The Impact of Fine Materials Selection in Superpave Design and Production William Tell Inn Holiday I

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• Adding Value by Increasing the Use of Recycle
  (Part 2)
• Best Practices in RAP QC and Stockpile
  Management
• 36th Annual Rocky Mountain Asphalt
• Conference and Equipment Show
• February 19, 2009
• Denver, Colorado

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• By Tom Blair
• Director of Product Engineering
• Asphalt Group
• Schmidt Construction/
• Edw. C. Levy Co.
• 51445 West 12 Mile Rd.
• Wixom, MI 48393
• [phone]

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• About the Edw. C. Levy Co.

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LEVY IS ONE OF THE LARGEST RECYCLERS IN THE
UNITED STATES, AUSTRALIA, AND THAILAND

• WE HAVE BEEN RECYCLING SINCE 1918.
• WE PROCESS MILLIONS OF TONS OF SLAG IN THE U.S.
  PER YEAR THAT IS SOLD AS CONSTRUCTION MATERIALS.
  WE ALSO RECOVER MORE THAN A MILLION TONS OF
  METALLICS PER YEAR THAT ARE RECYCLED BACK INTO
  THE STEEL MAKING PROCESS.
• WE PROCESS AND UTILIZE NEARLY A HALF A MILLION
  TONS OF RECYCLED ASPHALT PAVEMENT (RAP) PER YEAR
  IN OUR ASPHALT MIXES AND HAVE BEEN USING RAP
  SINCE 1975.

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Edw. C. Levy Co. U.S.A.
Operations in 11 States
Asphalt Production Paving Sand Gravel
Operations Quarry Operations Steel Mill
Services Trucking Aggregate Docks Sand, Gravel,
Limestone, S.F. Slag, B.F. Slag Ready Mix Concrete
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Asphalt Production Paving
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Colorado

• Asphalt Production Paving
• Quarry Operations
• Sand Gravel Operations
• Trucking

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DELTA YARD
COLORADO SPRINGS
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• RAP QUALITY CONTROL AND STOCKPILE MANAGEMENT

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• A BRIEF HISTORY OF USING RAP
• 1970s EXPERIMENTAL JOBS FROM 70 UP TO 100
  RAP ANY WAY WE COULD. NO MIX DESIGNS DUMP AND
  RUN. LOTS OF FAILURES
• 1980s CUT HOLES IN PLANTS AND HAD
  ENVIRONMENTAL ISSUES. LOTS OF STATES USED UP TO
  50 RAP. LITTLE OR NO QUALITY CONTROL TESTING. NO
  VOLUMETRIC AND VERY LITTLE ACCEPTANCE TESTING.
  MANY MORE FAILURES. THEN RAP COLLARS INVENTED TO
  PROVIDE A BETTER WAY TO INTRODUCE RAP INTO THE
  PLANT
• 1990s BETTER PLANT DESIGNS FOR INTRODUCING RAP
  INTO THE PLANT. THEN COUNTERFLOW PLANTS DESIGNED
  TO USE HIGH PERCENTAGES OF RAP. VOLUMETRIC
  TESTING INTRODUCED. LOTS OF QUALITY CONTROL
  TESTING FOR VOIDS ACCEPTANCE JOBS. MORE QUALITY
  ASSURANCE TESTING. GOOD RAP MIX PERFORMANCE

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• A BRIEF HISTORY OF USING RAP (cont.)
• LATE 1990s TO THE PRESENT EVEN BETTER ASPHALT
  PLANTS DESIGNED TO RUN HIGHER RAP PERCENTAGES YET
  BE EVEN MORE ENVIRONMENTALLY FRIENDLY. MORE
  EMPHASIS ON QUALITY CONTROL. TIGHTER ACCEPTANCE
  SPECIFICATIONS LIKE PWL. SUPERPAVE INTRODUCED.
  LOTS OF NEW RESEARCH ON MIXTURE PERFORMANCE AND
  RAP USE. EXCELLENT RAP MIX PERFORMANCE
• REMEMBER WHEN WE FIRST STARTED RECYCLING PAPER
  AND PLASTIC? THEY USED TOO HIGH OF A RECYCLED
  MATERIAL CONTENT AND THE PERFORMANCE WAS POOR.
  NOW THEY USE LESS RECYCLED MATERIAL CONTENT BUT
  PUT IT IN ALMOST EVERYTHING AND NO ONE KNOWS THE
  DIFFERENCE. SAME THING WITH AN ALUMINUM CAN OR
  YOUR NEW CAR. RAP ASPHALT MIXES CAN PERFORM
  BETTER THAN ALL NEW MATERIAL IF DONE CORRECTLY

