Download or read book Influence of Pavement Texture on the Evacuation of the Water from the Tire pavement Interface and on the Skidding of Vehicles written by R. Majcherczyk and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Significance of Pavement Texture written by Glenn G. Balmer and published by . This book was released on 1975 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This paper discusses the influence of roadway surface textures on the skid resistance, the speed-gradient, the wet-pavement accident rate, pavement wear, and the generation of tire-road interaction noise. The tendency of a vehicle to hydroplane is reduced by increasing the texture magnitude. Appropriate textures are developed by using open-graded asphalt friction surface courses and by grooving portland cement concrete with steel tines or a vibrating float while the concrete is plastic. Hardened pavements can be textured by grooving with a diamond saw or by resurfacing with an overlay. More development is needed in texture measurement techniques, especially in automating the stereo-photo interpretation method and the linear polarized laser technique"--Technical report documentation page

Download or read book Influence of Water Depths on Friction Properties of Various Pavement Types written by and published by . This book was released on 1974 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Texture Versus Skidding Measurements Frictional Aspects and Safety Features of Tire Pavement Interactions written by and published by . This book was released on 1975 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tire pavement Interaction Experimental Measurements and Modeling written by Mohammad O. Al-Assi and published by . This book was released on 2019 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Providing an adequate level of skid resistance is essential for the safety of motorists. Previous studies demonstrated that the number of crashes is reduced if pavements have sufficient friction, especially in wet conditions. Adequate pavement friction prevents the vehicle from sliding on the pavement surface and provides the grip needed to maintain control over the vehicle. The first phase of this study investigated experimentally the two major friction mechanisms (i.e., adhesion and hysteresis) that contribute to tire-pavement friction. It is postulated that the adhesion between rubber tires and pavements is highly influenced by the surface free energy. However, there are no previous studies carried out to investigate the adhesion between rubber tires and pavements using the surface free energy. The results demonstrated that adhesion friction can be quantified by measuring the surface free energy components of pavement surface aggregates and rubber materials. There was a fair correlation between the adhesive bond energy and the measured coefficient of friction. Higher adhesion between rubber materials and pavement surface provided higher friction. These results provide a fundamental understanding of the mechanisms of rubber-pavement friction and verification of the relationship between adhesion and friction. In addition, there was a strong correlation between friction and rubber rheological properties. Rubber materials with lower modulus provided higher friction compared to those with higher modulus. These results explain the change in skid resistance with temperature throughout the year. The second phase of this study examined different factors that affect skid resistance of pavement surfaces. These parameters included macrotexture, microtexture, and driving speed. The macrotexture of the pavement is related to aggregate gradation of the mix or surface texture pattern. The microtexture is influenced by the roughness of the aggregate particles and their resistance to abrasion and polishing under traffic. This study proposed a new model that can be used to estimate the skid number at a given speed between 20 mph and 60 mph as a function of both macrotexture and microtexture of pavement surface. This model was developed based on the measured frictional characteristics of field test sections. The proposed model can be used if the full-scale friction tester is not available or cannot be used due to the limited length of the test section (e.g., bridge deck). In addition, the model provides a tool to the pavement engineers to ensure adequate skid resistance at various operation speeds during the mix design stage and before the mix is used in the field. A given mix design can be modified to improve its frictional characteristics at early stage which leads to cost savings often spent on the application of surface treatments. The third phase of this study utilized the close-range photogrammetry (CRP) technique to measure the pavement macrotexture and microtexture. Texture parameters were calculated from the collected and analyzed images of the pavement surface. The results of the CRP texture measurements were compared to standard test methods. The CRP texture measurements had excellent correlation with the standard methods; however, the CRP offers simple and accurate, yet inexpensive alternative to the current methods used to measure surface macrotexture and microtexture. In addition, the CRP texture parameters were incorporated in the Persson friction model to predict skid friction as a function of rubber properties. The results demonstrated excellent correlation between measured and predicted friction. This study greatly simplified the texture parameter calculations needed in the Persson friction model with good accuracy.The last component of this study developed a 3D finite element model to investigate the effect of surface characteristics along with rubber properties on the contact stress between the standard skid test tire and pavement surface. Such simulation provides an in-depth understanding of tire-pavement interaction that would require expensive resources to examine in the field. Study parameters included various coefficient of friction, texture (e.g., smooth, and grooved), tire rolling conditions (fully skidding and free rolling) as well as temperature. The developed 3D FE model of the test tire was first validated with laboratory measurements before it was used to examine the effect of the study parameters on tire-pavement contact stresses. The results of the finite element simulations demonstrated that the stress distribution at the tire-pavement interface is non-uniform with maximum values towards the edges of the tire. These findings were consistent with the wearing pattern of the test tire in the field. In addition, the results also demonstrated that the shear stresses increased with surface friction while there was no significant change in the vertical stresses. The grooved surface exhibited higher vertical and shear stresses compared to pavement with smooth texture. The grooved texture is used to improve skid resistance and reduce the noise of pavement surfaces. In addition, temperature was found to have significant impact on the stresses at the tire-pavement interface. The finite element simulation results agreed with the laboratory and field measurements of pavement friction.

Download or read book An Evaluation of the Effects of Tread Depth Pavement Texture and Water Film Thickness on Skid Number speed Gradients written by David Crenshaw Mahone and published by . This book was released on 1975 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: The raw data and the initial curves for the study entitled, "An Evaluation of the Effects of Tread Depth, Pavement Texture, and Water Film Thickness on Skid Number-Speed Gradients" are so voluminous that they are included in the Supplement rather than in the final report of this study. For economy and convenience, they have been copied from the computer printouts. The individual test values are in Tables 1-33, with the tables having the same numbers as the sites they represent. Graphic representations of the data are given in three figures for each site. The first figure shows the speed gradient curve for each tire and water condition and is designated by the letter S followed by the number of the site it represents; the second shows the effect of tread depth for each speed and water condition and is designated by the letter T followed by the number of the site; and the third shows the effect of water film for each speed and tire condition and is designated by the letter W followed by the number of the site. Because sites 14 and 15 were tested for only two tire conditions and one water condition, they are not included in the graphic form.

Download or read book Road Surface Micro and Macrotexture Influence on Skid Resistance written by Murat Ergün and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The fast development of car technology has led to a steady increase ofthe speed of the vehicles. International studies show that increase causes increase in the accidents. The transport infrastructure such as pavement surface texture has not followed this development. In the wet weather, even at low speed, the skid resistance between the road surface and tyre can be quite low. International studies emphasise that there is a relation between the accident rate and the friction coefficient. The main goal of this study is to analyse the influence of road surface texture on skid resistance. The ultimate goal is to investigate the possibility of assessing pavement skid resistance by means of a new model which only uses surface texture parameters. In Chapter 1, the influence of skid resistance on the accident rates isexplained. Then, necessity of monitoring to road surface texture is highlighted. Thedefination of the surface texture is made in Chapter 2. The main surface texturedescriptors are surface texture (microtexture, macrotexture, and megatexture) and(un)evenness (longitudinal- and transverse evenness). The measuring methods ofsurface texture and (un)evenness are explained in Chapter 3. The description of skid resistance is explained from the historical development point of view in Chapter 4. In Chapter 5, the measuring methods of skid resistance are explained. Nowadays, different methods are in use to measure skid resistance.The main factors that affect skid resistance are pavement surface texture, the tyre, vehicle speed, and water film thickness as explained in Chapter 6. Recent researches on those factors are demonstrated. Then, the previously proposed models about skid resistance are explained in Chapter 7. In Chapter 8, the tests to study the influence of surface micro- and macrotexture on skid resistance are explained as mainly field and laboratory tests.The field tests are namely: skid resistance test by Odoliograph, the macrotexture by Mobile Laser Profilometer, and low-speed skid resistance spot tests by British Pendulum. Then, the cores are extracted from these spots. In the laboratory test, the new contactless microtexture measurement method is developed by using the Image Analysis Technique and applied on the extracted cores to measure microtexture of samples.The results of field and laboratory tests are presented in Chapter 9. The analysis of the results is made in Chapter 10.Finally, this study concluded that it is possible to predict the skid resistance of road surfaces by means of a new model which only uses surface texture parameters. Also, the road surface microtexture can be measurable with using the Image Analysis Technique. This study shows that it should be possible for systematic network monitoring of low friction spots on the road surface by using fast, non-contact texture measurement methods in the future.

