Bitumen is the binder in asphalt pavements. VTI conducts advanced tests on bitumen and carries out research about how this component affects the service life of the pavements. In ordinary asphalt mixtures, the binder content is normally about 5-6% by weight, which corresponds to about 10% by volume. Despite the low proportion, the properties of binder are very important for the durability of asphalt pavements as well as the climate imprint of the pavements.
At VTI, the research activities on binders can be traced back to the 1940s. VTI has worked on various types of research questions regarding binders (even hydraulic binders), such as material properties (chemical, physical and mechanical), morphology, modification, durability (ageing), additives, test methods and environmental issues.
In Sweden and all over the world, bitumen is the most common binder in bound layers of pavements, because it enables the relatively low construction cost, good comfort, excellent recyclability and simple construction and maintenance methods for asphalt pavements. Bitumen is a viscoelastic material, which means that its properties can vary depending on the temperature and loading frequency. We conduct research on the viscoelasticity of bitumen for studying its effects on asphalt pavements under different climate and traffic conditions.
We also carry out tests and analyses on bitumen.