international week 2021 - uantwerpen
TRANSCRIPT
International Week 2021
Sustainability in road and built construction
L.5.1 Sustainability improvement for heavy loaded road structures
Prof. Wim Van den bergh – Dr. David Hernando – Dr. Seyed Reza Omranian (UAntwerp)
[email protected]; [email protected]; [email protected]
Friday 12/March/2021
Contents
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▪ Interpretation of sustainability
▪ What’s a pavement?
▪ How to improve pavement sustainability
▪ Lessons learned from study case at Port of Antwerp
▪ Importance of resilience
▪ Pavement QC/QA
▪ Evaluation of pavement sustainability
What is sustainability?
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▪ Sustainable development▪ “Development that meets the needs of the present without compromising the
ability of future generations to meet their own needs” (Brundtland Commission)
▪ Sustainability in pavement▪ Needs of the present:
• Raw materials, energy, safety, durability, comfort
▪ Needs of future generations:• Raw materials, energy, safety, durability, comfort, environmental concerns, etc.
What is a pavement?
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▪ Multilayer structure
▪ Purpose of a pavement structure▪ Protect subgrade: reduce stresses & strains to tolerable level▪ Prevent excessive settlement or collapse▪ Remove water: structural integrity and safety
▪ 80-90% of paved surfaces are asphalt (petroleum refinery)
Subbase Course
Base Course
Subgrade (existing Soil)
PAVEMENTSTRUCTURE
Asphalt or Portland Cement ConcreteShoulder
How can we improve pavement sustainability?
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Design Production Execution Maintenance
(Consultant)
• Material selection• Thickness
(Contractor)
• Material with lower environ. Impact (WMA, HWMA, cold technology)
• Materials with enhanced performance (polymers, engineered soils)
• Recycled materials (RAP, RCA, crumb-rubber, slag, fly ash)
• Reduce transportation (local materials, in-place recycling, mobile plants)
• More efficient asphalt plants (greenenergy)
(Contractor/Owner)
• QA/QC (density)
(Owner)
• M&R strategy (crack sealing, surface treatment, mill and fill)
What makes port areas special?
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▪ Traffic
▪ Environment▪ Moisture
▪ Subgrade▪ Low bearing capacity, plasticity (silty, clayey soils)
Design of pavement structures – A case study
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▪ Design loads▪ General approach: number of repetitions of 100-kN equivalent single axle load
(ESAL)
▪ Port areas
163 kN/tire Rear axle (unloaded): 205 kN/tireFront axle (loaded): 258.8 kN/tire
Design of pavement structures – A case study
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▪ Preliminary design
▪ Approach to improve sustainability (reduce thickness)• Engineered granular layers: reinforce soils
• Bound bases
5 cm
25 cm
30 cm
30 cm
AC
Granular base
Granular
subbase
AC surface
Design of pavement structures – A case study
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▪ Alternative designs
▪ Significant reduction in total pavement thickness
5 cm
25 cm
30 cm
30 cm
AC
Granular base
Granular
subbase
AC surface 5 cm19 cm
30 cm
30 cm
AC
Granular base
Granular
subbase
AC surface
5 cm14 cm
25 cm
20 cm
AC
Lean asphalt
Granular subbase
AC surface
Preliminary Reinforced base Lean asphalt
Design of pavement structures – A case study
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▪ Structural response
Reinforced base Lean asphalt
Resp Season 100 kNLoaded
SCUnloaded
RSLoaded
RS
εt,AC
Cool -31.6 -83 -95.5 -117.6
Interm -47.2 -117.7 -133.1 -232.4
Warm -64.8 -151 -166.8 -268.1
σt,AC
Cool -0.941 -2.472 -2.846 -4.699
Interm -0.676 -1.686 -1.908 -2.888
Warm -0.425 -0.984 -1.085 -1.473
εv,SG
Cool 89 209.8 357.6 809.1
Interm 111.4 362.1 444.6 984.9
Warm 133.6 432.5 530.0 1148.4
Resp Season 100 kNLoaded
SCUnloaded
RSLoaded
RS
εt,LA
Cool -30.2 -92.6 -110.6 -236.9
Interm -35.6 -107.7 -128.2 -269.1
Warm -41.6 -124.9 -148.1 -306.0
σt,LA
Cool -0.348 -1.067 -1.275 -2.541
Interm -0.41 -1.241 -1.477 -2.859
Warm -0.479 -1.437 -1.705 -3.226
εv,SG
Cool 46.0 144.8 174.6 353.9
Interm 57.9 181.3 218.1 433.3
Warm 73.6 229.8 276.1 541.7
What is resilience?
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▪ General definition▪ Ability to adapt to a change in surrounding conditions
▪ Resilience in pavements▪ Climate resilience:
• Warmer summers, colder spells, more intense rainfall
▪ Measures:• Drainage, enhanced performance materials (polymers)
What do we expect from a good pavement?
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▪ Withstand the loads and transfer andspread them to the sub grade
▪ Sufficient thickness and internal strengthto carry the traffic load including heavyvehicles.
▪ Prevent the water penetration andaccumulation inside the pavement to thebeneath layers.
▪ It should be smooth and durable andresist the deterioration due to the effectsof environmental conditions and heavyloads.
