This document describes a test method to determine the average depth of pavement surface macrotexture (see Clause 3) by measuring the profile of a surface and calculating the texture depth from this profile. The technique is designed to provide an average depth value of only the pavement macrotexture and is considered insensitive to pavement microtexture and unevenness characteristics.

The objective of this document is to make available an internationally accepted procedure for determination of pavement surface texture depth which is an alternative to the traditionally used volumetric patch technique (generally using sand or glass beads), giving comparable texture depth values. To this end, this document describes filtering procedures that are designed to give the best possible representation of texture depths determined with the volumetric patch method[13].

Modern profilometers in use are almost entirely of the contactless type (e.g. laser, light slit or light sheet, to mention a few) and this document is primarily intended for this type. However, this does not exclude application of parts of it for other types of profilometers.

This ISO 13473 series has been prepared as a result of a need identified when specifying a test surface for vehicle noise measurement (see ISO 10844:2014[6]). Macrotexture depth measurements according to this document are not generally adequate for specifying test conditions of vehicle or traffic noise measurements, but have limited applications as a supplement in conjunction with other ways of specifying a surfacing.

This test method is suitable for determining the mean profile depth (MPD) of a pavement surface. This MPD can be transformed to a quantity which estimates the macrotexture depth according to the volumetric patch method. It is applicable to field tests as well as laboratory tests on pavement samples. When used in conjunction with other physical tests, the macrotexture depth values derived from this test method are applicable to estimation of pavement skid resistance characteristics (see e.g. Reference [15]), estimation of noise characteristics and assessment of the suitability of paving materials or pavement finishing techniques.

The method, together with other measurements (where applicable), such as porosity or microtexture, can be used to assess the quality of pavements.

This document is adapted for pavement texture measurement and is not intended for other applications. Pavement aggregate particle shape, size and distribution are surface texture features not addressed in this procedure. The method is not meant to provide a complete assessment of pavement surface texture characteristics. In particular, it is known that there are problems in interpreting the result if the method is applied to porous surfaces or to grooved surfaces (see Annex B).

NOTE Other International Standards dealing with surface profiling methods include, for example, References [1], [2] and [3]. Although it is not clearly stated in these, they are mainly used for measuring surface finish (microtexture) of metal surfaces and are not intended to be applied to pavements.