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...
... middle of paper ...
...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.
Ski’s slide because when pressure is applied to snow it creates a thin layer of water between the ski and snow. As the pressure is released, the skier moves on from that point, the layer of water created by the skier refreeze ("WHY SKIS SLIDE”). The question this experiment will attempt to learn is which type of ski wax reduces the friction of the ski the best: rub on, paste, spray on, or hot?
Using the average distances, the equations d = (v02)/(2μg) and Ff = μFn were used to determine μ and the force of friction which are shown in Table 3. From the calculations, the average coefficient of friction on dry road was 0.705 and the average frictional force was 8016.27 N. The average coefficient of friction on wet road was 0.553 and the average frictional force was 6299.6 N. From the data, it is concluded that with a higher speed, the distance it takes to come to a complete stop is higher. The data also shows that wet road conditions decrease the coefficient of friction and frictional
Some of the biggest advances in automotive technology in the past 30 years have come in the area of safety. Spurred by improvements in microprocessor speed, miniaturization, and software development, the automobile continues to evolve. In addition to telemetric based services like OnStar, digital satellite radio and in-car e-mail, recent advances in braking technology have led to shorter stopping distances and increased control while driving in inclement conditions. All these developments have been possible because a certain device, the ECU, was integrated into the automobiles.
Having good traction on shoes are related to physics because good traction that the coefficient or friction between shoes and the floor must be high. A player uses static friction when placing their foot. Static friction allows a player not to slide but to stop and turn.
In conclusion, the labs explain that no matter what the surface area is the amount of friction does not change. Friction comes when two forces rub together. In lab 4.1, different surface types were tested. Frictions are affected by surface type, such as coarse sandpaper or. waxed paper, the friction would be different with a different surface type. In 4.2 the lab shows how friction is changed by surface type. While in 4.3, it is shown that the surface area is not a variable that changes the amount of friction on an
If you want to extend the life of your asphalt pavements you can use asphalt sealcoating, the process
These chemicals melt ice and snow by “lowering the freezing point of the snow-salt mixture” (Zhang) at the point of application. Before applying to roadways, liquid products are often added to abrasives or solids salts to not only make them easier to distribute, but to maintain contact with the roadways (AASHTO). According to the American Association of State Highway and Transportation Officials (AASHTO), “the most commonly used winter maintenance product is solid salt (NaCl), followed by salt brine and then sand or traction material” (AASHTO). Furthermore, liquid magnesium chloride and liquid calcium chloride were used by nearly 60 percent of respondent municipalities (AASHTO).
Presently the road project is receiving inadequate maintenance and is deteriorating over time. For simplification of economic evaluation of the project, ’ Without Project ‘ situation is assumed to be the situation where quality of service provided by the road is maintained at its present level by sustaining the condition of the road surface at its current level. Any further deterioration is controlled by maintenance activities aimed at sustaining the present situation. The level of expenditure on maintenance activities in order to ensure the situation is defined as ‘holding maintenance’ cost. The holding maintenance cost is assumed to include routine and recurrent maintenance
side of vehicle for fuel or oil leaks. Visually checks right side of vehicle ...
Its overall purpose is to use laser light technology to sense and measure reflected pulses. Differences in laser return times and wavelengths can then be used to make three-dimensional representations of the target. Therefore making this technology vital in determining the objects in front or behind the vehicle.
After getting an estimated idea about depth and volume of the potholes, these details can be made available to government agencies or municipal commission who monitors the quality and condition of the roads.
- The track is manufactured to have a sand paper surface. This is important to exert a sufficient side force on the tyre and is in good condition.
... the player’s shoes must have good traction, friction that allows movement. Good traction means that the coefficient of friction between the shoe and the floor must be high. A player must also use static friction when planting their feet in order to stop and turn without sliding across the floor due to static friction being greater than the sliding friction.
Texture of sediment affects its porosity and permeability, and reflects the original depositional environment. Texture is an important aspect in the description of sedimentary rocks, and can be useful in interpreting the mechanisms and environments of deposition. It is also a major control on the porosity and permeability of sediments. It can see on the figure 1.
Prior to there is any opinion of design methodology, it must be unequivocal that the selection of those roads that will advantage from the pavement preservation technique vested with chip sealing is the first and most elemental step in the design method. Chip seals are not meant to develop the structural competence of the pavement section. The formula for chip seal success is articulate framed by the following extract: