Influence of cooling medium on low temperature strength of asphalt binders

The effect of three different cooling media, ethanol, potassium acetate (PA) and air, on the strength of asphalt binder at low temperature is investigated with a modified Bending Beam Rheometer (BBR) and the Direct Tension Tester (DTT). Similar strength values are obtained in air and PA and significantly lower values are obtained in ethanol. The use of fluorescing markers demonstrates that ethanol diffuses in the asphalt binder, while diffusion does not occur when PA is used. Using size effect theory, BBR strengths in PA and in air are found to be equivalent to DTT strength in PA.