TNO studies the performance of asphalt materials, and tests and assesses asphalt mixtures, including innovative mixtures. This research enables us to indentify the risks and assess the performance of materials and structures for operators and market players.
Roads are designed and constructed to have a long service life. The average service life of national trunk roads surfaced with ZOAB (very open porous asphalt) is 12-15 years, while that of other types of asphalt road varies. However, the actual service life of any given surface is highly uncertain, so organising timely maintenance and scheduling renovation work is a difficult task. It is therefore useful to be able to obtain a precise prediction of the service life of a given surface layer. This makes it possible to allocate the right materials and techniques in order to continue to guarantee road performance. Because resurfacing is expensive, it is also worthwhile assessing whether service life can be extended. Preventive and timely maintenance can preserve road surfaces for longer, so that renovation or replacement can be postponed.
In recent years, TNO has focused on studying the life-cycle performance of ZOAB road surfaces and the underlying damage mechanisms. This involves assessing the material properties in relation to performance. The material properties of the road are the basis for estimating the conditions and loads that will result in damage (including ravelling). This helps road authorities and contractors in selecting road-construction materials and related structures.