Assessing the Tensile Properties of Asphalt Concrete

Abstract

The tensile strength of asphalt concrete is essential to control the rutting behavior of the pavement. In the present work, asphalt concrete mixtures were compacted at optimum binder content to a target density using roller compaction. Extra mixtures with 0.5 % binder content above and below the optimum were also prepared. Core specimens were extruded from the compacted slab samples for testing. The tensile strength of asphalt concrete was assessed using the indirect tensile strength test and the semi-circular bending test. It was detected that the tensile strength as obtained by SCB is five and half fold and five-fold higher than that obtained by ITS when the specimens are tested at (20 and 0) °C respectively. The SCB tensile strength increase by 72.1 % when the specimens are tested at 0°C as compared with the testing at 20°C. However, it was observed that the tensile strength obtained from the Semi-Circular Bend test (SCB) increases as the binder content increase when compared with that obtained from Indirect tensile strength test (ITS). The slope of the SCB – Binder content at both testing temperature relationship increases while the intercept declines as the binder content increase. This can refer to the sensitivity of the SCB test to the binder and temperature variation. The ITS declines when the testing temperature changes from (0 to 20 and 40) ° C by (48.3, and 80.1) %, (48.5, and 78.1) %, and (48.3, and 81.3) % for mixtures with (4.4, 4.9, and 5.4) % binder respectively.