new asphalt technologyasphaltmagazine.com/wp-content/uploads/archives/... · new asphalt technology...

The Magazine of the Asphalt Institute

Summer 2005Vol. 20, No. 2

The Magazine of the Asphalt Institute

Summer 2005Vol. 20, No. 2

New Asphalt TechnologyHMA Testing and Quality for the Future

Finding the Open Roadwith Roadtrip Nation

Summer 2005 Asphalt 1

* Akzo Nobel Surface Chemistry LLC, Willowbrook, ILAll States Asphalt, Inc., Sunderland, MAAlon USA, Dallas, TX* Andrie Inc., Muskegon, MI* ARR-MAZ Custom Chemicals, Inc., Winter Haven, FLAsphalt Materials, Inc., Indianapolis, INAsphalt Processors Incorporated, BARBADOSAsphalt Refining & Technology Company, Douglasvillle, GAAssociated Asphalt, Inc., Roanoke, VA* Astaris LLC, Saint Louis, MOBitumar Inc., Montreal, QC, CANADA* Bouchard Coastwise Management Corp., Melville, NYBP Global Bitumen – U.S., Whiting, INCalumet Lubricants, Indianapolis, INCanadian Asphalt Industries Inc., Markham, ON, CANADA* Canadian National Railway, Montreal, QC, CANADAChevron Corporation,, San Ramon, CAChevronTexaco – Asia Pacific Africa and Pakistan Region (Caltex),

Sydney, AUSTRALIACITGO Asphalt Refining Company, Plymouth Meeting, PACoastal Energy Corp., Willow Springs, MOColas, S.A., Paris, FRANCEConocoPhillips Company, Houston, TX* DeMenno/Kerdoon, Compton, CA* Dexco Polymers LP, A Dow/ExxonMobil Partnership, Houston, TX* DuPont, Wilmington, DE

* Dynasol L.L.C., Houston, TXEMCO Building Products Corp., LaSalle, QC, CANADAErgon Asphalt & Emulsions, Inc., Jackson, MSExxonMobil Lubricants & Specialties Company, Fairfax, VAExxonMobil Lubricants & Specialties Company, International,

Fairfax, VAGAF Materials Corporation, Wayne, NJThe Hudson Companies, Providence, RIHunt Refining Company, Tuscaloosa, ALHusky Oil Marketing Company, Calgary, AB, CANADAIKO, Chicago, ILImperial Oil, Toronto, ON, CANADA* Innophos, Inc., Cranbury, NJIrving Oil, Saint John, NB, CANADAIsfalt A.S., Uskudar, TURKEYJebro Inc., Sioux City, IAKokosing Materials, Inc., Fredericktown, OH* Kolbeck Petroleum, Inc., Wichita, KS* KRATON Polymers, Houston, TXLafarge Asphalt Engineering, A Division of Lafarge Construction

and Materials, Inc., Mississauga, ON, CANADAMarathon Ashland Petroleum LLC, Findlay, OHE. A. Mariani Asphalt Co., Inc., Tampa, FLMathy Construction Company, Onalaska, WIMcAsphalt Industries Ltd., Scarborough, ON, CANADAMcCall Oil and Chemical Corp., Portland, OR*MeadWestvaco Asphalt Innovations, Charleston, SCMurphy Oil USA, Inc., Superior, WINynäs Bitumen, Zaventem, BELGIUMOldcastle Materials Group, Washington, DC

Paramount Petroleum Corporation, Paramount, CA* Penn Maritime, Inc., Stamford, CTPetro-Canada Inc. Montreal, QC, CANADAPetroleo Brasileiro, S.A. – Petrobras, Rio de Janeiro, BRAZIL* Pioneer Oil LLC, Billings, MT* Ponderosa Petroleum Company, Parker, CORECOPE, Cartago, COSTA RICAREPSOL YPF, Madrid, SPAIN* Safety-Kleen Systems, Inc., Oil Recovery Division, Batavia, ILSan Joaquin Refining Co., Inc., Bakersfield, CASargeant Marine, Inc., Boca Raton, FLSemProducts, L.P., Tulsa, OKSeneca Petroleum Co., Inc., Crestwood, ILShell Canada Products, Montreal, QC, CANADAShell International Petroleum Company Limited, London, UNITED

KINGDOMShell Oil Products US, Houston, TXShelly & Sands, Inc., Zanesville, OHSK Corporation, Seoul, KOREA* Sprague Energy Corp., Portsmouth, NHSuit-Kote Corporation, Cortland, NY* TAMKO Roofing Products, Inc., Joplin, MOTerry Industries, Inc., Hamilton, OHTotal Petrochemicals USA, Inc., Houston, TXTrumbull Asphalt, A Division of Owens Corning, Toledo, OH* Ultrapave Corporation, Resaca, GAUnited Refining Company, Warren, PAU.S. Oil & Refining Company, Tacoma, WAValero Energy Corporation, San Antonio, TXVance Brothers Inc., Kansas City, MO

AI Membersas of 6/1/2005 (* — Affiliate Member )

It’s summertime! Most regions are now in full construc-tion swing following a busy training and tradeshowseason. If you’ve been paying attention, you’ll know

that a lot is changing. That is why we’re devoting this edi-tion of Asphalt to new asphalt technology.

If you serve the highway construction industry in any way,like me, you may have been asked this winter, “What’snew?” People wanted to know how the soaring prices ofcrude oil would affect their liquid asphalt supply this sum-mer and their prices. They wanted to know about AI’srecently completed publication, ER-215 Quantification ofthe Effects of PMA for Reducing Pavement Distress, on theeffectiveness of polymer modified asphalts—available nowat www.asphaltinstitute.org in our online store.Practitioners were eager to learn about life cycle costs andhow this information is used in the pavement-type selec-tion process. The list goes on.

This issue highlights the answers to some of those questionsby first bringing you an article co-authored by FHWA’s JohnBukowski and John D’Angelo. The article, HMA Testingand Quality for the Future focuses on using automation andnew technology to speed results and improve quality controland acceptance testing. Don’t miss it.

New technology surfaces in the form of thickness designs

too. The Asphalt Institute spent the last couple of yearsupdating its venerable thickness design software, sold for

years in a DOS version (I’m bet-ting there are some of you outthere that still use it.) and now itis NEW and Updated andreleased as SW-1 AsphaltPavement Thickness DesignSoftware. If you are interested inthickness design, you’ll want totake a look at AI’s one-day semi-nars being offered later this yearand dedicated exclusively to that topic. Keep an eye onour website for the dates and locations.

Technology advances mean equipment changes, too. Wetake a look at the state of the practice for reclaimedasphalt pavement (RAP) handling equipment.

I overhead someone ask the other day “California is mov-ing to Superpave?” Slowly but steadily, “Yes.” We show-case one such project along the Alameda Corridor—thefirst large scale use of Superpave mixes in that state, on aport-serving connector with 60 percent truck traffic. Thissummer CALTRANS is also is the process of convertingto PG graded binders, a collaborative process that hasinvolved many segments of the industry for a long time.

Training gets underway shortly and the Asphalt Institutewill be part of that, offering on-site classes to help get thetechnicians comfortable with the required testing regi-mens. New Asphalt Technology at work!

AsphaltPeter T. Grass, President

President’s Message

President’s Message

Now Available In Small, Medium, & LargeThe oscillatory system from Hamm creates horizontal sheer forces instead of vertically impacting.

No overcompacting • No damage to cold bottom or adjacent layers • Improved compaction of longitudinal

and transverse joints • Ultimate smoothness • Compaction in a wider temperature range • Available in the

59” wide, 7 ton, HD O70V, the 66” wide, 10 ton, HD O90V and the 78” wide, 12 ton, HD O120V

Making History Since 1878

Wirtgen AmericaHAMM Compaction Division • 6030 Dana Way • Antioch, TN 37013(615) 501-0600 • Fax (615) 501-0691

Asphalt 3Summer 2005

For the latest information from theAsphalt Institute, visit the Institute’swebsite at www.asphaltinstitute.org

Asphalt Institute2696 Research Park Dr.Lexington, KY 40511-8480(859) 288-4960

Agreement #40112592Canadian Return Address:Station AP.O. Box 54Windsor ON N9A [email protected]

Asphalt Magazine is printed in the USA andpublished by the Asphalt Institute, an internationalnonprofit organization sponsored by members of thepetroleum asphalt industry to serve both users andproducers of asphalt materials, through programs ofengineering service, research, and education.

Peter T. Grass, P.E., PresidentBrian Clark, PublisherDwight Walker, P.E., EditorJohn Davis, Contributing EditorLaura Doolittle, Designer

Copyright © 2005, Asphalt InstituteAll rights reserved.

FOR ADVERTISING INFORMATION CONTACT:John Davis . . . . . . . . . . . . 859-223-0993

[email protected]

Ed Misajet . . . . . . . . . . . . [email protected]

AsphaltSummer 2005 • Vol. 20, No. 2

1 President’s Message

3 Features

4 Asphalt News

8 Highlights of AAPT’s 80th Annual Meeting

10 Alameda Project Exceeds Expectations

14 Product Showcase: Asphalt Testing Equipment

16 New Asphalt Institute Thickness Design Software

18 HMA Testing and Quality for the Future

24 Quiet Pavement: Coming toa Highway Near You

26 Recycling Benefits for HMA Producers

28 Understanding the True Economicsof Using Polymer Modified Asphalt

34 AI Lab Corner

36 Finding the Open Road:Take a Roadtrip for Life

AsphaltFeaturesFeatures

Asphal

tNe

ws

New

s

4 Asphalt

AI and PRI Asphalt Technologies have launched anew state binder specification database. Each individ-ual specifications document summarizes the respectiveasphalt binder specifications for each of the 50 statehighway agencies. A standard format is used to listspecifications, methods and criteria, PG-plus tests andrequirements, typical grades, exclusions and theagency’s website where specifications can be found.Visit asphaltinstitute.org for details.

AI has developed a Proficiency Sample Program(PSP) for Roofing Asphalts, similar to the successfulprogram administered by the AASHTO MaterialsReference Laboratory (AMRL) for paving-gradeasphalt binders. The PSP will help users understandthe between-lab variability of some common tests forroofing asphalt binders described in ASTM D312,Standard Specification for Asphalt Used in Roofing.Visit asphaltinstitute.org for details.

The Asphalt Pavement Alliance(APA), the Safe, Quiet, Durable

Highway Institute and the NorthCentral Superpave Center will hold a confer-

ence on road noise at Purdue University November 1-

3, 2005. The conference will feature presentations onthe sources of road noise, demonstrations of noise levels

and presentations of how asphalt pavement can reduceroad noise. Visit asphaltalliance.com for details.

The Airport Pavement Workshop in Philadelphia,Pennsylvania, October 25-27, will provide up-to-dateinformation for those designing, constructing andmanaging asphalt airport pavements. The Workshopincludes a review of current specifications and advisorycirculars, detailed descriptions of materials, and pave-ment design, construction, and preservation practicesfor airports. For more information, see page 21.

The APA is sponsoring aPerpetualPavement openhouse/work-shop in Topekaand in BrownCounty,Kansas, onJuly 7-8,2005. Theworkshopwill featuretechnical

presentations and asite visit. There is no charge for attending the

event, but pre-registration is required. Email or call the

Kansas Asphalt Pavement Association [email protected] or 785-271-0132.

Spring 2005

Ed Schroeder of Asphalt Refining & TechnologyCompany, LLC receives his AImembership plaque from AIMembership Chairman LenNawrocki (left) of Valero and AI President Pete Grass (right).

Michel Jean of Canadian National Railway (center) receives his AI membership plaque from AI 2005 Chairman Bill Haverland of ConocoPhillips (left)and Len Nawrocki(right).

AI welcomes new members Asphalt Refining and Technology Company (ARTC), LLC of Douglasville,

Georgia, and Canadian National Railway of Montreal, Quebec.

Summer 2005

AsphaltNew

sNew

s

Asphalt 5

APA’s 2004 PerpetualPavement Awards werepresented in a specialceremony at the NationalCenter for Asphalt Technology(NCAT) at Auburn Universityin May 2005. Jack Lettiere,Jr., 2005 President ofAASHTO, made thepresentations. The winnerswere the Roads and AirportsDepartment of Santa ClaraCounty, California, and theDepartments ofTransportation of Colorado,Illinois, Kentucky, Minnesota,Ohio, South Carolina,Tennessee and Texas. ThePerpetual Pavement award isgiven to owners of asphaltpavements that are at least 35years old and have never had astructural failure. The roadmust demonstrate the qualitiesfrom long-life asphaltpavements: excellence indesign, quality inconstruction, and value to thetraveling public.

Pictured are the representatives of the winning agencies. Back row Eric Harm,Illinois DOT; Gerald Nicely, Tennessee DOT; Larry O’Donnell and LukeStango, co-chairmen of the APA; Jack Lettiere, AASHTO; Dan Collen, Countyof Santa Clara, California; and Tom Peterson, Colorado Asphalt PavementAssociation, who accepted on behalf of the Colorado DOT. Front row: SamBeverage, Kentucky Transportation Cabinet; David Kopp, Texas DOT; AndrewJohnson, South Carolina DOT; Aaron Behrman, Ohio DOT and PatrickHughes, Minnesota DOT.

To order, visit the Asphalt Institute website, www.asphaltinstitute.orgor call (859) 288-4961.

www.asphaltinstitute.org

HAT:AP-13

$15.00

Get the latest Asphalt Institute apparel...

AsphaltApparelApparel(back)

T-SHIRT:(XXL) AP142

(XL) AP14X

(L) AP14L

$12.00

Catch the latest AI DesignSoftware and get a FREElure with your order.

Buy either

SW-1 or SW-2 byDecember 31, 2005, and geta limited-edition Asphalt

InstituteRapala®

fishinglure FREE.

Call 859-288-4961 to order.

Asphal

tNe

ws

New

s

Summer 20056 Asphalt

More than 124,000 industry professionals fromaround the world attended CONEXPO-CON/AGG2005 during its five-day run March 15-19 at theLas Vegas Convention Center. The show featured thelatest equipment, product innovations and technologi-

cal advances of the construction, construction materi-als and power transmission industries. The showspanned more than 45 acres of exhibit space for the

2,400 exhibitors. International attendance topped21,000 with people attending from more than 130countries. The Asphalt Institute exhibited at the showand met with a variety of industry associates at theweeklong event.

Ever wonder why no one ever thought to put the twotogether? The Sakai Vibratory Pneumatic Tire Roller.All the great benefits of a vibratory and a pneumatic –rolled into one reliable machine. Superb on Superpaveand overlays of profiled surfaces. Ask about it!

www.sakaiamerica.com ¥ 1-800-323-0535


T he Association of Asphalt PavingTechnologists (AAPT) was estab-lished January 17, 1924, in

Chicago, Illinois. In the beginning, therewere only 19 charter members. However,

AAPT has since grown to exceed 1,000members from all parts of the world. Theinitial purpose of the Association was forthe advancement of asphalt paving tech-nology. Today, its purpose is defined byfour main objectives:

• To advance asphalt paving technology;

• To encourage communicationamong those charged with technicalresponsibility for the production andlaying of asphalt pavements, withproduction of materials or with con-

struction or construction equipment;

• To serve as a central point for

exchange of ideas related to the tech-nology of asphalt paving; and

• To conduct, encourage and collateresearch in the asphalt paving industry.

• A Government Engineers’ Forum washeld on Sunday, March 6. Discussiontopics included a new FederalHighway Administration initiative for QC/QA, and integration ofSuperpave mix design with newmechanistic-empirical pavementdesign.

• The technical presentations included23 papers. These were grouped intofive categories:1. Workshop Session;2. Binder Characteristics and

Evaluation;3. Mechanistic-Empirical Evaluation

of Models;4. Field Verification of Fatigue and

Permanent Deformation Models;and

5. Performance Modeling.

• A symposium titled Developments inQuiet HMA Pavements was held.

Another highlight of the meeting for the

Asphalt Institute (AI) came during themeeting’s banquet. AAPT conferred awards

of Honorary Membership on former AIDirector of Research (and AI Roll ofHonor Recipient) Vyt Puzinauskas and for-mer AI Member Representative (and AIDistinguished Service Award Recipient)Larry Santucci. Honorary membership is

the highest award conferred by AAPT onan individual. In their acceptance speeches,both Puzinauskas and Santucci noted the

role of the Asphalt Institute in their careers.

Next year’s meeting is in Savannah,Georgia, March 27-29, 2006, at theHyatt Regency Hotel.

Highlights of AAPT’s80th Annual Meeting

Panel discussion during theQuiet Pavements symposium.

By Mike Huner, P.E. • Asphalt Institute Field Engineer

One of the primary means of achievingthese objectives is through the publicationof the AAPT Journal. With its compilation

of reports on state-of-the-art technologiesand practices, the Journal is regarded as

one of the premier sources of literature forthe asphalt paving industry. The annualpublication began in 1928 and Volume 74

will be published this year. Another yearlyAAPT event is the Annual Meeting.Typically held in March, this meetingserves as a forum for technical presenta-tions, symposiums and workshops.

The 80th Annual Meeting of the AAPTwas held March 6-9, 2005, in LongBeach, California. With more than 260registered attendees from 17 countriesaround the world, this year’s meeting rep-

resented the highest attendance in the pastthree years. With a common interest in

research of materials and methods, the

attendees spanned a broad spectrum of theindustry, reaching materials suppliers, con-sultants, contractors, universities, govern-ment agencies and other researchers. Someof the highlights of the meeting were:


FEATURES:R e-use existing stockpiled (waste) asphalt materialsE asily portable, for on-site recycling and repairC ost savingsY ield - up to 10 tons per hourC apable of working 365 days a yearL ess costly alternative to cold mixE nvironmentally friendly!

