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Warm Mix Asphalt & Recycled Asphalt Pavements. Cassandra Simpson | Greg Stephenson Robert Patience | Rick Hennig. Background to US Mixes. Virgin Source Aggregates “Combined” Grading (eg passing ½” retained ¼”) More Variability in US Virgin Mixes Fractionated RAP (Single Size) - PowerPoint PPT Presentation

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Slide 1Warm Mix Asphalt

Background to US Mixes

More Variability in US Virgin Mixes

Fractionated RAP (Single Size)

More Important at High Percentages of RAP

Helps in Design of High RAP Mixes

Fractionating RAP and non-fractionated raw materials

AAPA 2010 Study Tour – WMA RAP

Background to US Mixes

Who owns the RAP

*

Integrates transportation functionality and ecological sustainability

Green Highways are:

www.greenhighways.org

Environmental issues are increasingly impacting on highway construction. The use of RAP and WMA are just some of the ways that these issues can be addressed.

Main driver for using RAP is economics & sustainability has become the new driver.

AAPA 2010 Study Tour – WMA RAP

Advantages of Recycling

Environmentally Responsible

Bitumen ~10 to 200 million years

Still high quality aggregate.

Advantages of Warm Mix Asphalt

Improved working conditions

Is Warm Mix the Future for Asphalt?

100% of production could be WMA in the future with up to 50% WMA within 5 years

AAPA 2010 Study Tour – WMA RAP

WMA + RAP - Benefits

Improves TSR values

www.aapa.asn.au

The main production benefit is the ability to run higher temperatures so that the exhaust gasses are at temperatures above their dew point (bag house).

Product benefits of WMA+RAP (which lead to improved performance) include:

Addressing the potential issue of the less aged WMA binder,

Increases the TSR of the resultant WMA+RAP blend

Ensures virgin aggregates are dry (due to super heating) prior to mixing with the virgin binder (and RAP)

Environmental benefits include:

Recycling reduces the dependence on natural resources (aggregates and crude oil)

Reduce “waste” to landfill

States That Have Tried WMA

& Higher RAP

RAP and WMA

Lower mixing temperature resulted in less oxidation & light oil remaining in virgin bitumen

Steam produced from drying RAP creates inert atmosphere

Recovered binder from WMA with 25% RAP has same rheological properties as recovered binder from HMA with virgin bitumen

Co-mixing (or interfacial mixing) of binders (virgin with RAP binder) is being investigated using an atomic force microscope. Additional work is also being undertaken to assess the resultant dynamic modulus of the WMA/RAP blend

Expanded RAP mixing study utilizing dynamic modulus E* evaluation criteria developed by Advanced Asphalt Technologies: Bonaquist & Christensen

E* from specified mixing and compaction temperatures compared to fully blended condition E* determined through the Hirsch model (assuming 100% blending of RAP and virgin binders)

AAPA 2010 Study Tour – WMA RAP

Specified Binder 58-28

25% RAP

DSR = Dynamic Shear Rheometer; G*/sin delta = Rutting Parameter of Superpave bitumen specification.

Original binder is PG58-28

Original binder (RTFOT Aged) is equivalent to the binder of hotmix after manufacture and placement

WMA (Post Plant) is the binder recovered from a WMA with 25% RAP

HMA (Post Plant) is the binder recovered from hotmix with 25% RAP

This basically indicates that the WMA (Post Plant) binder (containing 25% RAP) and the original binder (RTFOT Aged) are equivalent i.e. the addition of RAP stiffens the (WMA) binder to a level equivalent of the virgin binder in hotmix – addressing concerns that may exist with the tenderness of WMA.

AAPA 2010 Study Tour – WMA RAP

RAP and WMA

Will RAP and New Binders Mix at WMA Process Temperatures?

Co-mingled binder properties?

