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1. Pavement Performance Research on Fine Volcanic Ash Modified Asphalt
Mastic and Mixture
Zhiguo Chen1, a
, Zining Chen2,b
, Jiantao Wu1,c
and Haichen Yao3,d
1
Jilin Provincial Communications Scientific Research Institute, Changchun, Jilin, 130012, China
2
School of Transportation Science & Engineering, Harbin Institute of Technology,
Harbin, Heilongjiang, 150090, China
3
Jilin Communications Polytechnic, Changchun, Jilin, 130012, China
a
jcczg@vip.sina.com, b
chenzininghit@163.com,c
wujiantao.hit@163.com, d
haicheny@163.com
Key words: Volcanic ash, Compositly modified asphalt mastics, Modified asphalt mixtures,
Pavement performance, Cost-effective analysis.
Abstract: In this paper, based on advanced test methods such as laser particle sizer, scanning
electron microscope, DSR and BBR,studies on physical properties of fine volcanic ash are carried
out and the effect of single and composite modification on asphalt mastics and concrete by fine
volcanic ash are also studied. Cost-effective of asphalt concrete modified by fine volcanic ash are
analyzed as well. Results indicated fine volcanic ash can be qualified as a filler modifier for asphalt
mixture and it significantly improves asphalt pavement performance and reduces project cost. Fine
volcanic ash has favorable social and economic benefits and a broad application prospect.
Introduction
Under the combined effects of complicated natural conditions and increasing traffic load, asphalt
pavement damage occur. Application of polymer modified asphalt reduced the road early disease to
some extent, but increased highway construction cost. Mineral filler modifier is considerd an area of
asphalt modification research. Volcanic ash is a natural building material, with abundant resources
in China, mining convenience and low cost.It has tremendous social and economic benefits to apply
fine volcanic ash to asphalt modification, improve asphalt pavement performance, reduce road
disease, and cut down construction costs as well.
Volcanic Ash Properties
As one part of asphalt mixture, filler plays important role in determining asphalt mixture nature and
its properties affects filler-bitumen system significantly. Therefore, in-depth study about physical
and chemical properties of volcanic ash will make its role in asphalt mixture more clear. With
comparation with slag, underlying characteristics of volcanic ash are evaluated.
(1) Particle size test results indicate the major particle size of volcanic ash is smaller than slag,
distributing between hundreds of nanometers and a few microns, shown in table 1; Specific surface
area test showed that specific surface area of volcanic ash is larger than the fine powder, and varies
a lot depending on volcanic ash species. Volcanic ashes with almostly equal particle size showed
obviously different specific surface area, which is believed due to effects of particle surface
structure.
Table 1 Physical properties of fine volcanic ashes and mineral powder
Filler type Average particle size [nm]
Specific surface area
[m2
/g]
Mineral powder 1962 1.31
Volcanic
ash
FS 3 # 1901 45.05
CB1 # 1114 7.89
CB4# 1716 4.05
CB 6# 453 2.06
Advanced Materials Research Vols 255-260 (2011) pp 3382-3386 Online: 2011-05-31
© (2011) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AMR.255-260.3382
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans
Tech Publications, www.ttp.net. (ID: 141.117.125.76, Ryerson University Lib, Toronto-26/04/15,20:27:19)

2. In common, fineness of mineral filler determines surface area.Smaller partical size and larger
surface area means stronger interaction between asphalt and filler, with “structural asphalt”content
increased, thus improving bond strength between filler and bitumen [1,2,3] and resistance to high
temperature deformation and water moisture. Compared with slag, smaller fineness and larger
surface area of volcanic ash are beneficial to its modification to asphalt.
(2)Chemical composition analysis showed that volcanic ash contains elements Si, Al, Fe, K, Na,
Ca,Mg and a small amount of transition metal elements such as Fe, Ti, Mn, Cu, V, and Zn. XPS
analysis states that substances in volcanic ash mainly includes Si, SiO2, Al2O3, Fe2O3, Na2O, K2O,
CaO and MgO,among which SiO2, Al2O3 and alkaline oxides are helpful to pozzolanic reaction
acid-base reaction with asphalt anhydride acid, improving adhesion of asphalt and volcanic ash.