PROCESS1. Asphalt waste material (broken chunk, millings or RAP)

are loaded mechanically into the hopper.2. Hopper feeds material into drum, where indirect heat and

tumbling action work to breakdown (recycle) the materialinto a viable hot mix.

3. Recycled asphalt hot mix is available within approxi-mately 15 minutes.

4. The recycled hot mix can be discharge directly onto therepair site, or if statically positioned directly into a hotbox or patching truck.

5. Recycled hot mix is continuously available until therepair is complete.

6. Normal techniques are used to place and compact thehot mix asphalt.

**optional self propulsion permits job-site mobility independent of a

truck.

APPLICATIONSPothole Patching Utility cuts

Shoulder work Curbing

Electrical trenching repairs Catch basin repairs

Plumbing cuts Parking lots

Bridge repairs Drive ways

Airport maintenance Railway crossing repair

Small-medium paving jobs Soil remediation

All winter patching jobs Bike/walking path maintenance

Type Length Width Height Weight Diesel Rated Heating Fuel Per Ton(lbs) Engine Output System Consumption

BA4000F 174” 79” 79” 4400 1 cyl., 4.3 kW 4 tph Diesel 135kW Approx. 1 gal/tonBA7000F 212” 78” 80” 5500 1 cyl., 8.6 kW 7 tph Diesel 180kW Approx. 1 gal/tonBA1000F 266” 96” 96” 11000 2 cyl., 22 kW 10 tph Diesel 400 kW Approx. 1 gal/ton

4 TON BAGELA

7 TON BAGELA

10 TON BAGELA

21ST CENTURY EQUIPMENT CO.105 N. Main StreetGarnavillo, Iowa 52049563.964.2544888.964.2544Fax: 563.964.2746E-mail: [email protected]

Pay for BAGELA in60-180 working days.

TECHNICAL DATA

Join the valued familyof 100’s of BAGELA owners

10 Asphalt

Alameda Projectb y E d M i s a j e t

a n d J o h n D a v i s

Alameda Street is part of ahighway system connecting theports of Los Angeles and LongBeach with the IntermodalRailway Yard in downtownLos Angeles.

The Superpave portion of theAlameda project is performingvery well. There is no rutting

or deformation.

Asphalt 11

Highway engineers designed a portion of

Alameda Street using Superpave to with-stand Supertrucks, large container carri-

ers with heavy cargo loads, along withthe relentless Los Angeles sun and hugeESAL loadings. The roadway was

designed to address three potentialasphalt problems—rutting, fatigue crack-ing and low temperature cracking.Caltrans (California Department ofTransportation) and Los Angeles County

design engineers chose Superpave mix forthe pavement within their portion of theproject because they believed it wouldmeet the performance challenge.

Hot Sun and Heavy TrucksCaltrans and L.A. County design engi-neers considered climate and traffic con-

ditions. The hot Los Angeles sun plus the

heavy trucks could cause severe rutting ifthe pavement mix was not right. Caltranswanted a roadway that would be easy toconstruct and easy to maintain. L.A.County required that Superpave meet its

Type A mix specifications, which address-

es traffic loading, subgrade requirementsand highly crushed aggregate particles.

The Los Angeles County portion of theproject spanned a 6.3-mile section of

Alameda Street and was divided intothree sections, two of which wereapproved for Superpave mix. “We had tosatisfy both Caltrans’ and L.A. County’smix requirements,” said K. Brian Rickey,

P.E., Los Angeles County MaterialsEngineer and former Resident Engineerfor the Alameda project.

“The Alameda project was the firstmajor use of Superpave in L.A. County,

and maybe in the state,” said Rickey.“Because it was part of the ports access

demonstration projects, we were able to

use Superpave on the project. We didour homework before decidingSuperpave was the right choice to with-stand the extreme temperatures and theheavy traffic.”

The Alameda Corridor is a 26-mile super-cargo

highway connecting the ports of Los Angeles and

Long Beach and the Intermodal Railway Yard in

downtown Los Angeles. It accommodates 50 to

75 percent heavy trucks. When it was completed

five years ago, it handled 26,000 vehicles per day,

but 49,000 are expected by 2010.

Exceeds Expectations


According to Rickey, the county used aCaltrans 3/4-inch mix on one-third ofthe project and Superpave on the othertwo-thirds. “That ultimately provided usa good comparison between a traditionalmix and a Superpave mix.”

Superpave Mix DesignProject design engineers specified 20inches of Superpave mix on four inchesof aggregate for the Superpave section.The four inches of aggregate acted as aplatform for the asphalt. The 20 inchesof Superpave was placed from the aggre-gate base to the top of the roadway.

“We used one Superpave mix all the wayto the top,” said Rickey. “Because thematerial was so coarse, we asked the hotmix producer to put more fines in thesurface course mix, but within theSuperpave gradation specifications.”

Superpave Construction Rickey explained that constructing theSuperpave section did not require specialprocedures. “It was pretty normal. Outhere in California, we don’t have the bigtemperature swings that other states have,so we didn’t have to accommodate thecold weather. We didn’t have a projectthat mandated the use of tarps over thehot mix, so we used windrows and thatmade placing the mix easier.”

Rickey said that the construction portionof the project was easy compared to theadministration, coordination and inspec-tion challenges. “Heavy truck traffic,along with big asphalt tonnage, andcoordinating the requirements of numer-ous agencies was a constant challenge.” L.A. County administered several con-tracts totaling nearly $100 million over asix year period. “Our team worked with

the City of Carson, the City of LosAngeles, Caltrans, the Alameda CorridorTransportation Authority, the UnionPacific Railroad and others. I was the sin-gle point of contact for all of them. Iwasn’t able to be the main guy on theroadway, but I did pull plenty ofevenings myself inspecting the asphalt.”

Compaction On some projects around the UnitedStates compaction of Superpave mixeshas been a significant problem. But onthe Alameda project, compaction of theSuperpave mix was a fairly standard oper-ation. “In general the compaction waspretty consistent with traditional mixes,”said Rickey. “One difference is that weused a rubber-tire roller.”

Rickey said the initial placement of theSuperpave test strips gave the paving

crews an opportunity to understand whatthe mix was doing. “The crews were ableto determine the actual time necessary tolet the mix cool before beginning thebreakdown rolling. Once the pavingcrews understood how to compact thematerial, it took less rolling effort than itwould have for a traditional mix. Doingthe test strips helped us a lot.”

Night Work Only All the paving operations on theAlameda projects were done at night,which posed some challenging logisticalproblems for the construction team.“Placing a 24-inch thick structural road-way in a commercial zone with heavytraffic where you have big trucks comingin and out of driveways plus accommo-dating nighttime traffic from a big refin-ery, took a lot of traffic management,”said Rickey.


“We had to make arrangements for accessfor those businesses to get in and outevery night. We provided temporaryaccess ramps, then, when we were readyto pave, we ripped out the ramps andbegan paving.”

MaintenanceRickey noted that maintenance so far onthe Alameda Street project has been verylimited. The Superpave portion of theroadway is performing without rutting ordeformation of any kind. “I took a drivethrough the project not long ago and I wasamazed that even at the stop bars wherethe heavy trucks stop and then accelerate, Ididn’t see ripples in the striping.

“L. A. County has a five-year slurry pro-gram, but there has been no discussion tomy knowledge of including theSuperpave section in that program. The

only maintenance so far is picking uptrash, watering the trees and such—nopavement maintenance.”

PerformanceThe connector road from the Del AmoGrade Separation to the Superpave sec-tion of the Alameda was paved with atraditional AR4000 mix and that connec-tor road has noticeable rutting in it. Butas the connector enters the Superpaveportion, Rickey says the road is beautiful.“It has absolutely no rutting or deforma-tion.” He is thoroughly impressed withthe performance of the Superpave por-tion of Alameda Street and is happy tosay “Based upon a side-by-side compari-son, it is performing very well.”

“From an overall performance stand-point, I think everybody involved ishappy with it.”

APPLIED TEST SYSTEM’S new Pressure Aging Vessel simplifiesthe process and documents the data for ASTM D6521 proce-dures. Status screens prompt the user for action. The final

screen includes presentpressure, maximum andminimum temperatures,time out-of-target-range,and total time for com-plete 20-hour process.The complete process canbe run directly from thefront panel or from yourPC, with optional ATSremote monitor/controlpackage. For information,call David Howard at(724) 283-1212.

ANTON PAAR’S newSmartPave AsphaltRheometer has auto config-uration and automatedtemperature calibration todocument your entiremeasurement and calibra-tion. It conforms to allAASHTO and ASTMrequirements, including thenew temperature calibra-tion manager. The rapidPeltier heating and coolingsystem can double yourthroughput. For informa-tion, contact Anton PaarUSA Inc. at (800) 722-7556 or visit www.anton-paar.com.


