Comparative Study of The Asphalt Mix Stiffness Modulus Using Selected Test Methods – 2-Point Bending Test, 4-Point Bending Test and Indirect Tensile Test

The stiffness modulus of the asphalt mixture is a fundamental parameter in the understanding of the mixture strain behavior. It is also an essential design parameter of asphalt pavements. According to the European standards EN 12697-26, various test methods can be performed in order to determine this criterion. These tests are varying according to the loading type and the specimen dimensions and shape. The present paper deals with the study of three test methods: the 2-point bending test on trapezoidal specimens (2PB–TR), the 4-point bending test on prismatic specimens (4PB–PR), and the indirect tension test on cylindrical specimens (IT CY) used on three asphalt mixtures representing different structural pavement layers. The results show that the dual comparison of these tests, i.e., IT-CY and 4PB-PR, and 4PB-PR and 2PB-TR have indicated good correlation between each other. However, the comparison between the three tests did not substantiate to any general correlation.