Russian roads
New look

Colored asphalt

ABZ-1 OJSC has been producing colored asphalt since 2004. The Company produces red mastic asphalt. However, the laboratory of the enterprise has selected recipes of a wide color range both of compactible and mastic asphalt mixes.

Based on the results of the study of the colored coverings that can be used at the facilities of Saint Petersburg ABZ-1 OJSC offers a brief description of the possible variants. Various shades can be obtained in the following ways:

  1. colored asphalt coverings: it is possible to use coloring agents for road bitumen of sorrel color close to the red granite color or to use a colorless synthetic binder in combination with coloring agents,  which allows to obtain a wide range of colored road asphalt mixes for coverings;
  2. surface treatment of asphalt with colored broken stone;
  3. use of colored coverings with subsequent application of special paints and materials on various binders (synthetic, epoxy, polyurethane and others).

The 2nd and 3rd variants will be the least expensive but their use as coverings with intensive traffic is inexpedient due to the possible wear of certain areas where the mechanical impact is the highest.

A more expedient variant for roads with intensive traffic is use of materials that do not lose color as the pavement wears off. Most suitable for these purposes is the covering made from compactible or mastic asphalt from 3 to 7 cm thick. The best effect in choosing the shade is achieved by application of a colorless synthetic binder in the asphalt instead of bitumen. Such a binder is produced by many European oil-refining concerns. In this case to obtain a bright red color in production of asphalt it is necessary to use less inorganic coloring agent, the thickness of such coverings being 5 cm. it should be noted that A-type asphalt mixes produced on diorite, granite or diabase may partly lose its color as the grey stone material is exposed due to removal of the binder from the surface of the asphalt; therefore, the choice of the broken stone color is quite important.

It is possible to use granite or quartzite as broken stone providing red color shades. Mastic asphalt is less demanding of the broken stone color. This is due to the fact that the mass fraction of an asphalt binder conditioning the covering color in mastic asphalt is twice higher than in A-type asphalt; hence, the share of broken stone in mastic asphalt is 37% against 62% in compactible asphalt. Mastic asphalt can be produced both using colorless and ordinary bitumen; the only difference is the brightness of the covering color. To ensure a coarse surface it is necessary to strew the surface of the mastic asphalt with red crushed-stone fines at the rate of 10-12 kg/m2.

Thus, ABZ-1 OJSC considers three variants of red colored covering to be the most reasonable and long-lasting:

  • from small-grained A-type asphalt on a colorless binder using a coloring agent and red broken stone;
  • from A-type mastic asphalt on a colorless binder with red broken stone surface dressing;   
  • from A-type mastic asphalt on ordinary bitumen with polymers using a coloring agent and red broken stone surface dressing.

Each variant implies use of laying and transportation machinery and an asphalt plant cleaned from gilsonite residues; therefore, during the process of laying a colored covering these machines should not be used for other operations.