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THREE MAIN RULES FOR SUCCESSFUL RECYCLING OF
ASPHALT PAVEMENTS
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• 1. THE QUALITY OF THE PRODUCT
• MADE WITH RECYCLED MATERIALS
• MUST BE EQUAL TO OR BETTER
• THAN THE QUALITY OF THE
• ORIGINAL PRODUCT.
• AS GOOD OR BETTER
• DONT USE TOO HIGH OF A RECYCLED MATERIAL
  CONTENT.

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• 2. THE RECYCLED PRODUCT
• PRODUCED MUST BE COST
• EFFECTIVE.
• SOME DAY IT MAY BE ABLE TO COST MORE WHEN WE GET
  CREDIT FOR USING RECYCLED MATERIALS.
• THE GREAT THING ABOUT USING RECYCLED ASPHALT
  PAVEMENT (RAP) IS THAT IT LOWERS THE COST OF THE
  FINISHED PRODUCT AND CAN PROVIDE AS GOOD OR
  BETTER FINISHED PRODUCT THAN USING ALL NEW
  MATERIALS IF DESIGNED PROPERLY.

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• 3. WE MAY NEED TO CHANGE SOME
• OF THE OTHER RAW MATERIALS
• WE USE WITH THE RECYCLED
• MATERIAL AND SOME OF OUR
• PROCESSES TO MEET THE FIRST
• TWO RULES.
• DONT JUST SUBSTITUTE IN A RECYCLED MATERIAL
  WITHOUT DESIGNING FOR IT
• MOST OF THE TIME WHEN USING RAP WE NEED TO USE
  CLEANER AGGREGATES

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SO WHERE DO WE START?
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• RAW MATERIAL PILE MUST BE CLEAN
• DO NOT ALLOW ANYTHING OTHER THAN BROKEN ASPHALT,
  RETURNED ASPHALT, CLEAN-OUT ASPHALT, OR MILLINGS
  IN THE RAP RAW MATERIAL PILE. WE ONLY HAVE ONE
  PILE ALL GOOD.
• CHECK TRUCKS DUMPING MATERIAL IN YOUR RAW
  MATERIAL PILE FOR CONTAMINATION AND REJECT THEM.

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• KEEP THE CRAP OUT
• MUST BE CONSTANTLY MONITORED
• DONT WANT ANY TRASH, CONCRETE, BRICKS, CLAY,
  WOOD OR TOPSOIL IN THE RAP PILE
• SEND THE JUNK TO THE LANDFILL

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• KEEP THE RAW MATERIAL PILE BLENDED
• SPREAD OUT PLANT CLEAN OUT MATERIAL, WASTED SILO
  MATERIAL, AND RETURNED MATERIAL SO THAT IT
  DOESNT HARDEN INTO BIG CHUCKS. THIS MAKES IT
  HARD TO CRUSH AND CAN CAUSE POCKETS OF HIGH
  ASPHALT CONTENT FINISHED PRODUCT
• BUILD THE RAW MATERIAL PILE IN LAYERS AND SPREAD
  OUT MILLINGS SO THAT THE PILE WILL BE UNIFORM IN
  MATERIAL TYPE WHEN CRUSHED

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NOT TOO CONSISTENT
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NICE RAW MATERIAL PILE
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NOW WHAT DO WE DO WITH IT? CRUSHING, SCREENING,
FRACTIONATING, RAW MILLINGS
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• SHOULD WE CRUSH OR SCREEN THE RAP?
• IS CRUSHING REALLY NECESSARY?
• WHAT IS THE COST DIFFERENCE?
• IF WE SCREEN IT, WHAT SIZE?

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• CRUSHING OR SCREENING THE RAP SHOULD
  DEPEND ON
• THE SIZE OF THE MATERIAL IN YOUR RAW MATERIAL
  PILE
• CRUSHING BREAKS DOWN WEATHERED AGGREGATES AND
  ALLOWS DEBRIS TO BE REMOVED
• BIGGER IS CHEAPER, SMALLER IS MORE EXPENSIVE AND
  CREATES MORE FINES BUT BLENDS BETTER AND
  SEGREGATES LESS
• SCREENING SIZE DEPENDS ON THE TOP SIZE OF THE MIX
  IT IS GOING INTO. HOWEVER, SMALLER SIZES TRANSFER
  HEAT BETTER.

