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9th International Symposium on Lowland Technology
September 29-October 1, 2014 in Saga, Japan
SOIL CEMENT MIX DESIGN TEST FOR URGENT DISASTER REDUCTION
OF MT. BAWAKARAENG, INDONESIA
T. Harianto1, S. H. Nur2, I. Maricar2, A.A. Amiruddin2 and Masriflin3
ABSTRACT: A huge landslide disaster of Mt. Bawakaraeng in South Sulawesi, Indonesia has increased sediment rate
rapidly. Amount of sediment was approximated 2.5 million m3, most of the sediment has been deposited in the upper
side of Bili-Bili Dam overflowing area. This paper presents an experiment in order to utilize the sediment of Mt.
Bawakaraeng as a soil-cement mixture for road construction. The main objective of this study was intended to
characterize the index and engineering properties (soil gradation, water content, soil density, water absorption, and
compaction) of site-generated soil from Mt. Bawakaraeng. Furthermore, the cement mix design parameters
(compressive strength, elastic modulus, and permeability coefficient) were determined in order to utilize the sediment
material from the mountain. In the further work stage, a simple relation of soil cement compressive strength with
cement volume was generated for mix design determination of soil-cement. The result shows that the selected soil has a
good gradation with silt and sand contents are less than 40%. A linear relation of unconfined compressive strength and
cement volume was used for 7 and 28 days curing time. It shows that on the 28 days of curing time, the sample with
120 kg/m3 of cement has strength more than 4.65 N/mm2 which is acceptable with the desired strength of soil cement
minimum of 4.5 N/mm2. The coefficient of permeability of the same sample was found almost comparable with
concrete or very soft soil permeability. The results seem to have benefit for field application (i.e. road construction) as
a part of the urgent disaster sediment reduction.
Keywords: Soil cement, mix design, sediment, road construction, urban disaster.
INTRODUCTION
Mt. Bawakaraeng is one of the highest mountains in
the South Sulawesi. Last July 2005, hillside of MT.
Bawakaraeng caldera had collapsed and caused a huge
landslides disaster. It has induced debris flow resulting
from the collapse of caldera and producing a lot of
sediment on upstream river and often destructing
important infrastructures downstream. The high rainfall
intensity at the upper area of Mt. Bawakaraeng is very
potential to initiate sediment movement, may further
create hyper-concentrated flow such as debris flow with
high destructive power and deposited sediment toward
the Bili-Bili Dam (CTI, 2005).
The most critical situation where relatively high
pyroclastic flow towards Bili-Bili Dam (lower stream of
Jeneberang River, situated around 100 km southern part
of the collapse zones). The mold flow has causing
damage to the productive land area of Jeneberang River,
1
infrastructure facilities (i.e. access road, bridges, sabo
dam, etc), and local residential lives. Fortunately, the
presence of the sabo dam along Jeneberang River
(initially planned around 11 sites) has functions properly
to reduce the damage. Similar idea was adopted to build
such dam in the lower stream near Mt. Bawakaraeng
area. This development of sabo dam is part of the Urgent
Sediment Disaster Reduction Control Project for Mt.
Bawakaraeng. In this study, site-generated soil is used to
the several portions of facilities such as a dam body
instead of concrete and thus, construction cost is
expected to be lowered compared to concrete sabo dams.
The implemented type of sabo with soil cement
structures, which utilizes the river bed materials near the
site. This study is also considered in the construction of
sabo dam for urgent sediment reduction control of Mt.
Bawakaraeng lower basin project. From this view point,
it is believed that making use of the local materials will
contribute some advantages, such as good quality and
IALT member, Assoc. Professor of Civil Engineering Department, Hasanuddin University, Makassar 90245, INDONESIA,
[email protected]
2
Assist. Professor of Civil Engineering Department, Hasanuddin University, Makassar 90245, INDONESIA, [email protected]
3 Master student, Hasanuddin University, Makassar 90245, [email protected]
Harianto, et al.
