1.1 本规程涵盖了通过测量路面宏观结构和湿路面摩擦来计算国际摩擦指数（IFI）。IFI是在PIARC国际实验中开发的，用于比较和协调纹理和防滑性测量。该指数允许将不同设备的摩擦测量值统一为一个通用的校准指数。本规程规定了使用光滑胎面试验轮胎的装置的摩擦报告的统一性。 1.2 IFI由两个参数组成，这两个参数报告了60 km/h（F60）下的校准湿摩擦和湿路面摩擦的速度常数( S p ). 1.3 平均剖面深度（MPD）已被证明可用于预测湿路面摩擦的速度常数（梯度）。 2. 1.4 60时估计摩擦的线性变换 km/h提供校准的F60值。通过使用速度常数根据在任何速度下进行的测量来计算在60km/h下的估计摩擦，从而获得在60km/h时的估计摩擦。 1.5 以国际单位制（公制）表示的数值应视为标准。英寸磅当量是合理化的，而不是精确的数学转换。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 这是计算路面IFI的做法。IFI已被证明对摩擦测量设备的协调是有用的。F60和 S p 已经证明能够预测各种类型的摩擦测量设备的湿路面相关测量的速度依赖性。 2. 两个IFI参数（F60和 S p )已被发现是湿路面摩擦对轮胎打滑和车辆速度的依赖性的可靠预测因素。 5.2 IFI参数F60和 S p ，可用于使用变换方程计算另一滑移速度下的校准摩擦。 5.3 下面给出的IFI模型描述了在滑移速度为 S 以及在由不同类型的设备测量的摩擦值之间。 5.4 IFI模型的一个重要意义在于，与设备的摩擦测量不必处于实验中运行的速度之一。FRS可以在 S 并且总是被调整到FR60。因此，如果一个设备无法保持其正常运行速度，并且由于流量的原因必须以更高或更低的速度运行，那么该模型仍然可以很好地工作。那样的话 S 由车速决定( 五、 )可以转换为 S 通过相乘 五、 固定滑动设备的滑动百分比或乘以 五、 通过侧向力设备的滑移角的正弦。 5.5 这种实践没有解决与获得测量的摩擦或测量的宏观织构相关的问题。

1.1 This practice covers the calculation of the International Friction Index (IFI) from a measurement of pavement macrotexture and wet pavement friction. The IFI was developed in the PIARC International Experiment to Compare and Harmonize Texture and Skid Resistance Measurements. The index allows for the harmonizing of friction measurements with different equipment to a common calibrated index. This practice provides for harmonization of friction reporting for devices that use a smooth tread test tire. 1.2 The IFI consists of two parameters that report the calibrated wet friction at 60 km/h (F60) and the speed constant of wet pavement friction ( S p ). 1.3 The mean profile depth (MPD) has been shown to be useful in predicting the speed constant (gradient) of wet pavement friction. 2 1.4 A linear transformation of the estimated friction at 60 km/h provides the calibrated F60 value. The estimated friction at 60 km/h is obtained by using the speed constant to calculate the estimated friction at 60 km/h from a measurement made at any speed. 1.5 The values stated in SI (metric) units are to be regarded as standard. The inch-pound equivalents are rationalized, rather than exact mathematical conversions. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 This is the practice for calculating the IFI of the pavement. The IFI has proven useful for harmonization of the friction measuring equipment. F60 and S p have proven to be able to predict the speed dependence of wet pavement-related measurements of the various types of friction-measuring equipment. 2 The two IFI parameters (F60 and S p ) have been found to be reliable predictors of the dependence of wet pavement friction on tire slip and vehicle speed. 5.2 The IFI parameters, F60 and S p , can be used to calculate the calibrated friction at another slip speed using a transformation equation. 5.3 The IFI model given below describes the relationship between the values of wet pavement friction FRS measured at a slip speed of S and between the friction values measured by different types of equipment. 5.4 A significance of the IFI model is that the measurement of friction with a device does not have to be at one of the speeds run in the experiment. FRS can be measured at some S and is always adjusted to FR60. Thus, if a device cannot maintain its normal operating speed and must run at some speed higher or lower because of traffic, the model still works well. In that case, S is determined by the vehicle speed ( V ) which can be converted to S by multiplying V by the percent slip for fixed slip equipment or by multiplying V by the sine of the slip angle for side force equipment. 5.5 This practice does not address the problems associated with obtaining a measured friction or measured macrotexture.