Post on 18-Jan-2016
MODULE 3-3MODULE 3-3MODULE 3-3MODULE 3-3
Patching WithPatching WithBituminous Bituminous
MixturesMixtures
Patching WithPatching WithBituminous Bituminous
MixturesMixtures
Learning ObjectivesLearning Objectives
Describe the conditions that require Describe the conditions that require patching patching
Distinguish between hot-, cold-, and Distinguish between hot-, cold-, and proprietary mix patching materialproprietary mix patching material
Describe patching materials propertiesDescribe patching materials properties Describe procedures for throw and roll, Describe procedures for throw and roll,
semi-permanent, and automated semi-permanent, and automated patchingpatching
IntroductionIntroduction
Patching the existing pavement with Patching the existing pavement with bituminous materialsbituminous materials
Extends the service life of the existing Extends the service life of the existing HMAHMA
Used in the preparation of existing Used in the preparation of existing pavement prior to construction of an pavement prior to construction of an HMA overlayHMA overlay
Moderate Severity
High Severity
Patching ApplicationsPatching Applications
Definitions – Definitions – Bituminous Patching Bituminous Patching Materials Materials
Cold-mixCold-mix Often used as temporary patchesOften used as temporary patches Placed in stockpile and used over a Placed in stockpile and used over a
period of time (emulsion binders)period of time (emulsion binders) Special open-graded mixesSpecial open-graded mixes
Proprietary-mixProprietary-mix Cold mix with emulsified binderCold mix with emulsified binder Proprietary admixturesProprietary admixtures
Definitions – Definitions – Bituminous Patching Bituminous Patching Materials Materials
Hot-mix asphalt (HMA)Hot-mix asphalt (HMA)
Placed immediately while hotPlaced immediately while hot
Standard dense graded HMAStandard dense graded HMA
Why Do We Patch?Why Do We Patch?
Repair localized distressRepair localized distress
Improve motorist safetyImprove motorist safety
Reduce pavement roughnessReduce pavement roughness
Reduce the rate of deteriorationReduce the rate of deterioration
Repair pavement prior to overlayRepair pavement prior to overlay
Desirable Mix Desirable Mix Properties Properties Bituminous Patching Bituminous Patching
StabilityStability
AdhesivenessAdhesiveness
Resistance to strippingResistance to stripping
DurabilityDurability
Workability (cold-mix)Workability (cold-mix)
Storability (cold-mix)Storability (cold-mix)
Limitations and Limitations and EffectivenessEffectiveness
Patching may not be appropriate for all Patching may not be appropriate for all applicationsapplications
Temporary patches are temporaryTemporary patches are temporary
Structural design may not be Structural design may not be adequateadequate
Principal problem may not be Principal problem may not be correctedcorrected
Limitations and Limitations and EffectivenessEffectiveness
Bituminous patching is not Bituminous patching is not recommended for permanent repair of recommended for permanent repair of rigid pavementsrigid pavements
Hot-mix, full-depth patches provide Hot-mix, full-depth patches provide maximum effectivenessmaximum effectiveness
Not cost-effective when pavement is Not cost-effective when pavement is extensively deterioratedextensively deteriorated
0
10
20
30
40
50
60
70
80
Station50 100 1500
Def
lect
ion
Cracking
Pavement Repair
Pavement Survey Pavement Survey and Markingand Marking
PerformancePerformance
Winter maintenanceWinter maintenance ““Throw and Roll” the most cost effectiveThrow and Roll” the most cost effective Spray injection device also very Spray injection device also very
efficientefficient Summer maintenanceSummer maintenance
Semi-permanent patch Semi-permanent patch Pennsylvania found to be 3X more cost Pennsylvania found to be 3X more cost
effective on LCCA basiseffective on LCCA basis
Poor ConditionsPoor Conditions
Throw and RollThrow and Roll
Fill the hole with patching materialFill the hole with patching material Compact the patch using truck tiresCompact the patch using truck tires Verify that the compacted patch has Verify that the compacted patch has
some crown (between 3 and 6 mm).some crown (between 3 and 6 mm). Move on to the next pothole.Move on to the next pothole. Open the repaired section to traffic as Open the repaired section to traffic as
soon as maintenance workers and soon as maintenance workers and equipment are cleared from the area.equipment are cleared from the area.
Semi-Permanent Semi-Permanent PatchPatch
Mark patch boundariesMark patch boundaries Cut boundariesCut boundaries Clean and repair foundationClean and repair foundation Apply tack coatApply tack coat Fill the hole with patching materialFill the hole with patching material Compact the patchCompact the patch CleanupCleanup
Automated Patching Automated Patching EquipmentEquipment
Spray injection proceduresSpray injection procedures
Blow debris from holeBlow debris from hole
Spray hole with binder for tack coatSpray hole with binder for tack coat
Blow aggregate and binder into holeBlow aggregate and binder into hole
Top off with a layer of uncoated Top off with a layer of uncoated aggregate to prevent trackingaggregate to prevent tracking
May be rolled to improve smoothnessMay be rolled to improve smoothness
Automated Patching Automated Patching EquipmentEquipment
Automated Patching Automated Patching EquipmentEquipment
What’s Wrong Here?What’s Wrong Here?
What’s Wrong Here?What’s Wrong Here?
ReviewReview
What are the properties to look for in a What are the properties to look for in a patching material?patching material?
What are the major differences between What are the major differences between hot-, cold-, and proprietary mix hot-, cold-, and proprietary mix patching material?patching material?
Why do we patch?Why do we patch? What are appropriate applications of What are appropriate applications of
“throw and roll,” “semi-permanent,” and “throw and roll,” “semi-permanent,” and “automated” patching?“automated” patching?
Key ReferencesKey References
Wilson, T. P. 1998. Wilson, T. P. 1998. Long-Term Monitoring of Long-Term Monitoring of Pavement Maintenance Materials Test SitesPavement Maintenance Materials Test Sites. . FHWA-RD-98-073. Federal Highway FHWA-RD-98-073. Federal Highway Administration, Washington, DC.Administration, Washington, DC.
Wilson, T. P. and A. R. Romine. 1999. Wilson, T. P. and A. R. Romine. 1999. Materials and Procedures for the Repair of Materials and Procedures for the Repair of Potholes in Asphalt-Surfaced Pavements--Potholes in Asphalt-Surfaced Pavements--Manual of Practice.Manual of Practice. FHWA-RD-99-168. FHWA-RD-99-168. Federal Highway Administration, Washington, Federal Highway Administration, Washington, DC.DC.