(3)Studies show that[4] surface properties of fillers such as shape, angularity and surface
structure play an important effect on asphalt mixtures, which affect rheological properties of mortar
and optimum asphalt content in mixture, and then influence structural and mechanical properties of
asphalt concrete. Surface structure comparation of volcanic ash, diatomite and slag by scanning
electron microscopy are shown in figure 1.
①Mineral powder are polyhedral structure, with smooth surfaces, less angular, and uniform
distribution of larger particle size, on whose surface there are almost no micro-pores;
②Diatomite has extremely rough surface with huge amounts of permeable micro-pores;
③Compared with mineral powder, volcanic ash has smaller particle size, fluffy and rough
surface and irregular particle shape, partially porous holes are uniformly dispersed on whose surface
and the permeable mesopore formed by surface salient are in the majority.In general, volcanic ash
has well-developed pore structures.
a) mineral powder b) diatomite c) volcanic ash
Fig.1 SEM pictures of fillers (×50000)
From the view of surfacial microporous structure, there existed obvious difference between
volcanic ashes dominated by mesopores and diatomite with porous holes in majority. Unique
microporous structure of volcanic ash bound to affect its modification to asphalt.
Pavement Performance of Volcanic Ash Modified Mastic
Asphalt mastic is one of the most important part of asphalt concrete. Properties of mastic,to a large
extent, affect asphalt pavement performance. Volcanic ash modified mastic is made up of base
asphalt and volcanic ash instead of slag with certain filler-bitumen ratio. High and low temperature
properties of volcanic ash mastic are studied compared with slag mortar, and composite
modification by volcanic ash and polymers is further explored as well.
Performance of Volcanic Ash Singlely Modified Asphalt Mortar.High and low temperature
performance of volcanic ash modified asphalt mortar is shown in figure 2.
0
2
4
6
8
slag CB1# FS3# CB4# CB6#
rutting
factor
at
60℃（kPa）
0
50
100
150
200
250
300
350
400
450
500
slag CB1# FS3# CB4# CB6#
creep
stiffness
at
-12℃（MPa）
0.36
0.38
0.4
0.42
0.44
0.46
0.48
slag CB1# FS3# CB4# CB6#
creep
rate
at
-12℃
a) rutting factor b) creep stiffness c) creep rate
Fig. 2 High and low temperature properties comparision of modified asphalt mastic
Advanced Materials Research Vols. 255-260 3383

3. Compared with slag mortar, rutting factor G*/ sinδ of volcanic ash mastic significantly
increased, indicating that high temperature properties of volcanic ash mortar turned better than the
slag mortar; additionally the capability for volcanic ash to improve high temperature properties of
mastic varies a lot due to different volcanic ash species.
Creep stiffness of volcanic ash mortar significantly increased compared with slag mortar.
Analysis believe that rough surface texture and developed pore structure of volcanic ash make it get
great specific surface energy,which is helpful for volcanic ash to absorb light oil from asphalt,
resulting in increased volcanic ash mortar consistency, along with increased stiffness;
Creep rate of volcanic ash mortar is almost equal to that of slag mortar, indicating stress
relaxation capacity of volcanic ash mortar at low temperature is equivalent with slag mortar.
Performance of Volcanic Ash Compositly Modified Asphalt Mortar. High and low temperature
properties of mortar compositly modified by different fillers and 5% SBS are shown in figure 3.
