Study of the skid resistance of blends of coarse aggregates with different polish resistances

Abstract In France, the aggregates used in surface course must meet to very strict requirements. Indeed, the surface course sustains a lot of stresses which are caused by road traffic: high local pressure of contact with the wheels, friction and polishing. Due to these conditions, the aggregates used for that layer must meet requirements directly linked to their intrinsic characteristics. For these reasons, the aggregates possessing high mechanical properties are particularly needed. However, there are many inequalities on the territory because the production of aggregates is localised in a quarter of the departments. These inequalities (in terms of resources and needs) and the context of sustainable development led to wonder about a better management of the aggregates. This work is based on the study of behaviour of granular blends constituted with two materials having different characteristics. Many proportions have been established for these blends. The wear and polish resistances have been measured by traditional normalised tests (Micro-Deval and Polished Stone Value) completed by tests with the Wehner & Schulze machine. A procedure of preparation of the samples have been studied and defined for these tests. The results lead to the proposition of a mixture law to predict the properties of the granular blends.