RappinRappin’ on RAP’ on RAP

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Presented by Presented by

Thomas CarterThomas Carter

Twining Laboratories, SacramentoTwining Laboratories, Sacramento

Let’s Talk about WasteLet’s Talk about Waste

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Did you know….Did you know….

In 2001, United States residents, In 2001, United States residents, businesses, and institutions produced businesses, and institutions produced nearly 232 million tons of solid nearly 232 million tons of solid waste, which is approximately 4.5 waste, which is approximately 4.5 waste, which is approximately 4.5 waste, which is approximately 4.5 pounds of waste per person per day, pounds of waste per person per day, up from 2.7 pounds per person per up from 2.7 pounds per person per day in 1960. This means that 5% of day in 1960. This means that 5% of the world's people generate 40% of the world's people generate 40% of the world's waste. the world's waste.

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The Obvious Path for The Obvious Path for

Redemption is to RecycleRedemption is to Recycle

our Waste!our Waste!

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our Waste!our Waste!

Recycled QuantitiesRecycled Quantities

The United States EPA reports that The United States EPA reports that we recycle only 30% of our solid we recycle only 30% of our solid waste in this country. That means waste in this country. That means that of the 232 million tons of that of the 232 million tons of

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that of the 232 million tons of that of the 232 million tons of waste generated in the US, only 70 waste generated in the US, only 70 million tons were recycled away million tons were recycled away from landfills (hey, it’s a start!).from landfills (hey, it’s a start!).

Recycling Rates in the USRecycling Rates in the US(Amount Recycled vs. Amount Generated)(Amount Recycled vs. Amount Generated)

�� 70% Scrap Steel70% Scrap Steel

�� 45% Aluminum Cans45% Aluminum Cans

�� 56% Paper products56% Paper products

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�� 56% Paper products56% Paper products

�� 24% Plastic Soda Bottles (PET)24% Plastic Soda Bottles (PET)

�� 29% Glass Beverage Containers29% Glass Beverage Containers

�� 23% Magazines23% Magazines

Pavement RecyclingPavement Recycling

�� Of the 2.6 million miles of paved Of the 2.6 million miles of paved roads in the US, over 94 percent are roads in the US, over 94 percent are surfaced with asphalt.surfaced with asphalt.

�� Approximately 100,000,000 tons of Approximately 100,000,000 tons of

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�� Approximately 100,000,000 tons of Approximately 100,000,000 tons of asphalt pavement is removed from asphalt pavement is removed from existing roads each year. existing roads each year.

�� Of that amount, 80% is recycled Of that amount, 80% is recycled back into new pavementback into new pavement

RAP Makes SenseRAP Makes Sense

�� Conservation of Raw MaterialsConservation of Raw Materials

�� Conservation of Energy Conservation of Energy

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�� Preservation of the EnvironmentPreservation of the Environment

�� Preservation of Pavement Preservation of Pavement

GeometricsGeometrics

ConservationConservation

�� Saves on Raw MaterialsSaves on Raw Materials

•• Aggregates (diminishing reserves, Aggregates (diminishing reserves, permitting process)permitting process)

•• Binders (supply/demand issues)Binders (supply/demand issues)

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•• Binders (supply/demand issues)Binders (supply/demand issues)

�� Saves energySaves energy

•• Reduces impact of hauling and Reduces impact of hauling and processing virgin materialprocessing virgin material

Environmentally FriendlyEnvironmentally Friendly

�� Preserves the environment by Preserves the environment by reducing material taken to landfillsreducing material taken to landfills

�� At 100m tons, that’s about 65m ydAt 100m tons, that’s about 65m yd3 3

saved in landfill spacesaved in landfill space

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saved in landfill spacesaved in landfill space

�� No negative effect on air quality No negative effect on air quality since emission requirements on RAP since emission requirements on RAP processing and HMA production (with processing and HMA production (with RAP) must meet existing air quality RAP) must meet existing air quality requirements.requirements.

