APWA 2016 PWX 8/22/2016

1

Warming up to Sustainable Paving

New England Chapter APWADavid Field P.E.

Joe FlanaganMatt LaChance

What is Sustainability?Environment

Society

Economy

APWA 2016 PWX 8/22/2016

2

What is Sustainability?Ecologically viable and bearable

Economically equitable and viable

Socially equitable and bearable

Sustainable Pavements (Green Roads)Lower emissions and fuel consumption

Better quality construction

Recycling

Preservation maintenance

Less user delay

Smoother & quieter

Longer lasting roads costing less to maintain

APWA 2016 PWX 8/22/2016

3

Dedham’s Sustainable Pavement Program

Dedham, MA

We are here

APWA 2016 PWX 8/22/2016

4

Dedham, MABoston neighbor

25,000 residents

Dedham, MAApproximately 100 centerline miles

2007 PCI of 70 and falling

Underfunded maintenance budget

Entirely reliant on State funding

Roads deteriorating faster than they could be repaired

Not sustainable!

APWA 2016 PWX 8/22/2016

5

Enter the ConsultantConducted a network wide pavement evaluation

Develop multi-year prioritised list

Select a wide range of maintenance options

Create multiple funding scenarios

Work with DPW and elected officials tosecure additional funding

The GoalEmploy multiple rehabilitation strategies

Keep the “good” roads good while improving the the poor roads

Increase the average PCI from 70 to 80 by 2017

APWA 2016 PWX 8/22/2016

6

Nightmare on East Street

Paved in 2001, total joint failure by 2009

70% of surface course not bonded to intermediate course

20 year design life shortened to 9 years

Threatened to set back new roadway improvement program

The Lesson LearnedBetter specifications = better roads

Volumetric design with mat and joint density requirements

Appropriate lot sizes

Quality control + quality acceptance

Incentive/Disincentive

Show up for your projects!

APWA 2016 PWX 8/22/2016

7

The FixUltrathin bonded wearing course

Placed over localized repair and crack seal

Relatively low dollar/sqyd

Returned to 20 year service life

New option for preservation maintenance

Global Warming Solutions Act, 2008In August 2008, Governor Deval Patrick signed the Climate Protection & Green Economy Act

Requires an economy-wide reduction of greenhouse gas emissions

25% reduction of the 1990 level by 2020

80% reduction of the 1990 level by 2050

APWA 2016 PWX 8/22/2016

8

Warm Mix Asphalt, 2013MassDOT chooses WMA as the standard state specification and phases out HMA

WMA reduces fuel consumption and CO2 emissions by up to 35%

68% of the 891,000 tons of asphalt placed for MassDOT was WMA

Lower Mixing Temperatures, Lower Emissions

APWA 2016 PWX 8/22/2016

9

What is WMA?Same materials as HMA but uses an additive to lower workable tempratures

Produced with little or no plant modifications

Placed with conventional paving and compaction equipment

HMA at lower temperatures

Warm Mix Asphalt for Municipal Paving?

Early/late season paving

Longer haul distance/time

Longer Binder life

Better compaction

Longer lasting roads!

APWA 2016 PWX 8/22/2016

10

Advantages of Warm Mix Asphalt

Warm Mix Production Temperatures

APWA 2016 PWX 8/22/2016

11

Longer Binder Life

Lower mixing temps result in less oxidation of the binder

Binder remains more flexible, extending the life of the pavement

Binder HardeningBinder ages the most during the mixing process

Better compaction extends the life of the pavement

APWA 2016 PWX 8/22/2016

12

Longer Binder Life

Texas Transportation Institute Overlay Test Results

Longer Binder LifeTTI Overlay Test Results (Granite)

More flexible binders resist cracking

WMA

APWA 2016 PWX 8/22/2016

13

Better Compaction with WMA

HMA Time Available for CompactionAt 50 deg F air temp, 2” thick, HMA has only a 19 minute window of compaction

19 min TAC

APWA 2016 PWX 8/22/2016

14

WMA Time Available for CompactionWMA has 35 minute window of compaction

80% additional time to achieve density!

35 min TAC

Reduced Thermal Segregation

APWA 2016 PWX 8/22/2016

15

APWA 2016 PWX 8/22/2016

16

Back to East StreetFall paving

Limited window for road closure

Unseasonably cold morning

Two paving crews on hold

WMA saves the day!

The Results

APWA 2016 PWX 8/22/2016

17

The Results

Total Backlog: $23,652,204$10,192,000

Looking Forward

APWA 2016 PWX 8/22/2016

18

ConclusionBy employing the use of good pavement management, preservation maintenance, and in coordination with environmentally friendlier paving techniques, better specifications, and construction oversight, it is possible to find the balance between a community's ecological, social, and economic needs, while improving the overall condition of its infrastructure.

Questions?