Russian Engineers Training March 2011 Pavement Maintenance & Rehabilitation Dr. Michael Heitzman, PE Pavement Maintenance & Rehabilitation 1

Russian Engineers Training March 2011 Overview Part 1 Pavement Management Pavement Distress Routine Maintenance Minor Rehabilitation Major Rehabilitation Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Overview Part 2 Hot In-place Recycling Cold Recycling Full Depth Reclamation Rubblization Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Part 1 Pavement Management Pavement Distress Routine Maintenance Minor Rehabilitation Major Rehabilitation Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Pavement Management Why is Pavement Management Important Pavements deteriorate with time Roads in good condition cost less Assure good pavement serviceability to the traveling public Good PM strategies using maintenance and rehabilitation are cost-effective How do you manage your car - routine OR wait until it breaks down? Which costs more? More on this 2nd Wednesday AM Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Pavement Management System Russian Engineers Training March 2011 Pavement Management System Database of the pavement networks Database of pavement conditions (updated) Tools & procedures for pavement condition prediction Production of maintenance and rehabilitation strategies Maintenance cost estimate Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation 6

Russian Engineers Training March 2011 Pavement Deterioration Small % of pavement life EXCELLENT GOOD FAIR POOR VERY POOR FAILED Slow decreasing in condition Significant drop 75% OF LIFE $1.00 for rehabilitation here will cost $4.00 to $5.00 here TIME (years) Critical value Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation 7

Russian Engineers Training March 2011 Pavement Management With treatment Extend pavement life Good 75% OF LIFE Without treatment Poor TIME (years) Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Pavement Management (Monitor Performance) Pavement condition assessment Pavement condition assessment Pavement condition assessment Maint./Rehab activities required Maint./Rehab activities required Pavement Data Collection Pavement Data Collection Pavement Data Collection Life – cycle costs Non-monetary factors Select preferred alternatives Construction Construction Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Cost Considerations Fog seal $0.30 / m² Sand seal $0.70 / m² Crack Sealant $1.20 / m² Slurry seal $1.70 / m² Chip seal $1.80 / m² Db. chip seal $2.30 / m² Micro-surfacing $2.60 / m² Cape seal $3.40 / m² Mill and Inlay $11.60 / m² Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Cost Analysis Repair cost % Area repaired Overlay cost % Area repaired Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Part 1 Pavement Management Pavement Distress Routine Maintenance Minor Rehabilitation Major Rehabilitation Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Pavement Distress HMA Distress Rutting, Friction, Fatigue, Thermal Cracking, Aging PCC Distress Faulting, Cracking, Fatigue Premature vs Normal Distress Covered Tueday AM Match Distress with Maintenance/Rehab Techniques Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

How Should These Pavements be Rehabilitated? Russian Engineers Training March 2011 How Should These Pavements be Rehabilitated? Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Severe Longitudinal Cracking Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Severe Transverse Cracking Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Rutting Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Part 1 Pavement Management Pavement Distress Routine Maintenance Minor Rehabilitation Major Rehabilitation Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Routine Maintenance Preventative or stop-gap keep pavements in operational / safe condition applied on pavements above the condition limit slowing the rate of deterioration does not add structural capacity Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Routine Maintenance Patching Replace a partial depth or the full depth of the HMA layer and may include replacement of base and subbase layers. Repair structural and material related distresses such as alligator cracking, rutting, corrugation, slippage cracking. Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Routine Maintenance Crack Sealing Ceaning and sealing or resealing cracks on the HMA layer. Fill longitudinal cracks, transverse cracks, or joint reflection cracks. Primary purpose: prevent water infiltration (pavement overall in good condition; worthless otherwise). Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Part 1 Pavement Management Pavement Distress Routine Maintenance Minor Rehabilitation Major Rehabilitation Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Minor Rehabilitation Generally applied to the entire pavement section with the primary goal of slowing the rate of deterioration Applied on pavements above a condition limit Include the following types of treatment: Fog seal Rejuvenators Slurry seal Surface treatment Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Minor Rehab FOG SEAL Spraying a light coat of asphalt binder, usually an asphalt emulsion heated up to 150F (0.03-0.05 gall/sq.yd.) on the surface of an existing pavement. Prolong the life of an AC pavement, reduce raveling and improve waterproofing. Good for pavements with little or no traffic (includes paved shoulders). Without traffic, AC pavements tend t ravel and harden faster than pavements that support moderate to heavy traffic. Pavements closed to traffic for 12-24hrs to allow the material to cure. Asphalt emulsion: normally 1 part of emulsion to at least 4 parts of water. Also to 10 parts of water. Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Minor Rehab REJUVENATORS Russian Engineers Training March 2011 Minor Rehab REJUVENATORS Bituminous materials sprayed on the surface of an existing pavement using a distributor (0.02-0.08 gal/sq.yd. rate based on the condition of the HMA surface). Seal and waterproof pavement surface Penetrate the HMA surface and soften the asphalt binder. Reduce the rate of asphalt hardening  reduce the severity of temperature cracking. Check on the amount of rejuvenator to apply. If too high rate, some rejuvenator will not penetrate the surface and skid resistance reduced significantly. If excess rejuvenator  sanded and removed form the surface. Not to be applied on pavement surface already treated where there is already a large amount of asphalt (bitumen) near the surface; this will result in a sticky, soft surface. Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Minor Rehab SLURRY SEAL Russian Engineers Training March 2011 Minor Rehab SLURRY SEAL emulsion + water + well-graded fine aggregate + mineral filler Provide a surface seal or skid-resistant surface to structurally sound pavements Fill small cracks (< 1/8in width); larger cracks need to be repaired prior the treatment. Pavement with low to moderate level of traffic Applied when ambient temperature is above 60F and no danger of rain. Lower temperature and wet weather slow curing time or stop curing. Pavement closed to traffic for about 24hrs. New polymer mixtures allow re-opening section after 45 minutes. Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Slurry Seal – Construction Procedure Russian Engineers Training March 2011 Aggregate Bin Filler Bin Aggregate Flow Gate Aggregate Conveyor Belt Emulsion Injector Water Injector Slurry Pugmill Spreader Box Pavement Maintenance & Rehabilitation

