Relationship between absolute viscosity of polymer-modified bitumens and rutting resistance of pavement

Abstract

New polymer-modified bituminous binders require verification of the relationship between binder properties and road pavement performance, formerly found for conventional road bitumens. The paper deals with one particular problem of polymer-bitumen (PB) viscosity and bituminous mixture rutting resistance. Non-Newtonian, shear-dependent behaviour of PB in a viscosity meassurement has been characterized by a new equation proposed by the author. This equation enables calculation of the absolute (zero shear rate) viscosity of PB and is applied for evaluation of test results at 60and 90°C. The absolute viscosity of PB at 60°C has been correlated with the bituminous mixture's rutting resistance at 45°C. Correlation with other rheological properties of PB is also examined by means of multiple regression analysis.