ASTM E1960-07 (R2015) PDF Download

ASTM E1960-07 (R2015) is a standard practice that provides a method for calculating the International Friction Index (IFI) of a pavement surface. The IFI is a useful tool for harmonizing friction measurements obtained from different types of equipment. It consists of two parameters: F60, which represents the calibrated wet friction at a slip speed of 60 km/h, and Sp, which represents the speed constant of wet pavement friction.

The practice describes a model that relates the values of wet pavement friction measured at a slip speed (S) to the friction values obtained from different types of equipment. This allows for the prediction of friction at other slip speeds using a transformation equation. The IFI model takes into account the dependence of wet pavement friction on tire slip and vehicle speed.

One of the significant features of this standard is that friction measurements can be adjusted to FR60, even if the measuring device operates at a different speed due to traffic conditions. In these cases, the slip speed (S) is determined based on the vehicle speed (V) and the percent slip or slip angle for fixed slip or side force equipment, respectively.

It is important to note that this standard does not address the issues related to obtaining measured friction or macrotexture values. The values provided in the standard are in SI (metric) units, with the inch-pound equivalents being rationalized rather than exact conversions.