Common Recycle MaterialsCommon Recycle Materials

�� MaterialsMaterials

•• Hot Mix Asphalt (HMA)Hot Mix Asphalt (HMA)

•• Composite Asphalt ShinglesComposite Asphalt Shingles

•• Crumb Rubber from Discarded TiresCrumb Rubber from Discarded Tires

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•• Crumb Rubber from Discarded TiresCrumb Rubber from Discarded Tires

�� Resulting Recycled ProductsResulting Recycled Products

•• Hot Mix Asphalt (HMA) w/RAPHot Mix Asphalt (HMA) w/RAP

•• RHMARHMA--G from Crumb RubberG from Crumb Rubber

•• Aggregate Base and Shoulder Aggregate Base and Shoulder Backing ApplicationsBacking Applications

RAP PerformanceRAP Performance

�� Widespread use began in midWidespread use began in mid--1970’s1970’s

�� High RAP contents are allowed by High RAP contents are allowed by some agenciessome agencies

�� Depending on percent used, RAP can Depending on percent used, RAP can

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�� Depending on percent used, RAP can Depending on percent used, RAP can result in higher stabilities, but may result in higher stabilities, but may be prone to long term cracking if be prone to long term cracking if measures not taken during mix measures not taken during mix design process (binder evaluation)design process (binder evaluation)

�� Agencies apply conventional mix Agencies apply conventional mix design requirements to RAP designsdesign requirements to RAP designs

California RAP Specification California RAP Specification

TimelineTimeline

�� 1980’s 1980’s –– Initial Research on the use of RAP Initial Research on the use of RAP

�� 2000 2000 –– Recycled AC Task Group Formed to Recycled AC Task Group Formed to

develop specificationdevelop specification

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develop specificationdevelop specification

�� 2003 2003 –– RAP specification on server (15% Max.@ RAP specification on server (15% Max.@

Contractor’s option)Contractor’s option)

Hot Central Plant Hot Central Plant

RecyclingRecycling

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Using RAP in HMAUsing RAP in HMA

Sources of RAPSources of RAP

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Sources of RAPSources of RAP

MillingMilling

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DemolitionDemolition

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New Waste HMA and New Waste HMA and

Plant WastePlant Waste

�� HMA Returned to Plant, due to…HMA Returned to Plant, due to…

•• Over OrderingOver Ordering

•• Weather ShutWeather Shut--DownsDowns

•• Visual InspectionVisual Inspection

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•• Visual InspectionVisual Inspection

•• TemperatureTemperature

�� ByBy--Product of HMA Plant Product of HMA Plant ProductionProduction

•• StartStart--Up RejectUp Reject

•• Transitioning between Mix DesignsTransitioning between Mix Designs

RAP ProcessingRAP Processing

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Acceptable for RAP in HMA?Acceptable for RAP in HMA?

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Fractionated RAP ProcessingFractionated RAP Processing

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Typical ½ Minus Processed RAPTypical ½ Minus Processed RAP

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Best Management PracticesBest Management Practices

�� Incoming loads of RAP should be Incoming loads of RAP should be inspected to minimize inclusion of inspected to minimize inclusion of contaminated materialcontaminated material

�� Conical stockpiles are preferable to Conical stockpiles are preferable to horizontal since they will shed rain horizontal since they will shed rain

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horizontal since they will shed rain horizontal since they will shed rain water more readilywater more readily

�� Under no circumstances should Under no circumstances should heavy equipment be driven directly heavy equipment be driven directly on stockpileson stockpiles

Initial RAP ProcessInitial RAP Process

Control Testing Control Testing --

What are we looking for? What are we looking for?

Uniformity of the RAP gradingUniformity of the RAP grading

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�� Uniformity of the RAP gradingUniformity of the RAP grading

�� Uniformity of usable binder in RAPUniformity of usable binder in RAP

Typical RAP Stockpile GradationsTypical RAP Stockpile Gradations

SIEVESIEVE NN--EE SS--WW WW NN--WW EE SS--EE AVGAVG..

¾”¾” 100100 100100 100100 100100 100100 100100 100100

½” ½” 99.699.6 99.599.5 100100 100100 100100 100100 99.999.9

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3/8”3/8” 97.397.3 96.696.6 95.995.9 97.397.3 97.697.6 96.496.4 96.996.9

#4#4 77.977.9 76.276.2 76.176.1 78.178.1 78.178.1 77.177.1 77.377.3

#8#8 59.359.3 58.658.6 58.458.4 59.359.3 59.359.3 58.558.5 58.958.9

#30#30 35.535.5 35.635.6 35.735.7 37.337.3 35.535.5 36.136.1 36.036.0

#200#200 12.812.8 13.113.1 13.413.4 13.813.8 13.013.0 13.213.2 13.213.2

Residual Binder contained in Residual Binder contained in

RAPRAP

The binder content of RAP typically The binder content of RAP typically ranges between 3 and 7 percent by ranges between 3 and 7 percent by weight. The asphalt cement adhering weight. The asphalt cement adhering

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weight. The asphalt cement adhering weight. The asphalt cement adhering to the RAP aggregate is somewhat to the RAP aggregate is somewhat harder than new asphalt cement, harder than new asphalt cement, due primarily to exposure of the due primarily to exposure of the pavement to the environment. pavement to the environment.

