Observations, Analysis, and Prediction of Asphalt Cracking

Abstract

The various causes/categories of pavement cracking and generalized criteria for identification of potential deficiencies are presented in conjunction with case histories that relate to investigations of pavement distress. Asphalt binder properties,  such as viscosity and penetration are shown to relate well with thermal and combined thermal/load stress conditions. Although slightly more involved testing procedures are required, criteria have been developed for different yearly ESALS to identify a paving mixture’s resistance to top-down cracking. Dissipated creep strain energy parameters are obtained from indirect tension tests to define an energy ratio for separating cracked from uncracked pavements. It is difficult to interpret Falling Weight Deflectometer (FWD) data from cracked pavements unless special procedures are followed. At high pavement temperatures the influence of cracks will diminish and allow for improved determination of moduli for underlying  pavement layers and foundation/ subgrade soils. These analyses are enhanced when asphalt viscosity relationships with resilient moduli are used to assign E1 values for backcalculation. Relationships or procedures for estimation of any pavement layer or subgrade modulus are very beneficial in simplifying the interpretation or backcalculation of other layer moduli. Where possible, laboratory test parameters that relate directly to the behavior of paving mixtures should be  integrated in the design and performance models for asphalt pavements. Realistic, multiple/simplified, methods for design and/or evaluation of pavement performance are desirable over one specific approach since comparable results are an indication of reliability.