Establishment of relationships between asphalt content and distress levels (rutting, fatigue cracking, and low temperature cracking) during the mix design process is one of the major advantages of the SUPERPAVE mix design system.
These relationships, which are specific for the mix under consideration, can be employed to predict the expected loss in the distress oriented pavement life resulting from any deviation in asphalt content from the target optimum value. Those expected losses in pavement life can be used as rational basis for the construction related pay adjustment factors. The pay adjustment factors in this case will have the advantage of being “mix specific”.
The overall pavement performance life may be significantly affected when the specified asphalt content, aggregate gradation (job mix formula) and degree of compaction are not achieved in situ. Quantification of these effects is essential for rational pay adjustment factors in asphalt pavement construction.
This paper presents a scheme that employs data obtained during the SUPERPAVE mix design process to predict the “mix specific” expected loss (or gain) in pavement performance life resulting from any in situ deviation in asphalt content, aggregate gradation and relative compaction from the specified job mix formula and degree of compaction tolerance bands.
The proposed scheme can be easily programmed and become as part of the structure of the SUPERPAVE software.