RESULT AND DISCUSSION
Characteristics of Site-Generated Soil
Field and laboratory tests were conducted in
accordance with the following test items; site-generated
soil index properties (soil gradation, water content, soil
density, and water absorption), engineering properties
(compaction), and soil cement mix design parameters
(compressive strength and coefficient of permeability).
Characteristics of index and engineering properties of
site-generated soil material were investigated with
testing sequence as follows.
Grain Size Distribution Analysis
Soil sample for soil-cement mix design shall be
selected in consideration of grain size, which determines
strength of sabo soil-cement together with cement
volume. Preferable soil sample river bed material, which
contains a small amount of silt particles of less than
0.075 and bigger volume of cobbles than that of sand
The laboratory distribution curves of site-generated
soil for material less than 53 mm are plotted together
with the distribution curves of field gradation curves as
shown in Fig. 1
Sieve Analysis
METHODS AND MATERIALS
No.200
No.40
Hydrometer Analysis
100
Sample A1
Sample A2
Sample A3
Mixed (<53.0 mm)
80
Passing Finer, (%)
60
40
20
Boulders
Cobbles
1
Gravel
Coarse
0.1
Grain Diameter, mm
Sand
Fine
Coarse
Medium
0.01
Fine
0.001
0.002---
0.075 ---
19.1 ---
75 ---
10
0.425 ---
100
4.75 ---
0
1000
300 ---
The method used in this research is experimental
method which conducted in laboratory of soil mechanic
(Costet, 1983; Holtz, 1981). For laboratory test, the
samples are materials of less than 53 mm in diameter and
around 600 kg/pit in quantity for each quarry. Sample
taking is carried out in 3 (three) pits. Laboratory test
consists of sieve-analysis for materials taken from
sampling soil, density and water absorption ratio,
compaction test for site-generated soil, fabrication of
soil-cement, and unconfined compression test for sabo
soil-cement design
According to USER (1974) mix test of soil cement is
carried out on 3 (three) mixes, three different volumes of
cements, to observe the relations between cement
volumes of the assigned site and the engineering
properties such as the unconfined compressive strength,
compaction and permeability. Cement ratio used in this
project is set to 100 kg/m3, 150 kg/m3 and 200 kg/m3.
For covering the samples, polypropylene is used so as to
prevent water evaporation. Samples can be taken from
the molds after 3 days. Capping by mortar shall be made
when the surface of the bottom part is not smooth.
No.4
2.0 ---
cost saving. Relevant geotechnical investigation is
necessary prior to the further development to be
conducted in the work Geotechnical Investigation of
Sabo Soil Cement. Therefore, the investigation design
for soil cement mix design of Sabo Dam 7 at the lower
basin Jeneberang River was conducted in the soil
mechanic laboratory, Department of Civil Engineering,
Faculty of Engineering, Hasanuddin University.
In such cases, this soil cement mix design is
implemented for sabo dam structure to prevent the
natural disasters due to sediment, particularly pyroclastic
flow and debris flow (Sueyoshi, 2005; Surolelono,
2007). This design already used and construct to sabo
dams all over the Indonesia. In order to achieve the sabo
soil cement design objective, the following procedures
for mix design investigation of soil cement sabo dam
using the Jeneberang River bed of sabo dam as a sample.
This geotechnical investigation work aimed to
evaluate the engineering properties regarding to the
using of the local materials for construction of sabo dam.
This includes identification of physical and mechanical
properties of soil at the above sites, such as index
properties, gradation properties, and compaction
properties as well as unconfined compressive properties
and permeability coefficient of sabo soil cement
(Bowles, 1984; Das, 1994). The work shall also present a
job mix formula obtained from acceptable mix design.
Silt
Clay
U.S.C.S (United Soil Clasification System)
Fig 1. Gradation Curves of Site-Generated Soil for
Samples Group A1, A2, A3 and Mix
The distribution shows that sand fraction of sitegenerated soil is 11.97%, whereas gravel fraction of sitegenerated soil is about 64.81%. Cobble fraction of sitegenerated soil is 18.84%. The findings show that the soil
contains a small amount of silt particles of less than 1%
Soil Cement Mix Design Test for Urgent Disaster Reduction
2.30
3
Dry Unit Weight, gdry(gram/cm )
and bigger volume of gravels than that of sand and
cobble fractions.
