The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Ghim Ping Ong - One of the best experts on this subject based on the ideXlab platform.
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Analysing effect of roadway width on Skid Resistance of porous pavement
Road Materials and Pavement Design, 2015Co-Authors: Lei Zhang, Tien Fang Fwa, Ghim Ping Ong, Longjia ChuAbstract:The Skid Resistance available in different lanes of a multi-lane highway on a rainy day would vary because of the differences in surface run-off water thickness. This could happen on porous pavement surfaces when the rainfall intensity is high or when clogging of the porous surface layer occurs. This study presents an analytical numerical approach to analyse the relationship between the width of roadway and the Skid Resistance benefit of porous pavement. The analysis framework consists of a water-film thickness computation module and a Skid Resistance simulation model. An example case analysis is presented to illustrate the concept and framework of Skid number computation for the analysis of Skid Resistance variations on porous asphalt surfaces of different pavement widths. The simulation results demonstrate how porous pavement Skid Resistance would vary with pavement width under the influence of rainfall intensity and vehicle speed. It highlights Skid Resistance variations with road pavement width that d...
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Wet-Pavement Hydroplaning Risk and Skid Resistance: Analysis
Journal of Transportation Engineering, 2008Co-Authors: Tien Fang Fwa, Ghim Ping OngAbstract:This paper presents a numerical simulation of the wet-pavement Skid Resistance reduction process as the sliding speed of a locked wheel increases. The development of the three-dimensional finite-element model used for the simulation is presented in a companion paper. The proposed model is able to simulate tire-fluid-pavement interaction of a sliding locked wheel on a wet pavement for hydroplaning and Skid Resistance analysis. The verification of its ability to predict hydroplaning speed is found in the companion paper. In this paper, the validation of the predicted wet pavement Skid Resistance at different sliding wheel speeds is made by comparing it with measured values from six different experiments conducted by past researchers. A very good match is found between the computed values by the proposed numerical model and the measured data. The analytical model offers a useful tool to predict the magnitude of wet-pavement Skid Resistance at any given locked-wheel sliding speed. As an analytical model, it also produces valuable information on the deterioration mechanism of Skid Resistance. It shows quantitatively the following changes as the sliding speed of a locked wheel increases: a progressively reduced contact area; a progressively increased fluid uplift force under the tire; and the corresponding decreases in the normal contact force at the tire-pavement interface.
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wet pavement hydroplaning risk and Skid Resistance modeling
Journal of Transportation Engineering-asce, 2007Co-Authors: Ghim Ping Ong, T F FwaAbstract:The risk of hydroplaning and reduction of Skid Resistance are two major safety concerns in wet weathering traffic operations on highways and runways. The writers earlier developed an analytical computer model to simulate the phenomenon of hydroplaning. The simulation of wet-pavement Skid Resistance is analytically a more complex problem to handle than hydroplaning simulation. The present paper adopts a more elaborate theoretical approach and proposes an improved analytical computer model to simulate hydroplaning as well as the reduction of wet-pavement Skid Resistance as the sliding wheel speed increases. The theoretical formulation and development of a three-dimensional finite-element model based on solid mechanics and fluid dynamics is presented. The computed hydroplaning speeds by the proposed model were analyzed and verified against the well-known experimentally derived National Aeronautics and Space Administration (NASA) hydroplaning-speed equation. The analysis confirmed that the NASA equation is a special case of a general solution, and that it is applicable only to a specific range of tire footprint aspect ratios. An analysis of the decreasing trend of wet-pavement Skid Resistance with vehicle speed and its validation against measured experimental data will be the subject of another paper.
T F Fwa - One of the best experts on this subject based on the ideXlab platform.
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Skid Resistance determination for pavement management and wet weather road safety
International journal of transportation science and technology, 2017Co-Authors: T F FwaAbstract:Abstract Road accidents during wet weather have been a topic of major concern of road engineers in regions of wet-tropical climate and in other parts of the world during the wet season of the year. Road safety studies indicate that approximately 20% of all road accidents occurred during wet weather, and that the Skid Resistance of wet pavements have a major influence on the occurrences of wet-weather accidents. Monitoring of wet pavement Skid Resistance has been an integral part of a typical pavement management system. However, because of the lack of prediction capability of pavement Skid Resistance under various rainfall intensities, the minimum Skid Resistance threshold for safe wet-weather driving has been specified by highway agencies based on either engineering judgement or past experience. It is shown in this paper that the single-point minimum Skid Resistance threshold is inadequate to offer a complete description of the Skid Resistance performance of the pavement sections in question for effective management of a road network. It is unable to assess the risk involved in an actual wet-weather condition where the pavement surface water-film thickness and vehicle speed are different from standard test conditions. This limitation of the current system of specifying a minimum Skid Resistance threshold can be overcome by adopting a theoretically sound approach to represent pavement Skid Resistance under different conditions of water-film thickness and vehicle speed. This paper describes the theoretical basis of the approach and the development of a mechanistically derived three-dimensional finite-element Skid Resistance simulation model to predict Skid Resistance. The application of the proposed approach and the Skid Resistance prediction procedure in pavement management system and wet-weather driving safety assessment is presented.
