What are the ways of colored asphalt pavement?

What we usually refer to as colored asphalt pavement refers to the mixture made of decolorized asphalt and various colored stone materials, color materials and additives, and then the formation of colored pavement by paving and rolling; It has the advantages of bright and durable color, easy maintenance, etc. But for the specific approach, I believe that many friends are not clear; Here is a detailed explanation for you:

Asphalt binder coloring

A small number of colored asphalt pavement materials can be obtained by filling inorganic metal salt pigments in asphalt or asphalt mixture instead of the same volume of mineral powder. For example, if the iron oxide (commonly known as red clay) is added to the asphalt mixture, the red asphalt pavement material can be obtained. Blackish green asphalt pavement material can be obtained by adding 5% ~ 10% chromium oxide.

However, the color asphalt surface material obtained by this method is low in tone and dark in brightness, so it is recommended not to be used in the asphalt mixture with a large amount of stone and traffic wear loss in the project.

Color with colored aggregates

In the traditional hot grinding pavement process, after paving the asphalt sand rubber layer, the colored stone is used to replace part of the ordinary stone according to the amount of more than 5kg per square meter. When the asphalt sand rubber layer still maintains a sufficient temperature, the rolling is spread, so that the stone is partially embedded in the asphalt sand rubber layer, and the colored pavement can be formed. The amount of colored stone determines the colorfulness of this road surface.

Colored asphalt binder

Colored asphalt binder is a kind of artificial synthetic resin which is very close to the performance of road petroleum asphalt, mostly milk gray or milk yellow. In order to facilitate production, color cementing materials with good pigments can be mixed with sand and stone materials according to the grading requirements, and colorful asphalt pavement can be obtained.

Heating quality loss and aging and yellowing after long-term use are the main indicators to judge the quality of colored asphalt binder.