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• SHOULD WE FRACTIONATE IT?
• ADVANTAGES LESS MOISTURE, LESS STOCKPILE
  MANAGEMENT, LESS SEGREGATION
• DISADVANTAGES FINES TURN HARD UNLESS JUST IN
  TIME CRUSHING, WHAT TO DO WITH EXCESS FINES, NO
  STOCKPILE TO MINIMIZE VARIATIONS OR KEEP THE CRAP
  OUT, EXTRA FEEDER BINS, YARD SPACE, COST
  DIFFERENCE

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• SHOULD WE USE RAW MILLINGS?
• ADVANTAGES CHEAPER
• DISADVANTAGES POOR HEAT TRANSFER, MORE YARD
  SPACE, NO STOCKPILE TO MINIMIZE VARIATIONS AND
  SCREEN JUNK OUT, SOMETIMES DIFFICULT TO GET A MIX
  DESIGN IF MILLINGS ARE COMING FROM THE SAME JOB

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• CRUSHING
• BLEND THE RAW MATERIAL PILE WHILE FEEDING THE
  CRUSHER. MOVE POCKETS OF MILLINGS OR CLEAN-OUT
  MATERIAL OUT OF THE WAY IF NECESSARY TO HELP KEEP
  CONSISTENCY OF THE FINISHED PRODUCT.
• WORK A LARGE LOADING FACE OF THE RAW MATERIAL
  PILE TO FEED THE CRUSHER
• MAKE SURE THE RAP CRUSHER IS CLEANING DEBRIS OFF
  HIS SCREEN REGULARLY TO KEEP IT OUT OF THE
  FINISHED PRODUCT PILE.
• BUILD THE FINISHED PRODUCT PILE IN LAYERS. USE A
  DOZER OR A PROGRAMABLE STACKER

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• CRUSHING (cont.)
• DONT BUILD THE RAP FINISHED PRODUCT STOCKPILES
  TOO HIGH.
• MAKE SURE SOMEONE TAKES SAMPLES OF THE FINISHED
  PRODUCT DURING CRUSHING FOR TESTING AT SET
  INTERVALS. ALSO, TAKE SOME RANDOM SAMPLES TO
  COMPARE RESULTS.
• A GOOD RAP CRUSHER IS YOUR MOST VALUABLE RESOURCE
  IF HE BLENDS THE RAW MATERIAL AND FINISHED
  PRODUCT PILES UNIFORMLY AND KEEPS THE BAD
  MATERIAL AND JUNK OUT. THIS MATERIAL LIKE
  TOPSOIL, CLAY, TIRES, CONCRETE, BRICKS, AND WOOD
  MUST BE HAULED TO THE LANDFILL.

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• KEEP IT TESTED
• TEST THE RAP DURING CRUSHING ONCE EVERY 1000 TONS
  OR MORE AS IT IS BEING PRODUCED
• VERIFY PRODUCTION TEST RESULTS LATER WITH LOADING
  FACE SAMPLES DURING USE
• GIVE FEEDBACK TO RAP CRUSHER DURING CRUSHING IF
  CONSISTENCY IS NOT BEING MET
• TEST AND ADJUST THE VOLUMETRIC PROPERTIES OF THE
  MIX OFTEN TO ENSURE QUALITY

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• KEEP IT TESTED (cont.)
• WATCH OUT IF USING THE IGNITION FURNACE FOR AC
  CONTENTS OF THE RAP. IT IS BEST TO VERIFY THE
  RESULTS ONCE IN A WHILE WITH SPLIT SAMPLE TESTING
  USING A SOLVENT EXTRACTION WITH A GOOD SOLVENT.
• TO BE SUCCESSFUL, YOU PROBABLY WILL NEED
  INCREASED TESTING CAPABILITY FOR RUNNING RAP
  MIXES BECAUSE THEY CAN TAKE A LITTLE EXTRA WORK.

