Best Practices forBest Practices forHMA Joint Construction

Idaho Asphalt ConferenceMoscow, Idaho

October 25, 2007

John Duval, P.E.jd l@ ljduval@semgrouplp.com

Acknowledgements and ReferencesReferences

AI MS-22 ManualKandahl, Ramirez, and Ingram:NCAT Report 02-03Scheibel, Guevera,

d R tand Retzer:Presentation 2007 Utah Asphalt ConfUtah Asphalt Conf.Uhlmeyer: WSDOT Technote Reportp

Joint Construction

Good joints areGood joints are no mysteryBy followingBy following accepted best practices, we pare all capable of constructing l l tilong-lasting HMA joints

Poorly Constructed Joint

Joint Construction

Basic Joint Construction TechniquesBasic Joint Construction TechniquesLongitudinal JointsTransverse JointsTransverse Joints

Improved Joint Construction T h iTechniques

Paving and Rolling TechniquesEquipment Modifications / Specialty DevicesM t i lMaterials

Basic Joint Construction TechniquesTechniques

Joint Construction 101

Tack coldTack cold edgeOverlap pscreed 1-2 inches“Bump” excess to hot id b fside before

compaction

Bump Longitudinal Joint

Bump-Yes, Broadcast-No Transverse Joints

Staggered Longitudinal Joints

6 to 12 inches

Don’t let the joint fall in the wheel pathDon t let the joint fall in the wheel path

Hot Side

Improved JointConstruction TechniquesTechniques

Paving in Echelon Rolling Techniques

1 Rolling from Hot Side MI WI CO PA1. Rolling from Hot Side MI, WI, CO, PA

2. Rolling from Cold Side MI, WI, CO, PA

3. Rolling from Hot Side MI, WI, CO, PA6 inches

Source: NCAT Report 02-03

Hot Side Cold Side

Hot Side 6” Away Notched Wedge Joint

Notched Wedge Joint Notched Wedge Joint

Rolling a Wedge Joint Edge Restraining Device

Edge Restraining Device Cutting Wheel

Cutting Wheel Joint Maker

Joint Shoe Joint Shoe

NJ Tapered Joint 3:1 Rubberized Joint Sealant

NCAT Report NCAT Report Findingsg

Joint Technique EvaluationEvaluation

Density at jointVi l b tiVisual observation- CrackingCracking- Raveling

Evaluation Six-Year Average Ratings in PARatings in PA

RUBBERIZED JOINT SEALANT 9.88RUBBERIZED JOINT SEALANT 9.88CUTTING WHEEL 9.12ROLLING FROM HOT SIDE 6” 8 75ROLLING FROM HOT SIDE 6 8.75TAPERED WEDGE 3:1 7.75EDGE RESTRAINING DEVICE 6 75EDGE RESTRAINING DEVICE 6.75JOINT MAKER 5.50ROLLING FROM HOT SIDE 4 75ROLLING FROM HOT SIDE 4.75ROLLING FROM COLD SIDE 4.62

Impact

Highway agencies are beginning toHighway agencies are beginning to specify minimum density at jointJoint density should not be more thanJoint density should not be more than 2% lower than mat density

Good Joint = Superb PerformancePerformance

Experience has shown that the joint can p jbe compacted to within about 2% of the matG d k hi i i d ll iGood workmanship is required at all timesA little mistake can lower the joint density considerablyconsiderablyMore attention is needed in construction of the longitudinal jointt e o g tud a jo t

Got Density?

Thank You

John Duval, P.E.Field Engineer

3939 N.E. Hancock St., Suite 305Portland, OR 97212

jduval@semgrouplp.com(503) 473 8240(503) 473-8240