Analysis of local measurements of road pavement friction characteristics

The friction (skid resistance) , that is the sliding resistance that road pavement surface can give, is indispensable in road design because it is a fundamental element in vihecle/road interaction.There are several techniques for fiction measurement , that are based on punctual approaches (static measurement or low-speed measurement) or on continuous approaches (dynamic measurement or high-speed measurement) . All of them aim to reproduce the actual conditions of the contact between tyre and road pavement, employing ever more sophisticated devices corresponding to the traffic conditions on the road. Nevertheless the simplicity and quickness of execution of local measurements, and above all the skid resistance measurement by means of British pendulum Tester, make the punctual test the most employed technique and it is the most worldwide accepted as the base of comparison for the microtexture of road surface. This paper aims to compare the BPN measurement , that is characterized by the small contact area of the pendulum rubber slider, with the measurement carried out by means of a new instrument, based on the sliding of a rubber slider of significant larger size that covers a wide pavement area. The two procedures have been tested on the field and from their comparison derives a critical result analysis . the tests have been carried out on stone pavements and transitional bituminous.

Keywords:

skid reistance , static and dynamic measurement , road surface microtexture