Minor Rehab SURFACE TREATMENT Russian Engineers Training March 2011 Minor Rehab SURFACE TREATMENT Apply an asphalt binder followed by a layer of aggregate, rolled into the binder  Chip Seal If SAND  Sand Seal Provide a surface seal or skid-resistant surface to structurally sound pavements Single or double treatments applied Pavement with low to moderate traffic One-size aggregate with clean and cubical particles. Elongated particles may result in the submersion of the aggregate into the asphalt and consequent bleeding Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Surface Treatment – Construction Procedure Asphalt application 2. Rock application 3. Rolling/compaction 4. Sweeping/brooming 2 1 3 Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Minor Rehab OTHER TREATMENTS Russian Engineers Training March 2011 Minor Rehab OTHER TREATMENTS Cape Seal = Chip seal + Slurry seal Micro-surfacing: Slurry seal with high quality materials, dense graded aggregate, asphalt additives. Used to fill the wheel ruts up to 1.5 inches Provide stable, durable surface Applied when ambient temperature is above 60F and no danger of rain. Lower temperature and wet weather slow curing time or stop curing. Pavement closed to traffic for about 24hrs. New polymer mixtures allow re-opening section after 45 minutes. Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Part 1 Pavement Management Pavement Distress Routine Maintenance Minor Rehabilitation Major Rehabilitation Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Major Rehabilitation Applied to improve structural and / or functional requirements. Applied to deteriorated pavements, pavements deteriorating at a rapid rate, and pavements subjected to a change in traffic. Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Major Rehabilitation Overlays Pre-Overlay Repair Reflective Cracking In-place Recycling Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Major Rehab OVERLAYS Usually applied when pavement is in good condition May require minor repairs to the pavement prior to the HMA overlay HMA overlay over PCC pavements Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Overlay – Thickness Design Russian Engineers Training March 2011 Overlay – Thickness Design Total structural requirement (based on the needed Structural Number (a1), AASHTO, 1993) Limiting deflection approach (proposed by the Asphalt Institute, 1983) Limiting fatigue damage (mechanistic approach) Mechanistic analysis using elastic-layer theory and finite-element numerical methods. Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Overlay – HMA on HMA Pavement Russian Engineers Training March 2011 Overlay – HMA on HMA Pavement HMA thickness design Combined with other activities such as cold milling, hot recycling, and heater scarification Should perform minor repairs on the existing pavement prior to overlay Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Overlay – HMA on Concrete Pavements Russian Engineers Training March 2011 Overlay – HMA on Concrete Pavements HMA thickness design Structural condition of the PCC pavement Main issue: propagation of reflective cracks and further deterioration Discomfort generated by the reflective cracks Water infiltration Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Major Rehab PRE-OVERLAY REPAIR For PCC slabs Slab stabilization Fractured slabs Slab repair / replacement Load transfer restoration NCHRP synthesis will be published soon Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Pre-overlay Treatments of PCC Pavements Crack and Seat Crack size 2 feet max Must have existing good subgrades Concrete slab rubbilization Pavement is broken into pieces ranging from aggregate size to a max of 6-12in Compaction with a 10 ton steel wheel or vibratory roller Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Cracking and Seating Overlay Subgrade Soil Subbase Firm Foundation Cracks Short slab length (~2’) Good granular interlock Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Rubblization Slabs crashed into smaller pieces Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Post-overlay Treatments on HMA Layer Sawing and Sealing Joints Concede appearance of reflection cracking Objective: control rate of deterioration Reduces spalling of reflection cracks Slabs should have well-defined joints Saw cut MUST be directly above the underlying joint NCHRP synthesis will be published soon Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Sawing and Sealing Joints Russian Engineers Training March 2011 Reflective crack Overlay Old pavement Sealant Initial saw cut 1/3 depth Horizontal opening Joint reservoir Subgrade Vertical differential movement Pavement Maintenance & Rehabilitation

