Document ID: chunk:federal_register_of_legislation:F2021C00509:front:0:p29
Version: federal_register_of_legislation:F2021C00509
Segment Type: other
Provision Reference: 
Character Range: 85282–88350

this Regulation and the manufacturer shall take the necessary measures to re-establish to conformity.
Annex 8

SPECIFICATIONS FOR THE TEST SITE

1. Introduction

            This annex describes the specifications relating to the physical characteristics and the laying of the test track. These specifications based on a special standard[16]/ describe the required physical characteristics as well as the test methods for these characteristics.

           2. Required characteristics of the surface

           A surface is considered to conform to this standard provided that the texture and voids content or sound absorption coefficient have been measured and found to fulfill [all] the requirements of paragraphs 2.1 to 2.4 below and provided that the design requirements (para. 3.2) have been met.

           2.1. Residual voids content

            The residual voids content, Vc, of the test track paving mixture shall not exceed 8%. For the measurement procedure, see paragraph 4.1.

           2.2. Sound absorption coefficient

           If the surface fails to comply with the residual voids content requirement, the surface is acceptable only if its sound absorption coefficient, a < 0.10. For the measurement procedure, see para. 4.2. The requirement of paragraphs 2.1 and 2.2 is met also if only sound absorption has been measured and found to be a < 0.10.
           Note: The most relevant characteristic is the sound absorption, although the residual voids content is more familiar among road constructors. However, sound absorption needs to be measured only if the surface fails to comply with the voids requirement.
           This is motivated because the latter is connected with relatively large uncertainties in terms of both measurements and relevance and some surfaces therefore erroneously may be rejected when based only on the voids measurement.

           2.3. Texture depth

            The texture depth (TD) measured according to the volumetric method (see paragraph 4.3 below) shall be:
            TD > 0.4 mm

           2.4. Homogeneity of the surface

            Every practical effort shall be taken to ensure that the surface is made to be as homogeneous as possible within the test area. This includes the texture and voids content, but it should also be observed that if the rolling process results in more effective rolling at some places than others, the texture may be different and unevenness causing bumps may also occur.

           2.5. Period of testing

            In order to check whether the surface continues to conform to the texture and voids content or sound absorption requirements stipulated in this standard, periodic testing of

            the surface shall be done at the following intervals:
            (a) For residual voids content or sound absorption:
             When the surface is new;
               if the surface meets the requirements when new, no further periodical testing is required. If it does not meet the requirement when it is new, it may do later because surfaces tend to become