Volume 25, Issue 5 (September 1997)
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 stability test cannot be used directly for pavement thickness design and performance analysis. On the other hand, the triaxial test that measures fundamental engineering properties of friction-cohesive materials is a well understood and established test in civil engineering, and the authors have reported in an earlier paper that triaxial test properties 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-determined properties of an asphalt mixture, namely cohesion c, angle of friction φ and elastic modulus Ep, are statistically correlated with Marshall stability test properties of the asphalt mixture. The statistical analyses furnish useful information on the trends of variation of various material parameters as a function of mix properties. Potentially 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 possible to analyze pavement performance under loads for those pavements constructed based on Marshall mix design.