Road case - Svensk Leca

Introduction q 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 q 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 q Included production, transport and road construction work. q Top layer not included (not influenced by choice of light weight materials). q User phase excluded (considered mostly related to the bitumen layer, and thus independent on filling material) q End of life not included What is real life time of new roads? Will there ever be reuse of the materials? q We have applied the same system boundaries as in Vägverkets report.

Functional unit q 1 metre road length of chosen profile

Assumptions (1) q Road profile: (illustrations)

Assumptions (2) q 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 m 3 LWA is required for 1 m 3 of packed road material q Transport Vägverkets assumption of weight-limited transport is changed to volume- limited (110 m 3 /max 35 ton) Return transport not included (assumed 100% utilized) Assumed transport distance 200 km

Assumptions (3) q Construction work Diesel consumption in construction work included Assumed that escavated masses is disposed within 1 km q Data applied For LWA, data from 1997 (Vägverket) has been replaced by new data from 1999

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 materials

Results new LCA - Energy consumption

Results new LCA - Global warming potential

Results new LCA - Acidification

Results new LCA - Eutrophication

Results new LCA - POCP

Results new LCA - Waste

Results new LCA - comparison to previous LCA *) Electricity recalculated to consumption of hydro power and nuclear energy

Results new LCA - comparison to previous LCA

Results- Comparison between alternatives NB: Figures for Merolätt and EPS not based on new LCAs

Results- Comparison between alternatives

Discussion q 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 q Inclusion of the bitumen/asphalt layers would decrease the relative differences between the light weight materials q Sensitivity for difference in transport distance is highest for Merolätt, lowest for EPS

Conclusions q New results show much smaller differences between the 3 alternatives than in Vägverkets report q The chosen change in road profile had minor importance for the results - similar volumes of light weight materials applied q Main difference in results due to new values for material densities