Experimental study on mode I fracture toughness of different asphalt mixtures

Low temperature cracking is one of the main distresses observed in pavementsmade of hot mix asphalt mixtures. as a material property, the fracture toughness ofasphalt pavements is a fundamental parameter for estimating the load bearing capacity andresistance of cracked pavements against crack growth. in this paper, the fracture toughness(kic) of dierent and various compositions of asphalt mixtures is obtained experimentally,and the eects of asphalt characteristic specications and its composition are investigatedon the value of kic. several asphalt mixtures were prepared with three aggregate sizes, twoaggregate types (limestone and siliceous), dierent air void percentages ranging from 3.5 to8%, and two binders (60/70 and 85/100). other similar work has only studied the inuenceof limited characteristic parameters on the low temperature fracture resistance of asphaltmixtures. several semi-circular bend (scb) specimens subjected to three point bendloading were manufactured with dierent compositions and were then tested at ??15c.the experimental results showed the noticeable inuence of characteristic specicationsof asphalt mixtures on the value of kic. generally, the value of kic decreases for thosemixtures containing a smaller size of aggregates made of siliceous, with higher percentagesof air voids and softer binder types.