Coloured bituminous surfacings are used to make roads in urban or touristic areas more visually attractive and also for reasons of comfort and safety. In these materials black bitumen is replaced by a translucent synthetic binder, whose colour can easily be modified by pigments. This is done, for example, for the wearing course in tunnels. In tunnels, these light-coloured surfacings are preferred to traditional black surfacings as they provide an improvement in visibility and safety with a lighting saving of approximately 30%. Using microsurfacing overcomes the problems posed by removal of the heat and fumes produced when hot mixes are laid. This paper aims to present the results of research which has let the development of two coloured emulsion products that are able to meet the specifications for tunnel wearing courses. The first part of the paper deals with the development of a coloured microsurfacing with continuous or gap 0/6 grading. The laboratory mix design study is presented, then a number of applications, both white and red, are described. The second part of the paper deals with a light-coloured emulsion asphalt concrete with 0/6 grading that is laid with a paver in a thickness of 2 to 3 cm. The results of the laboratory studies which have established the performance of this product in terms of workability, rutting resistance and skidding resistance are described. We then present a worksite where the product was used. This product was awarded the Siemens Prize for Innovation in 2001. For the covering abstract see ITRD E135448.
Abstract