Failure Mechanism of Sustainable Asphalt Concrete under Environmental Influence

Abstract

The performance of asphalt concrete pavement changes under the influence of environment and dynamic loading; this can reveal their rheological characteristics and affect the sustainability and fatigue life of asphalt concrete. An attempt has been made in the present study to detect the failure mechanism of asphalt concrete mixture when practicing three levels of constant strain through the fatigue life and sustaining environmental influence. Slab samples of asphalt concrete mixtures were prepared with optimum binder content and compacted in the laboratory by roller. Beam specimens were extruded and tested for fatigue life under dynamic flexural stresses. Three testing environments (30, 20, and 5) ℃ and three constant strain levels (750, 400, and 250) Microstrain were implemented. The failure mechanism occurred in three stages when low strain level of 250 Microstrain was implemented regardless of the testing environment while five stages of failure are observed when moderate strain level of 400 Microstrain is considered. However, two stages of failure could be detected when the beam specimens were tested at high strain level of 750 micro strains. It was concluded that cold testing environment can control the decline in the flexural stiffness of asphalt concrete regardless of the implemented strain levels and enhance the fatigue life of asphalt concrete as compared with other testing environments.