What is asphalt mixture?
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▪ Several Types
Mix Design
Prime/Tack coat
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▪ Anionic
▪ Cationic
▪ Incorporation fiber
Paving
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Paving
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▪ Excellent evenness
▪ Uniform pre-compaction
▪ Homogeneous surface structure
▪ Installation at the right height level and right width
What are the goals of pavement compaction?
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▪ Smooth surface
▪ Uniform compaction
▪ No over compaction
▪ Avoid aggregate crushing
▪ Sustain required air voids
Incorporation of IT
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▪ Why is it important?
Incorporation of IT
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▪ Track and trace system
Incorporation of IT
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▪ Infrared thermal camera
Infrared camera is linked to GPS-system
Measuring width of road
Measurements per 25 * 25cm
Accuracy 1 – 2°C
Heat maps and detection of spots of non-
moving finisher
Incorporation of IT
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▪ Smart roller compactors
Analyses of road quality
GPS
Number of roller pass
Compaction temperatures and their impacts
EVIB considers stiffness during compactionDetecting risk areas
Surface quality control
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▪ Density measurement in situ
Measuring density after compaction
PQI-380 nonnuclear density gauge
Non-destructive test
Drilling Core
Validation
Evaluation of sustainability
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People
Profit Planet
Sustainability
ENVIRONMENTAL IMPACT
Life-cycle assessment
(LCA)
ECONOMIC IMPACT
Life-cycle cost
analysis (LCCA)
SOCIAL IMPACT
Comfort
Key Steps of LCA (ISO 14040)
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Step 1: Goal and scope
definition
Step 2: Inventory analysis
Step 3: Impact assessment
Ste
p 4
: In
terp
reta
tion
NOTES
Goal and scope
▪ Functional unit (reference unit)
▪ e.g.: lane-km, m2 pavement
▪ Life-cycle stages
▪ Analysis period
Inventory analysis
▪ Track environmental flows (inputs & outputs)
▪ Available life-cycle inventories (LCI)
▪ e.g.: Ecoinvent 3.6
Impact assessment
▪ Flows are translated into environmental impacts
Life-Cycle Stages
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MATERIAL EXTRACTION PRODUCTION
CONSTRUCTION
USEMAINTENANCE &
REHABILITATION
END OF LIFE
Cradle-to-gate
Cradle-to-laid
Cradle-to-grave
Cradle-to-cradle
Environmental impact indicators
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1. Global warming
2. Stratospheric ozone depletion
3. Ionizing radiation
4. Ozone formation, Human health
5. Fine particulate matter formation
6. Ozone formation, Terrestrial ecosystems
7. Terrestrial acidification
8. Freshwater eutrophication
9. Marine eutrophication
10. Terrestrial ecotoxicity
11. Freshwater ecotoxicity
12. Marine ecotoxicity
13. Human carcinogenic toxicity
14. Human non-carcinogenic toxicity
15. Land use
16. Mineral resource scarcity
17. Fossil resource scarcity
18. Water consumption
Comparison between LCA and Carbon Footprint
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LCACarbon
footprint
LCA
Carbon
footprint
Carbon
footprint
LCA
LCACarbon
footprint
A. B.
C. D.
Comparison between LCA and Carbon Footprint
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CARBON FOOTPRINT
Monocriterion
▪ Climate change (CO2eq)
LIFE-CYCLE ASSESSMENT (LCA)
Multicriteria
▪ Climate change (CO2eq)
▪ Resource depletion
▪ Human toxicity
▪ Eutrophication
▪ ….
Impacts
Methodology
Functional unit
Life-cycle stages
Inventory
Interpretation
ISO 14040 / ISO 14044
=
=
≈
More complex
ISO 14067 / GHG / PAS 2050
=
=
≈
Easier
Carbon Footprint as an Evaluation Tool
“Port of Antwerp together with its partners is working towards a climate-neutral port.” (Port of Antwerp, 2019)
“Today, the Commission presents a proposal to enshrine in legislation the EU's political commitment to be climate neutral by 2050.” (EC, 2020)
→ Why is carbon footprint a common evaluation tool?
▪ Easier to calculate (less impact categories)
▪ Easier to interpret (direct value: CO2eq)
▪ It can be a good indicator of overall environmental impact**
→ When is carbon footprint a good indicator of environmental impact?
▪ Energy-intensive processes30
Environmental Impact of Road Construction
→ Is road construction energy-intensive?
→ Are GHG emissions the only environmental impact of road construction?
▪ Raw material-intensive
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Study Case
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UseRAP
Use virgin aggregate
Carbon footprint
Life-cycle assessment
Road construction
• Functional unit: lane-m
• Cradle-to-grave
• Analysis period: 20 years
• Alternatives: RAP vs virgin aggregate
Key points
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▪ Interpretation of sustainability in pavement areas
▪ Measures to improve pavement sustainability at different stages
▪ What makes port areas of particular interest
▪ Lessons learned from study case at Port of Antwerp
▪ Importance of resilience
▪ Importance of QC/QA on durability and service life
▪ Evaluation of pavement sustainability
▪ LCA vs. Carbon footprint
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Thank you so much for your time and consideration