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wet pavement hydroplaning risk and Skid Resistance modeling
Journal of Transportation Engineering-asce, 2007Co-Authors: Ghim Ping Ong, T F FwaAbstract:The risk of hydroplaning and reduction of Skid Resistance are two major safety concerns in wet weathering traffic operations on highways and runways. The writers earlier developed an analytical computer model to simulate the phenomenon of hydroplaning. The simulation of wet-pavement Skid Resistance is analytically a more complex problem to handle than hydroplaning simulation. The present paper adopts a more elaborate theoretical approach and proposes an improved analytical computer model to simulate hydroplaning as well as the reduction of wet-pavement Skid Resistance as the sliding wheel speed increases. The theoretical formulation and development of a three-dimensional finite-element model based on solid mechanics and fluid dynamics is presented. The computed hydroplaning speeds by the proposed model were analyzed and verified against the well-known experimentally derived National Aeronautics and Space Administration (NASA) hydroplaning-speed equation. The analysis confirmed that the NASA equation is a special case of a general solution, and that it is applicable only to a specific range of tire footprint aspect ratios. An analysis of the decreasing trend of wet-pavement Skid Resistance with vehicle speed and its validation against measured experimental data will be the subject of another paper.
Tien Fang Fwa - One of the best experts on this subject based on the ideXlab platform.
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Analysing effect of roadway width on Skid Resistance of porous pavement
Road Materials and Pavement Design, 2015Co-Authors: Lei Zhang, Tien Fang Fwa, Ghim Ping Ong, Longjia ChuAbstract:The Skid Resistance available in different lanes of a multi-lane highway on a rainy day would vary because of the differences in surface run-off water thickness. This could happen on porous pavement surfaces when the rainfall intensity is high or when clogging of the porous surface layer occurs. This study presents an analytical numerical approach to analyse the relationship between the width of roadway and the Skid Resistance benefit of porous pavement. The analysis framework consists of a water-film thickness computation module and a Skid Resistance simulation model. An example case analysis is presented to illustrate the concept and framework of Skid number computation for the analysis of Skid Resistance variations on porous asphalt surfaces of different pavement widths. The simulation results demonstrate how porous pavement Skid Resistance would vary with pavement width under the influence of rainfall intensity and vehicle speed. It highlights Skid Resistance variations with road pavement width that d...
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Wet-Pavement Hydroplaning Risk and Skid Resistance: Analysis
Journal of Transportation Engineering, 2008Co-Authors: Tien Fang Fwa, Ghim Ping OngAbstract:This paper presents a numerical simulation of the wet-pavement Skid Resistance reduction process as the sliding speed of a locked wheel increases. The development of the three-dimensional finite-element model used for the simulation is presented in a companion paper. The proposed model is able to simulate tire-fluid-pavement interaction of a sliding locked wheel on a wet pavement for hydroplaning and Skid Resistance analysis. The verification of its ability to predict hydroplaning speed is found in the companion paper. In this paper, the validation of the predicted wet pavement Skid Resistance at different sliding wheel speeds is made by comparing it with measured values from six different experiments conducted by past researchers. A very good match is found between the computed values by the proposed numerical model and the measured data. The analytical model offers a useful tool to predict the magnitude of wet-pavement Skid Resistance at any given locked-wheel sliding speed. As an analytical model, it also produces valuable information on the deterioration mechanism of Skid Resistance. It shows quantitatively the following changes as the sliding speed of a locked wheel increases: a progressively reduced contact area; a progressively increased fluid uplift force under the tire; and the corresponding decreases in the normal contact force at the tire-pavement interface.
