Study of characteristic specification on mixed mode fracture toughness of asphalt mixtures

Low temperature cracking is one of the main deterioration and failure modes for pavements. Hence, in this paper the effect of asphalt characteristic on its mixed mode I/II low temperature fracture toughness is investigated experimentally. A large number of edge cracked semi circular bend specimens subjected to asymmetric three-point bend loading were tested for different hot mix asphalt mixtures made of various compositions. The influence of aggregate type and size, binder type and air void content were studied on the critical stress intensity factors of four mode mixtures ranging from pure mode I to pure mode II. The fracture toughness results showed the noticeable influence of asphalt characteristic specifications on the low temperature cracking behaviour of mixtures subjected to mixed mode loading.