ENGINEERING A PREVENTIVE MAINTENANCE PROGRAM Elements Selection of

ENGINEERING A PREVENTIVE MAINTENANCE PROGRAM

Elements ØSelection of pavement sections ØDesign treatment ØPreventive maintenance program ØQuality control ØMonitoring

Selection of Treatments Pavement condition v. Environmental distress v. Roughness v. Skid resistance

Distresses in Asphalt Pavement

Types of Distresses ØFatigue cracking ØRutting ØThermal cracking ØBlock cracking ØRoughness ØFrost effect ØPoor drainage effect ØWater bleeding & pumping ØStripping • Raveling • Bleeding/flushing • Polished aggregate • Slickness • Shoving • Slippage Cracking • Depression • Reflection cracking • Etc.

Fatigue Cracking Wheel load HMA s urface Base Subb ase Soil

Early Stage of Fatigue Cracking Advanced Stage of Fatigue Cracking

Fatigue Cracking

Rutting (Permanent Deformation)

Rutting

Rutting Reasons Unstable HMA Poor Compaction During Construction Poor Subgrade

Thermal Cracking

Thermal Cracking

Block Cracking

Roughness

Frost Effect Frost Heave

Poor Drainage

Water Bleeding & Pumping Depression due to Pumping

Stripping Separation of bitumen from aggregate

Raveling

Bleeding/ Flushing

Polished Aggregate

Shoving at Intersections

Shoving

Slippage Cracking Ø Poor bond between layers Ø Unstable HMA

Depression

Reflective Cracking

Reflective Cracking Mechanism

Combination of Distresses ØCombine treatments to repair all distresses ØCuring between treatments

Distress Identification Manual

Preventive Maintenance ØPreventive maintenance is not structural ØDurability is key ØDurability is related to treatment selection, material selection and proper construction

Environment Preventive maintenance is effective for correcting environmental distress • Prevents water intrusion • Renews the surface

Construction Considerations ØSpeed of construction ØLife of the treatment

Treatment Design ØNo structural design ØMaterial selection v. Aggregate characteristics v. Binder v. Quantities ØSpecifications

How effective are these treatments? ØIt depends on pavement condition ØThe better the condition before the treatment, the more effective the treatment is. ØIt varies with the type of treatment

Chip Seal Extent of Problem Distress Type Fatigue Cracking Linear / Block Cracking “Stable” Rutting Raveling Flushing/Bleeding Roughness Friction Loss Moisture Damage Shoving Minor Major Effective Marginal No Impact

Microsurfacing Distress Type Fatigue Cracking Linear / Block Cracking “Stable” Rutting Raveling Flushing/Bleeding Roughness Friction Loss Moisture Damage Shoving Extent of Problem Minor Major Effective Marginal No Impact

Milling with Thin HMA Overlay Distress Type Fatigue Cracking Linear / Block Cracking “Stable” Rutting Raveling Flushing/Bleeding Roughness Friction Loss Moisture Damage Shoving Extent of Problem Minor Major Effective Marginal No Impact

Ultrathin Bonded Wearing Course (Novachip) Distress Type Fatigue Cracking Linear / Block Cracking “Stable” Rutting Raveling Flushing/Bleeding Roughness Friction Loss Moisture Damage Shoving Extent of Problem Minor Major Effective Marginal No Impact

Cold & Hot In-Place Recycling Extent of Problem Distress Type Fatigue Cracking Linear / Block Cracking “Stable” Rutting Raveling Flushing/Bleeding Roughness Friction Loss Moisture Damage Shoving Minor Major Effective Marginal No Impact

Pavement Condition Periodic Applications Crack sealing Chip seal Time or traffic

Quality Control 1. Method or Recipe Specification (Past) 2. End Result (Quasi-Present) 3. Quality Assurance (Present) 4. Performance Based (Future? )

1. Method or Recipe Specification (Past) COUNTY CITY STATE VILLAGE Department of Transportation Library

Method Specification (continued) ØAgency defines means and methods for performing work ØSplit responsibility v. Contractor v. Agency

2. End Result Specifications ØAgency defines required properties ØContractor controls process to achieve properties ØResponsibility is contractor’s

3. Quality Assurance Specifications ØSeparates responsibility for process control and product acceptance ØEnsures that inspection plays an essential role QC n Pla

4. Performance Based Specifications ØContractor warranties performance for a specified period of time ØContractor controls design, materials, and construction

Monitoring Performance Collect Store Analyze

Monitoring Performance ØNew applications of existing methods ØApplication of emerging technology ØNeed to evaluate cost-effectiveness