A theoretical investigation into the 4 point bending test

Abstract

In the Netherlands use is made of a mechanistic asphalt pavement design strategy. Asphalt stiffness and fatigue properties are important inputs for this design approach. In the Netherlands these properties are traditionally determined by 4 point bending tests (4pb). In this paper the accuracy of that test is discussed on the basis of Finite Element modelling. It is shown that application of the EN-standard results in an underestimation of the stiffness by 3.2% (at 7500 MPa) and an underestimation of the phase lag by 0.4° (lag=20° and 20 Hz.). It is shown that a thorough analysis of the 4pb may reduce these errors to a stiffness that is underestimated by 0.88% and a phase lag which is overestimated by 0.1°. © RILEM 2012.