Effect of Characteristic Specifications on Fracture Toughness of Asphalt Concrete Materials

Abstract In this research, the fracture toughness (KIc) of different compositions of asphalt mixtures is investigated experimentally and the effects of asphalt characteristic specifications including the aggregate size, aggregate type (i.e. limestone and siliceous), air void percentage and bitumen type on fracture toughness is studied. Several edge cracked specimens with the shape of semi-circular and subjected to symmetric three point bend loading were manufactured with different compositions and then tested at-15oc. The experimental results showed the noticeable influence of characteristic specifications of asphalt mixtures on the value of fracture toughness. Generally, the value of fracture toughness decreases for those mixtures containing smaller size of aggregates made of siliceous with higher percentages of air voids and softer binder types