SustainableRoad Maintenance

Dragos Andrei, Ph.D., P.E., M.ASCE45th Annual MSA Conference

September 2013

About Dragos

• Associate Professor, Civil Engineering, California State Polytechnic University

• Previous experience with Fugro and MACTEC• P.E. California, Texas• Ph.D. Arizona State University, M.S. University of

Maryland• Director, Pavement Recycling and Reclaiming Center at

Cal Poly Pomona• Principal Engineer and Partner, West Coast

Engineering Consultants

Outline

• State of the Pavement• Sustainability and Sustainable Roads• “Green” Asphalt Maintenance/Rehabilitation

Strategies• “Green” Strategies for Concrete and Other

Pavements• Implementation of Sustainable Maintenance

Strategies

STATE OF THEPAVEMENT

Section 1

2013 California Statewide Local Streets and Roads Needs Assessment Findings:

• 81% of California roads are managed by cities and counties

• On average, these pavements are in “critical” condition

• The condition continues to decrease from one year to next

• The funding available for pavements is less than half of what would be needed to maintain the current condition …

Source: California Local Streets and Roads Needs Assessment, January 2013, http://www.savecaliforniastreets.org/

Caltrans 2011 State of the Pavement Findings:

• 50,000 lane miles to maintain• 53% in good to excellent condition• 22% in need of maintenance• 25% with structural deficiencies or poor ride• Overall condition better than 2007

Source: Caltrans State of the Pavement 2011,

http://www.dot.ca.gov/hq/maint/Pavement/Pavement_Program/PDF/2011_SOP.pdf

2007:

2011:

Bottom Line

• We inherited a vast road network:~ 50,000 lane miles state roads~ 200,000 lane miles local roads

• More than 50% of these pavements are “at risk”• For local roads, the funding available for

maintenance and rehabilitation is less than half the funding required to maintain the current condition.

• Traffic (demand) will continue to increase• $$$ Needs will continue to increase

How Did We Get Here?

• Build, build, build … but how about the future?– Don’t think about the future, enjoy the present …

• Who will maintain these pavements?– Not my problem … I will be retired by then

• Who will pay for this?– Don’t worry, THEY will find money, things will never

change … • How are THEY going to rebuild these pavements?– Don’t worry, there’s plenty of oil, cement, aggregate …

SUSTAINABILITYAND SUSTAINABLE ROADS

Section 2

Sustainability =

• Future generations• Responsibility beyond our life span• Responsibility beyond our species• Maintaining the delicate balance of forces

and factors that make the world a livable place

• Survival

Sustainability Paradigm

People

EnvironmentEconomy

Sustainable Roads: Key Features

• Durability• Low maintenance• Low emissions/energy• Recyclable• Permeable• Cool• Smooth• Quiet• Complete, aesthetically pleasing.

Without M&R, Pavements Will Fail …

VERY GOOD

VERY POOR

POOR

FAIR

GOOD

Pave

men

t Con

ditio

n In

dex

(PCI

)

Time/Traffic

Do NothingCurve

M&R Effect

Original Service LifeLife Extensiondue to M&R

M&

R Im

med

iate

Effe

ct

Long-Life, Low-Maintenance Roads• Modern Solutions:

– “Perpetual” asphalt concrete pavements– Continuously reinforced concrete pavements– Interlocking concrete pavers

• Maintenance and Rehabilitation:– Pavement management program– Preventive maintenance program– Recycling and reclaiming program

• Challenges:– High initial cost– Convincing the public to spend money on the good roads– Education– Design for Long-Life: > 50 years

Low-Emissions/Energy Construction and Maintenance

• Energy = fuel consumption = fossil fuels = emissions

• Greenhouse Gases (GHG): water vapor, carbon dioxide, methane, nitrous oxide, ozone, CFC, other

• Carbon Footprint: measure of carbon dioxide and methane emissions expressed in CO2e (carbon dioxide equivalent for 100 years global warming potential)

Source: The Environmental Road of the Future, Colas 2003

Carbon Footprint Categories:

• “Cold” M&R strategies: emulsion-based seals, cold recycling, full-depth reclamation, soil stabilization, etc.

• “Warm”: warm mix asphalt, maintenance treatments with warm mix additive, etc.

• “Hot”: hot in-place recycling, hot mix asphalt, etc.

• “Big Foot”: portland cement concrete (due to the manufacturing of cement and steel)

Hot In-Place Recycling (HIR)Cold In-Place Recycling (CIR)Cold Central Plant Recycling (CCPR)Full Depth Reclamation (FDR)

Road Recycling - Asphalt

RAPStore for later use in:Hot Mix Asphalt (HMA)Warm Mix Asphalt (WMA)Crushed Miscellaneous Base (CMB)

Recycle In-Place

Road Recycling – Portland Cement Concrete

Rubblization:Break and SeatCrack and Seat

RCAStore for later use in:Portland Cement Concrete (PCC)Hot Mix Asphalt (HMA)Crushed Miscellaneous Base (CMB)

Recycle In-Place

RAP, RCA Management

• Both concrete and asphalt are 100% recyclable• Avoid contamination of RAP/RCA stockpiles by

using good management practices:– Use single-source stockpiles– Separate stockpiles by size (fractionating)– Ensure drainage and cover stockpiles to prevent

excessive moisture– Use low slope to prevent segregation

• More information: http://www.morerap.us/ http://www.fhwa.dot.gov/pavement/recycling/rca.cfm

Recyclable Import

• RAS: Recycled Asphalt Shingles• Crumb Rubber from Waste Tires• Blast Furnace Slag• Coal Ash• Silica Fume• Others

Permeable Pavements

• Reduce stormwater runoff• Filter pollutants from water• Permeable pavements are also “cool”

pavements when wet!• More information:– Pervious concrete: http://www.perviouspavement.org/

– Porous asphalt: http://www.asphaltpavement.org/index.php?option=com_content&view=article&id=359&Itemid=863

– Permeable pavers: http://www.icpi.org/permeable

Source: A permeable paver demonstration, Austin's Ferry, Tasmania, Australia, J.J. Harrison, 2011

Cool Pavements

• Reduce the “heat island” effect by:– Shading– Increasing Solar Reflectance (Albedo)

• Painting/Coating low albedo materials• Use high albedo materials• Apply thin maintenance treatments with high albedo

materials: e.g. microsurfacing and whitetopping

– Increasing Thermal Emittance• Use permeable pavements, water retentive pavements

– More Info: http://www.epa.gov/heatisland/mitigation/pavements.htm

Source: Pavements and the Urban Heat Island Effect, Kamil Kaloush, 2010

Quiet Pavements

• Reduce the tire-pavement noise• Methods:– Open-graded friction course asphalt (+ rubber)– Diamond grinding concrete pavements– Noise barriers, sound walls– Lowered alignment

• Challenges:– Texture wears off with time and needs

maintenance/replacement

Source: Washington DOT Quieter Pavement Research, http://www.wsdot.wa.gov/Business/materialslab/quieterpavement

Source: Complete Streets, http://www.smartgrowthamerica.org/complete-streets/complete-streets-fundamentals/complete-streets-faq

Complete Streets

ASPHALTRECYCLINGIN-PLACE

Section 3

In-Place Asphalt Recycling Techniques

CP•Milling•Micro Milling

HIR•Surface Recycling (Resurfacing)•Remixing•Repaving

CR•Cold In-Place Recycling (CIR)•Cold Central Plant Recycling (CCPR)

FDR•Pulverization•Mechanical Stabilization•Bituminous Stabilization•Chemical Stabilization

Cold Planing/Milling Process

Cold Planing Applications

• Remove existing asphalt concrete surface before overlay or for cold recycling (in-place or central plant)

