International Journal of Engineering Trends and Technology (IJETT) – Volume 12 Number 8 - Jun 2014
Performance and Evaluation on Marshall Stability
Properties of Warm Mix Asphalt Using Evotherm and
Cecabase Rt®-A Chemical Additive
Manjunath K.R1, Dheeraj Kumar N2, Thippeswamy G.S3
1,2
Assistant Professor, Department of Civil Engineering, DSCE, India
3
Student, M.Tech, Highway Technology, DSCE, Bangalore, India
-------------------------------------------------------------------***----------------------------------------------------------------------Environment and the 1996 Germany’s consideration to
review asphalt fumes exposure limits. The United Nations’
discussions resulted in the 1997 Kyoto Accord, which
formalized a commitment by the signatory states to reduce
greenhouse gas emission to the 1990 levels, while the
Germany’s review of asphalt fumes exposure limits lead to
the formation of a partnership forum (The German
BITUMEN Forum) to discuss these considerations.
Reduction of mixing and placement temperatures became
the obvious answer and triggered the development of WMA
concepts and technologies (Croteau and Tessier 2008) [1].
Abstract
The Warm Mix Asphalts (WMA) is modified Hot Mix
Asphalt (HMA) which is produced, laid and compacted in
temperature which is lower than conventional HMA. The
WMA is produced by mixing chemical additives to the
conventional mix to improve the pavement performance. In
this study an attempt is made to compare the Marshall
properties of WMA produced with the chemical additive:
“Evotherm” and “Cecabase RT®”with HMA for Bituminous
Concrete (BC) Grade 1&2. The adopted mixing temperature
for HMA was 160°C and the mixing temperatures for WMA
was 130°C, with an additive dosage rate of 0.3% & 0.4% by
weight of the binder for Grade 1&2 respectively. The
optimum binder content was to be found out individually for
the mixture for different mixing temperatures and additive
dosage rate. The laboratory study concludes that Stability &
Marshall properties were improved for the WMA mix by the
addition of the additive.
1.2Objectives
The objective is to study the effect of mixing temperatures
of the mix of BC Grade 1&2, adopting Rothfutch gradation
for HMA and WMA. The present study includes the
preparation and testing of laboratory specimens for Marshall
Test of HMA mix at 160°C temperature and WMA mix at
130°C temperature with additive dosage rate of 0.3% and
0.4% by weight of binder for Grade 1&2 respectively, to the
required specifications.
Key Words: Doping, Marshall stability, Voids.
1. INTRODUCTION
2. LITERATURE REVIEW
1.1 General
The WMA technologies can be classified broadly as those
In general the WMA technology is now evolved with
reducing the production or mixing temperature of the asphalt
mix for up to 40º C by adding additives to the conventional
asphalt paving mix. This is a technology which allows the
mixing, lay down and compaction of asphalt mixes at lower
temperatures compared to HMA. In case of WMA
technology due to the addition of additive to the paving mix,
the temperature required for heating the aggregate is less
that is around 120º C. Thus it reduces the fuel consumption
and greenhouse gases. The world focus on the development
of WMA technologies may be traced back to two distinctive
events: the 1992 United Nations’ discussions on the
resistance and water stability, the result show that Warm
Asphalt Mix gets excellent performance.
Graham and Brian (2005) [3] studied about Aspha-Min use
in Warm Mix Asphalt. Two aggregates, granite and
limestone were used. The Superpave gyratory compactor
was used to determine the mixture compatibility at different
ISSN: 2231-5381
I.
 That use water in the mix
 That use organic additive or wax in the mix
 That use chemical additives or surfactants mix.
Xijuan Xu, (2011) [2] Warm Mix Asphalt is low-carbon,
environmentally friendly asphalt mixture. This kind mixture
not only save resources, reduce harmful gap emissions, but
also to maintain the asphalt mixture in a better use of
quality. In the article, by adding additives to reduce the
viscosity of asphalt, we reach the effect of reducing the
temperatures of mixture mixing and compaction. At the
same time, we do experiment on study high temperature
stability,
low
temperature
crack
temperatures. Mixes were compacted at 149° C, 129° C,
110° C and 88° C, with mixing temperature about 19° C
above the compaction temperature. The additive Aspha-min
was added at rate of 0.3% by mass of the mix.