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• RAP MIX DESIGN HINTS
• START WITH THE RAP AND DESIGN AROUND IT. USE
  CLEANER AGGREGATES IF NECESSARY TO MEET ALL THE
  SAME CRITERIA AS FOR VIRGIN MIXES.
• MAKE SURE YOU KNOW ALL THE PROPERTIES OF THE RAP
  AC CONTENT/STIFFNESS, GRADATION, SPECIFIC GRAVITY
  AND ABSORPTION, DELETERIOUS, PARTICLE SHAPE, AND
  ANGULARITY.
• WATCH WHAT GRADE OF VIRGIN BINDER YOU SELECT.
  BUMPING THE TOP AND BOTTOM IS OFTEN TIMES TOO
  SOFT AND CAN RESULT IN SOFT MIXES. NEW RESEARCH
  SHOWS CHANGING GRADES OF VIRGIN ASPHALT IN RAP
  MIXES MAY NOT BE NECESSARY.

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• FEEDING THE PLANT
• IF POSSIBLE, AVOID DOUBLE HANDLING THE FINISHED
  PRODUCT TO PREVENT SEGREGATION
• USE AS BIG OF A LOADING FACE AS POSSIBLE ON THE
  FINISHED PRODUCT PILE TO FEED THE RAP BIN
• LOAD OUT PERPENDICULAR TO THE DIRECTION THE
  STOCKPILE WAS BUILT IN
• SMALLER SIZES OF SCALPER SCREENS ALLOW BETTER
  HEAT TRANSFER, DRYING, AND MIXING OF THE RAP WITH
  THE AGGREGATE AND AC.

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• FEEDING THE PLANT (cont.)
• CALIBRATE THE RAP FEEDER OFTEN.
• WATCH THE PERFORMANCE OF THE RAP FEEDER AND
  PREVENT BRIDGING OR FLOW PROBLEMS WITH THE
  FEEDER. LINE THE BINS.
• MAKE SURE YOU HAVE THE CORRECT ASPHALT CEMENT
  CONTENT OF THE RAP ENTERED INTO YOUR PLANT
  CONTROLS

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• KEEP IT HOT
• MAKE THE AGGREGATE HOT ENOUGH IN THE PLANT FOR
  GOOD DRYING AND HEAT TRANSFER TO OCCUR
• DONT RUN THE PLANT TOO FAST
• MONITOR MOISTURE CONTENTS OF THE RAP OFTEN AND
  UPDATE THE PLANT CONTROLS
• IF USING STIFFER ASPHALT CEMENTS, MAKE THE MIX
  HOTTER
• WHEN IT IS WET OR COLD USE LESS RAP

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• TO KEEP IT PERFORMING
• BE CAREFUL IF KEEPING THE MIX OVERNIGHT. WATCH
  SILO STORAGE TIME AND FOR DELAYS
• ADD A LITTLE EXTRA ASPHALT CEMENT TO ACCOUNT FOR
  ABSORPTION IF THE MIX WILL BE STORED FOR AN
  EXTENDED PERIOD
• KNOW THE EFFECTS ON VOLUMETRIC PROPERTIES AND
  ADJUST ACCORDINGLY. DONT BE AFRAID TO ADJUST THE
  MIX PROPERTIES DURING PRODUCTION.
• CONTROL THE VARIABILITY IN ALL PHASES OF THE
  PROCESS

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• HOW MUCH SHOULD WE USE?
• CAN WE CONTROL THE VOLUMETRIC PROPERTIES?
• CAN YOU GET THE VMA HIGH ENOUGH ABOVE THE MINIMUM
  IN THE DESIGN STAGE TO ACCOUNT FOR PLANT
  DEGRADATION AND ABSORPTION DURING PRODUCTION?
• WHAT ARE THE SPECIFICATION LIMITS?
• DO WE HAVE ENOUGH SUPPLY OF RAP?
• DO WE HAVE CLEAN AGGREGATES TO BLEND WITH THE RAP
  TO MEET VMA AND VOIDS?

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• HOW MUCH SHOULD WE USE? (cont.)
• WHAT ARE OUR PLANT LIMITATIONS?
• WHAT ARE OUR AIR PERMIT LIMITATIONS?
• IS THERE ANY OPERATIONAL RESISTANCE?
• IS THERE ANY CUSTOMER RESISTANCE?
• WHAT DO YOU FEEL COMFORTABLE WITH?

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LETS KEEP RAP THE NATIONS TOP RECYCLED MATERIAL
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THANK YOU!
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• QUESTIONS?