Interfacial Mixing Study

Atomic Force Microscope

Lab Mixing Studies

Dynamic Modulus Evaluation

Co-mixing (or interfacial mixing) of binders (virgin with RAP binder) is being investigated using an atomic force microscope. Additional work is also being undertaken to assess the resultant dynamic modulus of the WMA/RAP blend

Expanded RAP mixing study utilizing dynamic modulus E* evaluation criteria developed by Advanced Asphalt Technologies: Bonaquist & Christensen

E* from specified mixing and compaction temperatures compared to fully blended condition E* determined through the Hirsch model (assuming 100% blending of RAP and virgin binders)

AAPA 2010 Study Tour – WMA RAP

NCHRP 9-43 - Sasobit

Sterling, VA 20166

100000

0.00001

1.4979187362

31.4715937245

1000000

0.000001

1.3799389198

23.9849556526

Recoveredbinder

wr relative to TD

Count

wr at Tr

G*, Pa

Fitted Binder G* and Hirsch Model Estimates at SPT Temperatures and Freqauencies

1.97E+06

G*, Pa

Measured E*

Sample 1

Sample 2

G*, Pa

100062996.261358

96103494.1297825

93038748.6989695

76904351.8509593

45894102.4851302

46799888.1644654

41609618.407297

37525069.0612734

17369814.5127846

19280995.387901

15297486.3204266

15709939.1452385

5366533.44413295

6635898.40706188

4580508.55352839

5579479.97053302

1355423.07942858

1899818.92571095

1120871.34976263

1672789.64390694

283616.179755483

454702.901540304

227607.122172374

424332.954241672

50273.1712968219

92192.8397491941

39275.837833642

91905.9030101143

7754.8803298773

16141.2744278981

5921.2886945949

17244.381424263

1069.9494319744

2494.9209054701

801.7812180567

2853.4774692802

This workbook is used in conjunction with the Simple Performance Test System to develop dynamic

modulus master curves. It has the capability to solve a modified version of the 2002 Design Guide master

curve equation, Equation 1.

Max

The maximum limiting modulus is estimated from mixture volumetric properties using the Hirsch model

and a limiting binder modulus of 1 GPa (145,000 psi), Equations 2 and 3.

ú

ú

ú

ú

û

ù

ê

ê

ê

ê

ë

é

= limiting maximum mixture dynamic modulus

VMA = Voids in mineral aggregates, %

VFA = Voids filled with asphalt, %

(

)

= fitting parameters

This workbook is used in conjunction with the Simple Performance Test System to develop dynamicmodulus master curves. It has the capability to solve a modified version of the 2002 Design Guide master

curve equation, Equation 1.

Max = limiting maximum modulus

, , and c fitting parameters

The maximum limiting modulus is estimated from mixture volumetric properties using the Hirsch model

and a limiting binder modulus of 1 GPa (145,000 psi), Equations 2 and 3.

)(000,435000,200,4

100

1

1

000,10

000,435

100

1000,200,4|*|

max

VFA

VMA

VMA

P

VMAxVFA

VMA

PE

c

c

(2)

where

58.0

58.0

)(000,435

650

)(000,435

20

VMA

VFA

VMA

VFA

P

c

(3)

E*

max

= limiting maximum mixture dynamic modulus

VMA = Voids in mineral aggregates, %

VFA = Voids filled with asphalt, %

If viscosity-temperature data are not available for the binder used in the mixture, the workbook can be used

to solve a master curve equation using shift factors from the Arrhenius equation, Equation 4.

25.295

11

14714.19

)log(

1

*)log(

T

E

t

a

e

Max

E

(4)

Where:

1.

3.

A spreadsheet to perform the 2002 Design Guide fit (VTSFIT)

4.

A summary report spreadsheet of the 2002 Design Guide fit

(VTSMASTERREPORT)

5.

6.