• Correction of longitudinal profile and cross-slopes

• Restore pavement smoothness or help achieve better smoothness upon resurfacing

• Restore surface friction (micro-milling)

CP Pattern Comparison

• Tool spacing and pattern, drum speed and advance rate, will influence the final milled pattern:

Source: Milling for Smoothness, Eric Baker, Roadtec 2013, http://www.arra.org/index.php?option=com_docman&task=doc_download&gid=510&Itemid=157

CP Equipment

CP Project SelectionVERY GOOD

VERY POOR

POOR

FAIR

GOOD

Cold Planing

Pave

men

t Con

ditio

n In

dex

(PCI

) Hot In-Place

Recycling

Cold Recycling

Full Depth Reclamation

Time/Traffic

More CP Resources

• Basic Asphalt Recycling Manual, ARRA and FHWA, Second Edition: expected January 2014

• Asphalt Recycling and Reclaiming Association, http://www.arra.org/presentations/cold_planing.pdf

Hot In-Place Recycling (HIR): Remixing

Hot In-Place Recycling (HIR): Repaving

HIR Methods

• Recycling: add rejuvenating agent, no additive• Remixing: add rejuvenating agent and additive:– Virgin aggregate– Asphalt cement– Plant mix HMA

• Repaving: remixing + HMA overlay• Stages:– Single: up to 2 inch depth– Multiple: up to 3 inch depth

HIR Applications

• Purpose: rejuvenate/renew/improve the asphalt concrete surface, up to 2-3 inches deep

• Use to address raveling, weathering, bleeding, other types of distress confined to the pavement surface.

• Will not mitigate structural problems• Can be covered with chip seal or other thin

maintenance treatment

HIR Equipment

• Heating units• Milling/Scarifying unit• Drying/Mixing unit• Paver

• Rollers• Rejuvenating Agent• Admixture truck

Source: Martec, http://martec.ca/2010/11/november-2010-ar2000-super-recycler-at-tradeshow/

HIR Train

Source: Brian Hansen, Dustrol, Inc.

HIR Equipment

HIR Project SelectionVERY GOOD

VERY POOR

POOR

FAIR

GOOD

Cold Planing

Pave

men

t Con

ditio

n In

dex

(PCI

) Hot In-Place

Recycling

Cold Recycling

Full Depth Reclamation

Time/Traffic

More HIR Resources• Basic Asphalt Recycling Manual, ARRA and FHWA, Second Edition:

expected January 2014• Construction Inspection Checklist #11 Hot In-Place Asphalt

Recycling Application, FP2 and FHWA http://www.fhwa.dot.gov/pavement/preservation/ppcl00.cfm a second edition of this checklist is available in print and will soon be available online.

• Caltrans Maintenance Technical Advisory Guide (MTAG) Volume I - Flexible Pavement Preservation Second Edition, Chapter 13: In-Place Recycling, http://www.dot.ca.gov/hq/maint/MTA_GuideVolume1Flexible.html

• Hot In Place Asphalt Recycling, Brian Hansen, Dustrol, Inc., http://www.savemyroad.com/cir_hir/files/Hot-In-Place-Asphalt-Recycling.pdf

HIR Construction Checklist Contents

• Document Review• Project Review• Materials Checks• Preconstruction

Meeting• Pavement Preparation• Equipment Inspections

• Weather Requirements• Mix Design• Traffic Control• Project Inspection• Opening to Traffic• Common Problems and

Solutions

Cold In-Place Recycling (CIR)

CIR Applications

• Restore the structural integrity of the top 2-4 inches of the asphalt concrete

• Cover with HMA overlay or thin maintenance treatment

• Effective in treating distress confined to the pavement surface as well as thermal cracking.

• CIR is generally softer than HMA and may delay reflective cracking.

