Pavement Evaluation
Pavement performance is a function of its relative ability to serve traffic over a period of time (Highway Research Board, 1962). Originally, a pavement’s relative ability to serve traffic was determined quite subjectively by visual inspection and experience.
Reviewed by licensed engineers · How we review
Overview
Condition and ride
Surface Distress
Surface distress is "Any indication of poor or unfavorable pavement performance or signs of impending failure; any unsatisfactory performance of a pavement short of failure" (Highway Research Board, 1970).
Pavement Condition Rating Systems
Based on measurements of roughness, surface distress, skid resistance and deflection, pavements can be assigned a score that reflects their overall condition.
Present Serviceability Index
The present serviceability index (PSI) is based on the original AASHO Road Test PSR. Basically, the PSR was a ride quality rating that required a panel of observers to actually ride in an automobile over the pavement in question.
Roughness
Pavement roughness is generally defined as an expression of irregularities in the pavement surface that adversely affect the ride quality of a vehicle (and thus the user).
Skid Resistance
Skid resistance is the force developed when a tire that is prevented from rotating slides along the pavement surface (Highway Research Board, 1972). Skid resistance is an important pavement evaluation parameter because:
Structural testing
Deflection
Pavement surface deflection measurements are the primary means of evaluating a flexible pavement structure and rigid pavement load transfer.
Deflection Based Nondestructive Pavement Analyses
This topic will be oriented toward techniques which can be used to interpret nondestructive testing, NDT, data from the Falling Weight Deflectometer, FWD.
FWD AREA Parameter
FWD tests produce a series of numbers that describes the deflection basin shape. Although these numbers are descriptive, it is often desired to use a single number as a index of the deflection basin shape.
Ground Penetrating Radar
GPR is a nondestructive field test that can provide a continuous profile of existing road conditions. GPR can utilize high-speed data collection at speeds up to 50 mph, thus requiring less traffic control and resulting in greater safety.
Dynamic Cone Penetration Test
The Dynamic Cone Penetration Test provides a measure of a material’s in-situ resistance to penetration.
Super heavy loads
Super Heavy Load Analysis
Superheavy loads are defined as loads that exceed 254,300-lbs. gross vehicle weight, exceed the maximum permissible weight on any axle or axle group, or exceed 200,000 pounds with less than 95 feet of axle spacing.
Damage from Superheavy Load Moves
The typical damages related to superheavy load moves are summarized as follows: