RELATING TRIAXIAL TEST PROPERTIES OF ASPHALT MIXTURES TO MIX PARAMETERS DETERMINED BY MARSHALL STABILITY TEST

The conventional method of asphalt mix design based on the Marshall st ability test cannot be used directly for pavement thickness design and performance analysis. On the other hand, the triaxial test that measu res fundamental engineering properties of friction-cohesive materials is a well understood and established test in civil engineering, and th e authors have reported in an earlier paper that triaxial test propert ies of asphalt mixtures can be used to study analytically the response of the mixtures under loads. In an effort to establish a link between the two tests, this paper illustrates that the three triaxial test-de termined properties of an asphalt mixture, namely cohesion c, angle of friction phi and elastic modulus E-p, are statistically correlated wi th Marshall stability test properties of the asphalt mixture. The stat istical analyses furnish useful information on the trends of variation of various material parameters as a function of mix properties. Poten tially useful statistical regression predictive models are derived for predicting material parameters of the Marshall stability tests using the triaxial test properties, and vice versa. Such models make it poss ible to analyze pavement performance under loads for those pavements c onstructed based on Marshall mix design.