PM from road pavement and winter tyre interaction · 2005. 10. 17. · 10 from road pavement and winter tyre interaction. Mats Gustafsson, Transport and Environment Workshop, SMHI,

Mats Gustafsson, Transport and Environment Workshop, SMHI, 051004-05

Mats Gustafsson

PM10 from road pavement and winter tyre interaction


Aim of road dust research


• 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)


How do we study this?

• Generating ”clean” wear particles in a road simulator

exchangable pavement

4 exchangable tyres with electric motors run the machine



• 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


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)


PM10 concentration (tyres and pavement)

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Con

cent

ratio

n of

PM

10 (m

g/m

3 )

Dense asphalt, granite, studded tyres, 70 km/h



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3 )

SMA, quartzite, studded tyres, 70 km/h




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cent

ratio

n of

PM

10 (m

g/m

3 )

difference between resistant and less resistant pavement





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Con

cent

ratio

n of

PM

10 (m

g/m

3 )

SMA, quarzite, friction tyres, 70 km/h






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Con

cent

ratio

n of

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10 (m

g/m

3 )

SMA, quarzite, friction tyres, 70 km/h


difference between studded and friction tyres




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


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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


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Diameter [µm]

Cum

ulat

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conc

entra

tion-

%

SMA, quartzite, studded, 70 km/h



Dense asphalt, granite, studded, 70 km/h

Cumulative concentration-%, PM10


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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


SEM, Dense asphalt, granite, studded tyres

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200

400

600

800

1000

12001

O

Si

KAl

KNa Fe


SEM, SMA, quartzite, studded tyres

0

2000

4000

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8000G4Si

Fe

O

AlCl K


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5000

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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


TEM, sub-micron particles

Source?


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 + friktionsdäck 30 km/h



Tyre particles?

Sub-micron particles

Friction tyres

Studded tyres

Diameter (nm)


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5000

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15000

20000

25000

30000

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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


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).


Friction material in the road simulator


2004-02-11

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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


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



0

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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


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50

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400

log diameter

Tid (minuter)

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(min

uter

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log diameter

Tid (minuter)

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(min

uter

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With

friction material

Without

friction material

30

50

70



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.


…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)


…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


VTI-reports from WearTox at www.vti.se

VTI-rapport 520 and 521

Booklet about road dust


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


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


Thanks for listening!

Documents

PM from road pavement and winter tyre interaction · 2005. 10. 17. · 10 from road pavement and winter tyre interaction. Mats Gustafsson, Transport and Environment Workshop, SMHI,