(ARRHENIUSMASTERREPORT)

DATA Spreadsheet

All data needed to develop a master curve is input in the highlighted cells in the

DATA spreadsheet. This includes VMA and VFA for computing the limiting maximum

modulus, A and VTS parameters for the binder for use in the 2002 Design Guide shift

factors, the reference temperature, and the measured dynamic modulus data. If only two

specimens were tested, leave the data cells for Specimen 3 blank. Note: A and VTS

parameters are only needed for the 2002 Design Guide master curve (VTSFIT)

VTSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to the

2002 Design Guide master curve, Equation 1. Use the solver function tool on the yellow

highlighted cell (Cell J25) to minimize the sum of the squared errors between the

measured and predicted values. Initial estimates for the optimization should be input in

Cells B4 to B7. Suggested initial estimates are given. After solver optimizes Cell J25,

the final values of the master curve parameters are given in Cells B4 to B7.

VTSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the VTSFIT

spreadsheet. It includes the measured data, the optimized master curve parameters, and

plots of the dynamic modulus master curve, the shift factors, and the phase angle master

curve.

ARRHENIUSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to a

master curve using Arrhenius temperature shift factors, Equation 4. Use the solver

function tool on the yellow highlighted cell (Cell I25) to minimize the sum of the squared

errors between the measured and predicted values. Initial estimates for the optimization

should be input in Cells B4 to B7. Suggested initial estimates are given. After solver

optimizes Cell I25, the final values of the master curve parameters are given in Cells B4

to B7.

ARRHENIUSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the

ARRHENIUSFIT spreadsheet. It includes the measured data, the optimized master curve

parameters, and plots of the dynamic modulus master curve, the shift factors, and the

phase angle master curve.

1.

3.

A spreadsheet to perform the 2002 Design Guide fit (VTSFIT)

4.

A summary report spreadsheet of the 2002 Design Guide fit

(VTSMASTERREPORT)

5.

6.

(ARRHENIUSMASTERREPORT)

DATA Spreadsheet

All data needed to develop a master curve is input in the highlighted cells in the

DATA spreadsheet. This includes VMA and VFA for computing the limiting maximum

modulus, A and VTS parameters for the binder for use in the 2002 Design Guide shift

factors, the reference temperature, and the measured dynamic modulus data. If only two

specimens were tested, leave the data cells for Specimen 3 blank. Note: A and VTS

parameters are only needed for the 2002 Design Guide master curve (VTSFIT)

VTSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to the

2002 Design Guide master curve, Equation 1. Use the solver function tool on the yellow

highlighted cell (Cell J25) to minimize the sum of the squared errors between the

measured and predicted values. Initial estimates for the optimization should be input in

Cells B4 to B7. Suggested initial estimates are given. After solver optimizes Cell J25,

the final values of the master curve parameters are given in Cells B4 to B7.

VTSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the VTSFIT

spreadsheet. It includes the measured data, the optimized master curve parameters, and

plots of the dynamic modulus master curve, the shift factors, and the phase angle master

curve.

ARRHENIUSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to a

master curve using Arrhenius temperature shift factors, Equation 4. Use the solver

function tool on the yellow highlighted cell (Cell I25) to minimize the sum of the squared

errors between the measured and predicted values. Initial estimates for the optimization

should be input in Cells B4 to B7. Suggested initial estimates are given. After solver

optimizes Cell I25, the final values of the master curve parameters are given in Cells B4

to B7.

ARRHENIUSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the

ARRHENIUSFIT spreadsheet. It includes the measured data, the optimized master curve

parameters, and plots of the dynamic modulus master curve, the shift factors, and the

phase angle master curve.

2. A data entry spreadsheet (DATA)

3. A spreadsheet to perform the 2002 Design Guide fit (VTSFIT)

4. A summary report spreadsheet of the 2002 Design Guide fit (VTSMASTERREPORT)

5. A spreadsheet to perform the Arrhenius fit (ARRHENIUSFIT)

6. A summary report spreadsheet for the Arrhenius fit (ARRHENIUSMASTERREPORT)

DATA Spreadsheet

All data needed to develop a master curve is input in the highlighted cells in the DATA spreadsheet. This includes VMA and VFA for computing the limiting maximum modulus, A and VTS parameters for the binder for use in the 2002 Design Guide shift factors, the reference temperature, and the measured dynamic modulus data. If only two specimens were tested, leave the data cells for Specimen 3 blank. Note: A and VTS parameters are only needed for the 2002 Design Guide master curve (VTSFIT)

VTSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to the 2002 Design Guide master curve, Equation 1. Use the solver function tool on the yellow highlighted cell (Cell J25) to minimize the sum of the squared errors between the measured and predicted values. Initial estimates for the optimization should be input in Cells B4 to B7. Suggested initial estimates are given. After solver optimizes Cell J25, the final values of the master curve parameters are given in Cells B4 to B7.

VTSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the VTSFIT spreadsheet. It includes the measured data, the optimized master curve parameters, and plots of the dynamic modulus master curve, the shift factors, and the phase angle master curve.

ARRHENIUSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to a master curve using Arrhenius temperature shift factors, Equation 4. Use the solver function tool on the yellow highlighted cell (Cell I25) to minimize the sum of the squared errors between the measured and predicted values. Initial estimates for the optimization should be input in Cells B4 to B7. Suggested initial estimates are given. After solver optimizes Cell I25, the final values of the master curve parameters are given in Cells B4 to B7.

ARRHENIUSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the ARRHENIUSFIT spreadsheet. It includes the measured data, the optimized master curve parameters, and plots of the dynamic modulus master curve, the shift factors, and the phase angle master curve.

MBD015A195B.doc

(

)

[

]

{

}

)

Max = limiting maximum modulus

(, (, ( and c fitting parameters

The maximum limiting modulus is estimated from mixture volumetric properties using the Hirsch model and a limiting binder modulus of 1 GPa (145,000 psi), Equations 2 and 3.

ú

ú

ú

ú

û

ù

ê

ê

ê

ê

ë

é

VMA = Voids in mineral aggregates, %

VFA = Voids filled with asphalt, %

(

)

WMA + RAP - US Practices

Texas DoT – 33%-50% of all WMA work contain RAP

North Carolina (Boggs) – only use WMA with RAP (15-20%)

South Carolina (Banks) – view RAP inclusion as insurance

California (Granite) – a means of achieving a similar binder to that of hotmix

Texas limits the amount of RAP in their specifications to 20% in wearing courses, 30% in the binder/intermediate courses and 40% in lower layers (greater than 100mm from the pavement surface). Also, if the RAP is not processed and fractionated, these maximum allowable limits are reduced by 10% i.e. 10%, 20% and 30% respectively.

North Carolina allows WMA only on secondary roads.

South Carolina limits the amount of RAP in their specifications to 10-20% in wearing courses, 10-25% in the binder/intermediate courses and 30% in base layers and is dependent on the mix type. Banks indicated that RAP eliminates stripping concerns and stiffens the binder to address tenderness/rutting concerns. RAP is also used to bump a PG grade rather than using an expensive intermediate grade (PG76 = PG70+RAP)

AAPA 2010 Study Tour – WMA RAP

Superpave Guidelines

use specified binder grade

use one full binder grade lower

Tier 3: Over 25% RAP (>35% for WMA)

use blending charts to determine required binder grade

Superpave guidelines exist for RAP% in hotmix but not currently for WMA. The values in red are currently being proposed by various industry personnel.

AAPA 2010 Study Tour – WMA RAP

Determining Blended Binder Grade

Production and Paving Notes

Make sure the burner is tuned for the temperature.

Keep bag-house temperature above condensation point - higher % RAP in WMA helped increase temperature of bag house.

Consider superheating aggregate ahead of RAP.

Follow normal placement practices.

Short Term Ageing of WMA Binders During Production (laboratory ageing protocols)*

Differences Between Field Produced WMA and HMA Volumetric Properties

Increased RAP Usage with WMA*

Shingle Use with WMA*

Rubber Use with WMA*

*

*

High RAP Mix Design

NCHRP 9-46 Mix Design and Evaluation Procedure for High Reclaimed Asphalt Pavement Content in Hot Mix Asphalt

Objective: Develop mix design method and specification for HMA containing up to 50% RAP.

