Recycling of Asphalt

Recycling of Asphalt

The main cause of deterioration on asphalt roads is the aging or oxidation of bituminous binders, leading to hardening over time. Today, the recycling of deteriorated old asphalt roads and their use in new asphalt road construction has become one of the primary concerns of the industry, both environmentally friendly and economically viable. The useful lifespan of asphalt pavement varies depending on factors such as traffic load, environmental conditions, foundation construction, material quality, water drainage, and more. It is possible to recycle damaged or expired asphalt pavements by milling them from the road surface for use in new bituminous hot mixtures. Aggregate and bitumen are limited and valuable natural resources. The reuse of bituminous binders and aggregates from milled old Hot Mix Asphalt (HMA) pavements will not only reduce costs but also contribute to environmental protection. In Europe, 50 million tons of reclaimed asphalt pavement (RAP) are produced annually, and this material is reused in new bituminous mixtures. Germany, Sweden, the Netherlands, and France are among the leading countries in RAP usage. There are two main applications for asphalt recycling: hot recycling at the asphalt plant and cold recycling in place. Depending on the traffic density of the road where the recycled asphalt will be applied, either the hot or cold recycling method can be chosen. For example, hot applications are preferred for roads with heavier traffic, while cold mixtures are more commonly used on roads with medium to low traffic density.

1. Colored Asphalt

Colored asphalt is produced by adding pigments to the asphalt mixture; however, the bitumen obtained from refineries is black. Therefore, the color of asphalt colored with pigments always tends to be black.

Additionally, iron oxide or similar pigments consist of very fine micronized particles. The use of powdered pigment at the asphalt production site is quite challenging, as the pigment color spreads throughout the entire environment during production.

As an alternative, the asphalt surface can be coated with a colored UV-resistant paint. While painting the asphalt surface seems like a good and practical solution, it has been observed that the paint can peel, wear, crack, or fade over time.

Ready-to-use colored synthetic asphalt binders have been developed to overcome such issues.