Asphal

tPr

oduc

t Sho

wcas

ePr

oduc

t Sho

wcas

e

DESPATCHINDUSTRIES’high performanceRolling Thin-Filmoven is especiallydesigned for test-ing the effect ofheat and air on amoving film ofasphalt in accor-dance with ASTMD2872 andAASHTO T240. Inside chamber dimensions are 16 inches wide,17.5 inches deep and 13.5 inches high; maximum temperature400°F/204°C, 240V/60hz with digital temperature controls andremovable bottle carousel. For information, call DespatchIndustries at (952) 469-8278 or visit www.despatch.com.

INSTROTEK’SCoreDry pro-duces repeat-able dryweights forconsistenttest results in15 minutes orless. Samplesstay cool andsafe during the drying process, which preserves sample compo-sition so you have dry weights in minutes, without degrading orchanging the sample characteristics. The CoreDry uses highvacuum technology and an electronic desiccation system toextract water from the sample, evaporate it and condense it in acooling trap. For information, call InstroTek at (919) 875-8371 oremail [email protected].

BARNSTEAD INTERNATIONAL’S Pyro-Clean glassware cleaningsystem uses only heat at 800 to 900°F to remove organicmaterials like tars, resins, polymers, char or virtually any organ-ic residue, leavingyour glasswaresparkling clean.Glassware comesclean without usingacids, caustics or anyother chemical or sol-vent cleaners. For information, call BarnsteadInternational at (563) 556-2241 or visitwww.barnstead.com.

Asphalt

Testing

Equipment

AsphaltProduct ShowcaseProduct Showcase

R/H SPECIALTY & MACHINE, INC.’S FD-4A™ force-measuringadapter is engineered for accurate measurement of the force in tensile testing asphalt specimens in a ductility machine. It iscapable of canceling out the specimen weight while registeringthe force exerted on the test material. Built-in electronics communicate tensile loads to a digital readout/controller unit.Calibration apparatus and data acquisition software are included. For information, call (812) 232-0781 or [email protected].

FLIR SYSTEM’SThermaCamE65 InfraredCameraensures consis-tent materialsapplication tem-perature for theasphalt indus-try. The light-weight, easy-to-use E65 is the

most accurate hand-held infrared camera on the market today.The E65 includes LCD screen, storage of up to 200 thermalimages with text notations, seamless PC image downloadingwith QuickView software. For information, call (800) 464-6372or visit www.flirthermography.com.

BROOKFIELD ENGINEERING hasadded new bi-directional communi-cation to its most popular instru-ment, the DV-II+ Viscometer. Thenew DV-II+Pro model offers sim-plicity of operation for single pointviscosity measurement or can beconfigured to run automated testsfor multiple point data collectionwithout the involvement of theoperator or computer. The DV-II+Pro is totally compatible withBrookfield Viscometers and acces-sories currently in use.For information, call (508) 946-6200 or email [email protected].

PAVEMENTTECHNOLOGY, INC’SLaboratory AutomaticGradation Unit (AGU)is a particle-size ana-lyzer that conducts acomplete sieve analy-sis automatically andtransmits the accumu-lated data to a com-puter. The AGU features an Automated Loading System thatallows a user to stage up to seven samples (40-45lbs) for grada-tion analysis or material separation. The AGU has a carouselthat is used to collect graded samples and aggregate for materi-al separation. The carousel can accommodate eight five-gallonbuckets. For information, call (770) 388-0909 or [email protected].

PINE INSTRUMENT COMPANY’S Rotary Asphalt Wheel Testercontinuously rotates the specimen between three Hamburg style

wheels. Each rotation ofthe specimen providesthree load cycles, speed-ing up testing time. Thereis no need to mount multi-ple specimens to performthe test—a single speci-men is all that is required.Wheel velocity is con-stant, unidirectional, andeasily adjusted from thecontrol panel. For infor-mation, call (724) 458-6391 or visit www.pine-inst.com.

This showcase

features some of the

latest innovations

in asphalt sampling

and testing technology.


I n 2001, the Asphalt Institute beganto explore the idea of updating itscomputerized pavement design tools

for highways, heavy wheel loads and air-ports. The DOS-based programs, HWY,HWLOAD, AIRPORT and the structur-al analysis tool DAMA, had long beenrespected among design professionals forease and simplicity of use. But the pro-grams were overdue for conversion to theMicrosoft Windows® operating system toallow more accessibility to the currentgeneration of pavement designers.

Originally, the development team was

charged with simply converting the indi-vidual programs to Windows. Soon it

became apparent that there was an oppor-tunity to repackage the programs into aunified pavement design tool that could

provide users with a much broader rangeof applications. The development teamconverted and integrated the proceduresinto a single, powerful and easy-to-usepavement design tool. SW-1, ThicknessDesign Software, as it is now known, wasunveiled as the Asphalt Institute’s primarythickness design tool in December 2004.

This article outlines some of the techni-cal merits of the SW-1 system, including

its foundation on mechanistic-empiricaldesign principles, its broad range of capa-

bilities and the power of the companion

User’s Guide.

Mechanistic-Empirical Design at its CoreThe Asphalt Institute methods for pave-

ment design are based on mechanistic-empirical (M-E) methods. As shown inthe figure below, M-E design proceduresconsist of two parts: 1) calculating keystresses, strains and deflections in a loadedpavement structure, and 2) relating themto actual pavement performance.

The developers of SW-1 harnessed thepower of the M-E calculation engine tocreate specialized solutions for the mostcommon applications, such as highways,

roads, streets, parking lots, overlays, com-mercial and general aviation airports,ports and heavy industrial yards. Forthose users craving a bit more power,SW-1 offers the capability to performAdvanced Structural Analysis using the

core M-E analysis engine.

Some of the advantages of the M-E-based

design methods are the ability to easilycharacterize highway and street trafficusing the common Equivalent Single AxleLoad (ESAL). Airport and heavy wheelloads are characterized using single wheel

loads or specific aircraft gear configura-tions. In the SW-1 design methods, theuser is allowed to vary the climate byselecting the mean annual air temperature(MAAT). Users can characterize subgradestrength through the use of resilient mod-ulus (Mr), California Bearing Ratio

The Development of SW-1:

New Asphalt Institute

AI’s new SW-1, Thickness Design Software, is based on mechanistic-empirical design principles.

(CBR) and R-Value. SW-1 provides ele-gant M-E design solutions based on com-mon engineering design inputs. Theresult is a powerful, yet practical, pave-

ment design tool that everyone can use.

Broad Capabilities in anIntegrated DesignSW-1 offers engineers a single point ofreference for asphalt thickness design and

analysis. Whether the project entails thedesign of a multilane interstate highway,a commercial airport, a container han-

dling yard or an automobile parking lot,SW-1 provides a solution. The broadcombination of capabilities in SW-1allows an engineer to design an airportrunway pavement one day and use the

by John Duval, P.E. Asphalt Institute Field Engineer

SW-1 is used forhighway pavement

design.


Planned Staged Construction and HeavyWheel Load Applications. Each of thesesix chapters includes a discussion of themethod and at least one example to fur-ther assist users in applying the softwareto their own projects.

The final chapter, Chapter 12, includes adiscussion and an example of how to con-

duct Advanced Structural Analysis usingthe SW-1 core M-E calculation engineDAMA. Users will find that each examplecomes pre-loaded in the SW-1 software,making the User’s Guide a powerful toolfor getting the most out of the program.Download a FREE 30-day trial version ofSW-1, Thickness Design Software, today atwww.asphaltinstitute.org.

Thickness Design Softwaresame familiar tool to design a city streetpavement the next.

Users can switch quickly between designprojects on SW-1’s main screen. Known asthe Project Definition tab, this is whereusers define a new project, open an exist-ing project or save a new file upon startingthe program. With a few simple clicks ofthe mouse, users can set up a project, e.g.a new highway pavement or an overlay foran airport runway. Once the project isdefined, SW-1 prompts the user to inputthe required data on a sequence of screens.Once the input data is entered, the final

step is to click on the Results tab.

User’s GuideSuccessful software programs are usuallyaccompanied by complete documentation.

SW-1 is no exception. The developmentteam wrote the 108-page User’s Guide toserve as a companion to the program dur-

ing installation and operation. The firstthree chapters of the User’s Guide describe

step-by-step instructions for installing andconducting basic operations of the soft-ware, such as creating and organizing datafiles and project records, defining projects,viewing results and printing reports.

Chapter 4 discusses how climate is char-acterized using the MAAT. Chapter 5

provides details on entering subgrade

information using Mr, CBR, or R-Value.Chapters 6-11 cover each of the primarypavement design methods: GeneralAviation Airports, Air Carrier Airports,Highways/Roads/Streets, Overlay Design,

SW-1 can be used todesign heavy wheelload facilities.

Asphalt PavementThickness Design

SeminarFeaturing:Asphalt Institute SW-1

Thickness Design Software

This one-day course teaches the basics of Asphalt Institute thickness designmethods for asphalt pavements. Participants will set up and work throughexample designs in the new SW-1 Thickness Design Software for highways,airports, heavy wheel loads and other appplications.

DATES AND LOCATIONSAug. 30 Anaheim/Fullerton, CASept. 1 Seattle, WA

Oct. 17 Boston, MAOct. 19 Atlanta, GAOct. 21 Minneapolis, MN

To register for the seminar or to purchase SW-1,call (859) 288-4961 or visit www.asphaltinstitute.org.

$19500[ ]8PDHs

Take $40 off registration with purchase of SW-1


By John D’Angelo and John Bukowski

Office of Pavement Technology, FHWA

O ver the past 15 years, there havebeen significant changes in hotmix asphalt (HMA) quality con-

trol, testing and acceptance practices. Inthe past, it was common for the highwayagency to do all the quality control test-ing and use that same data for accept-ance. The standard for quality controlwas asphalt content and gradation.

Density was typically evaluated by com-

paring the roadway to a lab-compactedspecimen, possibly made long before theproject even started. If the ingredientswere proportioned correctly, the pave-ment should perform well.

Today what we measure and who doesthe measuring has changed. The contrac-tor does the quality control testing.Binder content and gradation are typical-

ly still part of the quality control pro-gram but they are not the controlling fac-tors in determining the quality of themix. Quality control today is typicallybased on the volumetric properties of themix and density is based on in-place airvoids determined from the maximumspecific gravity. Additionally, some high-

way agencies now use the contractor’s

tests to determine pay values.

From Art to ScienceThe testing of HMA is changing from

aggregate particles captured by video cam-era (black, white and gray format). Theblack and white images are analyzed forform and angularity; gray images are ana-lyzed for texture. The AIMS evaluation

reduces the variability of test results andspeeds up the testing process. Potentially,it may replace the coarse aggregate angu-larity, fine aggregate angularity and flatand elongated particles tests.

The results from the AIMS are beingused to determine a more direct relation-

ship between aggregate properties and

HMA pavement performance. A study iscurrently underway to determine therelationship between AIMS test resultsand the Superpave repeated load, perma-nent deformation performance test.

HMA Testing and Quality for the Future

an art to a science. New tests that pro-vide more accurate and performance-related mix properties are being devel-oped for use in the quality controlprocess. For example, the shape, angular-

ity and texture properties of coarse andfine aggregates can be quickly and easilymeasured by a new aggregate imagingsystem (AIMS) developed by Dr. EyadMasad and the Federal HighwayAdministration (FHWA). The AIMS can

be used in the quality control of aggre-gates during their production, and themeasured characteristics can be related to

pavement performance.

The AIMS evaluates the shape and tex-ture characteristics of coarse and fineaggregates by analyzing the images of the

The aggregate imaging systemmeasures the shape, angularityand texture of aggregates.


The Superpave PerformanceTester was developed as asmall, compact unit that fitsinto a field lab or trailer. Thesoftware used to operate theequipment was developed withease of operation in mind andautomatically goes throughnumerous self-checks to assurethat the test is properly set up.

Traditional ProcessControlProcess control is the contrac-tor’s quality control system formonitoring the HMA manu-facturing operation. The traditionalapproach to process or quality control is

to evaluate a series of independent tests.This approach includes such steps asdetermining if the proper binder is in thecontractor’s tank and the right aggregatesare in the stockpiles. It includes cold feed

checks to make sure the proper amountof each stockpile is being added to thefeed belt. This is where an AIMS evalua-tion can be used to check if the aggre-gates in the stockpile match the materials

used in the original mix design.

Traditionally, the owner agency wasexpected to perform testing for accept-ance analysis while separate quality con-trol testing was performed by the con-

tractor. But reductions in owner agencystaff have made it increasingly difficult to

perform adequate and timely testing. For

high production operations, the conceptof a few samples to represent largeamounts of material also places high riskson the owner agency or the contractor.To address these concerns, new

The Superpave PerformanceTester is used to measure thestiffness or strength of HMA.


approaches to testing and increasedreliance on automation are likely.

New TechnologyAutomated testing, data managementand computer-controlled manufacturingpotentially allow for reduced testingwhen these technologies can be appliedto hot mix production and placement.Ultimately it is envisioned that real-timegathering of production information mayreduce the time gap between productionand data availability and improve thereliability of that data.

Applying the TechnologyIn 2004, a project was initiated by theAlabama DOT, working with theNational Center for Asphalt Technology(NCAT), to evaluate a number of specificdevices for automated sampling and test-ing of component materials. In-line vis-cometers were used to check the binder

being fed into the plant. Sensors wereused to measure the moisture in the

aggregate. Automated belt samplers wereused to obtain a sample of the virginaggregates from the conveyor before it

entered the dryer. An automated sampledryer and gradation device, integratedwith the belt sampler, provided rapidfeedback about the consistency of theaggregate and its conformity to the job

mix formula. In the future, each of theautomated technologies can be integratedas a system with programmable controls,data acquisition and report generation.

New Paving TechnologyComputer-equipped rollers—or intelli-

gent compaction—is one emerging tech-

nology that will allow greater control andoversight of the compaction process,resulting in better, more uniform density.Vibratory rollers with a measurement/control system can automatically control

compaction parameters in response tomaterials stiffness measured during thecompaction process.

The rollers can also be equipped with adocumentation system that allows con-tinuous recordation, through an accuratepositioning system of roller location andcorresponding density-related output.

The information can include number ofroller passes and roller-generated materi-

als stiffness measurements. This outputcan enhance the ability of the rolleroperator and/or project inspection per-

sonnel to make real-time corrections inthe compaction process. This output isavailable for inspector review, allows fora plan-view plot of stiffness throughout adesignated section of roadway and pro-

vides a link to a pavement managementsystem database.

Ultimately this technology will providenew tools for measurement of in-placepavement properties. Through the use of

computers, modeling, and innovativesoftware, intelligent asphalt compactionequipment offers the potential to

improve operations, result in more uni-form pavement density, reduce inspectionrequirements, and provide a long-termquality record that can be related to pave-ment performance.

Automated TestingThe quality assurance system of thefuture will include new processes andinnovative testing equipment. This willnot mean, however, that increased orexcessive testing will be done. It willmean that we use all the tests to give us abetter overall picture of what is being pro-duced and how it relates to performance.

Under the future system, devices such as

the AIMS will be used at the plant tocheck the aggregate as it is delivered toverify specifications compliance, and to

check that the aggregate is similar to thematerial used during the original design.After the initial tests, the automated sys-tem takes over with continuous monitor-ing of production. When the monitoring

indicates aggregate changes, additionaltesting may be done.

The system of the future may allow thetesting frequency to be dramaticallyreduced. Unlike current practice where

samples are taken every 500 or 1,000tons, the automated systems may allowsamples to be taken every other day—

just to verify that the process is working.

Mix AcceptanceThe idea that we can make one or two tests

An in-line viscometer can beused to check the stiffness of theasphalt binder being pumpedat the HMA mixing plant.

Belt-mounted moisture sensorscan be used to monitor themoisture content of aggregateentering the plant.

PH

OT

O C

OU

RT

ES

Y O

F N

CA

T

PH

OT

O C

OU

RT

ES

Y O

F N

CA

T

on a material and decide if it has thedesired quality is outdated. HMA produc-tion has to be looked at as a manufacturingprocess. There are many steps that have tobe checked in that process to assure qualitywith some type of performance measure atthe end. The new tests and plant automa-


tion processes that are becoming availablewill look at HMA in a new way.

For example, this is where the SuperpavePerformance Tester could come into thepicture. The process might go like this:the production process control and quali-

ty control are established; the system hasbeen calibrated and running smoothly. Atthis point the performance properties ofthe mix, as determined by the SuperpavePerformance Tester, are used to acceptthe mix for payment. This testing wouldbe done at the start-up of the project andat extended intervals during production.If the process control indicates a problemhas occurred, a sample can be taken andtested later.

HMA testing in the future will use quickaccurate tests on the initial components.Plant automation will assure that theproduction process runs smoothly andlimited quality control testing will verifythe process. Finally performance tests willbe evaluated to accept the material. Thenwe will have an advanced quality assur-ance system that tells us more about thematerial we are placing on the roadwayand how it performs.

An automated belt samplingdevice can be used to samplethe aggregate before it entersthe dryer.

An automated sample dryer andgradation device can be integratedwith a belt sampler to providedata on aggregate consistency.

PH

OT

O C

OU

RT

ES

Y O

F N

CA

T

TEREX | CEDARAPIDS VersaScreedThe new Terex | Cedarapids VersaScreed gives asphalt contractors infinitely variable paving widths ranging from 10 to 17 ft (3 to 5.2 m). Twin-zone electric screed heating delivers uniform temperatures across the entire screed width, ensuring quality mat texture and smooth joints.

TEREX | CMI PR950 COLD PLANERWith its 950 hp (708 kW) diesel engine, 86 in (218 cm) standard cutter and optional 150 in (381 cm) wide cutter,the new PR950 cold planer from Terex | CMI is the most productive and powerful machine in its class! The PR950 works at 0 to 170 ft/min (0 to 45 m/min).

TEREX | CEDARAPIDS CR662 RoadMixThe new CR662 RoadMix machine introducedby Terex | Cedarapids addresses the need for an asphalt material transfer vehicle, that also combats mix segregation, can be used on base courses and – with the attachement of a screed – works as a remix asphalt paver.

TEREX QMA OR IMPULSE CONTROL SYSTEMS

“We set one customer up to run his HMA plant with the latest QMA Controls in a control

house usually fitted with Impulse Controls.The integration of equipment formerly

sold under the CMI and Cedarapids brands gives today’s customers great flexibility,”

Eric Hutchison, Terex Roadbuilding.

TEREX SUPER PORTABLE HMA SYSTEMS

Terex Roadbuilding’s E150 Portable Counterflow Drum with Baghouse and Dust Handling System

delivers big-drum performance in a small package. Sized for easy transport at just

33 ft 2 in (10.1 m) long, the E150 produces up to 150 tons (135 tonnes) of hot mix an hour.

TEREX ASPHALT PLANT AUDIT PROGRAMTerex asphalt plant audits optimize performance and

maximize uptime. The resulting report details, regardless of brand, the plant equipment, process changes, components

and costs to bring your plant up to peak performance — so you earn more on every ton of asphalt you produce.

1-888-TEREXRBThe Strength of Many. The Power of One.


By Wayne Jones, P.E., Asphalt Institute Field Engineer

The squeaky wheel gets thegrease! This adage has been truesince 5000 B.C. when man first

used wooden wheels to haul heavyloads. The latest variation of this oldsaying goes something like this: anoisy pavement gets the attention ofthe pavement engineer. Recentactions by public agencies haveproven that community outcries for qui-eter pavements have been heard.

BackgroundBy definition, noise is any unwanted orexcessive sound. Noise, especially trans-portation noise, has become one of the

most pervasive forms of pollution intoday’s environment. It affects our lives athome, at work and at play.

Urban noise is an indication of economic

activity and commerce, and up to apoint, an improving quality of life. Butin extreme situations, it can lead to anxi-ety, stress and other health problems.When that happens, noise needs to becontrolled or abated.

European ExperienceThe quest for quiet pavements originated

in Europe where the preservation of his-toric vistas prevents the use of noise bar-rier walls. Most of the efforts inEuropean countries have been on theelimination of the noise at the source.

Currently there are two differentapproaches to achieve quieter hot mix

asphalt (HMA) pavements in Europe.One method uses thin overlays with neg-atively textured, gap-graded mixes such

as stone matrix mixtures. The secondmethod calls for single or double layersof open-graded porous surface mixes thatabsorb both water and air and do notallow them to become trapped between

the tire and the pavement.

Research at the Transportation ResearchLab in the United Kingdom (UK) foundno loss of skid resistance when specifyingHMA surfaces and a 3 to 6 dBA reduc-

tion in noise generated when comparedto other types of pavement. Such a

reduction in noise is roughly the equiva-

lent of increasing the distance from twoto four times between the source and thelistener. Based on these findings, the UKhas launched a ten-year program to over-lay the majority of their high-speed

motorways with HMA to pro-mote noise reduction.

Arizona ExperienceArizona paved a 1500-foot stretchof freeway in the Phoenix area withan open graded friction course(OGFC) to improve skid resistanceand visibility during heavy rains.When motorists noticed the dis-tinct reduction in noise provided bythe new pavement surface, theybegan asking “Why can’t we have a

similar overlay near our neighborhood?”The local media picked up on the public’s

interest and ran feature stories about thequiet pavement surface. From this public

outcry, came AZDOT’s commitment tooverlay all of the freeways in the Phoenixarea with OGFC. The overlay program

proved to be so successful at reducing noiselevels around the city that the PhoenixMetropolitan Planning Organizationagreed to loan AZDOT $34 million toaccelerate the overlay program.

Research in California has shown that aquiet pavement overlay can maintaingood acoustic qualities for the majorityof its life. If the pavement remains quiet,then an agency will not have to renew

the surface based on acoustic perform-ance. When the surface needs to be reha-

bilitated, the new overlay can incorporate

the latest quiet pavement technology.

Based on the Arizona experience andresearch in California, the FederalHighway Administration has announced

Highway Traffic

Neighbors

Commerce

Rail

Buses

Others

Recreational

Aircraft

Urban Noise Components

QUIET PAVEMENT — Coming to a Highway Near You

Figure 1

the “Quiet Pavements Pilot Program” thatallows credit for quiet pavement technolo-gy. Under the program, a state can take upto a 5-decibel credit for the use of quietpavement surfaces. They must agree to re-apply a quiet HMA surface when monitor-ing shows that the old pavement is noisy.

Elsewhere Around the CountryDuring recent public hearings on pave-ment selection in Ohio, citizens fromone community complained about a par-ticularly noisy stretch of newly recon-structed Portland cement concrete (PCC)pavement. As a result, Ohio has begun toresearch quiet pavement technology andnow considers noise a secondary factor inthe pavement selection process.

The National Center for AsphaltTechnology (NCAT) has begun to moni-tor and catalog pavement noise levelsfrom around the country using a close-proximity (CPX) noise measuring trailer.By using the CPX procedures, tests can

be done at highway speeds. To date theyhave measured over 320 pavement sur-

faces. They have found that HMA pave-ments with the smallest top-sized aggre-gates tend to produce the lowest noise

level. Figure No. 2 shows the results forall pavement types in NCAT’s database.


QuietPavement.comTo learn more about tire/pavement noise,

log on to www.quietpavement.com, anew website sponsored by the AsphaltPavement Alliance. The site has links to

information about the history of roadnoise, case studies, and a tool that lets

you compare the decibel levels of com-mon neighborhood noises such as peoplecarrying on a conversation, a dog bark-ing, a blender and a jackhammer. One ofthe links is to streaming video files taken

by NCAT’s CPX trailer while doing actu-al noise measurements on Phoenix free-ways. The file shows the dramatic differ-ence between the original PCC pavementand the new OGFC surfaces. Also on the

site is an interactive section where youcan build your own community and testthe noise readings produced by selectingdifferent pavement types.

Figure 2

For more about quietpavement technology, visitquietpavement.com.

Noise Level by Surface Type

Tras

vers

eT

ine

d P

CC

P

Lon

git

ud

inal

lyT

ine

d P

CC

P

Dia

mo

nd

Gro

un

d P

CC

P

De

nse

G

rad

ed

HM

A

Sto

ne

Mat

rix

Asp

hal

t

Co

urs

e G

rad

ed

OG

FC

>5

/8 in

Co

urs

e G

rad

ed

OG

FC

>3

/8 in

De

cib

el (

A)

110

105

100

95

90

85

80

Max

Low

-Avg


projects containing RAP have been costeffective and long lasting. As a result,most agencies now allow RAP in theirhighway mixes.

Contractor PerspectiveHMA producers can use RAP with rela-tively inexpensive additions to their mixing

plants. For Doug Fog, Plant OperationsManager for Brooks Construction, recy-

cling is a critical component of his opera-tion. “Recycling is extremely important tous. We view it as a tremendous commodity

for Brooks. We have eight plants and weuse RAP at six of them. So it is a big partof what we are doing,” stated Fog.

Like many contractors, Brooks

Construction relies on the use of RAP togain more access to state highway jobopportunities. “Our state allows recyclingon many of the larger highway jobs andif you want to get those, you better runRAP,” said Fog. The key to using RAP

successfully, according to Fog, is to besmart about it.

In order to maximize the efficient use ofRAP, Brook Construction manages thereclaimed materials. “We separate ourRAP stockpiles so that they are ready touse in specific mixes. We have stockpiles

of surface, intermediate and base gradesand we try to use them properly. Forexample, the surface grade has a high ACcontent. And the RAP has the same topsize as the mix’s virgin aggregate, whichmakes it very easy to use,” stated Fog.

Methods of RecyclingThe most common method of recyclingis through heat transfer. RAP is added tosuperheated aggregates, typically 450-plus ºF—depending on atmosphericpressure, moisture content, ambient tem-perature and type of aggregate. This heattransfer process can be accomplished ineither a batch or drum mixing plant.

There are several methods of batch plantrecycling. The most commonly usedmethod is to introduce RAP from a sepa-rate bin and feed it into a pug mill orweigh hopper via belt conveyor and chute.Up to 40 percent RAP can be recycled

using this method. The factors that canaffect the production rate include altitude,virgin aggregate type, ambient tempera-

ture and dryer efficiencies.