Major Rehab REFLECTIVE CRACKING Russian Engineers Training March 2011 Major Rehab REFLECTIVE CRACKING Shearing stress HMA bending stress HMA overlay Tip of the joint or working crack Void A B C Old PCC pavement Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Reflective Cracking – HMA on PCC Prevent reflective cracking: Geo-textiles contribution related to climate Geotextiles or fabrics Stress relieving or stress absorbing membrane interlayers “Band aid” type crack sealants Ineffective Research produced mixed results about effectiveness in Area II Very effective from Rollings, R. (1989), “Design of Airfield Overlays”, 2nd International Symposium on pavement evaluation and overlay design, Rio de Janeiro, Brazil. Pavement Maintenance & Rehabilitation

Reflective Crack Control Measures Russian Engineers Training March 2011 Reflective Crack Control Measures Interlayer systems Stress-relieving interlayer Crack-arresting interlayer Pre-overlay treatments (Crack & seat, rubbilizing) Pre-overlay repairs (slab repair, stabilization) Post-overlay treatments (saw cut and seal joints) Increased overlay thickness Some methods to prevent reflection cracking include also: Sand Asphalt; Geotextile; Geomembrane/Geocomposite Grid/ Steel Netting Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Interlayer Systems Reinforcement: - Stiff materials to compensate for lack of HMA tensile strength Strain tolerant (Stress relief): - Soft materials to dissipate strain energy by deforming itself Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Stress-Absorbing Interlayers Russian Engineers Training March 2011 Stress-Absorbing Interlayers Old pavement Vertical differential Movement Stress concentration Membrane Subgrade Soil Horizontal opening Overlay Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Interlayer System: an Example at Louisiana DOT Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation 52

Russian Engineers Training March 2011 Interlayer System: an Example at Louisiana DOT - Conclusions Stone Interlayer showed about 1/2 of the conventional cracking after 10 years of service. • Stone Interlayer had almost 4 times the performance life of conventional soil cement. • Stone interlayer systems are more economical. • Structural capacity, ride, and rutting are similar. • RAP is an effective alternative for stone. TR News Issue Number: 233 (2004) Publisher: Transportation Research Board Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation 53

Russian Engineers Training March 2011 Interlayer System: Examples Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation 54

Russian Engineers Training March 2011 Interlayer System: Examples Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation 55

Reduction in Reflection Cracking Russian Engineers Training March 2011 Reduction in Reflection Cracking Material Trans. Long. Polyguard 665 35 % 0.3 % Royston #108 90 % 0 % Royston #10AR 35 % 0 % PavePrep 5 % 2 % POLYGUARD PAVEMENT MEMBRANES are rubberized asphalt waterproofing adhesive, laminated to polypropylene fabric backings. The laminated membrane is wound onto a disposable silicone treated release sheet to prevent the membrane from sticking onto itself while in the roll. Royston: membrane and adhesive coat Roadglas is a woven glass fiber roving fabric. It has a tensile strength of about 800 lbs per inch. A polymer-modified asphalt binder called Roadbond was used with the Roadglas system. Bituthene: Self-adhesive rubber/bitumen polyethylene waterproof membrane for basements and sub-structures. Petrotac: stress absorbing membrane Roadglas 29 % 0 % Bituthene H.D. 50 % 0 % Petrotac 30 % 0 % Pavement Maintenance & Rehabilitation

Increased Overlay Thickness Russian Engineers Training March 2011 Increased Overlay Thickness Delays the occurrence of reflective cracks Cracks propagate about 25 mm per year Reduces temperature fluctuations in underlying pavement Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Major Rehab IN-PLACE RECYCLING Russian Engineers Training March 2011 Major Rehab IN-PLACE RECYCLING Hot In-place Recycling Cold In-place Recycling Full Depth Reclamation Rubblization Covered 2nd Tuesday Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation

Russian Engineers Training March 2011 Questions? Part 1 Pavement Management Pavement Distress Routine Maintenance Minor Rehabilitation Major Rehabilitation Pavement Maintenance & Rehabilitation Pavement Maintenance & Rehabilitation