RAP Binder PropertiesRAP Binder Properties

The degree of hardening depends on The degree of hardening depends on several factors: several factors:

�� The original properties of the asphalt The original properties of the asphalt cementcement

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cementcement

�� Mixing temperatureMixing temperature

�� Degree of compaction in the field (inDegree of compaction in the field (in--place air voids)place air voids)

�� Age of pavementAge of pavement

RAP Binder PropertiesRAP Binder Properties

SampleLocation

RAP Oil Content %(ASTM D 2172)

Absolute Viscosity

140 F in Poise(ASTM D 2171)

N/E Side 4.26 41902

S/W Side 4.13 49949

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S/W Side 4.13 49949

West Side 4.0445682

N/W Side 4.11 40870

East Side 4.26 53410

S/E Side 4.21 43088

AVERAGE 4.17 4581745817

Mix DesignMix Design

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HMA with RAPHMA with RAP

Mixture Design ConsiderationsMixture Design Considerations

RAP considerationsRAP considerations::

•• UniformityUniformity

•• Usable asphalt content Usable asphalt content

•• Aggregate gradationAggregate gradation

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•• Aggregate gradationAggregate gradation

•• Binder properties (above 15%)Binder properties (above 15%)

�� Produced RAP HMA considerationsProduced RAP HMA considerations

•• Same as any other HMA MixtureSame as any other HMA Mixture

Mix DesignMix Design

�� Material EvaluationMaterial Evaluation

•• Reclaimed Asphalt Pavement (RAP)Reclaimed Asphalt Pavement (RAP)

•• Asphalt Binders/Recycling Agents Asphalt Binders/Recycling Agents

�� Selection of Virgin Binder and Selection of Virgin Binder and AggregatesAggregates

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AggregatesAggregates

•• Type and AmountType and Amount

�� Mix Design ProceduresMix Design Procedures

•• Conventional (Marshall or Conventional (Marshall or HveemHveem))

•• SuperpaveSuperpave

Evaluation of RAPEvaluation of RAP�� RAP Mixture CompositionRAP Mixture Composition

•• Asphalt ContentAsphalt Content

•• GradationGradation

�� Recover Asphalt BinderRecover Asphalt Binder•• Less than 15% RAPLess than 15% RAP

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•• Less than 15% RAPLess than 15% RAP�� n/an/a

•• Greater than 15% RAP Greater than 15% RAP �� Viscosity of RAP BinderViscosity of RAP Binder

�� Drop a Grade from Specified (>15 to Drop a Grade from Specified (>15 to 25%)25%)

�� Blending Charts (>25%)Blending Charts (>25%)

Composite Cold Feed plus RAPComposite Cold Feed plus RAP

SieveSieve Cold FeedCold Feed

(85%)(85%)

RAPRAP

(15%)(15%)

CombinedCombined

GradingGrading

1”1” 100100 100100

¾”¾” 9999 100100 9999

Combined Gradation (Drum Plant)

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¾”¾” 9999 100100 9999

3/8”3/8” 6666 9797 7171

#4#4 4444 7777 4949

#8#8 3232 5959 3636

#30#30 1818 3636 2020

#200#200 3.73.7 13.213.2 5.15.1

Combined Gradation(Batch Plant)

Hot Bin Gradings plus RAPHot Bin Gradings plus RAP

SieveSieveBin 4Bin 4

(13%)(13%)

Bin 3Bin 3

(19%)(19%)

Bin 2Bin 2

(17%)(17%)

Bin 1Bin 1

(36%)(36%)

RAPRAP

(15%)(15%)

CombinedCombined

GradingGrading

1”1” 100100 100100

¾”¾” 9494 100100 100100 100100 9999

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¾”¾” 9494 100100 100100 100100 9999

3/8”3/8” 22 2020 9696 100100 9999 7171

#4#4 11 44 1818 9898 8383 5252

#8#8 22 7777 6464 3838

#30#30 22 4444 3939 2222

#200#200 1.21.2 13.513.5 14.214.2 5.95.9

HMA Production with HMA Production with

RAPRAP

Using Drum PlantsUsing Drum Plants

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Using Drum PlantsUsing Drum Plants

