve a lighter color for exposed fair-faced concrete
finishes. Beside that, it also results a higher ultimate strength compared with the ordinary
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Effects of GGBFS to the Compressive Strength, Workability and Time Span Between Mixing and
Compacting of Concrete Paste
concrete with only Portland cement and also provides more enviromentally friendly material
compared with the Portland cement [1].
Many research have been conducted to understand the behavior of GGBFS material in
replacing the ordinary Portland cement. D Suresh and K Nagaraju investigated the
characteristics of concrete with partial replaement of cement with GGBS. The results showed
that the setting time of concrete with GGBS is slightly extended for about 30 minutes. This
effect will be pronounced at the higher level s of GGBFS. Concrete containing GGBS also
retain its workability longer than the concrete with only Portland cement. [2]
Kimmi Garg and Kshipra Kapoor also made a review on GGBFS as a cement replacing
material. The result confirm the reseach by A Suresh and K Nagaraju. They reported the
benefits of using GGBS in concrete which are providing the eco-friendly material, more
aesthetically pleasing appearance, and extending the concrete setting time. Moreover, it can
produce more resistance to sulphate attacks [3]
One parameter to measure a concrete workability is by looking at the slump values. S.
Arivalagan wrote a paper about sustainable studies on concrete with GGBS as a replacement
material in cement. The results found that by the slump values increase by the increasing of
GGBS percentage in replacing the ordinary Portland cement. But the degree of workabillity of
cconcrete was still in normal range with the addition of GGBS up to 40% replacement level
[4]. Pradip Nath and Prabir Kumar S studied effect of GGBFS on setting, workability and
early strength properties of fly ash geopolymer concrete cured in ambient condition. In here,
they found the opposite result compared with S. Arivalagan report. They found that by
increasing the percentage of GGBFS replacing level, slump value of the fresh concrete turn to
decrease. More investigation is needed in order to check whether it was caused by the
addition of fly ash and geopolymer in the concrete paste [5].
Pradip Nath and Prabir Kumar S [5] have also check the setting time of concrete
containing GGBFS. The result showed that the increasing of GGBFS replacement level lead
to the decrements of the setting time. It was the opposite of result found by [2] and [3]. Once
again it has to be investigated the effect of adding fly ash and geopolymer to the concrete
material.
In the case of concrete strength, there was a lot of studies discuss about this. First study by
. Arivalagan [4] found that the concrete compressive strength in day 7th and 28th decrease as
the percentage of GGBFS replacement level increase. Pradip Nath and Prabir Kumar [5]
proposed the opposite result where the compressive strength of concrete in day 10th, 28th and
56th are consistently increase by the increasing of GGBFS replacement level. M. Shariq, J.
Prasad and A. K. Ahuja studied the strength development of cement mortar and concrete
incorporating GGBFS. In mortar specimens, they found that the optimum percentage of
GGBFS replacing level is 20% which consistently resulted a highest compressive strength in
day 28th, 56th, 90th, 150th and 180th compared with the plain mortar and also the higher
replacement level of GGBFS. For concrete specimens, t is found that the optimum percentage
of GGBFS replacing level is 40% because it resulted highest compressive strength started in
day 40th. In day 28th, the ordinary concrete specimen still has a highest compressive strength
compared to all specimens [6].
Other studies regarding the compressive strength of concrete containing GGBFS have
conducted by Santosh K. K, G. V. Rama R. and P. Markandeya R. They confirmed the result
from [6] that the optimum replacing level of GGBFS on the concrete mix is 40% which
resulted the highest concrete compressive strength in day 28th and 90th [7]. This result is also
confirmed by Shahab S., Attaullah S. and Mukesh C. L which studied the strength
development characteristics of concrete produced with blended cement using ground
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Sri Murni Dewi, Lilya Susanti, Hendro Suseno
granulated blast furnace slag (GGBS) under various curing condition [8]. M. Shariq, J. Prasad
and A. Masood also found the similar result in their paper titled effect of GGBFS on time
dependent compressive strength of concrete [9]. Finally, Ygendra O. P., P. N. Patil and A. K.
Dwivedi found a differnt result compared with the previous studies. In their study titled
GGBS as partial replacement of OPC in cement concrete-an experimental study confirmed
that the concrete compressive strength decrease as the percentage of GGBS replacement level
increase [10].
One paper by A. Karimpour investigated the effect of time span between mixing and
compacting on roller compacted concrete containing GGBFS [11]. In here, he found that the
compressive strength of concrete specimens decrease as the increase of GGBFS level. This
result was occurred in all time span between mixing and compacting which are 30, 60, 120
and 180 minutes.
Due to some different result from the previous papers studied about the effect of GGBFS
to the compressive strrength, workability and time span between mixing and compacting of
concrete paste, so it is still needed more research regarding this topics. The present paper
mainly focused on investigating the effect of GGBFS to the compressive strength, workability
of concrete which is measured by slump values and also time span between mixing and
compacting of concrete paste.
2. EXPERIMENTAL PROCEDURES
2.1. Specimens preparation
This research used standard concrete cylinder as specimens with the dimension of 15 cm in
diameter and 30 cm in cylinder height. The normal concrete paste specimens were varied on
the percentage of GGBFS replacement level, concrete compressive strength, water - cement
ratio and also the ages of concrete specimens in order to test the concrete compressive
strength later after the concrete specimens reach their ages. Similar specimens were also made
for 2 hours mixing time concrete paste. Below, Table 1 shows the variation of specimens for
each normal and 2 hours mixing concrete and Table 2 shows the amount of specimens for
each normal and 2 hours mixing concrete. Total of 240 normal concrete cylinders were used
in the present research. Other 240 specimens were also employed but these concrete paste
specimens are mixed in 2 hours before they are filled into the cylinder molds. So, the total
concrete cylinder specimens were 480 including 240 specimens of normal concrete and 240
specimens of 2 hours mixing concrete.
Table 1 Variation of specimens for each normal and 2 hours mixing concrete
Variable
A
Description
GGBFS replacement level (%)
B
Concrete ages (days)
C
Concrete strength (MPa)
D
Water:cement ratio
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Notation
1
2
3
4
1
2
3
1
2
1
2
Variation
0
10
40
70
7
28
56
22.83 (K-275)
29.05 (K-350)
0.3
0.4
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Effects of GGBFS to the Compressive Strength, Workability and Time Span Between Mixing and
Compacting of Concrete Paste
Table 2 Amount of specimens for each normal and 2 hours mixing concrete
A1
B1
B2
B3
D1
D2
D1
D2
D1
D2
C1
5
5
5
5
5
5
A2
C2
5
5
5
5
5
5
C1
5
5
5
5
5
5
60
A3
C2
5
5
5
5
5
5
60
C1
5
5
5
5
5
5
A4
C2
5
5
5
5
5
5
60
C1
5
5
5
5
5
5
C2
5
5
5
5
5
5
60
2.2. Slump Test Procedures
Slump test was conducted according to Indonesian Standard 1972:2008 [12] using Abrams
cone equipment with top diameter as 102 mm and bottom diameter as 203 mm. The height of
the cone as 305 mm and 1.5 mm of minimum plate thickness. A steel bar was used to level
and compact the concrete paste. Concrete paste was filled into the Abrams cone in three steps,
one-third part of cone height for each step. Indonesian Standard have mentioned the allowable
slump value for plate, beam, column and wall structure as 15 cm and 7.5 cm for maximum
and minimum value. In the present research, the slump values were also compared with this
allowable value according to the code.
2.3. Compressive Strength Test Procedures
The compressive strength of each specimen was calculated after tested using compression
machine. From the compression machine, maximum load data was obtained. The maximum
data then is divided by the area of the cylinder top part. The top part of each specimen is
laminated by melted sulfur in order for leveling the concrete cylinder surface without
affecting the compressive strength of the concrete specimens.
3. EXPERIMENTAL RESULTS
3.1. Slump Values
For each concrete mixing plan, slump value was measured using Abrams cone according to
Indonesian Standard 1972:2008 requirement. The result of slump values for all varied
concrete paste specimens is shown through Table 3 for normal concrete and Table 4 for two
hours mixing concrete. For two hours mixing concrete specimens, slump value was measured
twice, once after 15 minutes mixing time, and once more after 2 hours mixing time so the
reduction of slump values can be measured.
Table 3 Average slump values for normal concrete
GGBFS
(%)
0
10
40
70
0
10
40
70
0
Concrete
Strength
K 275
K 275
K 275
K 275
K 275
K 275
K 275
K 275
K 350
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w/c
ratio
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.3
253
Slump
(cm)
8.50
11.67
10.00
9.50
17.33
17.17
17.50
19.83
12.00
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GGBFS
(%)
10
40
70
0
10
40
70
Concrete
Strength
K 350
K 350
K 350
K 350
K 350
K 350
K 350
w/c
ratio
0.3
0.3
0.3
0.4
0.4
0.4
0.4
Slump
(cm)
12.33
9.50
10.83
18.17
16.17
18.17
19.50
Table 4 Average slump values for two hours mixing concrete
GGBFS Concrete
(%)
Strength
0
K 275
10
K 275
40
K 275
70
K 275
0
K 275
10
K 275
40
K 275
70
K 275
0
K 350
10
K 350
40
K 350
70
K 350
0
K 350
10
K 350
40
K 350
70
K 350
w/c
ratio
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
0.3
0.3
0.3
0.3
0.4
0.4
0.4
0.4
Slump
(normal)
(cm)
14.00
16.50
12.17
11.33
17.83
13.50
16.50
13.83
11.50
11.17
9.33
11.00
16.67
13.67
16.00
13.83
Slump (120 m)
(cm)
1.33
2.17
7.50
2.50
2.67
5.83
6.50
9.83
1.00
1.33
1.50
2.00
3.33
4.50
11.00
8.67
25
K 350 & w/c 0.3
K 350 & w/c 0.4
20
Slump (cm)
Slump
Reduction (%)
90.48
86.87
38.36
77.94
85.05
56.79
60.61
28.92
91.30
88.06
83.93
81.82
80.00
67.07
31.25
37.35
K 275 & w/c 0.4
15
K 275 & w/c 0.3
10
5
0
GGBFS
0%
GGBFS GGBFS
10%
40%
GGBFS level
GGBFS
70%
Figure 1 Relationship of GGBFS levels and slump values for normal concrete specimens
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Effects of GGBFS to the Compressive Strength, Workability and Time Span Between Mixing and
Compacting of Concrete Paste
In order to make it easier to understand the relationship of GGBFS levels and slump
values, Table 3 then pictured through Figure 1. The allowable minimum and maximum slump
values according to Indonesian Standard 1972:2008 was also included in those figure to
measured the slump level of each specimen whether it still fulfill the requirement or not. From
the Figure 1, it can be seen that all concrete specimens with water-cement ratio as 0.3 have
fulfilled the required slump values. It means that water-cement ratio as 0.4 is to high to be
applied in the concrete mix design for any level of GGBFS. Beside that, it can be known that
the slump values tend to increase with the increasing of GGBFS level, especially for high
water-cement ratio. Table 4 is also figured through Figure 2 in order to observe the trend of
slump value for each variation. From Table 4, the reduction of slump values after 2 hours
mixing is very high especially for small water-cement ratio which can reach 80% from the
initial slump values. For higher water-cement ratio, the slump reduction reach the average
value of 50%. Much smaller than the previous one. Confirmed the result of Figure 1, the
initial slump values of specimens with water-cement ratio as 0.4 in the Figure 2 also do not
meet the requirement of Indonesian Standard. But for specimens with after 2 hours mixing
concrete paste, only specimens with water-cement ratio as 0.4 which can fulfill the
requirement of Indonesian Standard. It means that for the field case which the batching plan is
far from the project location, higher water-cement ratio is needed to maintain the allowable
slump level according to the code. Moreover, higher level of GGBFS resulted higher slump
values which is profitable to be used for longer distance of concrete batching plan.
20
slump 15 m K 275 w/c 0.3
Slump (cm)
slump 15 m K 275 w/c 0.4
slump15 m K 350 w/c 0.3
15
slump 15 m K 350 w/c 0.4
slump 240 m K 275 w/c 0.3
10
slump 240 m K 275 w/c 0.4
slump 240 m K 350 w/c 0.3
5
slump 240 m K 350 w/c 0.4
0
GGBFS 0% GGBFS 10% GGBFS 40% GGBFS 70%
GGBFS level
Figure 2 Relationship of GGBFS levels and slump values for two hours mixing concrete specimens
3.2. Compressive Strength Test
All concrete cylinder specimens were tested using Compression Machine. It was classified
according to the ages of concrete which are 7 days, 28 days and 56 days. Results of the
compression test are drawn through Figure 3 for normal concrete specimens and Figure 4 for
two hours mixing concrete specimens.
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Sri Murni Dewi, Lilya Susanti, Hendro Suseno
Figure 3 Compressive strength of normal concrete specimens
Figure 4 Compressive strength of two hours mixing concrete specimens
Due to the behavior of GGBFS which can delay the increment of concrete compressive
strength to more than 28 days, so the present research compared the compressive strength of
concrete specimens start from the age of 7 days to 56 days. According to the results of two
above figures, it can be found that the compressive strength of two hours mixing concrete
specimens generally higher than the compressive strength of normal concrete specimens. It
can be caused by the lower water-cement ratio resulted from two hours mixing concrete
process. Because the longer mixing time, some water have reacted with the cement so that the
amount of water decrease. It make the resulted concrete paste become thicker compared with
normal mixing time concrete. Smaller water-cement ratio results higher compressive strength
in general. But the thicker concrete paste make the molding process more difficult. The result
of compressive test indicated that the compressive strength of two hours mixing time
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Effects of GGBFS to the Compressive Strength, Workability and Time Span Between Mixing and
Compacting of Concrete Paste
specimens have 37% higher strength than normal concrete in the ages of 7 days. In 28 days,
two hours mixing time specimens have 48% higher strength followed by 21% higher strength
in 56 days of concrete age. The optimum level of GGBFS used in the concrete paste is 40%. It
is indicated by the highest concrete strength resulted from 40% GGBFS replacement level
specimens compared with the other GGBFS percentage both for normal mixing concrete and
also two hours mixing concrete specimens.
4. CONCLUSIONS
Results of the present research indicated that the workability of the concrete paste decrease
significantly after two hours mixing time. The decrements can reach 80% for low watercement ratio and 50% for higher water-cement ratio. In the other hand, the increasing
replacement level of GGBFS resulted higher workability of concrete paste. But this
workability has to be checked according to the allowable values stated in the Standard. The
compressive strength of two hours mixing concrete is higher compared with the normal
mixing concrete. It is caused by the thicker concrete resulted by two hours mixing time can
increase the compressive strength. The optimum level of GGBFS used in the concrete paste is
40%. It is indicated by the highest concrete strength resulted from 40% GGBFS replacement
level specimens compared with the other GGBFS percentage both for normal mixing concrete
and also two hours mixing concrete specimens.
ACKNOWLEDGEMENT
This research was supported by PT Krakatau Semen Indonesia in corporate with PT Semen
Indonesia (Persero) Tbk.
REFERENCES
[1]
en.wikipedia.org, Ground granulated blast-furnace slag.
[2]
D. Suresh and K. Nagaraju, “Ground granulated blast slag (GGBFS) in concrete – a
review,” IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE), vol. 12(4) ver
VI, pp. 76–82, 2015.
[3]
Er. K. Garg and Er. K. Kapoor, “A review on ground granulated blast-furnace slag as a
cement replacing material,” International Journal of Engineering Research and
Management (IJERM), vol. 03(07), pp. 214–217, 2016.
[4]
S. Arivalagan, “Sustainable studies on concrete with GGBFS as a replacement material in
cement,” Jordan Journal of Civil Engineering, vol. 8(3), pp. 263–270, 2014.
[5]
P. Nath and P. K. Sarker, “Effect of GGBFS on setting, workability and early strength
properties of fly ash geopolymer concrete cured in ambient condition,” Construction and
Building Materials, vol. 66, pp. 163–171, 2014.
[6]
M. Shariq, J. Prasad and A. K. Ahuja, “Strength development of cement mortar and
concrete incorporating GGBFS,” Asian Journal of Civil Engineering (Building and
Housing), vol. 9(1), pp. 61-74, 2008.
[7]
S. K. Karri, G. V. R. Rao and P. M. Raju, “Strength and durability studies on GGBFS
concrete,” SSRG International Journal of Civil Engineering, vol. 2(10), pp. 34-41, 2015.
[8]
S. Samad, A. Shah and M. C. Limbachiya, “Strength development characteristics of
concrete produced with blended cement using ground granulated blast furnace slag
http://www.iaeme.com/IJCIET/index.asp
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Sri Murni Dewi, Lilya Susanti, Hendro Suseno
(GGBS) under various curing conditions,” Sadhana, DOI 10.1007/s12046-017-0667-z,
2017.
[9]
M. Shariq, J. Prasad and A. Masood, “Effect of GGBFS on time dependent compressive
strength of concrete,” Construction and Building materials, vol. 24, pp. 1469-1478, 2010.
[10]
Y. O. Patil, P. N. Patil and A. K. Dwivedi, “GGBS as partial replacement of OPC in
cement concrete-an experimental study,” International Journal of Scientific Research,
2(11), pp. 189-191, 2013.
[11]
A. Karimpour, “Effect of time span between mixing and compacting on roller compacted
concrete (RCC) containing ground granulated blast furnace slag (GGBFS),” Construction
and Building Materials, 24, pp. 2079-2083, 2010.
[12]
National Standardization Institution, Indonesian Standard 1972:2008 – Concrete Slump
Test Method, 2008
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