Correlation equations to skid resistance measurements between GripTester and British Pendulum

Abstract

Skid resistance is a measurement of the friction offered by a pavement.  There exist many types of equipment (tribometers) to measure skid resistance, but the measures obtained with two different equipment can not be directly compared. To solve that, two method to harmonize measures are commonly used. One method uses correlation equations between tribometers, and the other method permits to obtain a friction index (IFI, International Friction Index) that is independent of the equipment used. This last method was defined in the widely known experiment developed by the World Road Association (PIARC). In Chile, both methods was used. In this paper a third method has been derived from the IFI relationships. It developed correlation equations between skid resistance registered with different equipment. Using such equations, equivalent skid resistance values that correspond to one type of tribometer can be obtained from skid resistance measures performed with another tribometer to different texture values. This method was applied to obtain harmonization equations between GripTester and British Pendulum. The results show a good correlation between both equipments, and a statistically significant incidence of the texture in the predicted equivalent skid resistance value.