Role of a food grade additive in the high temperature performance of modified bitumens

A good adhesion between bitumen, the common binder used in the construction of pavements, andmineral aggregates is a key property for optimal performance of the road paving material (asphalt). Moreover, as bituminous material is viscoelastic in nature, an improvement of its mechanical responsedoes represent an equally important factor in the design of roads. To date, a variety of chemical compoundshas been tested as bitumen modifiers and evaluated in their capacity to improve the adhesion of binderto the aggregates and promote an increase of the bitumen softening point, especially in warm ambientconditions. This contribution explores, for the first time, the potentialities of a class of lipophilic food gradeadditives, i. e., non-toxic and eco-friendly biocompatible compounds, acting both as adhesion promotersand as rheological modifiers. Their effects on the high temperature mechanical performance of a testedbitumen have been investigated through time cure rheological measurements and the sol-transitiontemperature determined in a wide range of temperatures. Measurements of the contact angle betweenthe aggregate surface and modified bitumens preventively blended with increasing amounts of food gradeadditives were also carried out. We believe that those results could provide an alternative opportunity touse additives from natural resources in the design of sustainable and much more performant asphalts. (C) 2017 Elsevier B.V. All rights reserved.