Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Mats Gustafsson
PM10 from road pavement and winter tyre interaction
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Aim of road dust research
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
• Wear particles from pavement and winter tyres
• Physical and chemical properties?
• Factors affecting their formation?
• Are they as dangerous to health as exhaustparticles? (not further discussed here)
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
How do we study this?
• Generating ”clean” wear particles in a road simulator
exchangable pavement
4 exchangable tyres with electric motors run the machine
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
• Generating ”clean” wear particles in a road simulator
• Measurements and analysis of
• Concentration
• Size distributions
• Elemental composition
• Morphology
How do we study this?
Filter sampling
Size distributions
SEM and TEM
Concentration
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Used combinations
Pavement Tyre Friction material1. Dense asphalt, granite Studded -
2. SMA*, quartzite Studded -
3. SMA, quartzite Friction -
4. SMA, quartzite Studded Crushed stone
5. SMA, quartzite Friction Crushed stone
6. SMA, quartzite Friction Sand
7. SMA, quartzite Studded Sand
*SMA = stone mastic asphalt (skelettasfalt)
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
PM10 concentration (tyres and pavement)
0
1
2
3
4
5
6
00:0
0
01:0
0
02:0
0
03:0
0
04:0
0
05:0
0
06:0
0
Time (h)
Con
cent
ratio
n of
PM
10 (m
g/m
3 )
Dense asphalt, granite, studded tyres, 70 km/h
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
PM10 concentration (tyres and pavement)
0
1
2
3
4
5
6
00:0
0
01:0
0
02:0
0
03:0
0
04:0
0
05:0
0
06:0
0
Time (h)
Con
cent
ratio
n of
PM
10 (m
g/m
3 )
SMA, quartzite, studded tyres, 70 km/h
Dense asphalt, granite, studded tyres, 70 km/h
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
PM10 concentration (tyres and pavement)
0
1
2
3
4
5
6
00:0
0
01:0
0
02:0
0
03:0
0
04:0
0
05:0
0
06:0
0
Time (h)
Con
cent
ratio
n of
PM
10 (m
g/m
3 )
difference between resistant and less resistant pavement
SMA, quartzite, studded tyres, 70 km/h
Dense asphalt, granite, studded tyres, 70 km/h
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
PM10 concentration (tyres and pavement)
0
1
2
3
4
5
6
00:0
0
01:0
0
02:0
0
03:0
0
04:0
0
05:0
0
06:0
0
Time (h)
Con
cent
ratio
n of
PM
10 (m
g/m
3 )
SMA, quarzite, friction tyres, 70 km/h
difference between resistant and less resistant pavement
SMA, quartzite, studded tyres, 70 km/h
Dense asphalt, granite, studded tyres, 70 km/h
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
PM10 concentration (tyres and pavement)
0
1
2
3
4
5
6
00:0
0
01:0
0
02:0
0
03:0
0
04:0
0
05:0
0
06:0
0
Time (h)
Con
cent
ratio
n of
PM
10 (m
g/m
3 )
SMA, quarzite, friction tyres, 70 km/h
difference between resistant and less resistant pavement
difference between studded and friction tyres
SMA, quartzite, studded tyres, 70 km/h
Dense asphalt, granite, studded tyres, 70 km/h
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
0.5
1
1.5
0.1 1 10 100Diameter [µm]
dm/d
logD
p [m
g/m
³]
SMA, quartzite, studded, 70 km/hSMA, quartzite, studded, 50 km/hSMA, quartzite, studded, 30 km/h
Mass size distribution, PM10
•Mass size distribution similar for different speeds
•Concentration increaseswith speed
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
1
2
3
4
5
6
0.1 1 10 100
Diameter [µm]
% o
f tot
al m
ass
of d
istri
butio
n
SMA, quartzite, studded, 70 km/hSMA, quartzite, studded, 50 km/h
SMA, quartzite, studded, 30 km/hDense asphalt, granite, studded, 70 km/h
increasing share with increasing speed
decreasing share with increasing speed
PM10-2,5PM2,5
% of total mass distribution, PM10
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11
Diameter [µm]
Cum
ulat
ive
conc
entra
tion-
%
SMA, quartzite, studded, 70 km/h
SMA, quartzite, studded, 50 km/h
SMA, quartzite, studded, 30 km/h
Dense asphalt, granite, studded, 70 km/h
Cumulative concentration-%, PM10
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
200
400
600
800
1000
1200
0 10 20 30 40 50 60 70 80
Hastighet [km/h]
Kon
cent
ratio
n av
par
tikla
r 0
,523
-10
µm
[µg/
m³]
Dubbdäck 0,523-10 µm [µg/m³]
Friktionsdäck 0,523-10 µm [µg/m³]
Relation to speed, particles 0,523-10 µm
Speed
Con
cent
ratio
nof
par
tcle
s0,5
23-1
0 µm Studded tyres
Friction tyres
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
SEM, Dense asphalt, granite, studded tyres
0
200
400
600
800
1000
12001
O
Si
KAl
KNa Fe
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
SEM, SMA, quartzite, studded tyres
0
2000
4000
6000
8000G4Si
Fe
O
AlCl K
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
10 100 1000Geometrisk diameter [nm]
dN/d
logD
p
30 km/h 031008 11:54-12:16
50 km/h 031008 14:11-14:33
70 km/h 031008 16:16-16:38
70 km/h 030603 11:56-14:01
Denseasphalt, granite
SMA, quartzite
Number size distribution, sub-micron particles
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
TEM, sub-micron particles
Source?
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
10 100 1000
Geometrisk diameter (nm)
dN/d
logD
p [#
/m³]
Granit + dubbdäck 70 km/h
Kvartsit + dubbdäck 70 km/h
Kvartsit + dubbdäck 50 km/h
Kvartsit + dubbdäck 30 km/h
Kvartsit + friktionsdäck 30 km/h
Kvartsit + friktionsdäck 50 km/h
Kvartsit + friktionsdäck 70 km/h
Tyre particles?
Sub-micron particles
Friction tyres
Studded tyres
Diameter (nm)
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
5000
10000
15000
20000
25000
30000
0 10 20 30 40 50 60 70 80
Hastighet [km/h]
Kon
cent
ratio
n av
par
tikla
r 1
6-72
3 nm
[#
/m³]
Dubbdäck 16-723 nm [#/cm³]
Friktionsdäck 16-723 nm [#/cm³]
Relation to speed, particles 16-723 nm
Speed
Con
cent
ratio
nof
par
tcle
s16-
723
nm Studded tyres
Friction tyres
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Tire Road surface Speed (km h-1)
Number of measurements
Emission factor (particles vehicle-1 km-1)
Non studded tires
Rubber 50 1 3.7•1011
Non studded tires
Rubber 70 1 1.1•1012
Non studded tires
Quartzite, ABS (stone mastic
asphalt)
50 1 3.8•1011
Studded tires Quartzite, ABS (stone mastic
asphalt)
70 1 1.9•1012
Studded tires Quartzite, ABS (stone mastic
asphalt)
50 1 6.1•1011
Studded tires Granite, ABT (asphalt concrete)
70 2 3.1•1012
From Dahl, A. et al., 2005 (submitted to Atmospheric Environment)
Emission factors for sub-micron particles
Comparison: 2.7 ±1.1•1014 particles vehicle-1 km-1 in road tunnel with 95% gasoline powered LDV, 5% diesel powered LDV with an average speed of 70 km h-1 (Kristensson et al., 2004).
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Friction material in the road simulator
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
2004-02-11
0
1
2
3
4
5
6
7
8
9
10
11
12
09:0
0:00
10:0
0:00
11:0
0:00
12:0
0:00
13:0
0:00
14:0
0:00
15:0
0:00
16:0
0:00
17:0
0:00
18:0
0:00
19:0
0:00
Tid efter start
PM10
(mg/
m3)
500 g/m2 15 km/h
30 km/h 500 g/m230 km/h
500 g/m2 15 km/h
500 g/m215 km/h
30 km/h 50 km/h
5
6
78
9
10
11
Concentration of PM10 using crushed stone
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
2
4
6
8
0.1 1 10 100
Diameter [µm]
dm/d
logD
p [m
g/m
³]
natursand+dubb
natursand+friktion
kross+dubb
kross+friktion
• Unwashed sand producesmore PM10 than crushedstone
• Studded tyres produce morePM10 than friction tyres
Crushed stone+friction tyres
Cruched stone+studded tyres
Sand+friction tyres
Sand+studded tyres
Mass size distribution, PM10
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0
1
2
3
4
5
6
0,1 1 10 100
Diameter [µm]
% o
f tot
al m
ass d
istri
butio
n
crushed stone+studded
crushed stone+friction
sand+studded
sand+friction
related to studded tyres?
% of total mass distribution, PM10
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
0 0.5 1
50
100
150
200
250
300
350
400
log diameter
Tid (minuter)
0 0.5 1log diameter
20
40
60
80
100
120
140
160
180
200
Tid
(min
uter
)
0 0.5 1
50
100
150
200
250
300
350
400
50
100
150
200
250
300
350
400
log diameter
Tid (minuter)
0 0.5 1log diameter
20
40
60
80
100
120
140
160
180
200
Tid
(min
uter
)
With
friction material
Without
friction material
30
50
70
Mass size distribution, PM10
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Some important conclusions…
• Studded tyres generates 40 - 50 times higher concentrations of PM10 thanfriction tyres on the same pavement.
• A dense asphalt with granite generates several times higher PM10concentrations than an SMA with quartzite.
• Higher speed causes higher PM10 concentrations and a higher share of finer particles (PM2.5).
• Sub-micron particles are formed during wear between tyres and pavement. Tyres are a potential source.
• Washed crushed stone generates less PM10 than unwashed sand, irrespective of tyre type.
• The particles are strongly dominated by mineral particles. Tyre and bitumen have not been identified in the SEM studies.
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
…pointing at parameters important for modelling road dust PM10 emissions in ”studded tyre countries”
• Studded tyre effect
• Pavement properties
• Speed
• Effect of winter sanding (material properties, sizedistribution)
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
…and how they could be applied…
• Reduce concentrations and effects of road dust PM10through:
• reducing the use of studded tyres
• using pavements producing less and also less inflammatory particles
• reducing speed
• Using washed friction material for winter sanding
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
VTI-reports from WearTox at www.vti.se
VTI-rapport 520 and 521
Booklet about road dust
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
VTI research related to road dust
Operation and maintenance
•emissions
•materials
•strategies
Road building
•emissions
•materials
Tyres and traffic
•emissions
•frequency
•models
•behaviour
Measurements
•particle concentration
•traffic
•meteorology
Experiments
•Road simulator
Technicaldevelopment
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Ongoing projects
•PM10 in railway environments, 2004-2005
•Dust minimized operation, 2004-2006
•NanoWear - Nano particles from wear of tyres and road pavement?, 2005-2007
•WearEm - Emissions of wear particles, 2005-2008
•Dusting from pavements and traction materials, 2005-2007
Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05
Thanks for listening!