There is an emphasis on recycled materials and reducing the amount of energy required to produce asphalt. Low-temperature asphalt is one such development. Asphalt’s core ingredients are aggregate, bitumen, additives, and air. Bitumen is produced in various grades of hardness. Depending on the mix and grade of bitumen used, it is possible to lay road surfaces to meet a variety of requirements.
Colored asphalt is increasingly being used not only in road construction but also in gardens and landscape architecture. Colored asphalt pavement can be used to differentiate bike paths from roads and direct traffic. It is also suitable for highlighting dangerous points and in making areas more attractive. For instance, functional colour differentiation can highlight pedestrian and bicycle paths, thus increasing the safety of road users.
LANXESS is offering Bayferrox® and Colortherm® pigments for colouring bituminous mixtures used as raw materials for all asphalt types such as grid mastic asphalt, noise-reducing and semi-rigid asphalt, and asphalt concrete. The color is influenced mainly by the type of bitumen used. Dark bitumens are most commonly colored red by using inherently heat-stable iron oxide red pigments with high tinting strength. By using a clear polymer bitumen, the color spectrum can be extended to even yellow or green surfaces.
LANXESS pigments provide further decisive benefits. Bayferrox® 130A red pigment, for example, provides the highest heat stability in the market. Since it is produced via the Laux-Process, the product’s colour is not influenced even at the high manufacturing temperatures that are applied during the production of mastic asphalt. Bayferrox® 130A is also available in low-melt PE bags which can be dosed manually and directly into the asphalt mix.