RAP Feed to Parallel Flow RAP Feed to Parallel Flow

Drum MixerDrum Mixer

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RAP Feed to Counter Flow RAP Feed to Counter Flow

Drum MixerDrum Mixer

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Double Barrel with CoaterDouble Barrel with Coater

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HMA Production with HMA Production with

RAPRAP

Using Batch PlantsUsing Batch Plants

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Using Batch PlantsUsing Batch Plants

Adding RAP at PugmillAdding RAP at Pugmill

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Adding RAP into Weigh BucketAdding RAP into Weigh Bucket

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Production Quality Production Quality

ControlControl

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Production Quality ControlProduction Quality Control(as necessary)(as necessary)

�� Sample virgin aggregates (cold feed Sample virgin aggregates (cold feed or hot bins) for gradationor hot bins) for gradation

�� Sample RAP feed for moisture and Sample RAP feed for moisture and gradationgradation

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gradationgradation

�� Sample “wet mix” for mix properties Sample “wet mix” for mix properties (voids, stability, etc)(voids, stability, etc)

Best Management PracticesBest Management Practices

�� ProvideProvide aa suitable,suitable, safesafe samplingsamplingdevicedevice toto samplesample thethe RAPRAP

�� For batch plants, mix the RAP and For batch plants, mix the RAP and the virgin aggregate adequately in the virgin aggregate adequately in

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�� For batch plants, mix the RAP and For batch plants, mix the RAP and the virgin aggregate adequately in the virgin aggregate adequately in the the pugmillpugmill, allowing sufficient , allowing sufficient discharge of moisture before discharge of moisture before introduction of virgin binder introduction of virgin binder

Best Management PracticesBest Management Practices

•• ForFor drumdrum plants,plants, protectprotect thethe RAPRAPfromfrom directdirect contactcontact withwith thethe burnerburnerflameflame byby meansmeans ofof aa shield,shield,separator,separator, secondsecond drumdrum oror otherothermethodmethod..

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methodmethod..

•• IntroduceIntroduce thethe binderbinder intointo thethe mixermixerafterafter thethe virginvirgin aggregateaggregate andand RAPRAPhavehave beenbeen combinedcombined..

Section 39 on RAP HMASection 39 on RAP HMA

ProductionProduction

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Section 39 on RAP HMASection 39 on RAP HMA

�� Process RAP from asphalt concreteProcess RAP from asphalt concrete

�� You may process RAP throughout the You may process RAP throughout the project’s life. project’s life.

�� Prevent contamination and Prevent contamination and

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�� Prevent contamination and Prevent contamination and segregation of RAPsegregation of RAP

�� Stockpile on smooth surfaces free Stockpile on smooth surfaces free from debris and organic materialfrom debris and organic material

�� RAP stockpiles must be RAP stockpiles must be homogeneoushomogeneous

Section 39 on RAP HMASection 39 on RAP HMA

�� HMA with RAP must comply with HMA with RAP must comply with provisions for HMA, with exception of provisions for HMA, with exception of no aggregate quality requirements no aggregate quality requirements for RAP aggregatefor RAP aggregate

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�� You may substitute virgin HMA You may substitute virgin HMA aggregate with RAP up to 15%aggregate with RAP up to 15%

�� RAP may not be used in OGFC or RAP may not be used in OGFC or RHMARHMA--GG

Section 39 on RAP HMASection 39 on RAP HMA

�� JMF must include the percent of RAP JMF must include the percent of RAP usedused

�� If you change the assigned RAP If you change the assigned RAP percentage by more than 5% within percentage by more than 5% within

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percentage by more than 5% within percentage by more than 5% within the 15% limit, you must submit a the 15% limit, you must submit a new JMFnew JMF

�� Use Lab Procedure LPUse Lab Procedure LP--9 to develop 9 to develop mix designmix design

Section 39 on RAP HMASection 39 on RAP HMA

�� For drum plants, determine virgin For drum plants, determine virgin aggregate moisture content and RAP aggregate moisture content and RAP moisture content at least twice a day moisture content at least twice a day during production and adjust the during production and adjust the plant controller. plant controller.

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plant controller. plant controller.

�� For batch plants, determine RAP For batch plants, determine RAP moisture content at least twice a day moisture content at least twice a day during production and adjust the during production and adjust the plant controller.plant controller.

