sustainability and the rta - engineers australia
TRANSCRIPT
Sustainability and the RTACurrent Thinking
Con Lambous - Senior Environmental Specialist (Sustainability)
Justin Moss - Pavement Technologist (Strategic Performance)
Roads and Traffic Authority NSW
2
Presentation Overview
» Environmental business risks facing road industry
» Impacts of government policies and legislation
» RTA’s sustainability focus
» Reducing pavement carbon emissions
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The Future: Environment and Business Risks
� Climate Change
- Carbon trading scheme: price applies to carbon from 2011/12
� Oil supply constraints
- 2000: Australia 95% self sufficient.
- 2015: will import half our needs as peak oil impacts
� Electricity
- Prices increasing. Up as much as 40% in 2008
� Water
- Security of supply & increasing price
� Waste Management
- Increasing levies and costs
� Quarried Materials
- Security of supply
4
NSW Government Response
State Plan Priority E3 targets:
□ 2000 equivalent greenhouse levels by 2020
□ 60% greenhouse emission reduction by 2050
NSW Climate Change Action Plan
□ Adaptation
□ Mitigation
NSW Government Sustainability Policy
□ All Budget dependant agencies to be Carbon Neutral by 2020
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RTA’s Green Plan
�Green Leadership in Research, Policy and Communications
� Developing Green Partnerships
� Reducing Our Footprint
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RTA Carbon Footprint –Results of traffic lamp replacement project
-
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
2000-01 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08
Ele
ctri
city
Co
nsu
mp
tio
n i
n R
TA
Tra
ffic
Sig
nal
s (M
Wh
) E
lect
rici
ty C
on
sum
pti
on
in
RT
A T
raff
ic S
ign
als
(MW
h)
Ele
ctri
city
Co
nsu
mp
tio
n i
n R
TA
Tra
ffic
Sig
nal
s (M
Wh
) E
lect
rici
ty C
on
sum
pti
on
in
RT
A T
raff
ic S
ign
als
(MW
h)
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Climate Change Adaptation – Key Issues and Projects for RTA
• Climate change action plan – adaptation and
mitigation
• Climate change scenarios, mapping and modelling
for low lying areas
• Review of standards related to road design –
increased storms and winds
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Developing a Carbon Calculator for Road Projects
9
Typical output from the carbon construction carbon model
Construct ion Greenhouse Gas Emissions InventoryConstruct ion Greenhouse Gas Emissions InventoryConstruct ion Greenhouse Gas Emissions InventoryConstruct ion Greenhouse Gas Emissions Inventory
984.2
902.0
440.3 424.9385.6
321.2273.8
236.5190.8
77.0 75.017.0 13.3 0.1
0
200
400
600
800
1,000
1,200
Operation of site
plant and
equipment
Vegetation
clearance and
transport
Embodied
emissions of
cement
Embodied
emissions of
coarse
aggregate
Operation of site
vehic les
Hot mix asphalt
processing
energy
Transport of
materials
Embodied
emissions of
bitumen
Embodied
emissions of lime
Embodied
emissions of fine
aggregate
Use of
purchased
electricity
Embodied
emissions of
steel
Waste transport
and disposal to
landfill
Embodied
emissions of
steel (recyc led)
Gre
en
ho
use
Ga
s E
mis
sio
ns
(tC
O2
e)
Gre
en
ho
use
Ga
s E
mis
sio
ns
(tC
O2
e)
Gre
en
ho
use
Ga
s E
mis
sio
ns
(tC
O2
e)
Gre
en
ho
use
Ga
s E
mis
sio
ns
(tC
O2
e)
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Impacts of changing waste
regulations
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Waste regulated areas
12
0
20
40
60
80
100
120
140
160
200
0
200
1
200
2
200
3
200
4
200
5
200
6
200
7
200
8
200
9
201
0
201
1
201
2
201
3
201
4
201
5
201
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RTA’s Approach to Sustainability
Waste Levy $$$ - impacts
$
Year
Now
Sydney Metro
Extended area
POEO ActAmended 2005
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RTA’s Future Issues and Focus
Sustainable Procurement Strategies •Increasing pressure on RTA to reduce the impact of its goods and services•RTA commencing development of sustainable supply chain strategy
Project Assessment•Environmental assessments will increasingly require estimates of carbon impacts and mitigation measures •Development of calculators and guidelines.