Water Content Determination
Five series water content determination were done in
considering four groups grain size and mixed group in
size < 53.5 mm, the results are summarized in Table 1.
Water content of site-generated ranges from 2.95% to
7.50%, for group size diameter 53-37.5 mm is 2.95%
and 7.50% (smaller than 4.75 mm). In case of mixed
grain size group is about 4.56%, good comparable with
the average values of group samples results (4.81%).
Table 1. Water Content Conditions of Site Generated
Soil for each Group Sizes
Testing No.
-
Testing Items
Container Number
Grain Size Group in mm
53.00-37.50 37.50-19.10 19.10-4.75
-
-
-
< 4.75
Mixed (Dia < 53.0 mm)
-
-
-
Weight of Container, (W1)
Gram
66.63
253.90
69.40
111.17
399.20
Weight of Container+Wet Soil, (W2)
Gram
710.10
759.37
718.85
798.13
2473.40
Weight of Container+Dry Soil, (W3)
Gram
691.77
739.47
688.15
750.20
2380.07
Weight of Water, (Ww)={(W2)-(W3)}
Gram
18.33
19.90
30.70
47.93
93.33
Weight of Dry Soil, (Ws)={(W3)-(W1)}
Gram
625.13
485.57
618.75
639.03
1980.87
Water Content, w=(Ww)/(Ws)*100%
Gram
2.95
4.08
4.96
7.50
4.56
Average of Water Content (Ratio), w
%
4.81
Density and Water Absorption Determination
Density at oven-dry condition of site-generated soil
is around 2.182-2.451 t/m3 and for face-dry condition is
about 2.373-2.527 t/m3. Whereas density at apparent-dry
condition is around 2.654-2.791 t/m3 and specific gravity
of material smaller than 4.75 mm is Gs= 2.762.
Compaction Properties
Compaction curves for different sample groups are
shown in Fig. 2. Optimum moisture content design of
site-generated soil at 95% is expected 8.1% with
maximum dry unit weight 1.985 ton/m3. It is seem that
the compaction curves tend to develop without peak, this
might be due to coarse fraction of this site-generated soil
to be predominantly as shown in the above gradation
curves.
MIX DESIGN TEST OF SOIL CEMENT
It was stressing in the sabo soil-cement manual that
the most important part for sabo construction is soil
cement mix design. Mix design test should be carried out
Assumed Curves for Mixed
Material
2.20
g dry opt =2.10 gram/cm 3
2.10
Group A1
Group A2
Group A3
Mixed < 53.5 mm
Poly. (Mixed < 53.5 mm)
g dry-opt 95 =1.985 gram/cm 3
2.00
w opt = 13.0 %
w opt 95 = 8.10 %
1.90
1.80
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
Moisture Content, w(%)
Fig 2. Compaction Curves of Site-Generated Soil for
Samples Group A1, A2, A3 and Mix.
at site and laboratory to 1) grasp properties of sabo soilcement and 2) to decide the cement volume to be mixed
to the site-generated soil so that the structure to be made
by sabo soil-cement would satisfy the predetermined
required soil cement strength.
In such cases, mix design test would be performed to
determine proportionally the required amount of cement,
soil, and water. Therefore, a series mix test might be
considered for both field and laboratory test toward sitegenerated soil as well as for the desired soil cement
strength. For utilization plan of soil cement, the outlined
design procedures consist of design (desired and mix)
strength level of soil cement, soil cement trial-mix
design test, determination of cement volume, and design
mix of soil cement.