Section 39 on RAP HMASection 39 on RAP HMA

�� Perform RAP quality control testing Perform RAP quality control testing each day of productioneach day of production

�� Sample RAP once daily and Sample RAP once daily and determine the RAP aggregate determine the RAP aggregate

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determine the RAP aggregate determine the RAP aggregate gradation under Laboratory gradation under Laboratory Procedure LPProcedure LP--9 9

�� Submit the results to the Engineer in Submit the results to the Engineer in writing with the combined aggregate writing with the combined aggregate gradation.gradation.

Caltrans Requirements for Caltrans Requirements for

Production of HMA w/RAPProduction of HMA w/RAP

�� Same requirements as HMASame requirements as HMA

�� Maximum aggregate temperature Maximum aggregate temperature shall not apply (batch plants)shall not apply (batch plants)

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shall not apply (batch plants)shall not apply (batch plants)

�� Maximum Mix Temperature does Maximum Mix Temperature does apply (325apply (325°°F)F)

Lab Procedure 9Lab Procedure 9

“Hot Mix Asphalt (HMA) using up to“Hot Mix Asphalt (HMA) using up to

15% Reclaimed Asphalt Pavement 15% Reclaimed Asphalt Pavement

(RAP)”(RAP)”

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http://www.caltrans.ca.gov/hq/esc/Translab/

ofpm/fpmlab.htm

How Much RAP Can be Realistically be Used?

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City of Los AngelesCity of Los Angeles

�� In March 1995, the City of Los In March 1995, the City of Los Angeles passed a motion requiring Angeles passed a motion requiring that that allall asphalt surfacing purchased asphalt surfacing purchased by city departments shall include a by city departments shall include a by city departments shall include a by city departments shall include a minimum of 15 percent RAP. minimum of 15 percent RAP. Today, they routinely use 20Today, they routinely use 20--25% 25% RAP for all street applications.RAP for all street applications.

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The The GreenbookGreenbook

�� Any HMA mix with up to 15% RAP is Any HMA mix with up to 15% RAP is considered conventional HMA, and considered conventional HMA, and must meet the requirements of must meet the requirements of Section 206Section 206--6.6.Section 206Section 206--6.6.

�� HMA using greater than 15% is HMA using greater than 15% is termed RAC (termed RAC (recylcedrecylced asphalt asphalt concrete) and subject to detailed concrete) and subject to detailed recovered binder testing and recovered binder testing and evaluation under Section 206evaluation under Section 206--7.7.

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Procedures for selecting the quality of asphalt cement or Procedures for selecting the quality of asphalt cement or

recycling agent are outlined in ASTM D4887.recycling agent are outlined in ASTM D4887. This This

specification includes a viscosity blending chart, which specification includes a viscosity blending chart, which

enables the designer to determine the percentage of enables the designer to determine the percentage of

recycling or rejuvenating agent (or soft asphalt cement) to recycling or rejuvenating agent (or soft asphalt cement) to

Binder Blending for High % RAPBinder Blending for High % RAP

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recycling or rejuvenating agent (or soft asphalt cement) to recycling or rejuvenating agent (or soft asphalt cement) to

add to the total binder in order to achieve a desired value of add to the total binder in order to achieve a desired value of

absolute viscosity for the recycled asphalt binder. absolute viscosity for the recycled asphalt binder.

The Asphalt Institute’s manual on asphalt hot mix recycling The Asphalt Institute’s manual on asphalt hot mix recycling

also provides trial mix design examples that indicate how to also provides trial mix design examples that indicate how to

use a viscosity blending chart to design a recycled hot mix.use a viscosity blending chart to design a recycled hot mix.

Location % RAP Dates of Construction

North Carolina 40 % September 2007

South Carolina 30 and 50 % October 2007

Wisconsin 25 % November 2007

What is Happening Elsewhere?What is Happening Elsewhere?

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Wisconsin 25 % November 2007

Florida 45 % December 2007

Kansas 30 to 40 % May 2008

Delaware 35 % Summer 2008

Minnesota (MnROAD)

30 % 2008

Illinois 10 to 50 % allowed 2008

In Summary…In Summary…

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RAP Makes SenseRAP Makes Sense

�� Over 30 years of successOver 30 years of success

�� Increases efficient use of State’s Increases efficient use of State’s material resourcesmaterial resources

Technology available to produce, Technology available to produce,

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�� Technology available to produce, Technology available to produce, test, and use RAP efficientlytest, and use RAP efficiently

�� Selected projects How about LEED Selected projects How about LEED creditscredits

THANK YOU

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