Stacey Amy (2008) [4] evaluated warm mix asphalt
technology by using Sasobit. In this study the nominal
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International Journal of Engineering Trends and Technology (IJETT) – Volume 12 Number 8 - Jun 2014
maximum aggregate size of Superpave 9.5mm and 12.5mm
were used. The mix is produced using penetration grade 6422 binder, designated by VDOT SM-9.5A mixture and
VDOT SM-12.5A mixture. The super pave gyratory
compactor was used for the compaction. Mix production
was carried out at different temperatures of 149ºC, 162ºC
and 121ºC. WMA additive Sasobit was added at a rate of
1.5% by weight of the binder. The results concluded using of
the additive lowered the air voids and improved the
compactibility.
Elie and Edward (2011)[5] conducted laboratory test for the
Cecabase RT® Warm Mix Additive using an aggregate of a
size 19.0mm as specified by Caltrans Standard specification
and NDOT specification for Road and Bridge construction.
PG 64-28 polymer modified asphalt binder was used for the
study. Temperature of 160ºC and 132ºC were maintained for
the preparation of HMA and WMA mixes respectively.
Cecabase RT®warm mix additive was added to asphalt
binder at a rate of 0.4% by weight of binder. Mix design was
carried out according to Caltran and NDOT specification for
the HVEEM design method.
index
5
Water
absorption
test
IS-2386
part III
0.25%
Max 2%
Table-3.2: Physical properties of Bitumen.
SI.
Test
Obtained
Properties
No.
method
values
Penetration(mm)
IS: 1203 1
(100g, 25˚C, 5
65
1978
sec)
Softening
IS: 1205 2
52.4
point(˚C)
1978
Ductility at 25˚C IS: 1208 3
100
(mm)
1978
IS: 1202 4
Specific gravity
1.01
1978
Flash point
IS: 1209 5
280
test(˚C)
1978
6
Fire point
IS: 1209 315
test(˚C)
1978
3. MATERIALS AND METHODOLOGY
Plain bitumen of Viscosity Grade 30(VG 30) was used for
the preparation of specimens. The basic test results of the
bitumen are tabulated in Table 3.1. The aggregates which
have good and sufficient strength, hardness, toughness and
soundness have to be chosen. Crushed aggregates produce
higher stability. The properties of bituminous mix are very
much dependent on the aggregate size and their grain size
distribution. Ministry of Road Transport and Highway
(MoRTH) specifies the gradation for different layers of the
bituminous courses. The tests conducted to check the
physical properties and there results are tabulated in Table
3.2.
3.1 Additives
Evotherm:
There are three technologies produced by Evotherm –
Evotherm ET (often referred as just Evotherm) which has
eventually been replaced by Evotherm DAT and
Evotherm3G.
Evotherm ET (Emulsion Technology) uses a chemical
package of emulsification agents and antistripping agent
SI.
No.
1
2
3
4
Table -3.1: Physical properties of Coarse aggregates.
Test
Obtained
IS
Properties
method
values
Specifications
Crushing IS-2386
25.1 %
Max 30%
value
part IV
Abrasion IS-2386
34.38%
Max 35%
value
part IV
Impact
IS-2386
23.9%
Max 27%
value
part IV
Combined
Flakiness IS-2386
21.56%
Max 30%
and
part I
Elongation
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additives to improve aggregate coating, mixture workability
and compaction.
Evotherm makes up 30 percent mass of the binder and it
decreases the viscosity of the binder at lower mixing
temperatures, which leads to fully coated aggregates at the
same temperature. It is delivered in the form of bitumen
emulsion. Different chemical packages are available for
different aggregate types (with different adhesion agents).
The majority of the water in the emulsion flashes off as
steam when the emulsion is mixed with the aggregates. This
process reduces the production temperature by 30 percent.
Evotherm DAT (Dispersed Asphalt Technology) is the same
chemical package diluted with a small amount of water
which is injected into the asphalt line just before the mixing
chamber. It decreases the viscosity of the binder at lower
mixing temperatures, which leads to fully coated aggregates
at. This process reduces the production temperature by 30%.
Evotherm 3G it is water-free form of Evotherm. Since this is
a relatively new product, and there is no information
available about its properties from independent research.
Cecabase RT®:
The additive Cecabase RT® is the reference technology for
the production of warm mix asphalt (WMA). Adding a
liquid surfactant into the bitumen allows a 40°C (70°F)
temperature drop of the asphalt mix production and paving
processes, which turns into savings on the energy bill and
lower GHG emissions. Cecabase RT® 945 is CECA's
leading additive for the production of warm mix asphalt
(WMA) since 2007. With or without recycled pavement
(RAP), the additive Cecabase RT® 945 brings workability,
compaction and adhesively to a wide range of asphalt mixes
and techniques. CECABASE RT® has no impact on the
class of bitumen or on its rheology. Moreover, it reduces the
ageing of the bitumen when the mix is manufactured. The
higher the temperature of the asphalt mix, the more oxidised
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International Journal of Engineering Trends and Technology (IJETT) – Volume 12 Number 8 - Jun 2014
120
100
80
% Passing
it becomes. By lowering the temperature, CECABASE RT®
will reduce the ageing of the bitumen and increases the
lifetime of the road.