Grain Size Curves of the Selected Sabo Soil
Selection of site-generated soil to be used for sabo
soil cement should be selected in consideration of grain
size, which determines strength of sabo soil-cement
together with cement volume. Grain size distribution of
soil (see Fig. 1), which was selected for sabo soil cement
as represented in Fig. 3, characterizes that sand fraction
of site-generated soil is 11.97%. Gravel fraction of sitegenerated soil is about 64.81%, whereas Cobble fraction
is 18.84%. The findings show that the soil contains a
small amount of silt particles of less than 1% and bigger
volume of gravels than that of sand and cobble fractions.
It seems that the selected soil shows that weight of
silt and sand are less than 40 % in most cases of sabo
soil. The maximum grain size for the INSEM method is
mostly 150 mm, which is decided from thickness of a
layer and capability of compaction machine. The
selected soil for sabo soil-cement was collected at the
river bed with good gradation, which contains a small
Harianto, et al.
Fabrication of Mix Soil Cement
amount of silt particles of less than 0.075 (less than 5 %)
and more volume of sand than that of cobbles.
100
Sample A1
Sample A2
Sample A3
Mixed (<53.0 mm)
60
40
Passing Finer, (%)
80
20
Fabrication of specimen must be prepared by
considered the schedule for laboratory test, namely 1)
unconfined compression test and 2) permeability test.
Preparation of specimen in this test is referred to the
test items as described in the standard procedure. Prior to
the compression and permeability test, the followings
test should be confirmed and/or prepared in addition to
the materials for the test such as soil, cement and water.
For specimen curing time, samples was taken from the
molds after 3 days and wrapped by polypropylene bags
or aluminum foil to avoid dry out.
0
0.1
1
10
100
1000
Grain Diameter, mm
Fig 3. Gradation Curves of the Selected Soil for Sabo
Soil Cement
Soil Cement Mix Formulation
Table 2. Typical Calculation Sheet for Specimen
Material Requirement with Cement Amount 150 kg/m3
Number of Specimen
Sabo Soil
Cement Amount
: -.: Site-Generated Soil
kg/m3
: 150.00
Calculation Condition
Dia. of Mold
Height of Mold
Vol. of Mold, V
Mix Design Parameters
: 15.00 cm
: 30.00 cm
3
: 5301.4 cm
Quantity
- Specimen Dry Density (1)
2.150
- Specimen Water Content (2)
- Specimen Wet Density (3)
- Water Content of Material (ω%)
- Mold Volume, φ×h = 15cm×30cm
- Specimen Wet Weight / 1 Mold
Remarks
t/m3
8.00
%
2.322
t/m3
4.17
%
0.005301
m3
12.310
kg
Mix Design Formulation
Calculation per Mold
Cement + SiteGenerated Soil
0.795
kg
2. Total Water Amount/1 Mold
(Spec. Wet Density - Spec. Dry Density) ×V
0.912
kg
3. Material /1 Mold (Wet Weight)
((1)-Cement Amount)×(1+Material Water Cont./100)×V
11.045
kg
4. Material /1 Mold (Dry Weight)
3/(1+Material Water Cont./ 100)
10.603
kg
5. Amount of Water Contained
3-4
0.442
kg
2-5
0.470
kg
in Material / 1 Mold
to add / 1 Mold
Material Requirement
Material Requirement
Quantity
Cement Amount (C)
0.795
kg
Site-Generated Soil Dia. <53.5 mm (Ms)
11.045
kg
liter
Water Volume (W)
0.470
Specimen Wet Weight per Mold (Mm)
12.310
kg
Specimen Density (rc)
2.322
t/m3
10.0
Sample-1
Sample-2
Sample-3
8.0
6.0
4.0
Cement 100 Kg/m
Curing 7 Days
2.0
10.0
Sample-2
Sample-3
8.0
6.0
4.0
3
Cement 200 Kg/m
Curing 7 Days
2.0
0.0
3
0.0
0.0
0.5
1.0
1.5
2.0
Axial Strain, ε (%)
2.5
3.0
0.0
0.5
1.0
1.5
2.0
2.5
Axial Strain, ε (%)
Quantity
Material 1 Mixing(2x3 Spec.) for 7 and 28 Days
pc
Number of Specimen
7.000
Specimen Premium
20.000
%
Cement Amount (C)
Site-Generated Soil Dia. <53.5 mm (Ms)
6.680
kg
92.778
kg
Water Volume (W)
3.946
kg
103.403
kg
Total Weight of Specimen
12.0
Sample-1
Quantity
Cement Amount×V
Material Content per Mold
The unconfined compression test is carried out for
specimens who have three different cement volumes to
evaluate the relation between cement volume and
unconfined compression strength. In order to identify
such as relations between cement volumes per one site,
cement ratio used in this project was set to 100 kg/m3,
150 kg/m3, and 200 kg/m3. Under these test cement
volumes, the soil cement specimens were made to
investigate the unconfined compressive strength under
three cases of cement volume with curing time 7 and 28
days. Figs. 4 and 5 show the condition of compression
curves for compression test with cement volume 100 200 Kg/m3
12.0
1. Cement Weight /1 Mold
6. Amount of Water
Unconfined Compression Test of Soil Cement
Axial Stress, σ28 (N / mm2)
0.01
Axial Stress, σ28 (N / mm2)
0.001
Fig. 4 Typical Conditions of Compression Curves for
Compression Test; Cement Volume 100 and 200 Kg/m3
with Curing Time 7 Days
3.0
Soil Cement Mix Design Test for Urgent Disaster Reduction
Sample-2
14.0
Sample-3
12.0
10.0
8.0
6.0
4.0
Cement 100 Kg/m
Curing 28 Days
2.0
Sample-1
16.0
Sample-2
14.0
Sample-3
12.0
10.0
3
8.0
6.0
4.0
Cement 200 Kg/m
Curing 28 Days
2.0
0.0
3
0.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
0.0
0.5
Axial Strain, ε (%)
1.0
1.5
2.0
2.5
3.0
Axial Strain, ε (%)
Fig. 5 Typical Conditions of Compression Curves for
Compression Test; Cement Volume 100 - 200 Kg/m3
and Curing Time 28 Days
The unconfined compressive strength of soil-cement
with cement is obtained in the range 6.95 – 8.81 N/mm2
for 7 days and 8.01-14.46 N/mm2 for 28 days specimen
curing time. The result tends to increase linearly with the
addition of cement volume. Whereas the specimen wet
density is obtained in the range 2.237-2.273 t/m3 for 7
days age and 2.270-2.353 t/m3 for 28 days specimen age,
it seems the unconfined compression strength slightly
increase with the addition of cement.
Permeability Test of Soil Cement
The purpose of a permeability test is to observed the
water-tightness of soil cement. Permeability test was
carried out for specimens with three (3) different volume
of cement to grasp relation between cement volume and
permeability coefficient.
1.00E-02
Curing 14 Days
Permeability Coefficient, kc
(Cm/Sec)
1.00E-03
Typical relationships of soil-cement permeability and
cement volume are shown in Fig. 6. The curve of soil
cement permeability coefficient tends to decrease
slightly with the increasing of cement volume. In the
range of cement volume 120 kg/m3, coefficient of
permeability is the order of 3.51x10 -6 cm/second and
almost comparable with concrete or very soft soil
permeability. the permeability coefficient of soil
cement at age 28 days was observed slightly lower in
the range of 2.53x10-6 – 7.86x10-6 cm/sec for cement
volume 100-200 Kg/m3. Similar trend was also
observed for specimen wet density and water content
i.e.; 2.171-2.330 t/m3 and 6.453-8.661%, respectively.
Determination Mix of Sabo Soil Cement
For determination mix of soil cement, a simple
relationship could be observed by plotting the
compressive strength curves versus cement volume with
different curing time.
