Are the European standards prEN 12697-11 and -12 able tot limit the amount of flints in asphaltic mixtures? : [paper Congress Euroasphalt& Eurobitumen, Vienna, May 2004]

High amounts of flint in Dutch asphalt concrete mixes leads to poor adhesion between aggregate and bitumen. The Netherlands is largely depended on aggregate that contains flint. For this reason the amount of flint in Dutch mixes is limited to a maximum of 15%. However in the European asphalt concrete drafts (in the prEN 13108-serie) this restriction is not allowed anymore. For this reason, the CROW-working group CIENA carried out research to tackle this problem. In this paper the results of this test program is reported. In this paper a correlation is made between the amount of flints and the European test standards?Affinity between aggregate and binder? (prEN12697-11) and ?Water sensitivity? (prEN12697-12). In this study the influence of the amount of flints in asphalt concrete mixes is tested. In this research in some cases relations have been found between the amount of flints and the results obtained by using the two mentioned European Standards. However, in most cases this correlation is not clear. It is concluded that for a limited number of cases only one test method is able to give the same result as observed in the road. Therefore, much work has to be done to have a relevant test method to predict the poor adhesion of flint in aggregate