60
40
20
0
0.01
Figure -3.1: Evotherm and Cecabase RT®
3.2 Doping of additives
For the present study 0.3% and 0.40% was adopted as the
additive dosage for preparation of the specimens for
grade1&2 respectively. Additives were added 0.3% and
0.4% volumetrically using 2.5ml plastic syringe and the
molten bitumen 130˚C (266˚F) was stirred manually using a
glass rod while adding additives and additional stirring for
10 minutes was done for uniform mixing of the additive with
the bitumen.
Figure -3.2: Doping of additive.
26.5
19
13.2
9.5
4.75
2.36
1.18
0.6
0.3
0.15
0.075
6
mm
15%
100
100
100
77
7.1
6
2.9
1.8
1.35
0.95
0.7
Dust
Obtained
Desired
40%
100
100
100
100
100
88
68
45
32
15
8
Gradation
100.0
92.9
66.3
60.1
43.6
36.2
27.6
18.3
13.0
6.1
3.3
Gradation
100
79-100
59-79
52-72
35-55
28-44
20-34
15-27
10
5
2.0
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100
1000
LOWER LIMIT
UPPER LIMIT
MID LIMIT
OBTAINED GRADATION
Figure -3.3:Obtained gradation of Bituminous concrete
(BC) Layer, Grade-1
Table -3.4: Composition of Bituminous concrete (BC)
Layer, Grade-2 (MoRTH-2004)
sieve
size
20
mm
12
mm
6
mm
Dust
Obtained
Desired
Gradation
25%
15%
20%
40%
Gradation
19
84
100
100
100
96.0
100
13.2
69
95.6
98.9
100
91.4
79-100
9.5
39
89.4
93.45
100
81.9
70-88
4.75
15
44.9
68.9
100
64.3
53-71
2.36
0
29
46
97
52.4
42-58
1.18
0
19
17.2
89
41.9
34-48
0.6
0
3.9
12
78
34.2
26-38
0.3
0
0.87
8
48
20.9
18-28
0.15
0
0.05
2.1
35
14.4
20
0.075
0
0.05
0.55
15
6.1
10
100
% Passing
sieve
size
12
mm
25%
100
100
45
34
10
0.5
0.05
0.05
0.05
0
0
1
10
Sieve size (mm)
120
Table -3.3: Composition of Bituminous concrete (BC)
Layer, Grade-1 (MoRTH-2004)
20
mm
20%
100
64.6
0
0
0
0
0
0
0
0
0
0.1
80
60
40
20
0
0.01
0.1
LOWERLIMIT
MID LIMIT
1
Sieve size (mm)
10
100
1000
UPPER LIMIT
OBTAINED GRADATION
Figure -3.4: Obtained gradation of Bituminous concrete
(BC) Layer, Grade-2
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International Journal of Engineering Trends and Technology (IJETT) – Volume 12 Number 8 - Jun 2014
Percent Air
Voids, Va (%)
VMA (%)
VFB (%)
3.3 Marshall Test
The Marshall Test was carried out on HMA mixes by
varying the bitumen contents of 5.0%, 5.5% and 6.0% for
Grade 1 and bitumen contents of 5.0 to 7.0% for Grade 2 at
mixing temperatures of 160°C and WMA mixes with
varying bitumen contents of 5.0%, 5.5% and 6.0% for Grade
1 and bitumen contents of 5.0 to 7.0% for Grade 2 at mixing
temperatures of 130°C for an additive dosage rate of 0.3% &
0.4% by weight of the binder for Grade 1&2 respectively .
Three specimens were prepared for each binder content. The
specimens’ were compacted manually (75 blows per side)
using Marshall Compaction Hammer. To determine the
Optimum Binder Content (OBC) of the mixes on maximum
stability, maximum unit weight and 4 percent air voids is
considered. The test was carried out according to the ASTM:
D: 1559-65.
