Towards an Accurate Stress Dependant Time & Frequency Domain VE Response Model for Bituminous Binders

Abstract

Linear viscoelastic properties of bituminous binders for short loading times are analyzed using dynamic mechanical analysis methods. Dynamic Shear Rheometer (DSR) test with parallel plate (PP) configuration is widely used for this purpose. Due to the complex stress distribution over the cross-section of the test sample, application of this setup for nonlinear material characterization, however, has been limited. Cone-and-Plate (CP) setup on the other hand provides a relatively uniform shear stress distribution. Due to this geometrical advantage a new CP configuration were developed and used to conduct constant-stress response measurements. Application of the setup for response measurement was first verified by comparing the CP and PP results obtained at low stress levels. The effects of the non-uniform stress distribution on fatigue results were also evaluated. Using material properties obtained from dynamic tests, simulation of time-domain relaxation tests with short loading times were in good agreement with experimentally obtained relaxation test results at low stress levels. Binder response at higher stress levels exhibits a nonlinear, stress dependent, behavior.Road and Railway EngineeringCivil Engineering and Geoscience