0
20
40
60
80
100
120
slag CB1# FS3# CB4# CB6#
rutting
factor
at
60℃（kPa）
single modification
composite modification
0
100
200
300
400
500
600
slag CB1# FS3# CB4# CB6#
creep
stiffness
at
-12℃（MPa）
single modification
composite modification
0.34
0.36
0.38
0.4
0.42
0.44
0.46
0.48
slag CB1# FS3# CB4# CB6#
creep
rate
at
-12℃
single modification
composite modification
a) rutting factor b) creep stiffness c) creep rate
Fig.3 Properties comparision of asphalt mastic compositly modified by fillers and SBS
It can be seen from figure 3 that compared with single modification by volcanic ash, rutting
factor G * / sinδ of compositly modified asphalt mortar by SBS and volcanic ash increased
exponentially, indicating that SBS significantly improved high temperature stability of mortars,
among which rutting factor improving rate of volcanic ash mortar by SBS exceeded the slag mortar.
Compared with the single modification, creep stiffness of asphalt mortar compositely modified
by slag and SBS increased, while all of volcanic ash mortar stiffness were reduced except for FS3 #
and CB6#. At the same time, creep rate decrease range of volcanic ash mortar is less than slag
mortar, it can be concluded that low temperature properties of composite modification by SBS and
volcanic ash is obviously better than slag.
Volcanic Ash Modified Asphalt Mixture Performance
In order to verify modification effect of volcanic ash mortar, comparative studies on road
performance of asphalt mixture modified by volcanic ash are carried out.
Asphalt Mixture Performance Singlely Modified by Volcanic Ash. Data from table 2 indicated
that dynamic stability of asphalt mixtures modified by volcanic ashes were better than that of
mineral powder mixture; trabecular bending strain of volcanic ash modified mixtures was roughly
equal to that of slag asphalt mixture, which are consistent to the conclusion from properties studies
of volcanic ash singlely modified asphalt mastics.
Table 2 Pavement performance indexes of volcanic ash singlely modified asphalt mixture
Filler type Mineral powder CB1# FS3# CB4# CB6#
Dynamic stability [time/mm] 988 1488 1434 1420 1668
Trabecular bending strain [ µε ] 2532 2590 2391 2607 2526
Marshall residual stability [%] 85.8 86.0 106.9 109.6 80.2
Residual strength ratio splitting
freeze-thaw [%]
85.4 94.6 80.7 86.1 78.3
3384 Advances in Civil Engineering, CEBM 2011

4. Performance of AC Asphalt Mixture Compositly Modified by Volcanic Ash. Data in table 3
show that compared with AC asphalt mixture compositly modified by slag and 5% SBS, anti-rutting
performance of volcanic ash and SBS compositly modified mixture significantly increased and low
temperature cracking resistance changed little.
Table 3 Pavement performance of AC asphalt mixture compositly modified by ash and 5%SBS
Filler type Mineral powder CB1# FS3# CB4# CB6#
Dynamic stability [times/mm] 2603 3428 4438 4650 4014
Trabecular bending strain [ µε ] 3160 3222 3653 2769 2865
Marshall residual stability [%] 85.4 93.7 112.2 87.3 89.3
Residual strength ratio
splitting freeze-thaw [%]
80.1 86.1 80.4 89.5 80.2
Performance of SMA Asphalt Mixture Compositly Modified by Volcanic Ash. Datas in table 4
showed that compared with SMA asphalt mixture compositly modified by slag and 5% SBS, high
temperature performance of volcanic ash and SBS compositly modified mixture significantly
increased and low temperature cracking resistance turned better,which are in agreement with
conclusion about properties of volcanic ash and 5% SBS compositly modified asphalt mastics.
Table 4 Pavement performance of SMA asphalt mixture compositly modified by ash and 5%SBS
Filler type Mineral powder CB1# FS3# CB4# CB6#
Dynamic stability [times/mm] 2932 3408 4875 4438 4964
Trabecular bending strain [ µε ] 2823 2806 2921 2924 3113
Marshall residual stability [%] 87.1 80.9 112.0 106.0 92.1
Residual strength ratio splitting
freeze-thaw [%]
85.0 90.0 80.4 80.8 84.5
Cost-effective Analysis about Volcanic Ash Modified Asphalt Mixtures
Studies have indicated that volcanic ash modified asphalt mastics and mixtures both displayed
excellent road performances. Simple analysis of the cost-effective is as follows.
Composite Modification by Volcanic Ash and 3%SBS. Test data from table 5 shows that
pavement properties of asphalt mixture modified by CB 1 # and 3% SBS is almost equal to that of
slag and 5% SBS modified mixtures and both satisfy the relevant road specification standard. Cost
comparison of two asphalt mixtures shown in table 6 indicated production cost of ash and 3% SBS
compositly modified asphalt mixture is lower than 5% SBS modified mixture with savings of 10.7
yuan per ton of asphalt mixture, achieving same excellent pavement properties while effectively
cutting down project cost.
Table 5 Performance comparison of modified AC asphalt mixture
Modified asphalt mixture type Slag and 5%SBS CB1# and 3%SBS
Dynamic stability [times/mm] 2603 2647
Trabecular bending strain [ µε ] 3160 3178
Marshall residual stability [%] 85.4 90.9
Residual strength ratio splitting
freeze-thaw [%]
80.1 85.2
Table 6 Cost comparison of modified AC asphalt mixtures
Modified asphalt mixture type Slag and 5%SBS CB1# and3%SBS
SBS cost per ton of asphalt mixture[yuan] 41.7 25.0
Filler cost per ton of asphalt mixture [yuan] 7.5 13.5
Total [yuan] 49.2 38.5
Advanced Materials Research Vols. 255-260 3385

5. Composite Modification by Volcanic Ash and 5%SBS.Test results in table 7 indicate that AC
asphalt mixture compositly modified by CB6# and 5% SBS displays more excellent high temperature
road performance than SBS modified SMA mixture, with up to 4014 times / mm of dynamic stability.
Cost comparision of two asphalt mixtures shown in table 8 indicated that production cost of AC
asphalt mixture compositly modified by ash and 5% SBS is lower than SBS modified SMA mixture
with savings of 68.3 yuan per ton of asphalt mixture.
Table 7 Performance comparison of modified AC and SMA asphalt mixtures
Modified asphalt mixture type
SMA mixture with slag
5%SBS and 0.3% fiber
AC mixture with
CB6# and 5%SBS
Dynamic stability [times/mm] 2932 4014
Trabecular bending strain [ µε ] 2823 2865
Marshall residual stability [%] 87.1 89.3
Residual strength ratio
splitting freeze-thaw [%]
85.0 80.2
Table 8 Cost comparison of modified AC and SMA asphalt mixtures
Modified asphalt mixture type
SMA mixture with slag
5%SBS and 0.3% fiber
AC mixture with
CB6# and 5%SBS
SBS modified asphalt cost per ton of mixture
[yuan]
258.0 210.7
Filler cost per ton of mixture [yuan] 15.0 13.5
Fiber cost per ton of mixture [yuan] 19.5 0.0
Total [yuan] 292.5 224.2
Conclusions
Physical features of volcanic ash, fine particle size, rough surface texture and well-developed pore
structure included, qualified volcanic ash as a filler modifier for asphalt mixture.
Volcanic ash can significantly improve high temperature stability of asphalt mortar and mixture,
and in low temperature performance to some extent;compared with single modification by volcanic
ash, composite modification by ash and SBS can greatly improve high temperature performance and
low temperature cracking resistence of asphalt mixture as well; SMA asphalt mixture modified by
volcanic ash and SBS can further enhance the road performance.
Economic analysis showed that volcanic ash not only improved pavement performance of asphalt
mixture, but also saved project cost.
References
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3386 Advances in Civil Engineering, CEBM 2011

6. Advances in Civil Engineering, CEBM 2011
10.4028/www.scientific.net/AMR.255-260
Pavement Performance Research on Fine Volcanic Ash Modified Asphalt Mastic and Mixture
10.4028/www.scientific.net/AMR.255-260.3382