4.2
3.5
3.7
19.5
73
16.5
88.5
16.7
85.6
Stability (kN)
20
15
HMA
10
Evotherm
5
Cecabase
RT®
0
Grade-1
Grade-2
4. ANALYSIS AND RESULTS
Properties
Binder (%)
HMA
BC GRADE-1
Cecabase
Evotherm
RT®
Optimum
binder
5.70
5.70
5.70
content (%)
Stability (kN) 10.41
13.34
13.44
Flow(mm)
4.6
3.5
3.7
Bulk
2412
2501
2470
density(kg/m³)
Percent Air
4.8
4
4.2
Voids, Va (%)
VMA (%)
17.5
15.8
16.2
VFB (%)
78
88.4
85.4
Table -3.6: Marshall stability test results for Grade-2
Properties
Binder (%)
Optimum
binder
content (%)
Stability (kN)
Flow(mm)
Bulk
density(kg/m³)
HMA
BC GRADE-2
Cecabase
Evotherm
RT®
2550
Bulk density (Kg/m3)
Table -3.5: Marshall stability test results for Grade-1
Figure -3.5: Comparison of Stability obtained from using
various additives.
2500
HMA
2450
Evotherm
2400
Cecabase
RT®
2350
2300
Grade-1
Grade-2
Figure-3.6: Comparison of Bulk density obtained from
using various additives.
6
5
Air voids (%)
The Marshall Test results of HMA for BC at 160°C and also
specimens with 0.3&0.40% WMA additive at 130°C is
presented in Table -3.5 and Table -3.6. The graphs were
plotted for bitumen content and Marshall Stability, Bulk
density and Air voids. The bitumen content corresponding to
maximum stability, Bulk density and 4.0% air voids was
obtained and the average of the three bitumen contents was
calculated and treated as optimum bitumen content (OBC).
OBC values of HMA and WMA for BC different
temperature is tabulated in Table 3.5 and Table -3.6
HMA
4
Evotherm
3
Cecabase
RT®
2
1
6.40
6.40
6.40
13.48
5.5
16.78
4
16.55
4.2
2367
2486
2436
0
ISSN: 2231-5381
Grade-1
Grade-2
Figure -3.7: Comparison of volume of air voids obtained
from using various additives.
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International Journal of Engineering Trends and Technology (IJETT) – Volume 12 Number 8 - Jun 2014
5. CONCLUSION
Stability, flow, bulk density, voids in the mix, VFB and
OBC was done for 130˚C temperatures.




The OBC was found to be 5.7% and 6.4% for HMA
at 160˚c temperature of the mix of BC Grade 1&2.
The maximum stability for 60/70 grade bitumen is
achieved at 130˚C temperature with additive dosage
rate of 0.3% and 0.4% by weight of binder for
Grade 1&2 respectively.
From Marshall stability test, it can be concluded
that, there is an increase in stability up to 28% and
27%grade1 and 24% and 22% grade-2 at 130˚C for
60/70 bitumen for Evotherm andCecabase RT®
respectivelyafter adding to the mix .Hence the
warm mix additives be used as an alternative for
HMA.
The addition of WMA additive for Evotherm and
Cecabase RT® improves the bulk density of the
mix by 5% maximum. Hence 130˚C temperature
with additives shows better and maximum bulk
density.
REFERENCES
1. Jean-Martin Croteau, and Bernard Tessier (2008). “Warm Mix Asphalt
Paving Technologies: a Road Builder’s Perspective” Paper presentation of
annual conference Transportation Association of Canada
2. Xijuan Xu. (2011), “Performance of Low-Carbon Environmental Warm
Mix Asphalt”, American Society of Civil Engineers”.
3. Graham, C. H. and Brian, D. P. (2005). “Evaluation of Aspha-Min zeolite
for use in warm mix asphalt.” National Centre for Asphalt Technology
Report 05-04. Auburn University, Auburn, Alabama.
4. Stacey, P. E., and Amy, H. (2008). “Laboratory Evaluation of Warm
Asphalt Technology for use in Virginia.” Virginia Transportation Research
Council Report. In cooperation with the U.S Department of Transportation,
VTRC 09-R11.
5. Elie Y. Hajj and Edward M. Cortez(2011) “Evaluation Of The Cecabase
Warm-Mix Additive”, University Of Nevada Reno, in association with
CECA Arkema Group, Nevada 89557
6. MoRTH “Specifications for Roads and Bridge Works”- 2004, Fifth
revision, Indian Roads Congress, New Delhi.
7. S.K. Khanna and C.E.G. Justo, Highway Material testing (Laboratory
Manual), Nemchand and Bros, Roorkee 1997.
8. Mix Design Methods for Asphalt Concrete and Other Hot-Mix types,
Manual Series No.2, Sixth Edition, Asphalt Institute, Lexington, Kentucky.
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