Another, less commonly used, RAP-entrymethod is through the bucket elevator.When using this method, some contrac-

tors remove the screens from the batchtower and feed RAP up the elevator. Thismethod can be successful provided someadditional proportioning control is inplace. This method enables the contrac-tor to operate his batch plant somewhat

like a drum mix plant.

A batch plant modification may be nec-

essary to deal with steam that is generat-ed when the virgin aggregate comes intocontact with cold, wet RAP—culminat-ing in a steam explosion. The contractormay have to add exhaust duct work to

RecyclingBenefits for HMAProducersT

oday’s hot mix asphalt (HMA) pro-ducers are constantly trying differentmethods to improve asphalt quality

and increase profits while satisfying statespecifications. One means of accomplish-

ing this goal is by incorporatingreclaimed asphalt pavement (RAP) into

the asphalt mix.

RAP is typically produced by milling anexisting asphalt pavement or by crushingchunks of an old pavement that has beenremoved. Through the years, completed

RAP can be introduced into the mix viaan integrated, in-line feeding system.

vent the steam back to the dryer’s exhauststream and pollution control equipment.

Drum Mix RecyclingLike batch plant recycling, there are vari-ous methods used for adding RAP in acontinuous mix, or drum, plant. Themost common method is the center-entry method. RAP is introduced to thedrum downstream and away from theburner flame, and is protected by a denseveil of virgin aggregate that provides ashield from direct exposure to the burnerflame. Asphalt is then blended into thefinal mix by the mixing drum’s flightingsystems and steel dams. If properlyaccomplished, this method can accom-modate up to 50 percent RAP.

Other methods of recycling with a drumplant include the use of a secondary drumor by using a pugmill. Some contractorshave elected to use a plant having a sec-ondary mixing drum after the virgin aggre-


gate has been heated in aseparate dryer. The driedaggregate is discharged fromthe dryer to a blendingdrum where the RAP,asphalt binder and fillers areall blended together beforedischarge into a silo system.

A pugmill can be used inmuch the same way as ablending drum. Virginaggregate, RAP and filler aremixed together away fromexposure to the burnerflame thus eliminating the problems thatexist in some continuous mix plants.

Multiple BenefitsIn addition to the obvious benefits ofreducing production costs and providingan HMA mix that is equal to or betterthan a virgin mix, recycling asphalt pave-ments have the added environmental

benefits of:• Reusing valuable, and perhaps scarce,

aggregates;• Reducing the amount of virgin asphalt

binder needed; and• Conserving valuable landfill space from

unnecessary disposal of old asphalt. Thus, using RAP provides multiple bene-fits—cost savings, conservation and longlasting pacvements.

A secondary mixing drum that is used to blendthe RAP and virgin components is shown on theleft. The primary dryer is on the right.


This is a follow-up to the related article pub-

lished in the Spring 2005 edition of Asphalt

magazine that discussed the new Asphalt

Institute (AI) study titled Quantifying the

Effects of PMA for Reducing Pavement

Distress. The results were published in AI

Engineering Report (ER) 215 and summarized

in AI Informational Series (IS) 215.

T his study analyzed an extensivecollection of field performancedata, making direct comparisons

between polymer modified asphalt (PMA)mixes and unmodified conventionalmixes. The data included 84 pairs of PMA

and unmodified companion test sectionsfrom the FHWA Long Term Pavement

Performance (LTPP) program and othergovernmental agency test sections locatedacross the United States and Canada.

While comparisons are insightful regard-ing relative pavement performance differ-

ences between PMA and conventionalmixes under similar conditions, they donot directly answer the question of how

much longer a pavement should beexpected to last with PMA. To quantifythe expected improvement in pavementlife based on the field data, the study usedmechanistic-empirical prediction models

for rutting and load-related fatigue crack-ing. Projected service-life increases werethen reported based on specific site condi-tions of the foundation, existing pavementand drainage as well as traffic and climate.A final part of the study showed how atypical maintenance and rehabilitationschedule for unmodified HMA pavementscould be extended with the use of PMAjust in the wearing surface, as well as inboth the wearing surface and base layers.

The purpose of life cycle cost analysis(LCCA) is to evaluate the overall long-term economic efficiency between com-peting alternative investment options.

Typically in LCCA, costs of all activitiesover the analysis period are computedback to a net present worth (NPW),accounting for the discount rate overtime. This article uses LCCA to com-pare the activity timelines of alterna-tive PMA strategies provided in thereferenced report.

Assumptions made in this analysis arebased on constructing a 14.5-inch thickHMA pavement, maintenance activities

based on Pennsylvania DOT policy, ananalysis period of 40 years and a discountrate of 4 percent. Prices and quantities

assumed are shown below.

MIX PRICES (from Maryland DOT’s Pavement Selection Process)

Wearing (PG 64-22)Wearing (PG76-22)Binder and Base (PG 64-22)Binder and Base (PG 76-22)MillingHMA PatchingQuantities (per mile)Mainline: 2-lanes @12 ft. ea.Shoulders: 1 @ 10 ft. and 1 @ 4 ft.

$36/ton or $1.97/sy-in$41/ton or $2.24/sy-in$35/ton or $1.91/sy-in$40/ton or $2.19/sy-in$1.40/sy$36/sy

14,080sy8,212sy

BY MARK BUNCHER AND CARLOS ROSENBERGER, ASPHALT INSTITUTE

ASSUMED PRICES AND QUANTITIES

Understanding the TrueEconomics of Using PolymerModified Asphalt throughLife Cycle Cost Analysis


The three example scenarios shown inthe referenced report are:

1)Using conventional unmodifiedmixes for all layers

2)Using PMA for the top 2-inch wearing surface only

3)Using PMA for both the wearingsurface and bottom 4-inch base layer (consistent with a PerpetualPavement).

The schedule of maintenance and reha-bilitation activities associated with eachof these alternatives was shown in Figure1 of the related article in the last editionof Asphalt.

The initial cost and NPW (back to Year0) of each activity during the 40-yearanalysis period for Scenarios 1, 2 and 3are shown in the three tables to the right.Costs are based on the per-mile quanti-ties provided in the earlier table. WithScenario 1, resurfacing is scheduled for

years 10 and 28 and structural overlaysfor years 18 and 34. By using PMA in

the wearing course (Scenario 2), theresurfacings at years 10 and 28 are elimi-nated. By building a Perpetual Pavement

and using PMA in the wearing and basecourses (Scenario 3), the structural over-lays at years 18 and 34 are replaced withresurfacings. The total NPW, or life cyclecost, is tabulated for each scenario.

The table on the next page summarizesand compares the initial and life cyclecosts for each of the three scenarios.Scenarios 4 and 5 were added to take amore conservative approach, where the

2.5-inch binder course was also modifiedjust below the modified 2-inch wearing

course to achieve the same extended per-

formance in Scenarios 2 and 3 respective-ly. While PMA increased initial construc-tion cost by 1 percent per inch of PMAused, the overall life cycle cost savingsover 40 years was substantial. Even with

YEAR0

10

18

2834

ACTIVITYHMA Construction10” Base2.5” Binder2” WearingResurfacing2” Mill/Fill1% Patching(not on shoulders)Structural Overlay2” Mill3% Patching and Scratch2.5” Binder2” Wearing(including shoulders)Same as Year 10Same as Year 18Annual Maintenance ($1.8K/yr)

COST, $668K

87K

285K

87K285K73K

NPW, $668K

58K

141K

29K75K33K

Total NPW: $1,005K(costs are per mile)

YEAR0

18

34

ACTIVITYHMA Construction10” Base2.5” Binder2” WearingResurfacing2” Mill3% Patching and Scratch2.5” Binder2” Wearing(including shoulders)Same as Year 18Annual Maintenance ($1.8K/yr)

COST, $682K

298K

298K73K

NPW, $682K

147K

79K33K

Total NPW: $941K(costs are per mile)

YEAR0

18

34

ACTIVITYHMA Construction10” Base2.5” Binder2” WearingResurfacing2” Mill/Fill(including shoulders)Same as Year 18Annual Maintenance ($1.8K/yr)

COST, $709K

141K

141K73K

NPW, $709K

70K

37K33K

Total NPW: $849K(costs are per mile)

SCENARIO 1: USING UNMODIFIED HMA FOR ALL LAYERS

SCENARIO 2: USING PMA FOR WEARING COURSE (TOP 2")

SCENARIO 3: PERPETUAL PAVEMENT: PMA FOR WEARING (TOP 2") AND BASE (BOTTOM 4") COURSE


the more conservative Scenarios 4 and 5where more PMA was used, the life cyclecost savings were 4.5 percent and 14 per-cent respectively.

It should be noted that this analysis doesnot consider user delay costs, whichwould be reduced with the longer servicelives of PMA mixes. Considering userdelay costs makes the use of PMA evenmore attractive.

It is important to emphasize that theseare examples illustrating the framework

for an analysis to quantify the long-termeconomic benefits of using PMA, or anyother premium mix for that matter. Each

agency should use their unique set ofestimated LCCA inputs such as perform-ance periods, prices, designs, strategies,discount rates and user cost considera-tions.

When performing LCCA, agenciesshould consider the extended perform-ance lives that are typically achieved fromusing PMA or any premium mix. Whencomparing asphalt and concrete pave-

ment alternatives, this applies as well.Too often, the performance periods

assumed for initial asphalt construction

and overlays do not consider theimprovements realized for using premi-um materials and mixes.

Scenario

1) All layers unmodified

2) PMA for Wearing (2”) Course

3) Perpetual Pavement: PMA for Wearing (2”) and Base (4”) Courses

4) More Conservative Approach:

PMA for Wearing (2”), Binder (2.5”) and Base (4”) Courses

with same schedule as Scenario 2

5) More Conservative Approach:

PMA for Wearing (2”), Binder (2.5”) and Base (4”) Courses

with same schedule as Scenario 3

Initial Cost, $

669K

682K

709K

698K

725K

LCC

Savings, %

—

6.5%

15.5%

4.5%

14.0%

Initial Cost

Increase, %

—

2.0%

6.0%

4.5%

8.5%

LCC

1,005K

941K

849K

964K

864K

SUMMARY OF COSTS

MAKESTHE ASPHALT RUBBER BLENDING PLANT

YOU NEEDTO GET THE JOB DONE RIGHT.

(480) 991-0450www.StratcoGlobal.com

TM A STRATCO GLOBAL COMPANY . . . producing equipment since 1928.

To get the job done right, you need world class technology. That's why you need TM.

‘s Asphalt Rubber Blending Plants are custom engineered to be compatible with any asphalt hotmixplant. ‘s control systems are versatile and easy to operate with real-time viscosity measurement. Wealso offer two convenient designs:

• A 45 ton per hour unit on two trailers and • A 15 ton per hour unit on a single trailer.

To consistently produce the highest quality asphalt rubber binder, you need the most efficient and reliablesystem engineered. That's .

™

™

AsphaltAd 5/12/05 4:59 PM Page 1


Asphalt PavementThickness Design SeminarFeaturing:Asphalt Institute SW-1 Thickness Design Software

This one-day course teaches the basics of Asphalt Institute thickness designmethods for asphalt pavements. Participants will set up and work throughexample designs in the new SW-1 Thickness Design Software for highways,airports, heavy wheel loads and other appplications.

To register for the seminar or to purchase SW-1,call (859) 288-4961 or visitwww.asphaltinstitute.org.

$19500[ ]8PDHs

Take $40 off registration with purchase of SW-1

DATES AND LOCATIONSAug. 30 Anaheim/Fullerton, CASept. 1 Seattle, WA

Oct. 17 Boston, MAOct. 19 Atlanta, GAOct. 21 Minneapolis, MN

Evaluating Laboratory Fatigue

Performance of Asphalt MixturesAsp

halt

FO R L A B S E RV I C E S CO N TAC T M I K E A N D E R S O N AT M A N D E R S O N @ A S P H A LT I N ST I T U T E . O RG

Figure 1: Flexural Beam Fatigue Fixture

Figure 2: Typical Beam Fatigue Data — Single Test Condition

The Asphalt Institute’s lab is available toperform research,testing andtraining.

Lab

Corn

erLa

b Co

rner


Fatigue cracking was one of the threeprincipal distresses identified by theStrategic Highway Research Program

(SHRP) that is experienced by asphalt mix-tures in service. As part of the acceleratedperformance testing program of SHRP,researchers at the University of California atBerkeley refined laboratory fatigue testingand analysis procedures using the four-pointflexural beam fatigue fixture (Figure 1). Inthe test, an asphalt mixture beam specimen(2” x 2.5” x 15”) is produced and tested at aspecified strain level and temperature (usually20°C) by repeatedly loading the specimen inthe center of the beam. As the specimenfatigues, microcracks are formed and thestiffness of the asphalt mix specimen decreas-es. As the microcracks increase, the specimenstiffness decreases rapidly (Figure 2).

Flexural beam fatigue data is analyzed princi-

pally by plotting mix stiffness as a functionof loading cycles. The number of cycles tofailure, Nf, is defined as the loading cycle

when the mixture stiffness drops to 50 per-cent of the original stiffness. SHRP researchindicated that the cycles to failure in the flex-ural beam fatigue test could be related to theactual number of loading cycles required to

cause fatigue cracking of asphalt pavements.In the laboratory, the fatigue test is oftenused to compare the expected fatigue per-formance of different asphalt mixtures usingdifferent aggregates, asphalt binders, andmodifiers.

For more information or to get a quote on

performing flexural beam fatigue testing and

analysis, please contact either Mike Anderson([email protected]) or GaryIrvine ([email protected]).

United States, butone thingremained con-stant: the road.

“The open roadis really a symbolfor life. A big part

of life is to go outthere and exploreall the different

roads you can,” saysMarriner. “By physically getting on theroad, you gain a new understanding oflife. And the road is a very valuable toolthat most people don’t recognize. Believeme, a good road is the best, especiallywhen you are in a shaky RV!”

Finding your own RoadRoadtrip Nation has released its thirdbook, Finding the OpenRoad: A Guide to Self-Construction Ratherthan Mass Production,which shares the histo-

ry of Roadtrip Nationand a how-to-roadtrip

guide, in addition to more thanfifty interviews from recent trips. “Thebook features a step-by-step plan for

determining your own route, which isimportant because you should never stopexploring,” says Marriner. “Road trips arenot just for college students. We know apoliceman in New York who, every sum-

mer, plans a weeklong road trip for theentire family.

“Roadtripping helps keep you from focus-ing only on the day-to-day routine. Thepoint is to keep widening the lens toexplore and discover new things about life,”adds Marriner. “Get out of your comfort

zone. Meet new people. Then define your

own road and be passionate about it.”

For more information, visit the

Roadtrip Nation website at

www.roadtripnation.com.


“What should I do with my life?”

That’s the question Mike Marriner, BrianMcAllister and Nathan Gebhard askedthemselves four years ago after graduatingfrom college in Southern California. Threemonths and 17,000 miles later they foundan answer and a mission by “road-trip-ping” in a shaky neon green RV to meetand interview the chairman of Starbucks,a lobsterman from Maine, the first femaleSupreme Court Justice, the director ofSaturday Night Live, and over 75 othersuccessful leaders and career professionals.

Hitting the RoadThey booked the interviews with no con-nections. Rather, they used an old schooltactic known as the “cold call” with the aid

of 411 directory assistance. The three alsofilmed each interview on the trip—whichthey dubbed “Roadtrip Nation”—with one

purpose in mind: “To collect their storiesand learn how they got to where they are

today,” says MikeMarriner. “The people weinterviewed didn’t have itfigured out in their early20s, but we wanted toknow how they made

their decisions. What wastheir compass at criticalpoints in their lives? How

did they define their own roads in life?”

What the three learned changed theirperspectives completely. “We were reallyimpacted by Manny the lobsterman in

Maine and Howard Schultz, the founderof Starbucks,” says Marriner. “When yousit down and talk with these men, youlearn that they each followed the samerelative philosophy. For Manny, it waslife on the sea. For Howard, it was coffee.But each knew what he liked and waspassionate about it.”

Telling the StoryThe fledgling filmmakers soon found anaudience as the first Roadtrip Nationdocumentary aired on PBS affiliatesacross the country in 2003 and was later

published as a best-selling book. Thissummer a 12-part PBS series will feature

three other simultaneous roadtrips of col-lege students as they traveled across thenation during the summer of 2004.

Life on the RoadSo what do the founders of RoadtripNation think about asphalt pavements?“When you get that perfect, smooth

beautiful road, the experi-ence is unbelievable. Andour mood in the vehicle isreally affected by the quali-ty of the trip,” saysMarriner. “Asphalt definite-

ly contributed to the overallexperience and I think theroad construction industry

is doing important work.”

Through their camera lens, RoadtripNation documented a variety of peopleand places represented throughout the

“When you get thatperfect, smoothbeautiful road,

the experience isunbelievable.”

by Brian Clark

CALUMENT LUBRICANTSCOASTAL ENGERGY

CORPORATION

IRVING OIL

MCCALL OIL& CHEMICAL COMPANY

PETRO-CANADA

ASTARIS LLC

TAMKO ROOFING PRODUCTS, INC.

2005

ASPHALT REFINING& TECHNOLOGY COMPANY, LLC

CHEVRON CORPORATION

This publication is issued with the support of the Member Companies of the Asphalt Institute.

PRSRT STDUS POSTAGE

PAIDASPHALT INSTITUTE

2696 Research Park DriveLexington, KY 40511www.asphaltinstitute.org

new asphalt technologyasphaltmagazine.com/wp-content/uploads/archives/... · new asphalt technology...

Documents