AAPA 2010 Study Tour – WMA RAP

Questions?

10

100

1000

10000

Background to US Mixes

More Variability in US Virgin Mixes

Fractionated RAP (Single Size)

More Important at High Percentages of RAP

Helps in Design of High RAP Mixes

Fractionating RAP and non-fractionated raw materials

AAPA 2010 Study Tour – WMA RAP

Background to US Mixes

Who owns the RAP

*

Integrates transportation functionality and ecological sustainability

Green Highways are:

www.greenhighways.org

Environmental issues are increasingly impacting on highway construction. The use of RAP and WMA are just some of the ways that these issues can be addressed.

Main driver for using RAP is economics & sustainability has become the new driver.

AAPA 2010 Study Tour – WMA RAP

Advantages of Recycling

Environmentally Responsible

Bitumen ~10 to 200 million years

Still high quality aggregate.

Advantages of Warm Mix Asphalt

Improved working conditions

Is Warm Mix the Future for Asphalt?

100% of production could be WMA in the future with up to 50% WMA within 5 years

AAPA 2010 Study Tour – WMA RAP

WMA + RAP - Benefits

Improves TSR values

www.aapa.asn.au

The main production benefit is the ability to run higher temperatures so that the exhaust gasses are at temperatures above their dew point (bag house).

Product benefits of WMA+RAP (which lead to improved performance) include:

Addressing the potential issue of the less aged WMA binder,

Increases the TSR of the resultant WMA+RAP blend

Ensures virgin aggregates are dry (due to super heating) prior to mixing with the virgin binder (and RAP)

Environmental benefits include:

Recycling reduces the dependence on natural resources (aggregates and crude oil)

Reduce “waste” to landfill

States That Have Tried WMA

& Higher RAP

RAP and WMA

Lower mixing temperature resulted in less oxidation & light oil remaining in virgin bitumen

Steam produced from drying RAP creates inert atmosphere

Recovered binder from WMA with 25% RAP has same rheological properties as recovered binder from HMA with virgin bitumen

Co-mixing (or interfacial mixing) of binders (virgin with RAP binder) is being investigated using an atomic force microscope. Additional work is also being undertaken to assess the resultant dynamic modulus of the WMA/RAP blend

Expanded RAP mixing study utilizing dynamic modulus E* evaluation criteria developed by Advanced Asphalt Technologies: Bonaquist & Christensen

E* from specified mixing and compaction temperatures compared to fully blended condition E* determined through the Hirsch model (assuming 100% blending of RAP and virgin binders)

AAPA 2010 Study Tour – WMA RAP

Specified Binder 58-28

25% RAP

DSR = Dynamic Shear Rheometer; G*/sin delta = Rutting Parameter of Superpave bitumen specification.

Original binder is PG58-28

Original binder (RTFOT Aged) is equivalent to the binder of hotmix after manufacture and placement

WMA (Post Plant) is the binder recovered from a WMA with 25% RAP

HMA (Post Plant) is the binder recovered from hotmix with 25% RAP

This basically indicates that the WMA (Post Plant) binder (containing 25% RAP) and the original binder (RTFOT Aged) are equivalent i.e. the addition of RAP stiffens the (WMA) binder to a level equivalent of the virgin binder in hotmix – addressing concerns that may exist with the tenderness of WMA.

AAPA 2010 Study Tour – WMA RAP

RAP and WMA

Will RAP and New Binders Mix at WMA Process Temperatures?

Co-mingled binder properties?

