conserving energy and materials in hot mix presentations... · five plants and five sets of...

Regional Issues North Central Superpave Center Update

Rebecca McDaniel, NCSC OAPC/NCAUPG Technical Conference February 2, 2011

Today’s Topics Regional Issues NCSC Activities

Research Areas RAP ETG Training Lab Services Communication

Regional Issues Economy Recycling Warm Mix Asphalt Compaction – longitudinal joints Quality and Performance Safety

NCSC Focus Areas Recycling RAP ETG RAP Evaluation and CIR Mix Design RAP in Surface Courses

Surface Characteristics Use of Local Materials Quiet Pavements Friction in Pavement Management

NCSC Focus Areas Pavement Performance Porous Friction Course Performance Low Void Mixes Longitudinal Joints Continued Evaluation of SPS9 Project

Planned New Research Projects Effects of Foaming in WMA Mixes Optimizing Lab and Field Compaction Frictional Performance of 4.75mm Mixes Tire-Pavement Noise Monitoring

And more!

National Interest in RAP Strong incentives to increase RAP use Material and energy costs Binder costs rose over 300% in 2007 & 2008

Material supply issues Environmental concerns

Growing demand RAP in more mixes (i.e. surfaces) Higher RAP quantities

Major research efforts nationwide

HMA Recycling ETG FHWA initiated in May 2007 Purpose – Coordinate, develop national

guidance and recommendations on RAP use Demo projects, document performance,

share info, best practices, research

RAP mixes can perform as well as or better than virgin mixes.

RAP ETG wants to show states how to successfully use 25% RAP and more.

NCSC Study on RAP Plant Mixes

Reclaimed Asphalt Pavement

Binder Grade 0% 15% 25% 40%

PG 58-28 X X

PG 64-22 X X X X

Five plants and five sets of materials studied.

The RAP mixes were not as stiff as expected.

High, intermediate and low temperatures

The binder did not stiffen linearly with increasing RAP content.

In most cases, dropping the virgin grade to PG58-28 for 25% RAP was not necessary.

Results

One Example

100

1000

10000

100000

1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06

Log

|E*|,

MPa

Log Reduced Frequency, Hz

PG64-22 versus PG58-28

MixC (25% RAP)

MixE (25% RAP)

MixD (40% RAP)

MixF (40% RAP)

IDT Strength Example 1

-28

-22

-16

-10

2000

2500

3000

3500

JH-A JH-B JH-C JH-D JH-E JH-F

Pvmt. C

racking Tem

perature, °C

Stre

ngth

, kPa

Mixes

Strength

Temperature

IDT Stiffness Example 2

-22

-16

-10

20

30

40

EB-A EB-B EB-C EB-D EB-E EB-F

Pvmt. C

racking Tem

perature, °C

Stiff

ness

, GPa

Mixes

Stiffness

Temperature

For these materials Grade change at 15% not necessary

Low, intermediate and high temperature

properties acceptable to 25%

Pretty good blending of RAP and virgin binders to 25% RAP

Based on this research And testing RAP sources from across

the state

INDOT increased RAP contents to: 25% with no change in grade

40% with a grade change

Spec change has been adopted

RAP in Surface Courses Evaluate effect of poor quality RAP on

friction Lab study of “crummy” RAP blended with

steel slag, ACBF slag, crushed gravel Field evaluation of RAP surfaces on low

volume roads Data analysis underway; report by Spring

Surface Characteristics

Surface Characteristics/Performance RAP in Surface Courses Friction – NMAS, aggregate type,

gradation Use of Local Aggregates in Surfaces Friction in Pavement Management System Thermoplastic Pavement Marking Material Evaluation of new aggregate sources

Porous Asphalt Surfaces New Generation Open Graded Friction

Courses Porous European Mix Porous Friction Course

For noise control and safety Reduced splash and spray High friction (macrotexture)

Pavement Porosity

Long Term Field Evaluation I74 Eastbound East of Indianapolis Constructed August 2003

Comparison of SMA, PFC and HMA Texture Friction Noise Performance

The Materials 9.5mm mixtures, Steel Slag and PG76-22

PFC designed at 18-22% air voids Old OGFC designed at 12-15% voids Polymer modified binder and fiber

Design Gradations

0

control points

20

40

60

80

100

Sieve

Cum

ulat

ive

% P

assi

ng

PFC

SMA

HMA

0.075 0.15 0.6 1.18 2.36 4.75 9.5 12.5

SMA vs. PFC

Conventional HMA

Changes in Noise vs. Traffic

747576777879808182

0 10 20 30 40 50 60no. of axle passes, 10^6

SPL,

dB

(A)

PFC at 100 km/hSMA at 100 km/hDGA at 100 km/h

10/2006

6/2005

5/2006

10/2006

10/20065/2006

5/2006

6/2005

6/2005

4/2007 5/2007

5/2007

7/2007

7/2007

7/2007

10/2007

10/2007

10/2007

8/2008

8/20088/2008

Changes in Texture

0.0

0.5

1.0

1.5

2.0

0 10 20 30 40 50 60no. of axle passes, 10^6

MPD

, mm

PFCSMADGA

10/2008

9/20035/2006

11/2006

8/2005 11/2005 10/2006

9/2003

4/2007

4/2007

8/2007

10/20077/200

10/2007

10/2008

Changes in Friction (F60)

0.1

0.2

0.3

0.4

0.5

0.6

0 10 20 30 40 50 60no. of axle passes, 10^6

F60

PFCSMADGA9/2003

8/2005 11/2005 10/2006

5/2006

11/2006

9/20034/2007

4/2007

7/2007

10/2007

10/2007

8/2007

For SMAFor PFC

10/2008

10/200

After Five Years Texture decreased slightly after two years then

stabilized Noise increased slightly, now steady PFC significantly quieter PFC and SMA friction the same PFC reduced splash and spray PFCs can hold up in Midwestern applications

(when used properly) Did require somewhat more salt

Other Studies Quiet Pavements European style surfaces in American terms Extensive lab study FHWA funded

Low Void Mixes How low is too low? NCAT Track performance, Accelerated

Pavement Testing and lab testing

Training Activities Customized training on request Our place or yours Example – Wisconsin Project Manager (Field

Personnel) Training Five sites around the state Half day classroom, afternoon plant/project tour

Webinars Perpetual Pavements More planned

Laboratory Services AMRL Accredited Lab Binder, Mixture, Aggregates

Third Party Testing Research Testing New Product Evaluations Test Equipment/Protocol Evaluations

Communications Newsletter Publication resuming in Spring Free distribution On-line versions available

Website Searchable database Technical information Calendar of events

Communications Presentations Recycling Best Practices Pavement Design Factors Affecting Durability Effect of Low Air Voids Research Updates - National, Regional, Local

More info:

Rebecca S. McDaniel Technical Director North Central Superpave Center P. O. Box 2382 West Lafayette, IN 47906 765/463-2317 ext. 226 rsmcdani@purdue.edu https://engineering.purdue.edu/NCSC