POSSIBILITIES OF A SEMI-CIRCULAR BENDING TEST

The possibilities of a Semi-Circular Bending (SCB) test on semi-cylindrical specimens is investigated as an alternative to the Indirect Tensile Test (ITT) to determine the flexural strength, stiffness and fatigue behaviour of asphalt concrete. Finite element analysis relations for the stresses and deformations under SCB have been derived. Based on these relations the tensile strength and fatigue behaviour of two asphalt mixes were determined with laboratory tests. These results have been compared with ITT results on the same mixes. It can be concluded that the SCB gives results comparable with ITT for the tensile strength. The determination of stiffness requires accurate measurement of the relatively small vertical deformations under loading. Fatigue tests can also be carried out. The SCB test can be used as a mix design test for performance related specifications and a reliable quality control test for mix production and road construction. A standard test set-up is proposed.