With increasing heavy traffic and concomitant Swiss wide implementation of road noise reduction measures, mainly through laying of semi-dense asphalt concrete SDA, aggregate loss will be increasingly significant. The test methods proposed by CEN in TS 12697-50 to determine the loss of aggregate are not satisfactory. Their conception does not allow measurements on site and shows several other questionable constructive test parameters. Altogether they do not seem really proven and because of the high investment costs, their acquisition is limited to few  laboratories. The project focuses on the development of test methods that circumvent the mentioned draw-backs: the apparatus is meant to be employable in the laboratory as well as on the road and the method shall be easy and affordable. In a first step different test methods are tested on laboratory compacted SDA. Only the most promising method(s) will further be evaluated and compared to one method from TS 12697-50. After that the resistance to aggregate loss of different types of SDA will be evaluated and compare with other hot-mixes, while introducing the influence of climatic conditions. Further, the test methods will be implemented on site on new and old SDA surface layers. The focus will be on the precision of the measurements and on the establishment of requirements for type testing, acceptance testing and residual service life.

Project Period

2017 - 2020