Technology Change•Innovation in energy and greenhouse reduction to help reduce environmental footprint of projects (e.g. low energy construction materials)•Electricity supply: alternative fuels, renewable energy and cogeneration
Sustainability Performance Reporting•Increasing corporate and government sustainability reporting requirements
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Sustainable PavementsImplementations & Case Studies
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»Asphalt Pavements and Surfacing
□Recycled aggregate
□Scrap Rubber additives
□Recycled asphalt (RAP)
RTA’s Approach to Sustainability
Sustainable Pavements
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»Flexible pavements
□Recycled Base
□Recycled material for SMZ
RTA’s Approach to Sustainability
Sustainable Pavements
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»Rigid Pavements and Bridges
□Cement replacements / supplements
□Manufactured sands
RTA’s Approach to Sustainability
Sustainable Pavements
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Key Recycled Construction Material Projects
• Review of Material Specs (RTA QA 3051 & 3052) to allow wider
range of recycled materials in base and sub-base
+
1919
Glass in Concrete & AsphaltSand & Cement-substitute (SCM)
2020
Key Recycled Construction Material Projects
2121
Key Recycled Construction Material Projects
2222
Fly Ash5-10% utilised / balance to landfill
2323
Fly AshConcrete manufactured aggregates
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RTA’s Approach to Sustainability
Slag in RTA Construction & Issues
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Slag in RTA construction
Slag Types
»Blast Furnace Slag
•Crushed and screened “BFS”
•Granulated “GBFS”
• Ground Granulated “GGBFS”
»Steel Furnace Slag - “SFS” or “BOS”
•Crushed and screened
»Electric Arc Furnace Slag– “EAF”
•Crushed and screened
Iron
Steel
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Slag in RTA construction
Pavements & Slag Usage
Asphalt
Select (mod)
Select
Subgrade
CementedNatural
BFS / SFSHeavily Bound
Lean Mix
Concrete
CementedHeavily / Bound Concrete
Base
ConcreteSubbase
BFS
•as graded base/subbase material
•unmodified (5MPa ~ 12 months)
•modified – crushed BFS aggregate
and GBFS / crusher dust, activated
with 2% GGBFS/lime
SFS / BFS / EAF
•used in Newcastle (repl BFS)
•heavier / higher compactive effort
•Freelime expansion issues > weathering required
GGBFS as modifier
•lime/GGBFS as binder in nat mats
•Improves durability / capacity
•Slow set (vs cement) for extended
working times
BFS Crusher Dust as SMZ
•Minus 6mm “dust” sometimes
used in Select
GGBFS as binder (SCM)
•can be used in Subbase or Base
•replaces up to 70% of cement
•Improves/changes workability
•Reduced water demand
•less shrinkage
•Increases cohesiveness
•Slower set and strength gain
– affects logistics / trafficking
•Reduces paste porosity >
reduced bleed
SFS in Asphalt
• coarse aggregate
• high skid resistance
• high stress pavements
• strong interlock
• resistance to stripping
• blended with natural for
grading
GGBFS in Cemented Layers
•as binder
•usually 2% blend with lime (85/15)
•Insitu deep lift stabilisation
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1 m1 m
minimumminimum
covercover300 typ
»GGBFS as a binder in concrete:
□ for severe corrosion environments
(Exposure Categories B2 and C) -
significantly reduces the ingress of
chlorides (protects reinforcement)
□Replaces up to 65% of cement
□Slower strength gain impacts stripping
and prestressing
□higher ultimate strength
□ flyash generally used as alternative
Slag in RTA construction
Bridge Construction
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Challenges
RTA Annual Usage & Haulage
~200,000 THeavily Bound Bases EFA/SFS
BFS
~200,000 TModified or Bound Bases BFS
~100,000 TAsphalt using SFS
$$$
$$$
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1 m1 m
minimumminimum
covercover300 typ
»RTA Cement and Specifications
□ room for innovation – min. levels of GGBFS in concrete
pavements
»Rigid Pavements - plastic shrinkage cracking
□ reduced bleeding good for surface quality,
□entrapped mix water can worsen surface plastic shrinkage
cracking (particularly in hot and windy conditions)
»Rigid Pavements - GBFS as a fine aggregate
(sand)
□Coarse nature impacts on workability and finishing
Issues
Final Issues
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» www.rta.nsw.gov.au/
environment
□ Environmental Policy
» www.rta.nsw.gov.au/
doingbusinesswithus
□Technical Directions
□Guideline Documents
□Specifications
•Roadworks
•Bridgeworks
□Specification Guides
More information
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» RTA interested in working with industry to find solutions to
address climate change and sustainability issues
» Increased likelihood of sustainability requirements in RTA
contracts
» Increased focus on sustainability in statutory approvals
» Broad adoption of recycled materials in construction often leading
to improved performance
RTA’s Approach to Sustainability
Key Messages