Moisture damage and low temperature cracking of modified bituminous mixtures for road pavements

This paper presents an experimental evaluation of moisture damage and low temperature cracking behavior of three bituminous mixtures (Stone Mastic Asphalt, wearing course and base course asphalt concretes), made with steel slag aggregate and different asphalt binders (hard and soft polymer modified bitumen as well as crumb rubber modified bitumen). The asphalt concretes, designed with the traditional Marshall procedure, were tested under aged and unaged conditions. Indirect Tensile Strength Test were used in order to characterize the mixes. The experiments demonstrate that bitumen modified with crumb rubber (from scrap tires), allows to re-use a large amount of steel aggregate (up to 93%, depending on the mixes), with satisfactory results in terms of moisture and low temperature cracking resistance, also in the aged conditions.