Laser Crack Measurement System for Pavement-Management Sytems

Pavement-management systems (PMS) can work effectively only when they are constructed by organically combining all activities concerned with road pavement (planning, design, construction, maintenance, rehabilitation, evaluation, economic analysis, and research) and the data bank [1]. Then, the most important items are the establishment of a serviceability index, which represents pavement quality, and a prediction of performance, which is represented by the relation between time (and/or traffic) and the index. Pavement quality consists of two primary factors: riding quality and skid resistance. The factors influencing riding quality are pavement distress and/or roughness. Three major factors of pavement distress are cracking, rutting, and longitudinal profile [2].

Pavement surface texture has significant impacts on tire-pavement friction. Vehicle maneuvers such as braking and cornering require sufficient skid resistance to maintain vehicle stability. Furthermore, pavement skid resistance can affect tire wear, rolling resistance, road noise, discomfort, and wear in vehicles (ISO, 1997). There are two classes of pavement textures related to skid resistance, i.e. micro texture and macro texture. The classification is generally based on specific texture wavelength range and typical peak–peak amplitude. In particular, micro texture refers to surface texture with wavelength range less than 0.5 mm and typical peak–peak amplitude less than 0.2 mm, while the corresponding ranges for macro texture are 0.5–50 mm and 0.2–10 mm.

Micro texture indicates the degree of the polishing of a pavement surface. In comparison, macro texture has a more direct effect on skid resistance. It is associated with the coarseness of road surface, which affects w...

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...ooking down in such a way as to scan the entire 4m width of the road surface with 1mm resolution. This configuration allows the direct measurement of many different types of surface defects by simultaneously acquiring high resolution 3D and intensity data. Laser Crack Measurement System (LCMS) is able to work with traffic flow (speed up to 100 Km/hr) that cause massive time and accident reduction (due to not closing the road lane through inspection period) and LCMS can determine the following pavement characteristics: rutting (rut depth, rut type), Macro-texture measurements over 100 % of the lane width, 3D and 2D data to characterize cracks, pot holes, raveling, sealed cracks, joints in concrete, tinning, etc, Day and night operation, IRI and longitudinal profile, Slope and cross fall. Also, it can be concluded that Laser Devices outputs are accurate and repeatable.