A new laboratory method to evaluate the influence of aggregate temperature on the binder-aggregate bonding: first results

Research paper by Saannibe Ciryle Somé, Vincent Gaudefroy, Didier Delaunay

Indexed on: 26 Jun '13Published on: 26 Jun '13Published in: Materials and Structures


In this paper, the effects of aggregates temperature reduction in asphalt mix manufacturing process have been analyzed in terms of complex modulus, fatigue and stripping resistance according to standard tests. The limits of these conventional standardized tests have been analyzed and a new method has been developed to estimate the bitumen-aggregate bonding quality when aggregate temperature is reduced. This method is based on the thermal contact resistance (TCR) assessment at the bitumen-substrate interface which reflects the contact imperfection at the microscopic scale. The study has shown that the TCR decreases when the aggregate temperature increases. Consequently, the TCR could be used as a bonding quality criterion in asphalt manufacturing condition when aggregates temperature is reduced. The results have been well correlated with a modified mechanical stripping test developed. It has been proved that when aggregates temperature decreases, the TCR increases and the stripping resistance decreases due to the poor bitumen-aggregates bonding.