Road case - Svensk Leca. Introduction q The Swedish National Road Authority (“Vägverket”) has performed LCA of three alternative light weight materials.

Road case - Svensk Leca

Introduction

The Swedish National Road Authority (“Vägverket”) has performed LCA of three alternative light weight materials for road construction:

Leca LWA

Merolätt (biproduct from steel production)

EPS (expanded polystyrene)

Conclusions from Vägverket

Environmental loads:

• Mainly from energy consumption related to production of materials (for Merolätt, also transport)

• Construction of road is of minor importance, independent of material

• EPS >> LWA >> Merolätt

• Difference between Leca and Merolätt smaller than between Leca and EPS.

• Reuse or energy recovery after demolition of road may substantially reduce impacts from all 3 alternatives

Purpose of our work

Perform an LCA of an LWA road construction, based on new, realistic assumptions

Compare the results of the new LCA with those in the report from Vägverket, and discuss the differences

Evaluate how the new assumptions might influence the results of the comparison

System boundaries Included production, transport and road construction

work.

Top layer not included (not influenced by choice of light weight materials).

User phase excluded (considered mostly related to the bitumen layer, and thus independent on filling material)

End of life not included What is real life time of new roads? Will there ever be reuse of the materials?

We have applied the same system boundaries as in Vägverkets report.

Functional unit

1 metre road length of chosen profile

Assumptions (1)

Road profile:

(illustrations)

Assumptions (2)

Material densities Vägverket: Applied dimensional density to calculate material needs and

transport

We have applied dry densities to calculate material needs and transport

We have assumed that 1,1 m3 LWA is required for 1 m3 of packed road material

Transport Vägverkets assumption of weight-limited transport is changed to volume-

limited (110 m3/max 35 ton)

Return transport not included (assumed 100% utilized)

Assumed transport distance 200 km

Assumptions (3)

Construction work

Diesel consumption in construction work included

Assumed that escavated masses is disposed within 1 km

Data applied

For LWA, data from 1997 (Vägverket) has been replaced by new data from 1999

LWA Packedvolume(m3)

Producedvolume(m3)

tonnes/m3

weight(tonnes)

Vägverket 37 37 522 19,2Ourassumptions

37,4 41,1 260 10,7

% difference + 1 % + 11 % - 50 % - 44,3 %

Results: Consumption of materials pr. m road

In addition, consumption of sand in the road base is eliminated with the new profile

Results: Consumption of alternative materialsMerolätt Packed

volume(m3)

Producedvolume(m3)

tonnes/m3

weight(tonnes)

Vägverket 52,7 52,7 813 42,2Ourassumptions

48,5 53,4 760 40,6

% difference - 8 % + 1,3 % - 6,5 % - 3,8 %

EPS Packedvolume(m3)

Producedvolume(m3)

tonnes/m3

weight(tonnes)

Vägverket 30,6 30,6 100 3,06Ourassumptions

29,5 29,5 20 0,59

% difference -3,6 % -3,6 % -80 % -80,7 %Concrete 3,45

Results new LCA - Energy consumption

Energy Consumption

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

50000

Production Construction Transport Total

MJ

/m r

oad

Bioenergy (recycled)

Fossil energy (recycled)

Hydropower (primary)

Bioenergy (primary)

Nuclear energy (primary)

Fossil energy (primary)

Results new LCA - Global warming potential

Global Warming Potential

0

500

1 000

1 500

2 000

2 500

3 000

3 500

Production Construction Transport Total

kg

CO

2-e

qu

iva

len

ts /

m r

oa

d

CO2 from recycled energy carriers

CO2-equivalents other than recycledenergy carriers

Acidification

0

2

4

6

8

10

12

14

16

18

20

Production Construction Transport Total

kg S

O2-

eq

uiv

ale

nts

/ m

ro

adResults new LCA - Acidification

Results new LCA - Eutrophication

Eutrophication

0

10

20

30

40

50

60

Production Construction Transport Total

kg O

2-e

qu

ival

en

ts /

m r

oad

Results new LCA - POCP

Photochemical Ozone Creation Potential (Smog)

0

100

200

300

400

500

600

700

800

900

1 000

Production Construction Transport Total

g e

the

ne

-eq

uiv

ale

nts

/ m

ro

ad

Results new LCA - Waste

Waste

0

2

4

6

8

10

12

Production Construction Transport Total

kg w

aste

/ m

ro

ad

Industrial waste

Hazardous waste

Results new LCA - comparison to previous LCA

Energy

0102030405060708090

100

Vägverket*) Our results

GJ

/ m r

oad

Bioenergy (recycled)

Fossil energy (recycled)

Hydropower (primary)

Bioenergy (primary)

Nuclear energy (primary)

Fossil energy (primary)

*) Electricity recalculated to consumption of hydro power and nuclear energy

Results new LCA - comparison to previous LCA

Environmental impacts, relative to consumption of LWA

0 %

20 %

40 %

60 %

80 %

100 %

Re

lati

ve

val

ue

s

Vägverket

Our results

Results- Comparison between alternatives

Primary fossil energy

0,00

50,00

100,00

150,00

200,00

250,00

300,00

lwa merolätt eps

GJ

/ m r

oad

Vägverket

Our results

NB: Figures for Merolätt and EPS not based on new LCAs

Results- Comparison between alternatives

GWP

0100020003000400050006000700080009000

lwa merolätt eps

ton

CO

2 e

qu

ival

en

ts

Vägverket

Our results

Results- Comparison between alternatives

Waste

0,0020,0040,0060,0080,00

100,00120,00140,00160,00180,00200,00

lwa merolätt eps

kg Vägverket

Our results

Results- Comparison between alternatives

Acidification

0

10

20

30

40

50

60

70

lwa merolätt eps

kg S

O2-

eq

uiv

ale

nts

Vägverket

Our results

Discussion

Merolätt is a by-product of iron production. Environmental loads from Merolätt is based on economic allocation

Changed economic value will influence the results heavily

Inclusion of the bitumen/asphalt layers would decrease the relative differences between the light weight materials

Sensitivity for difference in transport distance is highest for Merolätt, lowest for EPS

Conclusions

New results show much smaller differences between the 3 alternatives than in Vägverkets report

The chosen change in road profile had minor importance for the results - similar volumes of light weight materials applied

Main difference in results due to new values for material densities