EXPERIMENTAL-STUDY OF PURE BITUMENS IN TENSION, COMPRESSION, AND SHEAR

Two nominally identical pure bitumens, commonly employed for pavement construction in the United Kingdom, were tested in uniaxial tension, c ompression, and shear, over a wide range of temperatures, stresses, an d strain rates. The bitumens were found to exhibit linear viscous beha vior at low stress levels, and power-law creeping behavior at higher s tress levels. The temperature dependence was found to follow the Arrhe nius relationship at temperatures immediately above the glass transiti on and the Williams, Landel, and Ferry (WLF) equation at higher temper atures. Below the glass transition temperature,the Eyring plasticity m odel was found to hold. Constitutive models that reflect the physical mechanisms of steady state and transient deformation are proposed. The fracture properties of the bitumens are also discussed. (C) 1997 The Society of Rheology.