pavement maintenance 1: part 2: distress identification idaho roads scholar program
TRANSCRIPT
PAVEMENT MAINTENANCE 1:Part 2: Distress Identification
Idaho Roads Scholar Program
Learning Objectives
Recognize Asphalt Pavement Distresses
Know the Causes of Main Types of Distress
Determine Which Pavements are Good Candidates for Pavement Preservation
What pavement characteristics indicate pavement condition?
Visible performance indicators Functional indicators Structural indicators
Non-Visible defects Environmental effects on materials Load-related damage
What techniques are used to assess pavement condition?
Visual distress surveys Roughness surveys Friction surveys Drainage evaluation Shoulder surveys Deflection testing
Progression of Pavement Deterioration
Pavement Distress Categories Load
Example: Fatigue Cracking Climate
Example: Weathering/Raveling Other
Construction
Load Related Distresses
Fatigue Cracking Potholes Rutting Edge Cracking Shoving
Fatigue Cracking
Possible Causes Weak base/subgrade Thin pavement / under designed Poor Drainage Overloading
Bottom-up cracking
Fatigue Cracking
Fatigue Cracking
Longitudinal/Transverse Cracking
150 mm
50 mm
Washington State - Top-Down inAsphalt Pavements > 150 mm
M32
M32CORE
TRL
Rutting
In Subgrade/Base Design Problem
In the AC Layer Plastic Flow--Material/Mix Design Consolidation--Compaction Surface Wear
Rutting
Rutting
Rutting in Subgrade/Base
originaloriginalprofileprofile
weak subgrade or underlying layerweak subgrade or underlying layer
asphalt layerasphalt layer
subgradesubgradedeformationdeformation
Rutting in Asphalt Layer
originaloriginalprofileprofile
weak asphalt layerweak asphalt layer
shear planeshear plane
originaloriginalprofileprofile
Wheel path consolidationWheel path consolidation
Improper Improper compactioncompaction
Rutting in Asphalt Layer
Potholes
Severe, uncorrected result of another distress Alligator Cracking Raveling Failed Patches
Thin/Weak Pavement
Potholes
Edge Cracking
Poor lateral support Settlement of underlying material
poor drainage frost heave shrinkage/drying of soil
Aggravated by high traffic levels
Edge Cracking
Shoving
“Washboarding” Occurs at high stress locations
Intersections Steep Grades Ramps
Weak unstable mix Unstable base
Shoving
Climate Related Distresses Block Cracking Joint Reflective Cracking Thermal Cracking Weathering/Raveling
Block Cracking
Divides the pavement into rectangular pieces
1ft x 1ft to 10ft x 10ft Oxidation (Aging) Low AC% Mix Absorptive Aggregates
Block Cracking
Reflective Cracking
Generally over PCC pavements Caused by movement of the
underlying layer Vertically (Load) Horizontally (Thermal)
Reflective Cracking
Longitudinal/Transverse Cracking Transverse cracking is generally
thermally induced Longitudinal Cracking
paving lane joints poor compaction
Longitudinal/Transverse Cracking
Longitudinal/Transverse Cracking
Longitudinal/Transverse Cracking
Weathering/Raveling
Loss of aggregate on the surface Poor Compaction Cold/Wet Weather Construction Dirty Aggregate Low AC% Overheating Mix
Weathering/Raveling
Other Distresses
Bleeding Bumps/Sags Corrugation/
Shoving Depressions Lane/Shoulder
Drop Off
Patching/Utility Cuts
Polished Aggregate
Railroad Crossings
Slippage Cracks
Bleeding
Excessive Asphalt Too much asphalt in mix Too much crack sealant below
overlay Too heavy prime or tack coat?
Low air voids
Bleeding
Bleeding
Slippage Cracks
Caused by a shear plane in the pavement structure Too little tack Too much tack
Slippage Cracks
Primary HMA DeteriorationInitial Mechanisms of Deterioration
Asphalt Asphalt HardeningHardening
Various Various ChangesChanges
Environment /Environment /AgingAging
Material /Material /MixMix
Load / Load / TrafficTraffic
Plastic Plastic DeformationDeformation
Surface wearSurface wear
Primary HMA DeteriorationLoad-Related Distresses
Load
PlasticPlasticDeformationDeformation
RuttingRuttingRuttingRutting
Fatigue CrackingFatigue CrackingFatigue CrackingFatigue Cracking
Primary HMA DeteriorationTraffic-Related Distresses
Traffic
Surface Surface WearWear
Friction LossFriction Loss
PolishingPolishingPolishingPolishing
Primary HMA DeteriorationEnvironment/Aging-Related Distresses
Environment/ Aging
Asphalt Asphalt HardeningHardening
Block CrackingBlock CrackingBlock CrackingBlock Cracking
Raveling/WeatheringRaveling/WeatheringRaveling/WeatheringRaveling/Weathering
Primary HMA DeteriorationMaterial/Mix-Related Distresses
Material Problems
Bleeding/FlushingBleeding/FlushingBleeding/FlushingBleeding/Flushing
Friction LossFriction Loss
Secondary HMA DeteriorationInfluence of Moisture Infiltration
Cracks +
MoistureInfiltration
Deteriorated CracksDeteriorated CracksDeteriorated CracksDeteriorated Cracks
Breakdown of Breakdown of Existing CracksExisting Cracks
Secondary HMA DeteriorationInfluence of Moisture Infiltration
PotholesPotholesPotholesPotholesCracks Cracks ++
MoistureMoistureInfiltrationInfiltration
Subgrade Subgrade SofteningSoftening
Loss of Fines (Pumping)Loss of Fines (Pumping)Loss of Fines (Pumping)Loss of Fines (Pumping)
Lane-to-Shoulder Drop-offLane-to-Shoulder Drop-offLane-to-Shoulder Drop-offLane-to-Shoulder Drop-off
Edge CrackingEdge CrackingEdge CrackingEdge Cracking
Preservation Candidates
Preservation treatments must be applied when: Pavements are in good
condition Corrective actions
required on only a small area of the total pavement
Preservation Candidates
Pavements are not candidates for preservation: Pavements in poor
condition Substantial repairs
required Structural deficiencies
Time or Traffic
Pa
vem
ent
Co
nd
itio
n In
dex10
0
0
Preventive Preservation Candidates
These Pavements are not Preservation Candidates
Critical PCI
Preservation Candidates
Review Recognize Asphalt Pavement
Distresses Know the Causes of Main Types of
Distress Determine Which Pavements are Good
Candidates for Pavement Preservation
Questions?
Distress
Identification