This paper discusses the effects of ambient temperature and thermal cycling on the creep of bituminous pavement materials, based on the results of laboratory testing. Two types of aggregate, rounded and crushed, and two grades of bitumen, 49 and 86 pen, were used to prepare laboratory samples that were subjected to uniaxial creep testing. The effect of ambient temperature changes on the performance ofthe materials was investigated by thermal cycling and the effects on creep and mix stiffness reported. In summary, it was found that crushed gritstone aggregate showed creep-resisting properties superiorto those of round gravel aggregates. Furthermore, the addition of ethylene vinyl acetate copolymer to the mixes studied resulted in considerable reduction in creep, which was particularly marked at higher ambient temperatures. This paper appears in transportation research record no. 1228, Asphalt mixtures and asphalt chemistry.
Abstract