Ceiling renovation on the A52

Situation

In July 2009, the damaged road surface on the A52 motorway, which was in need of refurbishment between the Neersen and Mönchengladbach junctions, was renewed. The North Rhine-Westphalia State Road Construction Authority decided to use asphalt reinforcement. Existing cracks from lower asphalt layers very quickly break through a new asphalt layer due to external influences such as temperature fluctuations and traffic loads. These new cracks are called reflection cracks, as they are an exact replica of the cracks in the lower (older) asphalt layers. As a result, the rehabilitated carriageway quickly reverts to its previous condition. To increase the service life of the rehabilitated carriageway, the State Road Construction Authority of North Rhine-Westphalia used the asphalt reinforcement grid. The grid increases the tensile strength of the asphalt. Stress peaks above the cracks are absorbed and distributed over a larger area. This significantly delays the formation of reflective cracks.

Solution

First, the existing surface course and binder course were milled off. A fine milling machine was used to achieve a flat surface for the grid. Furthermore, on a finely milled substrate, the required quantity of bitumen emulsion (due to the smaller relative surface area) is lower than on a coarsely milled substrate. The asphalt reinforcement was then laid over the entire milled surface by a specialist contractor in accordance with the installation instructions. Following installation, the grid was covered with a 5 cm thick asphalt binder course (0/16S) and a 3.5 cm thick mastic chip seal (0/8S). The ease of installation and the smooth collaboration between all the companies involved meant that the construction project could be completed quickly and successfully.

Advantages

Asphalt reinforcement has proven its worth in a wide range of applications. Numerous scientific studies and many years of practical experience have shown that the use of asphalt reinforcement can extend maintenance intervals many times over. The associated savings lead to a significant reduction in the costs of maintaining asphalt road surfaces. The use of asphalt reinforcement grids is a technically sound and economical solution.