Best Practices for Best Practices for HMA Joint Construction Idaho Asphalt Conference Moscow, Idaho October 25, 2007 John Duval, P.E. jd l@ l jduval@semgrouplp.com Acknowledgements and References References AI MS-22 Manual Kandahl, Ramirez, and Ingram: NCAT Report 02-03 Scheibel, Guevera, dR t and Retzer: Presentation 2007 Utah Asphalt Conf Utah Asphalt Conf. Uhlmeyer: WSDOT Technote Report Joint Construction Good joints are Good joints are no mystery By following By following accepted best practices, we are all capable of constructing l l ti long-lasting HMA joints Poorly Constructed Joint
Transcript
Best Practices forBest Practices forHMA Joint Construction
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
