Germany – Research and development services and related consultancy services – Bereitstellung einer fachgerechten Bewertung von gegrindeten Oberflächentexturen auf Betonfahrbahnen in der ZEB - Berührungslose Ermittlung der Längsebenheit

The evaluation of longitudinal evenness requires, since the introduction of the Technical Testing Specifications for the non-contact measurement of road surfaces [1,2], the determination of the true longitudinal height profile. To measure the true longitudinal height profile, only the High-Speed Monitoring – method (HRM) is suitable to date. Comparable methods, such as an inertial profilometer (distance measurement in combination with an acceleration sensor), used in other countries, are currently not certifiable. However, the HRM method in its current form is not suitable for different surface structures such as grinding structures. Due to the material removal, a longitudinally directed, alternating ridge-and-groove pattern is created on ground surfaces, which can lead to large deviations in the relative height measurements of the laser sensors due to small local deviations of the multiple scanned points. Additionally, even small angles between the longitudinally directed structures and the direction of travel of the measuring vehicle can result in the imposition of an artificial unevenness. The accuracy of measurement systems that are based on non-contact measurement can therefore be strongly negatively influenced by the grinding structures. The aim of this project is to identify or develop and test a measurement method that enables the non-contact measurement of ground structures. To this end, the effects of the directed structures of grinding textures on the common measurement methods for determining longitudinal height profiles, such as the HRM beam, should be described and compared with special variants of these systems adapted for grinding textures or alternative measurement systems. The basis of this comparison should be measurements with the planograph, as this, due to the width of its measuring wheel, is not or less susceptible to the influences of a ground texture. In addition, a comprehensibly justified concept for calculating the longitudinal height profile points, taking into account the ridge and groove of the grinding textures, should be developed alongside the development of a non-contact, high-speed measurement method. Such a measurement method should ideally be usable for both condition assessment and contractual measurements and should function on all road surfaces known today.