The colour of asphalt mix, mainly for aesthetic reasons, has long been established. The range of colours, entirely determined by the composition of the bitumen, rich in asphaltenes and characteristically black resins, has practically been reduced to brownish red, green and grey. Albino bitumen, which has a low asphaltene content, is a partial solution. This binder produces colours similar to conventional asphalt bitumens but with less pigment. However, its mechanical characteristics, and consequently those of the asphlat mix, are reduced because it has a lower content of the hard bitumen component, asphaltene. The general volume has been increasing gradually and this has pushed the industry to develop a new material. Although it cannot be considered a bitumen from the point of view of its chemical composition, its physical characteristics have served as a target and have been in many ways improved. This new material, called a "synthetic binder" or clear binder, is a mix of resins, oils, polymers, agents that stabilize against ultraviolet light and other additives. The resulting colour is somewhere between light beige and caramel, it is easy to pigment an is in no way limited to any range of colours. For a little over ten years now hot mixes have been made with a synthetic binder aimed predominantly for use in parks and pedestrian area. In this paper, we discuss various experiments using synthetic binders as emulsions in typical cold technology applications. (A)
Samenvatting