Interfacial Mixing Study

Atomic Force Microscope

Lab Mixing Studies

Dynamic Modulus Evaluation

Co-mixing (or interfacial mixing) of binders (virgin with RAP binder) is being investigated using an atomic force microscope. Additional work is also being undertaken to assess the resultant dynamic modulus of the WMA/RAP blend

Expanded RAP mixing study utilizing dynamic modulus E* evaluation criteria developed by Advanced Asphalt Technologies: Bonaquist & Christensen

E* from specified mixing and compaction temperatures compared to fully blended condition E* determined through the Hirsch model (assuming 100% blending of RAP and virgin binders)

AAPA 2010 Study Tour – WMA RAP

NCHRP 9-43 - Sasobit

Sterling, VA 20166

100000

0.00001

1.4979187362

31.4715937245

1000000

0.000001

1.3799389198

23.9849556526

Recoveredbinder

wr relative to TD

Count

wr at Tr

G*, Pa

Fitted Binder G* and Hirsch Model Estimates at SPT Temperatures and Freqauencies

1.97E+06

G*, Pa

Measured E*

Sample 1

Sample 2

G*, Pa

100062996.261358

96103494.1297825

93038748.6989695

76904351.8509593

45894102.4851302

46799888.1644654

41609618.407297

37525069.0612734

17369814.5127846

19280995.387901

15297486.3204266

15709939.1452385

5366533.44413295

6635898.40706188

4580508.55352839

5579479.97053302

1355423.07942858

1899818.92571095

1120871.34976263

1672789.64390694

283616.179755483

454702.901540304

227607.122172374

424332.954241672

50273.1712968219

92192.8397491941

39275.837833642

91905.9030101143

7754.8803298773

16141.2744278981

5921.2886945949

17244.381424263

1069.9494319744

2494.9209054701

801.7812180567

2853.4774692802

This workbook is used in conjunction with the Simple Performance Test System to develop dynamic

modulus master curves. It has the capability to solve a modified version of the 2002 Design Guide master

curve equation, Equation 1.

Max

The maximum limiting modulus is estimated from mixture volumetric properties using the Hirsch model

and a limiting binder modulus of 1 GPa (145,000 psi), Equations 2 and 3.

ú

ú

ú

ú

û

ù

ê

ê

ê

ê

ë

é

= limiting maximum mixture dynamic modulus

VMA = Voids in mineral aggregates, %

VFA = Voids filled with asphalt, %

(

)

= fitting parameters

This workbook is used in conjunction with the Simple Performance Test System to develop dynamicmodulus master curves. It has the capability to solve a modified version of the 2002 Design Guide master

curve equation, Equation 1.

Max = limiting maximum modulus

, , and c fitting parameters

The maximum limiting modulus is estimated from mixture volumetric properties using the Hirsch model

and a limiting binder modulus of 1 GPa (145,000 psi), Equations 2 and 3.

)(000,435000,200,4

100

1

1

000,10

000,435

100

1000,200,4|*|

max

VFA

VMA

VMA

P

VMAxVFA

VMA

PE

c

c

(2)

where

58.0

58.0

)(000,435

650

)(000,435

20

VMA

VFA

VMA

VFA

P

c

(3)

E*

max

= limiting maximum mixture dynamic modulus

VMA = Voids in mineral aggregates, %

VFA = Voids filled with asphalt, %

If viscosity-temperature data are not available for the binder used in the mixture, the workbook can be used

to solve a master curve equation using shift factors from the Arrhenius equation, Equation 4.

25.295

11

14714.19

)log(

1

*)log(

T

E

t

a

e

Max

E

(4)

Where:

1.

3.

A spreadsheet to perform the 2002 Design Guide fit (VTSFIT)

4.

A summary report spreadsheet of the 2002 Design Guide fit

(VTSMASTERREPORT)

5.

6.

(ARRHENIUSMASTERREPORT)

DATA Spreadsheet

All data needed to develop a master curve is input in the highlighted cells in the

DATA spreadsheet. This includes VMA and VFA for computing the limiting maximum

modulus, A and VTS parameters for the binder for use in the 2002 Design Guide shift

factors, the reference temperature, and the measured dynamic modulus data. If only two

specimens were tested, leave the data cells for Specimen 3 blank. Note: A and VTS

parameters are only needed for the 2002 Design Guide master curve (VTSFIT)

VTSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to the

2002 Design Guide master curve, Equation 1. Use the solver function tool on the yellow

highlighted cell (Cell J25) to minimize the sum of the squared errors between the

measured and predicted values. Initial estimates for the optimization should be input in

Cells B4 to B7. Suggested initial estimates are given. After solver optimizes Cell J25,

the final values of the master curve parameters are given in Cells B4 to B7.

VTSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the VTSFIT

spreadsheet. It includes the measured data, the optimized master curve parameters, and

plots of the dynamic modulus master curve, the shift factors, and the phase angle master

curve.

ARRHENIUSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to a

master curve using Arrhenius temperature shift factors, Equation 4. Use the solver

function tool on the yellow highlighted cell (Cell I25) to minimize the sum of the squared

errors between the measured and predicted values. Initial estimates for the optimization

should be input in Cells B4 to B7. Suggested initial estimates are given. After solver

optimizes Cell I25, the final values of the master curve parameters are given in Cells B4

to B7.

ARRHENIUSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the

ARRHENIUSFIT spreadsheet. It includes the measured data, the optimized master curve

parameters, and plots of the dynamic modulus master curve, the shift factors, and the

phase angle master curve.

1.

3.

A spreadsheet to perform the 2002 Design Guide fit (VTSFIT)

4.

A summary report spreadsheet of the 2002 Design Guide fit

(VTSMASTERREPORT)

5.

6.

(ARRHENIUSMASTERREPORT)

DATA Spreadsheet

All data needed to develop a master curve is input in the highlighted cells in the

DATA spreadsheet. This includes VMA and VFA for computing the limiting maximum

modulus, A and VTS parameters for the binder for use in the 2002 Design Guide shift

factors, the reference temperature, and the measured dynamic modulus data. If only two

specimens were tested, leave the data cells for Specimen 3 blank. Note: A and VTS

parameters are only needed for the 2002 Design Guide master curve (VTSFIT)

VTSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to the

2002 Design Guide master curve, Equation 1. Use the solver function tool on the yellow

highlighted cell (Cell J25) to minimize the sum of the squared errors between the

measured and predicted values. Initial estimates for the optimization should be input in

Cells B4 to B7. Suggested initial estimates are given. After solver optimizes Cell J25,

the final values of the master curve parameters are given in Cells B4 to B7.

VTSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the VTSFIT

spreadsheet. It includes the measured data, the optimized master curve parameters, and

plots of the dynamic modulus master curve, the shift factors, and the phase angle master

curve.

ARRHENIUSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to a

master curve using Arrhenius temperature shift factors, Equation 4. Use the solver

function tool on the yellow highlighted cell (Cell I25) to minimize the sum of the squared

errors between the measured and predicted values. Initial estimates for the optimization

should be input in Cells B4 to B7. Suggested initial estimates are given. After solver

optimizes Cell I25, the final values of the master curve parameters are given in Cells B4

to B7.

ARRHENIUSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the

ARRHENIUSFIT spreadsheet. It includes the measured data, the optimized master curve

parameters, and plots of the dynamic modulus master curve, the shift factors, and the

phase angle master curve.

2. A data entry spreadsheet (DATA)

3. A spreadsheet to perform the 2002 Design Guide fit (VTSFIT)

4. A summary report spreadsheet of the 2002 Design Guide fit (VTSMASTERREPORT)

5. A spreadsheet to perform the Arrhenius fit (ARRHENIUSFIT)

6. A summary report spreadsheet for the Arrhenius fit (ARRHENIUSMASTERREPORT)

DATA Spreadsheet

All data needed to develop a master curve is input in the highlighted cells in the DATA spreadsheet. This includes VMA and VFA for computing the limiting maximum modulus, A and VTS parameters for the binder for use in the 2002 Design Guide shift factors, the reference temperature, and the measured dynamic modulus data. If only two specimens were tested, leave the data cells for Specimen 3 blank. Note: A and VTS parameters are only needed for the 2002 Design Guide master curve (VTSFIT)

VTSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to the 2002 Design Guide master curve, Equation 1. Use the solver function tool on the yellow highlighted cell (Cell J25) to minimize the sum of the squared errors between the measured and predicted values. Initial estimates for the optimization should be input in Cells B4 to B7. Suggested initial estimates are given. After solver optimizes Cell J25, the final values of the master curve parameters are given in Cells B4 to B7.

VTSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the VTSFIT spreadsheet. It includes the measured data, the optimized master curve parameters, and plots of the dynamic modulus master curve, the shift factors, and the phase angle master curve.

ARRHENIUSFIT Spreadsheet

This spreadsheet is set up for using the solver function to fit the measured data to a master curve using Arrhenius temperature shift factors, Equation 4. Use the solver function tool on the yellow highlighted cell (Cell I25) to minimize the sum of the squared errors between the measured and predicted values. Initial estimates for the optimization should be input in Cells B4 to B7. Suggested initial estimates are given. After solver optimizes Cell I25, the final values of the master curve parameters are given in Cells B4 to B7.

ARRHENIUSMASTERREPORT Spreadsheet

This spreadsheet provides an output of the optimized master curve from the ARRHENIUSFIT spreadsheet. It includes the measured data, the optimized master curve parameters, and plots of the dynamic modulus master curve, the shift factors, and the phase angle master curve.

MBD015A195B.doc

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Max = limiting maximum modulus

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The maximum limiting modulus is estimated from mixture volumetric properties using the Hirsch model and a limiting binder modulus of 1 GPa (145,000 psi), Equations 2 and 3.

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VMA = Voids in mineral aggregates, %

VFA = Voids filled with asphalt, %

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WMA + RAP - US Practices

Texas DoT – 33%-50% of all WMA work contain RAP

North Carolina (Boggs) – only use WMA with RAP (15-20%)

South Carolina (Banks) – view RAP inclusion as insurance

California (Granite) – a means of achieving a similar binder to that of hotmix

Texas limits the amount of RAP in their specifications to 20% in wearing courses, 30% in the binder/intermediate courses and 40% in lower layers (greater than 100mm from the pavement surface). Also, if the RAP is not processed and fractionated, these maximum allowable limits are reduced by 10% i.e. 10%, 20% and 30% respectively.

North Carolina allows WMA only on secondary roads.

South Carolina limits the amount of RAP in their specifications to 10-20% in wearing courses, 10-25% in the binder/intermediate courses and 30% in base layers and is dependent on the mix type. Banks indicated that RAP eliminates stripping concerns and stiffens the binder to address tenderness/rutting concerns. RAP is also used to bump a PG grade rather than using an expensive intermediate grade (PG76 = PG70+RAP)

AAPA 2010 Study Tour – WMA RAP

Superpave Guidelines

use specified binder grade

use one full binder grade lower

Tier 3: Over 25% RAP (>35% for WMA)

use blending charts to determine required binder grade

Superpave guidelines exist for RAP% in hotmix but not currently for WMA. The values in red are currently being proposed by various industry personnel.

AAPA 2010 Study Tour – WMA RAP

Determining Blended Binder Grade

Production and Paving Notes

Make sure the burner is tuned for the temperature.

Keep bag-house temperature above condensation point - higher % RAP in WMA helped increase temperature of bag house.

Consider superheating aggregate ahead of RAP.

Follow normal placement practices.

Short Term Ageing of WMA Binders During Production (laboratory ageing protocols)*

Differences Between Field Produced WMA and HMA Volumetric Properties

Increased RAP Usage with WMA*

Shingle Use with WMA*

Rubber Use with WMA*

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High RAP Mix Design

NCHRP 9-46 Mix Design and Evaluation Procedure for High Reclaimed Asphalt Pavement Content in Hot Mix Asphalt

Objective: Develop mix design method and specification for HMA containing up to 50% RAP.

AAPA 2010 Study Tour – WMA RAP

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