Paper by AL HAKIM AL NAGEIM POUNTNEY from ISCR 7th 1994 Vienna Austria
The paper discusses the role of non-destructive testing in pavement evaluation and the importance of bonding between its layers on back-calculated properties. Rigid composite pavement structures were analysed using the BISAR programme under different bonding coefficients (ks) between the asphalt and the concrete layers. The results indicate that: A small amount of debonding reduced the back-calculated moduli of the top and second layers in average by 20% and 8% of full adhesion case rospoctivoly. Deflections are very sensitive to the interface condition for the values of k between 1 0 and 10.2 m3/MN. Therefore the use of the interface friction coefficient in a fundamental back-analysis method allows for a more accurate calculation of the remaining life of the pavement, analysis of the causes of its failure, and more importantly, can be used as a quality control during construction and overlaying.