Download or read book Effects of Pavement Texture on Skid Resistance written by F. E. Behn and published by . This book was released on 1977 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Surface Texture Versus Skidding written by J. G. Rose and published by . This book was released on 1975-01-01 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pavement Macrotexture Review written by and published by . This book was released on 1980 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: This pavement macrotexture review is for highway engineers and administrators concerned with the improvement of pavement surface texture as a countermeasure for skidding accidents. A summary is presented of the fundamentals of tire-pavement skid resistance and the importance of pavement surface texture in reducing skidding accidents. This includes a discussion of the skid number and skid number-speed gradient and of the role of pavement surface microtexture and macrotexture in skid resistance. The most commonly used methods of measuring pavement macrotexture are described, and ways of achieving high macrotexture in new pavements and of restoring high macrotexture in existing pavements are given.

Download or read book Influence of Road surface Texture on Tire road Interface Traction Limits written by K. C. Ludema and published by . This book was released on 1969 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mechanistic Modeling of the Effect of Pavement Surface Texture and Roughness on Vehicle Rolling Resistance written by Shabnam Rajaei and published by . This book was released on 2019 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rolling resistance of a vehicle plays an important role in the vehicle's fuel consumption. There are different mechanisms involved in the rolling resistance, namely, vehicle dynamics, tire bending and deformation, and tire tread deformation. Pavement surface profile is one of the factors that influences the rolling resistance and it can be divided into four scales of roughness, mega-, macro- and micro-texture. These scales influence different mechanisms of the rolling resistance. The micro-texture scale, which has the shortest wavelengths (less than 0.5 mm), despite being very important for friction and safety, has a negligible effect on the rolling resistance of the tire. The macro-texture scale, with wavelengths smaller 50 mm, mostly affects the tread deformation and tire bending mechanisms of rolling resistance. The mega-texture scale, which includes both wavelengths within and beyond the tire contact patch (between 50 and 500 mm), affects the vehicle dynamics and suspension system in addition to the tire deformation and bending. The roughness scale consists of any wavelengths larger than 500 mm and therefore mostly affects the deformation in the vehicle's suspension. The main aim of this study is to evaluate the effect of these scales on the vehicle's rolling resistance. For capturing the effect of the full surface profile on rolling resistance a model is required such that it is capable of evaluating all of the mechanisms involved in the rolling resistance. Such a model should include the tire as well as the suspension system of the vehicle. Here, for modeling the deformations within the tire, including tire bending and tread deformation, a full 3D finite element tire model is developed and verified. For investigating the energy dissipation in the vehicle suspension system, the tire model is combined with a quarter-car mechanical model, which is a simplified system of a spring and a dashpot in parallel. After decomposition of the surface profile into the above-mentioned scales, the root mean square or RMS is chosen as a common parameter for surface profile characterization to have a robust comparison of the effect of these scales. The effect of each scale of the profile on the rolling resistance is then evaluated separately using the developed models. For each scale, the effect of profile on the tire as well as the suspension is assessed. Then the effects of different scales are compared with each other. The macro-texture scale is found to mostly affect the tire deformations and have a negligible influence on the suspension system. The effect of mega-texture is found to be considerable, influencing the rolling resistance within the tire more than the vehicle's suspension. The roughness scale, however, affects the suspension system more than the tire. For low values of RMS, all of the scales, regardless of their wavelength, influence the rolling resistance similarly. However, for higher RMS values, the mega-texture shows a higher total rolling resistance than roughness. Although high values of RMS for mega-texture can be related to local events in the road profile, they can influence the rolling resistance noticeably.In addition, a good agreement is found between the developed model and the existing empirical studies for different scales. Moreover, the influences of vehicle operating conditions including applied load, driving velocity, tire temperature, and inflation pressure on the effect of surface profile on rolling resistance are investigated.

