The Influence of Additives, Binder Content, and Constant Strain Levels on Fatigue Life of Asphalt Concrete

Abstract

Fatigue life of asphalt concrete is considered as a suitable measure of the suitability of its ingredient to act as a sustainable mixture. In the present work, asphalt concrete mixture was prepared with optimum binder requirements. Additional mixtures with ± 0.5 % binder from the optimum were also prepared. Two types of additives (coal fly ash and silica fumes) have been implicated into the asphalt cement in the wet process technique. Asphalt concrete mixtures were compacted into a slab mold with the aid of laboratory rollers. Beam specimens were obtained from the slab samples and tested for fatigue life at 20℃ environment using the four points bending beam apparatus. Three types of constant strain levels (750, 400, and 250) microstrain were implemented. It was observed that implication of coal fly ash additive exhibit higher fatigue life than the silica fumes treated mixture. However, both additives exhibit positive influence on the fatigue life as compared with the control mixture regardless of the constant strain level adopted for mixtures prepared with optimum binder content.