CIR Equipment

• Tankers• Milling machine(s)• Crushing and screening units• Mixer• Paver• Rollers

Milling Crushing and Mixing Unit

CIR Windrow

Water Emulsion

Windrow Elevator Paver

Rollers

Cold Central Plant Recycling (CCPR)

CIR Project SelectionVERY GOOD

VERY POOR

POOR

FAIR

GOOD

Cold Planing

Pave

men

t Con

ditio

n In

dex

(PCI

) Hot In-Place

Recycling

Cold Recycling

Full Depth Reclamation

Time/Traffic

More CIR Resources

• Basic Asphalt Recycling Manual, ARRA and FHWA, Second Edition: expected January 2014

• Construction Inspection Checklist #12 Cold In-Place Asphalt Recycling Application, FP2 and FHWA http://www.fhwa.dot.gov/pavement/preservation/ppcl00.cfm a second edition of this checklist is under final review by ARRA and FHWA.

• Caltrans Maintenance Technical Advisory Guide (MTAG) Volume I - Flexible Pavement Preservation Second Edition, Chapter 13: In-Place Recycling, http://www.dot.ca.gov/hq/maint/MTA_GuideVolume1Flexible.html

Full Depth Reclamation (FDR)

FDR Methods

• Pulverization• Stabilization– Mechanical = with aggregate or RAP– Bituminous = with emulsified or foamed asphalt– Chemical = with cement or other pozzolanic

materials• No. of Passes:– Single pass– Multiple pass

FDR Application

• Restore the structural integrity of the pavement over the entire treated depth

• Produce a uniform, stabilized, crack-free material by mixing asphalt concrete with underlying materials

• Cover with thin maintenance treatment, asphalt concrete or other surfacing material.

FDR Equipment

FDR with Cement

FDR with Emulsified Asphalt

Gradingand

Compaction

FDR Project SelectionVERY GOOD

VERY POOR

POOR

FAIR

GOOD

Cold Planing

Pave

men

t Con

ditio

n In

dex

(PCI

) Hot In-Place

Recycling

Cold Recycling

Full Depth Reclamation

Time/Traffic

More FDR Resources

• Basic Asphalt Recycling Manual, ARRA and FHWA, Second Edition: expected January 2014

• FDR Construction Checklist, PRRC – FHWA - ARRA available in print, it will be soon available online

• Full Depth Reclamation, ARRA: http://www.arra.org/presentations/full-depth_reclamation.pdf

IMPLEMENTATIONSection 4

Green Up!

• Use a pavement management system– Include sustainable maintenance and rehabilitation

strategies in the PMS (see article in August 2013 APWA Reporter)

– Keep the PMS data up to date• Add or include a pavement preservation

program– Define pavement preservation triggers/criteria– Establish default frequency for preservation

treatments

Green Up!

• Manage your resources better:– Even when damaged, pavements have value:

aggregate, asphalt, cement, steel, etc.– Use RAP/RCA best management practices– Reuse materials as much as possible

• Require minimum three design/rehabilitation alternatives for each project of which at least one should specifically address sustainability

Green Up!

• Don’t forget the 4 R’s: Right treatment, Right pavement, Right time, Right contractor.

• Learn more about sustainability and green rating systems for pavements:– LEED/Green Building Council– Greenroads– Invest– Green Up

“Green Up”

• Software application to compare pavement rehabilitation alternatives in terms of sustainability; not a rating system;

• Under development at Cal Poly Pomona;• Includes:– Materials– Technologies– Surface Properties– Life vs. Cost Analysis

Green Up: Materials

Green Up: Technologies

Green Up: Surface Properties and Life/Cost

Green Up: Alternative Comparison

Mill and Fill Mill, CIR and Overlay

Thank you

Dragos Andrei, Ph.D., P.E., M.ASCEAssociate Professor, Civil EngineeringDirector, Pavement Recycling and Reclaiming CenterCAL POLY POMONAdandrei@prrcenter.org

www.PRRCenter.org