Download or read book Analysis of Tire pavement Interaction and Pavement Responses Using a Decoupled Modeling Approach written by Hao Wang and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The proper understanding of tire-pavement interaction is important for the accurate analysis of load-induced stresses and strains in the pavement structure. This dissertation focuses on the analysis of the mechanism of tire-pavement interaction and the effect of tire-pavement interaction on pavement responses using a decoupled modeling approach. First, an air-inflated three-dimensional (3-D) finite element (FE) tire model was built and the interaction between a tire and a non-deformable pavement surface was simulated. The tire is modeled as a composite structure including rubber and reinforcement. The steady-state tire rolling process was simulated using an Arbitrary Lagrangian Eulerian (ALE) formulation. The developed tire-pavement interaction model is used to evaluate the mechanism of load distribution at the tire-pavement interface under various tire loading and rolling conditions. After that, a 3-D FE model of flexible pavement was developed to analyze pavement responses under various loading scenarios. This model utilizes the implicit dynamic analysis, simulates vehicular loading as a continuous moving load, and incorporates 3-D contact stresses at the tire-pavement interface. In the pavement model, the asphalt layer is modeled as a linear viscoelastic material and the granular base layer is modeled as a nonlinear anisotropic material. The FE pavement model was used to analyze critical pavement responses in thin and thick asphalt pavements considering different damage mechanisms. This dissertation concludes that knowledge of tire-pavement contact stress distributions is critical for pavement response prediction. Most importantly, the non-uniform distribution of vertical contact stresses and the localized tangential contact stresses should be considered in the mechanistic-empirical pavement design. The contact stress distributions at the tire-pavement interface are affected by vehicle loading (wheel load and tire inflation pressure), tire configuration (dual-tire assembly and wide-base tire), vehicle maneuvering (braking/acceleration and cornering), and pavement surface friction. Therefore, pavement damage should be quantified using accurate loading inputs that are represented by realistic tire-pavement contact stress distributions. Thin and thick asphalt pavements fail in different ways. Multiple distress modes could occur in thin asphalt pavements, including bottom-up fatigue cracking and rutting in each pavement layer. It was found that the interaction between the viscoelastic asphalt layer and the nonlinear anisotropic granular base layer plays an important role for the stress distribution within a thin asphalt pavement structure under moving vehicular loading. In thick asphalt pavements, near-surface cracking is a critical failure mechanism, which is affected by the localized stress states and pavement structure characteristics. Particularly, the effect of shear stress on the formation of near-surface cracking at multi-axial stress states is important and can not be neglected, especially at high temperatures.

Download or read book Effect of Water Film Thickness on Tire Pavement Friction written by DW. Harwood and published by . This book was released on 1990 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of an extensive experimental investigation of the thin water films of thickness less than 0.38 mm (0.015 in.) on the tire-pavement friction are presented. Both laboratory and full-scale field tests involving new measuring equipment were conducted, and a new device was developed for laboratory measurement of rubber-surface friction. Also, a new apparatus was built to measure thickness of thin water films formed on pavement surfaces. The results from the laboratory and field tests indicate that the tire-pavement friction can decrease significantly at very thin water films from 0.025 to 0.230 mm (0.001 to 0.009 in.). A quantitative measure of the effect of water-film thickness on tire-pavement friction is proposed. The effects of tire, vehicle speed, and pavement texture on pavement wetness sensitivity are also investigated.

Download or read book Water Film Thickness Effects on the Friction Between Tire and Pavement written by J. P. Besse and published by . This book was released on 1972 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book From Texture to Skid Resistance written by Xianhua Chen and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real-time measurement of the tire-road friction coefficient is extremely valuable for road-maintenance operations and highway safety management. This paper presents a systematic framework to predict skid resistance of wet pavement with a non-contact method, which could be a potential approach for real-time measurements of pavement friction. The grip potential of pavement is estimated according to the measured pavement texture based on theoretical simulation of the complete hysteresis and partial adhesive effects during tire sliding on wet pavement. Such a method could be potentially used for the purpose of harmonization analysis of skid resistance and potential capability of optimization of pavement surface texture.

Download or read book The Effects of Rainfall Intensity Pavement Cross Slope and Surface Texture on Water Depths and Resultant Friction Properties of Various Pavements written by Jerry Glenn Rose and published by . This book was released on 1971 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: