International Journal of Engineering Business
and Social Science
Vol. 1 No. 03, January-February 2023, pages: 248 - 256
e-ISSN: 2980-4108, p-ISSN: 2980-4272
https://ijebss.ph/index.php/ijebss
248
Addition of Fly Ash And Aluminum Slag As Cement Substitute
Materials To Cellular Lightweight Concrete
Yogie Risdianto
1
1
Department of Civil Engineering, State University of Surabaya, Surabaya 60231, Indonesia
E-Mail: yogierisdianto@unesa.ac.id
Submitted: 08-02-2023 Revised: 12-02-2023, Publication: 20-02-2023
Keywords
Abstract
Cellular Lightweight
Concrete; Aluminum Slag
; Fly Ash; Compressive
Strength; Density; Water
Absorption
The construction of non-structural elements of the building applies CLC
lightweight concrete at a lower cost than standard concrete due to faster work,
more temperature resistance, ease of handling, and lighter density. This study aims
to find the optimum percentage and effect of using aluminum slag and fly ash as a
partial replacement of cement in cellular lightweight concrete. The test object is
printed in a molding size of 5x5x5 cm3. The use of aluminum slag is 0%, 1.5%,
3%, 4.5%, 6%, and 7.5%, while the use of fly ash is 15% of the cement weight.
The tests carried out included volume weight, compressive strength, and water
absorption at the age of 3, 7, 14, 21, and 28 days. The results of this study, it can be
concluded that increasing the variation of aluminum slag with fly ash content
remains at 15% in each variation as a cement substitution, the most significant
variation is 1.5%. The optimum compressive strength test results at a variation of
1.5% of 4.1 MPa with the highest specific gravity of 752 gr/cm3, and water
absorption of 66.67%, it all specimens at the age of 28 days.
1. Introduction
Construction buildings that are often encountered, such as buildings, offices, and others, almost all of these
buildings use concrete as a building material. With the development of concrete technology, new modified
concrete is created, such as lightweight concrete, shotcrete, fiber concrete, high-quality concrete, very high-
strength concrete, self-compacted concrete, etc. most used in the world. Therefore, the variation of the concrete
itself is being studied more and more so that it can develop higher quality concrete, one of which is lightweight
concrete.
Lightweight concrete is a concrete mortar that has a lighter specific gravity than concrete mortar in general.
According to (Nasional, 2009) SNI 03-3449-2002 lightweight concrete mortar should not exceed the maximum
weight of lightweight concrete of 1850 kg/m3. One type of lightweight concrete mortar that is often encountered
(Ramamurthy, Nambiar, & Ranjani, 2009), is lightweight concrete CLC (Cellular Lightweight Concrete), which
is a lightweight concrete that contains many air pores caused by air bubbles added to the concrete mortar mixture
and through natural curing process(Anwar & Hafidz, 2019).
Substitution of aluminum slag ash is a material composition that functions to overcome the weaknesses of
cellular lightweight concrete, which can be the result of smelting unused aluminum as a pore filler in lightweight
concrete, thereby increasing mechanical strength in the form of compressive strength. And also the use of fly ash
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IJEBSS Vol. 1 No.03, January-February 2023, pages: 248 - 256
in concrete can increase the compressive strength of concrete properly while reducing the use of cement
(Zakariya, 2018).
Lightweight cellular concrete has a composition in the form of portland cement, silica cement, pozzolan
cement, pozzolan-lime or silica lime paste or a mixture of pastes derived from these materials and also has
trapped air cavities resembling the cell structure derived from air bubble formers or foam agents (Cement, 2013).
Aluminium Slag
Aluminum slag is a waste material resulting from the smelting of aluminum metal in the form of ash. The
primary aluminum smelting process produces primary ash or dross which still contains 20-45% aluminum
residue.
Aluminum slag waste is a type of hazardous waste and is included in the B3 waste category. Based on
Government Regulation (PP) Number 101 of 2014 concerning Management of Toxic and Hazardous Waste,
handling B3 waste requires special treatment and is not the same as waste other than B3(Reddy & Kumar, 2017).
Records from the Jombang Regency Environment Service (DLH) stated that the number of aluminum slag
processing entrepreneurs in Kesamben and Sumobito Districts was 60 entrepreneurs. In 2014, DLH noted that
there were 135 entrepreneurs running B3 waste processing businesses.
Figure 1.
Aluminum Slag
Fly Ash
According to ACI Committee 226, it is explained that fly ash has fine grains, which pass sieve No. 325 (45
milli micron) 5-27 %. Fly Ash is generally in the form of solid or hollow balls. Fly ash has a density of 2.23
gr/cm3, with a moisture content of around 4%. Fly ash has a specific gravity between 2.15-2.6 and is gray-black
in color. The particle size of fly ash from burning bituminous coal is smaller than 0.075 mm. Fly ash has a
specific area of 170-1000 m2/kg. The average particle size of sub-bituminous coal fly ash is 0.01 mm – 0.015
mm, the surface area is 1-2 m2/g, the particle shape is mostly spherical, that is, most of it is spherical, resulting in
better workability (Bella, Pah, & Ratu, 2017).
Based on Government Regulation number 101 of 2014 concerning Hazardous and Toxic Waste
Management, FABA is categorized as hazardous and toxic waste (B3) category 2. Then, there was a change to
Non-Hazardous and Toxic Waste (B3) according to Government Regulation (PP) 22 Years 2021 concerning
Implementation of Environmental Protection and Management. Thus, FABA can be used by the cement industry,
or the cement industry, such as bricks, tiles, paving blocks, and so on, because it has pozzolanic properties.
Comparison of Chemical Properties
Aluminum slag, fly ash, and cement are chemically similar. A comparison of the physical properties of
aluminum slag, fly ash, and portland cement can be seen in table 1.
Table 1
Comparison of the Chemical Properties of Aluminum Slag, Fly Ash, and Portland Cement
Comparison
Aluminium
Fly Ash (%)
Portland
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Components
Slag (%)
Cement (%)
CaO
3.2
1.71
65.3
SiO2
4.9
60.48
18.3
Al2O3
69.39
28.15
5.7
SO3
-
-
4.3
TiO2
1.9
-
0.5
-
-
0.2
Fe2O3
1.96
4.25
-
MgO
8,33
0.47
-
K2O
-
1.41
-
Na2O
-
0.14
-
L.O.I
-
1.59
-
Source: Setiawati (2018)
2. Materials and Methods
The research method used in this study was quantitative research results, using experimental methods. The
empirical design method in research is carried out by conducting experimental activities to obtain data through
observations in each experiment. The research data is in the form of quantitative data which is then processed in
order to get results.
The design of this study will be carried out experiments on the substitution of aluminum slag and fly ash for
cement in cellular concrete mixtures which aim to determine the unit weight, compressive strength, water
absorption and optimum percentage of cellular lightweight concrete. The percentage of aluminum slag that will
be added in the study is 0%, 1.5%, 3%, 4.5%, 6% and 7.5% by weight of cellular lightweight concrete, with a fly
ash percentage of 15%. Data collection was carried out by making test specimens for compressive strength tests
(5x5x5 cm3 cubes) tested at the age of 3, 7, 14, 21 and 28 days. The sample as primary data is used to analyze the
data. The use of the material requirements used as a mixture of test specimens is shown in table 2.
Table 2
Material requirements for a cube 5x5x5 cm3
Code
Sand
Cement
Water
Foam
AS
FA
SP
(kg)
(kg)
(liter)
(liter)
(gr)
(gr)
(ml)
A
2.604
1.107
651
2.083
0
195
5
B
2.604
1.087
651
2.083
20
195
5
C
2.604
1.068
651
2.083
39
195
5
D
2.604
1.048
651
2.083
59
195
5
E
2.604
1.029
651
2.083
78
195
5
F
2.604
1.009
651
2.083
98
195
5
Total
15.63
6.348
3906
12.50
292
1171
30
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Preparation of Tools and
Materials
Mix the main mixture with
the foam agent, stir until
homogeneous
Stir the mixture of
sand, cement, water,
aluminum slag, fly
ash according to the
mix design until it is
homogeneous
Data Collection
Start
Finish
Make foam from a
mixture of foam
agent: water = 1 : 25
in the foam
generator tool
Succeed
Added of SP
Print the results of
the mix into the mold
Dry at room temperature for:
3, 7, 14, 21, and 28 days
Testing of Test
Objects
Data Analysis
Figure 1
Flowchart for making test specimens
Volume Weight Testing
The concrete unit weight test is carried out before testing the compressive strength of the concrete. The
volume weight test is carried out to determine the unit between the weight of the test object and the volume of the
concrete test object. The formula for finding the volume weight is as follows:
volume weight (Bv) =
Description:
= Volume weight of the test object (Gram/cm3)
= Weight of the test object (Grams)
= Volume of the test object (cm3)
Compressive Strength
Testing The compressive strength test of concrete was obtained according to the standard according to
(ASTM, 2012) test the compressive strength of mortar concrete with a 5x5x5 cm3 cube test object. The formula for
finding the compressive strength is as follows:
Description:
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= Compressive strength ( or MPa)
= Maximum total load ( or N)
= Compression area (in
2
or mm
2
)
Water Absorption Test
Absorption test water in concrete is obtained according to (Nasional, 2009) SNI 03-0349-1989 explaining,
the test object is suitable for use if the water absorption capacity has a maximum value of 25% with a 5x5x5 cm3
cube test object with a maturity of 28 days. The formula for finding the compressive strength is as follows:
Description:
= Moisture content (%)
= Wet mass of the specimen that has been soaked in water for 24 hours (grams)
= Dry mass of the test object that has been in the oven for 24 hours (grams)
3. Results and Discussions
Material Test Results
Cement
The cement used has a specific gravity of 3.15 gr/cm3 which is the 40 kg Semen Gresik brand of PPC type
(Pozzolan Portland Cement).
Fine Aggregate
The sand used is a type of Pasuruan sand. The results of the sand test obtained are shown in Table 3, as well
as the sand gradation graph Figure 2.
Table 3
The Results of the Sand Test
No
Test Type
Test result
1
Specific gravity
2.231 gr/cm3
2
Weight Per volume
1,54 gram/cm3
3
Sludge levels
2,61 %
4
Sieve Analysis
Zona 2
5
Moisture Content
3,64 %
Figure 2.
The Graph of Sand Gradation Zone 2
Aluminum Slag
The aluminum slag used comes from the aluminum metal smelting home industry in Bakalan Village, District
Sumobito, Jombang Regency The aluminum slag used to pass through the 200 sieve has a specific gravity of 2.941
gr/cm3. Aluminum slag is used as a substitute for using cement.
0
10
20
30
40
50
60
70
80
90
100
0.15 0.30 0.60 1.20 2.40 4.80 9.60
Cumulative Percentage
No filter (mm)
Gradasi Batas Atas
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Fly Ash
The fly ash used passes through the 200 sieve and has a specific gravity of 2.941 gr/cm3. Fly ash is used as a
substitute for using cement (Utomo, 2016).
Foam Agent
Foam agent has a specific gravity of 0.04 g/cm3 which is produced by the foam agent used by the brand Foam
Agent GF 1420 for use in water with a ratio of 1:25 (1 liter of Foam Agent: 25 liters of water).
Compressive Strength Testing
The results of this compressive strength test were carried out at the age of 3, 7, 14, 21, and 28 days using the
UTM (Universal Testing Machine) tool. The table presents data for the compressive strength of aluminum slag
substitution variations of 0.0%, 1.5%, 3.0%, 4.5%, 6.0%, and 7.5% with 15% fly ash.
Figure 3.
Average Compressive Strength
Compressive strength decreases with increasing variations in aluminum slag. The decrease was due to the
increase in the small bubbles in the dough formed from aluminum slag resulting in more air being trapped and
causing cavities to appear in lightweight concrete. When aluminum slag is used within a certain range along with
mixed minerals such as fly ash, there will be an increase in the workability and mechanical properties of lightweight
concrete.
Figure 3 shows that the compressive strength test for each composition starting from 0% penis up to 1.5% is
increasing then decreasing until the composition is 7.5%. So, it can be concluded that the optimum compressive
strength of this lightweight concrete is a 1.5% composition of 4.1 MPa at 28 days of age.
Volume Weight Test
The results of this volume weight test were carried out at the age of 3, 7, 14, 21, and 28 days. The table
presents data for the volume weight of variations of aluminum slag substitution 0.0%, 1.5%, 3.0%, 4.5%, 6.0%, and
7.5% with 15% fly ash.
Figure 4. It is shown that the results of the volumetric weight test for each composition starting from 0%
control to 1.5% increased and then decreased to a composition of 7.5%. It can be concluded that the volume weight
of the test object increases up to 1.5% composition and decreases if the aluminum slag composition increases with
the fly ash material remaining 15%, but for the entire test object it still meets the requirements or is not too heavy.
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0% 1.5% 3% 4.5% 6% 7.5%
Compressive Strength
(MPa)
Aluminium Slag
3 Hari 7 Hari 14 Hari 21 Hari 28 Hari
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Figure 4.
Average Volumetric Weight
The results of this test use specimens that are 28 days old. Each specimen will be soaked in water for 24 hours
then wiped dry or SSD and put in an oven with a temperature of 110˚C for 24 hours. Before soaking, after soaking,
and after being in the oven, the test specimens are always weighed. The table presents data for water absorption of
aluminum slag substitution variations of 0.0%, 1.5%, 3.0%, 4.5%, 6.0%, and 7.5% with 15% fly ash. Based on
Figure 5. it shows that the water absorption test for each composition decreased at 1.5% composition by 66.67%,
then continued to increase to 7.5% composition by 74.40%.
Figure 5.
Graph of Water Absorption Test
Relation of Concrete Compressive Strength to Water Absorption
This research was conducted to increase the quality of cellular lightweight concrete mixtures. Thus, this
research can determine the optimum level of the substitute material used. The following is a graph of compressive
strength with water absorption to the percentage of aluminum slag and fly ash when the test object is 28 days old.
0.00
100.00
200.00
300.00
400.00
500.00
600.00
700.00
800.00
900.00
1000.00
0% 1.5% 3% 4.5% 6% 7.5%
Volumetric Weight
(kg/m3)
Aluminium Slag
3 Hari 7 Hari 14 Hari 21 Hari 28 Hari
62.00
64.00
66.00
68.00
70.00
72.00
74.00
76.00
0% 1.5% 3% 4.5% 6% 7.5%
Water Absorption
(%)
Aluminium slag
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Figure 6.
The Relationship Between Compressive Strength and Water Absorption at 28 Days of Age
Figure 6. It can be seen that the peak compressive strength was at the percentage of 1.5% aluminum slag and
at that time the water absorption was at a low position. So the optimum percentage of aluminum slag in terms of
compressive strength and water absorption of the test object at a composition of 1.5% is with a compressive strength
of 4.1 MPa and a water absorption of 66.67%.
Relationship of Concrete Compressive Strength to Volume Weight
Testing of compressive strength to unit weight of lightweight cellular concrete (CLC) bricks shows that they
are interconnected, this can be seen from the weight of each specimen affecting the compressive strength test.
However, there are several test objects that have volumetric weights that do not affect each other. This condition is
caused by incomplete drying so that there is a lower unit weight but the resulting compressive strength is greater.
In this study also showed that there were several specimens that had a low volume weight but high
compressive strength, so that the volume weight and compressive strength influenced each other. The cause of this
condition is that the test object is still at an early age, the volume weight is still large because it still contains a lot of
water, but the compressive strength shows a small value. This happens because the mixed reaction process is not
perfect. Meanwhile, the test object that has been aged for a long time has reduced water content so that the volume
weight has also decreased but the compressive strength shows a high value.
Figure 7.
Relationship Between Compressive Strength and Unit Weight at 28 Days Old
In Figure 7, it is explained that the 0% composition experienced an increase in volume weight and
compressive strength up to 1.5% composition and then decreased to 7.5% composition. The optimum value at the
age of 28 days is at a composition of 1.5% with a volume weight of 753 kg/m3 and a compressive strength of 4.1
MPa.
4. Conclusion
Based on the results of the research and discussion that has been done before, conclusions can be drawn as the
optimum percentage of using aluminum slag and fly ash in CLC lightweight concrete mixtures as a cement
substitution material is obtained in variations of 1.5% aluminum slag with 15% fly ash to the total weight of the test
0.0
1.5
3.0
4.5
6.0
0% 1.5% 3% 4.5% 6% 7.5%
0.00
20.00
40.00
60.00
80.00
Compressive Strength
(Mpa)
Aluminium Slag
Water Absorption
(%)
Resapan Air (%) Kuat Tekan (Mpa)
0.0
1.0
2.0
3.0
4.0
5.0
0% 1.5% 3% 4.5% 6% 7.5%
0.00
200.00
400.00
600.00
800.00
1000.00
Compressive Strength
(Mpa)
Aluminium Slag
Volume Weight
(kg/m3)
Berat Volume (kg/m3) Kuat Tekan (Mpa)
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object in each variation. The addition of variations of more than 1.5% aluminum slag causes a lower unit weight, so
the resulting compressive strength is also low. The effect of using aluminum slag and fly ash as a substitute for CLC
lightweight concrete mixture on compressive strength according to variations of aluminum slag 0%, 1.5%, 3%, 4.5%,
6%, and 7.5% with 15% fly ash increased from the variation 0% by 4 MPa to an optimum value of 1.5% by 4.1 MPa
and then decreased steadily by 3.9 MPa, 3.8 MPa, 3.7 MPa, and 3.7 MPa respectively at 28 days of age.
Suggestions
Based on the results of the research and discussion, there are several suggestions that can be taken as follows:
Conduct another in-depth study of cement substitution using the optimum percentage of aluminum slag of 1.5% and
fly ash of 15% with the addition of other ingredients to obtain better results. optimal. Treat the aluminum slag and fly
ash specimens with the addition of other materials as cement substitutes by curing, so that the test specimens do not
lose their water content. It is necessary to pay attention again to the implementation method at the stage of making
and mixing mortar and foam dough, because if the mixing process is uneven it can affect the results of the test object.
Furthermore, it is necessary to pay attention again when determining the comparison in the use of the water-cement
factor (FAS), because it can affect the results of the test object.
Acknowledgments
The authors would like to express their gratitude to everyone who contributed to this study in any way, whether
by financial backing, permission to conduct the research, expert advice, or assistance with collecting data.
5. References
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ASTM. (2012). Standard test method for foaming agents for use in producing cellular concrete using preformed
foam.
Bella, Rosmiyati A., Pah, Jusuf J. S., & Ratu, Ariansyah G. (2017). Perbandingan Persentase Penambahan Flyash
Terhadap Kuat Tekan Bata Ringan Jenis CLC. Jurnal Teknik Sipil, 6(2), 199–204.
Cement, American Society for Testing and Materials. Committee C. 1. on. (2013). Standard test method for
compressive strength of hydraulic cement mortars (using 2-in. or [50-mm] cube specimens). ASTM
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Nasional, Badan Standardisasi. (2009). Pengantar standardisasi. Jakarta: BSN, 198.
Ramamurthy, K., Nambiar, E. K. Kunhanandan, & Ranjani, G. Indu Siva. (2009). A classification of studies on
properties of foam concrete. Cement and Concrete Composites, 31(6), 388–396.
Reddy, Dr K. Chandrasekhar, & Kumar, S. Dinesh. (2017). Effect Of Fly Ash And Aluminium Powder On Strength
Properties Of Concrete. JournalNX, 3(07), 57–61.
Utomo, Gatot Setyo. (2016). Studi Penggunaan Catalyst, Monomer, dan Fly Ash Sebagai Material Penyusun Beton
Ringan Selular. Rekayasa Teknik Sipil, 3(3/REKAT/16).
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Monomer, Dan Fly Ash Sebagai Material Penyusun Beton Ringan Seluler. Rekayasa Teknik Sipil,
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© 2023 by the authors. Submitted
for possible open access publication
under the terms and conditions of the Creative Commons Attribution (CC BY SA) license
(https://creativecommons.org/licenses/by-sa/4.0/).
