Mastery the process of pavement friction measurement Stakes and methods

Knowing the state of a pavement's skid resistance is an essential step in meeting the safety and economic needs of a transportation infrastructure manager. A vital functional element for an airport, an aeronautical runway must enable aircraft to land and brake safely, especially in bad weather. To help the airport manager make decisions on corrective action, it is necessary to provide regular, reliable data based on robust measurement processes.

Used as a lever for improving practices and measurement quality, the assessment and control of measurement uncertainties are essential elements in many sectors of activity. In France, in the field of skid resistance, the pavement testing laboratory of the Service Technique de l'Aviation Civile (STAC) has carried out an assessment of its measurement uncertainties in order to better control its functional skid resistance measurement process, which has been included in a voluntary accreditation process in accordance with standard EN ISO/CEI 17025, establishing the general requirements for the competence of testing and calibration laboratories.

Given the specific nature of skid resistance testing and a lack of feedback, accreditation initiatives in the field of skid resistance measurement are rare and more difficult to implement than for other disciplines, due in particular to the problems associated with the multiplication of measurement methods and resources, but also to the lack of information available in specialized scientific literature on the implementation of such an approach specific to the field of skid resistance. Added to this is the lack of collective awareness of the need to control the measurement process, and the absence of a sufficiently restrictive regulatory framework at supranational level.

While an increasing number of pavement testing laboratories are seeking ISO 9001 certification (a standard that sets out the requirements for a quality management system), in order to improve the organization of their quality assurance, the fact remains that this effort needs to be pursued to the next level, i.e. accreditation to EN ISO/CEI 17025, i.e. verification of a laboratory's competence and suitability to carry out measurements.

Because accreditation to EN ISO/CEI 17025 can be a restrictive and costly process for a laboratory, particularly if it is not properly understood, this article proposes to share the lessons learned from an accreditation experience. We will provide answers to the following questions:

• how do you go about putting "test-critical" measuring instruments under metrological management?

• what are the sources of influence that impact measurement quality? how can they be...