18.0
Peak qc 7 Days
16.0
Unconfined Compressive Strength, qc
(N/mm2)
18.0
Sample-1
16.0
Axial Stress, σ28 (N / mm2)
Axial Stress, σ28 (N / mm2)
18.0
12
Peak qc 28 Days
14.0
Peak qc/2 7 Days
Peak qc/2 28 Days
12.0
12
10.0
8.0
12
y = 0.0323x + 0.7739
R2 = 1
6.0
Mix Stength 4.65 N/mm2
4.0
2.0
120kg/m
3
Curing 28 Days
y = 2E-05e -0.0145x
R 2 = 0.9368
1.00E-04
0.0
Average
0
Expon. ( Average)
25
50
75
100
125
150
175
200
225
250
Amount of Cement (Kg/m3)
Fig. 7 The compressive strength of sabo soil-cement
for various cement volume and curing time.
1.00E-05
Permeability Coeff.
3.51*10-6 Cm/Sec
1.00E-06
120kg/m3
1.00E-07
1.00E-08
0
25
50
75
100 125 150 175 200 225 250 275
3
Amount of Cement (Kg/m )
Fig. 6 Relation between
permeability of soil-cement
cement volume
and
The variation of unconfined compressive strength of
with cement volume is shown in Fig. 7. The compressive
strength of Sabo soil-cement for various cement volume
120 kg/m3 with curing time 28 days was obtained more
than 4.65 N/mm2. The sabo soil-cement with an average
age from 7 days to 28 days gives the unconfined
compressive strength ranging from 7.17 to 9.29 N/mm2.
In practice, by using 120 kg/m3 of cement is acceptable
for mix design of Sabo soil-cement with the desired
strength of soil- cement mix 4.5 N/mm2.
Harianto, et al.
CONCLUSIONS
ACKNOWLEDGEMENTS
The test results are summarized as follows.
1. Compaction curves for different sample groups
show that the optimum moisture content design of
site-generated soil at 95% is expected 8.1% with
maximum dry unit weight 1.985 ton/m3. It is seem
that the compaction curves tend to develop without
peak, the reason is that coarse fraction of sitegenerated soil to be predominantly with silt content
less than 1%.
2. The unconfined compressive strength of sabo soilcement are obtained in the range 6.95 – 8.81
N/mm2 for 7 days and 8.01-14.46 N/mm2 for 28
days. The curves tend to increase linearly with the
added of cement. The specimen wet density slightly
increase with the added of cement.
3. The curve of soil cement permeability coefficient
tends to decrease slightly with the increasing of
cement volume. In the range of cement volume 120
kg/m3, coefficient of permeability is 4.56x10-6
cm/sec and almost comparable with concrete or
very soft soil permeability. The results seem to
have benefit for field application (i.e. road
construction) as a part of the urgent disaster
sediment reduction.
The authors would like to acknowledge financial
support for this study provided by Hasanuddin
University through BOPTN Grant 2014 (representative
person, Dr. Tri Harianto.).
REFERENCES
USER, 1974, Earth Manual, Denver, Colorado, USA.
Public Works Department, 2005, Manual on Soil
Cement Sabo Dam, SNVT Merapi, Yogyakarta.
CTI, 2005, Supporting Report of ISM and CSG Material
Survey for Bawakaraeng Urgent Sediment Control
Project, CTI Engineering International Co., Ltd.,
Makassar.
Bowles, J. E., 1984, Physical and Geotechnical
Properties of Soils, Mc. Grave Hill, Singapore.
Costet, J. and Sanglerat, G., 1983, Course Critique de
Merchanique des Sots, Dunod, Paris.
Das, B. M., 1994, Principles of Geotechnical
Engineering, PWS Publishing Comp., Boston, USA.
Holtz, D.R. and Kovacs, W.D., 1981, An Introduction to
Geotechnical Engineering, Prentice-Hall, Inc.,
Englewood Cliffs, N.J. 07632, USA.
Sueyoshi, K., 2005, Design Report of Kaliadem Sabo
Dam, Yachiyo Eng. Co. Ltd., Yogyakarta.
Surolelono, K.B., 2007, Geotechnical Investigation
Report for Sabo Soil Cement of MT. Merapi, Faculty
of Engineering Gadjah Mada University, Yogyakarta.