A COMPARISON OF THE ZERO SHEAR VISCOSITY FROM OSCILLATION TESTS AND THE REPEATED CREEP TEST

Abstract

One of the promising candidates as a European binder performance indicator is the zero shear viscosity (ZSV) or the viscosity at zero shear rate. ZSV can be measured in a dynamic shear rheometer in an oscillation test or in a creep test. The diversity of binders that is available nowadays (wide range of penetration values, pure and modified, waxy binders, oxidised binders, etc.), requires the development of test methods applicable to all of these binders. This paper presents results of ZSV measurements in oscillation mode on a selection of four binders. The measurements are made with different rheometers in different labs, to study repeatability and reproducibility. The binders are also subjected to the repeated creep test proposed in the United States. The creep stiffness measured in this test was shown to be a more appropriate indicator for rutting than the parameter G*/sin delta, particularly for the case of PmBs. The two test methods for characterizing the rutting resistance of binders can thus be compared. For the covering abstract see ITRD E121480.