Upload
others
View
18
Download
0
Embed Size (px)
Citation preview
RappinRappin’ on RAP’ on RAP
11
Presented by Presented by
Thomas CarterThomas Carter
Twining Laboratories, SacramentoTwining Laboratories, Sacramento
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.
33
The Obvious Path for The Obvious Path for
Redemption is to RecycleRedemption is to Recycle
our Waste!our Waste!
44
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
55
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
66
�� 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
77
�� 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
88
�� 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)
99
•• 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
1010
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
1111
•• 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
1212
�� 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
1313
develop specificationdevelop specification
�� 2003 2003 –– RAP specification on server (15% Max.@ RAP specification on server (15% Max.@
Contractor’s option)Contractor’s option)
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
1818
•• 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
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
2424
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
2525
�� 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
2626
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
2727
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
2828
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
2929
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
Mixture Design ConsiderationsMixture Design Considerations
RAP considerationsRAP considerations::
•• UniformityUniformity
•• Usable asphalt content Usable asphalt content
•• Aggregate gradationAggregate gradation
3131
•• 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
3232
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
3333
•• 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)
3434
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
3535
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
3636
Using Drum PlantsUsing Drum Plants
HMA Production with HMA Production with
RAPRAP
Using Batch PlantsUsing Batch Plants
4040
Using Batch PlantsUsing Batch Plants
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
4444
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
4545
�� 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..
4646
methodmethod..
•• IntroduceIntroduce thethe binderbinder intointo thethe mixermixerafterafter thethe virginvirgin aggregateaggregate andand RAPRAPhavehave beenbeen combinedcombined..
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
4848
�� 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
4949
�� 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
5050
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.
5151
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
5252
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)
5353
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)”
5454
http://www.caltrans.ca.gov/hq/esc/Translab/
ofpm/fpmlab.htm
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.
5656
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.
5757
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
5858
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?
5959
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
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,
6161
�� 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