
It is crucial to have sustainablity in road construction. How do we lay an asphalt mixture at temperatures lower than normal? How to efficiently process asphalt? How to make road building more cost-effective? I believe this are the questions that must be answered if we are to make road construction more sustainable.
Bitumen – asphalt mixtures magic ingredient
Asphalt’s core ingredients are agregate, 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 wide variety of requiremetns. Regional and climatic conditions play a key role in defining these.
- Bitumen, and consequently the asphalt mixture is hard at room temperatures. During hot weather, it can deform when subjected to heavy load, such as trucks or semis.
- Harder grades of bitumen offer more stability. But at a cost of compaction. Harder bitumen are more difficult to compact.
- Low noise asphalt pavement is particularly open-pored, absorms tire noise and drains rain quickly.
- Colored asphalt pavement can be used to differentiate bike paths from roads and direct traffic. It is also ideally suited to highlighting dangerous points or making areas attractive.
Mixtures vary depending on the type of asphalt pavement that is required. Ensuring a good bond between the bitumen and old rubber, the additive recipe is adjusted in accordance with this.
Bitumen with a bounce
Rubber is a polymer. Polymers help modify bitumen. They lend elasticity to the bitumen, indirectly improve drainage thus preven aquaplaning, improve the durability of the surface, thereby reducing the need for maintenance and roadworks, and it also allows fewer ruts and cracks to form.
Polymers, such as rubber, make up about 15 percent of the bitumen in asphalt mixtures. “Using rubber from old tires conserves resources,” says Dr. Thomas Klein, a researcher from German.
Huge energy and time savings
Designed to advance the use of recycled materials in road construction, a test have been conducted. From the test we found that bitumen, rubber from old tires and aggregates combine well under certain conditions. We believe this information will help making road construction become more sustainable. It means that it is no longer necessary to produce rubber-modified bitumen as part of a separate process. This keeps costs low. At the same time, it retains the elasticity achieved by adding rubber, and helps the road surface to reform when, for example, heavy trucks drive over it during hot summer.