This paper addresses a study conducted in coherence with the Dutch SHRP satellite experiment (SHRP-NL). In the pre-selective stage of this program, the final test sections were selected from a series of candidate sections on the basis of homogeneity of geometry and traffic loading on the one hand, and load-carrying capabilities on the other. The Lacroix Deflectograph was used to determine the structural condition and homogeneity of the pavements. A procedure has been developed to estimate the residual structural integrity, expressed as an index of retained effective thickness. Deflectograph deflections and distress identification served as major input variables. The procedure makes use of the whole deflection basin and is not restricted to application of the maximum deflection only. The flexural rigidity, extracted from the deflection bowl proved a powerful parameter. Some 50 SHRP-NL test sections were analysed. Asphalt coring on cracks provided information on crack depth and whether cracks propagated top-down or bottom-up. Combination of the test and analysis results led to a procedure which allows quick assessment of the structural condition of an asphalt pavement structure on the basis of easy-to-measure data, incorporating an indication about the probable crack-mode (bottom-up or top-down). (A)
Samenvatting