sustainable steel bridge maintenance: sustasustainable sustainable steel bridge maintenance: the...

Sustainable steel bridge maintenance: SustaSustainable

Sustainable steel bridge maintenance:

The role of paint in a LCA A":inable steel bridge maintenance:

The role of paint in a LCA":CEPE Annual Conference 2014 in RigaDr. Irmgard Winkels – Sika Deutschland GmbH

Content

• Starting point• Goal and scope• Description of the study• Results of three different scenarios• Conclusions

Starting Point

• CEPE built up an LCI database for coatings raw materials and paint production models. A tool – called Eco Footprint Tool - was developed to calculate footprints of coatings based on this database

• Result: environmental data for 1 kg of liquid paint (cradle to exit gate)

Example for a footprint

Impact categories

Global Warming Potential or Carbon footprint (GWP) 3385.1 g CO2 eq

Ozone Depletion Potential (ODP) 298.2 μg CFC-11 eq

Photochemical Ozone Creation Potential (POCP) 1716.3 mg C2H4 eq Acidification Potential (AP) 20.6 g SO2 eq Eutrophication Potential (EP) 8317.9 mg PO4 eq

Energy Content

Non-renewable 62.5 MJ Renewable 2.7 MJ

Waste

Non-hazardous 26 g Hazardous 11 g

Resource Consumption

Non-renewable 3.9 kg Renewable 6 kg Water 147.5 kg

Protective Coatings sector group decision

Use this LCI database and Eco Footprint Tool to demonstrate how coatings can affect the sustainability of coated goods

Calculate the role of paint concerning the sustainability in steel bridge maintenance

Goal and scope

• Impact of varying coating thicknesses on the sustainability of a steel bridge

• Perspective of an infra-structure responsible department

• Functional unit: Building and maintaining a bridge on a rural road, passing over a motorway, for 100 years

Study and calculation

Done by Ecomatter based on assumptions given by CEPE,

e.g. durability of coating systems, duration of coating application and surface preparation

Alternative coating systems

Coating system 1

Coating system 2

Coating system 3

Zinc rich epoxy 80 µm 80 µm 80 µm

MIO-pigmented intermediate coat, epoxy - 120 µm 80 µm

MIO-pigmented intermediate coat, epoxy - - 80 µm

Acrylic urethane top coat 120 µm 80 µm 80 µm Repainting period / maintenance interval 15 years 25 years 40 years

Scenarios

Scenario 1: Full life cycle Bridge construction, disposal and maintenance,

including traffic disturbances.

Scenario 2: Bridge maintenance Maintenance, including traffic disturbances.

Scenario 3: Only coatingsOnly coating related emissions over the life

cycle.

Bridge Coating

SteelBridge Initial construction

Re-routing of traffic

Bridge disposal and

end of life

Bridge Maintenance

Bridge Coating

Scenario 1

Re-routing of traffic

Concrete

Scenario 3

Scenario 2

Use and maintenance

Maintenance additional activities, equipment and transport have not been included in the model.

Activity Type of road Disturbance Total time Period

Painting: Blasting + Primer coat

Motorway and rural A Road closure 16 h Weekend night

Painting: Intermediate coat Motorway and rural A Road closure 8 h Weekend night

Painting: Top coat Motorway and rural A Road closure 8 h Weekend night

Specification 1 Specification 2 Specification 3

Painting frequency 6 times / 100 years 3 times / 100 years 2 times / 100 years

Total time per activity (all coats) 24 h 32 h 40 h

Rerouting distance per activity 599.455 km 799.259 km 999.074 km

Spec 1 - Comp 1Spec 2 - Comp 1Spec 3 - Comp 1

GWP

TotalBridge Materials

CoatingsEnd of life

Traff ic

Glo

bal W

arm

ing

Pot

entia

l (G

WP

100

yea

rs) 2,400,000.0

2,200,000.0

2,000,000.0

1,800,000.0

1,600,000.0

1,400,000.0

1,200,000.0

1,000,000.0

800,000.0

600,000.0

400,000.0

200,000.0

0.0

Scenario 1: Full life cycle

Results for a life time of 100 years:

• Carbon footprint (expressed as GWP: Global Warming Potential)

• Initial bridge construction and associated traffic is about 2/3rd of the GWP

• The contribution of the coatings is ~ 1% of the GWP

• System 3: the best overall performance

• Similar conclusions for the other impact categories

System 1: 2 layer & 15 yrs



Conclusion

Differentiation of coatings systems not possible

Image courtesy of phanlop88 / FreeDigitalPhotos.net

Closer look necessary


GWP

TotalCoatings

Traff ic

Glo

bal W

arm

ing

Pot

entia

l (G

WP

100

yea

rs) 2,400,000.0

2,200,000.0

2,000,000.0

1,800,000.0

1,600,000.0

1,400,000.0

1,200,000.0

1,000,000.0

800,000.0

600,000.0

400,000.0

200,000.0

0.0

Scenario 2: Bridge maintenance


• Contribution of the coatings is ~ 2 % of the GWP

• Lower repaint frequency: less rerouting

• System 3: best overall performance, ~ 40% better GWP performance compared to system 1

• Similar conclusions for the other impact categories




GWP


ADP fossil

TotalCoatings

Traff ic

Abi

otic

Dep

letio

n fo

ssil

10,000,000.0

8,000,000.0

6,000,000.0

4,000,000.0

2,000,000.0

0.0


ODP, steady state

TotalCoatings

Traff ic

Ozo

ne L

ayer

Dep

letio

n P

oten

tial

.1


EP

TotalCoatings

Traff ic

Eut

roph

icat

ion

Pot

entia

l

700.0

600.0

500.0

400.0

300.0

200.0

100.0

0.0


Human tox

TotalCoatings

Traff ic

Hum

an T

oxic

ity P

oten

tial 250,000.0

200,000.0

150,000.0

100,000.0

50,000.0

0.0

Scenario 2: Other Impact categories




Total Coatings Traffic


POCP

TotalCoatings

Traff icPho

toch

em.

Ozo

ne C

reat

ion

Pot

entia

l

2,000.0

1,500.0

1,000.0

500.0

0.0


Freshwater Ecotox

TotalCoatings

Traff icFre

shw

ater

Aqu

atic

Eco

toxi

city

Pot

.

20,000.0

15,000.0

10,000.0

5,000.0

0.0


AP

TotalCoatings

Traff ic

Aci

dific

atio

n P

oten

tial 2,500.0

2,000.0

1,500.0

1,000.0

500.0

0.0


Marine Ecotox

TotalCoatings

Traff ic

Mar

ine

Aqu

atic

Eco

toxi

city

Pot

.

60,000,000.0

50,000,000.0

40,000,000.0

30,000,000.0

20,000,000.0

10,000,000.0

0.0


• For all impact categories, system 3 has the best overall performance over the whole life cycle.

• In general traffic is the dominant factor, but coatings has a higher relative contribution to toxicity and depletion of elements (ADP). System 1: 2 layer & 15 yrs




ADP elements

TotalCoatings

Traff ic

Abi

otic

Dep

letio

n el

emen

ts

1.2

1.0

0.8

0.6

0.4

0.2

0.0


Terrestric Ecotox

TotalCoatings

Traff ic

Ter

rest

ric E

coto

xici

ty P

oten

tial

1,400.0

1,200.0

1,000.0

800.0

600.0

400.0

200.0

0.0


Spec 1 - CoatingSpec 2 - CoatingSpec 3 - Coating

GWP

TotalAcrylic Topcoat

MIO IntermediateZinc Rich Primer

Glo

bal W

arm

ing

Pot

entia

l (G

WP

100

yea

rs) 16,000.0

14,000.0

12,000.0

10,000.0

8,000.0

6,000.0

4,000.0

2,000.0

0.0

Scenario 3: Coatings only




Total Year 0 Year 10 Year 20 Year 30 Year 40 Year 50 Year 60 Year 70 Year 80 Year 90 Year 100

GWP over Timeline (Moment when coating is applied)


• System 3: best overall performance

• Higher coating thickness: higher impact per application

• Higher impact of thicker coating specifications in YR0 is compensated over the life cycle by the lower painting frequency.

• Maintenance schedules are the main factor for the environmental impact of paints over the life cycle.

• Similar conclusions can be drawn when looking into other impact categories


GWP

TotalZinc Rich Primer

Acrylic TopcoatMIO Intermediate

Glo

bal W

arm

ing

Pot

entia

l (G

WP

100

yea

rs) 16,000.0

14,000.0

12,000.0

10,000.0

8,000.0

6,000.0

4,000.0

2,000.0

0.0

Scenario 3: Coatings only




GWP

Best results for system 3 again despite higher film thickness and higher number of layers.

• The amount of coating per year and the road closure days per year are the main drivers of the system:

• The extra layers and additional time that is needed to coat the bridge (and reroute traffic) are compensated by the lower painting frequency in the chosen scenarios

• The extra layers give a better performance over the entire life cycle.

Conclusions (I)

System 1: 2 layer & 15

years


years


yearsAmount of coating (kg) / year

40,6 31,2 26,3

Closure days / year 0,18 0,12 0,10

• For all scenarios, System 3 has the best overall performance during 100 years period.

• Direct impact caused by coatings is not significant, compared to the full bridge construction as well as to the need to reroute traffic. Variations in traffic disruptions during maintenance cause the main differences between the three specifications.

• Although the relative impact from building the bridge may change, the trends as presented are valid for different bridge sizes (length and width) if they follow similar maintenance cycles.

• The sustainability of the bridge is strongly determined by the durability of the coating system.

Conclusions (II)

Thank you

sustainable steel bridge maintenance: sustasustainable sustainable steel bridge maintenance: the...

Documents

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bridge maintenancemaintenance

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gate slide

life cycle bridge construction

durability of coating

scenarios scenario

role of paint