The application of the future European standards, following the GATT agreements, will bring on new tests and with them new requirements. To be able to select materials (for roadways) that satisfy Switzerland’s needs without downgrading Swiss material that meet the requirements usually asked from them, it is necessary to evaluate the influence of the percentage of round or partially round aggregates used in S type mixtures and special mixes such as those of SMA, MR, DRA types.

The restrictive application of the European standard regarding the percentage of round or partially round aggregates in bituminous mixes would mean that the gravel pits that produce this type of material couldn’t continue to do so without major modifications to their equipment. A less rigorous application of the European standard can be contemplated. But at present it isn’t possible to evaluate the effect of the choice of a less severe class (of crushed materials) on the users security as regards grip.

So this research aims to evaluate the influence of the crushed materials rate, along the lines of the future European standards, on the macrorugosity and microrugosity parameters of the surfacing used as wearing course.