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Skid Resistance EVALUATION OF CONCRETE PAVEMENT SURFACES
2003Co-Authors: Yang Pin, Tien Fang Fwa, Kelvin Lee, Yoo Sang ChooAbstract:Providing adequate surface frictional Resistance is a major requirement in the construction of concrete pavements, and the choice of surface finishing treatment method is an important factor that directly affects the Skid Resistance properties of the pavement surface. This paper reports the findings of a study conducted to examine the common surface texturing methods adopted in Singapore in respect of their effectiveness in providing a Skid resistant pavement surface. Five different finishing methods were studied. The study consisted of an experimental program that involved Skid Resistance testing of laboratory prepared specimens before and after accelerated wheel polishing test. The British pendulum tester was used in experimental program for Skid Resistance measurements. The study also performed a three- dimensional finite element analysis to verify the findings of the laboratory tests. The numerical verification confirmed the experimentally established trends of variation in Skid Resistance of different textured surfaces.
A G Kokkalis - One of the best experts on this subject based on the ideXlab platform.
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fractal evaluation of pavement Skid Resistance variations i surface wetting
Chaos Solitons & Fractals, 1998Co-Authors: A G Kokkalis, O K PanagouliAbstract:Abstract Pavement Skid Resistance has long been recognised as the primary factor to reduce traffic accidents. Skid Resistance is affected by a large number of parameters. This is the first in a series of two papers dealing with the road surface contribution to tire-pavement Skid Resistance giving special emphasis to the effect of a water film development on the pavement surface. Pavement surface texture is expressed by micro⧹macrotexture depth and density. Relative regression equations giving pavement Skid Resistance values have been reviewed and a well fitting regression equation has been derived. The mathematical background of fractal interpolation functions is then presented. An attempt is described to approximate the pavement surface texture with fractals by taking into account its accurate geometry. Through this approximation the procedure of pavement surface wetting is evaluated, in respect with its effect to Skid Resistance values. This attempt yields encouraging results, although it is apparent that further research is required.
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Skid Resistance and fractal structure of pavement surface
Chaos Solitons & Fractals, 1998Co-Authors: O K Panagouli, A G KokkalisAbstract:Abstract Pavement Skid Resistance has long been recognized as the most important parameter to reduce traffic accidents. The factors affecting Skid Resistance are numerous and very complicated. It is a difficult task to estimate the extent and direction of their overall contribution. This paper deals with the road surface contribution to tire-pavement Skid Resistance. Pavement surface is expressed through micro/macrotexture depth and density. An attempt is made to approximate this pavement surface texture with fractals, in order to take into account its accurate geometry. A qualitative relationship between pavement surface texture, expressed through fractal concepts, and Skid Resistance is recognized. This attempt yields encouraging results, although it is apparent that further research is required.
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PREDICTION OF Skid Resistance FROM TEXTURE MEASUREMENTS.
Proceedings of the Institution of Civil Engineers - Transport, 1998Co-Authors: A G KokkalisAbstract:It is well-known that the factors affecting tyre-pavement Skid Resistance are numerous and complicated. It is almost impossible to derive a relationship correlating all factors and yielding the value of Skid Resistance under any specific conditions. This paper deals with the road surface contribution to tyre-pavement Skid Resistance. Road surface is expressed through micro/macrotexture depth and spacing. Relative correlation equations have been reviewed and two regression equations have been derived. Data for the equations proposed have been obtained from The Greek Ministry of Public Works and from relevant research papers. The paper deals mainly with the influence of the following factors on Skid Resistance: the type of pavement surface texture; the existence of water film on the pavement surface; and the traffic and environmental wear. The regression equations proposed provide a quite close prediction to the expected variations of Skid Resistance due to the above factors. Improvement of the prediction equations will be continued by incorporating and classifying new data.
Malal Kane - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Skid Resistance evolution models
2012Co-Authors: Véronique Cerezo, Malal KaneAbstract:This paper presents results of a research aiming at modeling the evolution of road surface Skid Resistance using statistical and phenomenological approaches. Data are provided by a database composed of measurements collected on French roads during ten years: Skid Resistance values (Sideway Force Coefficient measured by SCRIM machine), macrotexture values (Mean Profile Depth), road geometry, traffic and age. Principal component analyses determine the connection between relevant factors. Analyses of variance enable the selection of independent variables used in the evolution laws. Various types of evolution laws are explored: linear regressions with one to four parameters, non-linear regressions and logarithmic functions. In parallel, model based on the combination of the main factors that can explain the Skid Resistance evolution is developed. This model takes into account both mechanical effect like polishing under traffic and ageing effect (changes in asphalt mix properties due to the weather effect). In a last part of the study, results obtained with the two approaches on a specific database are compared with results based on models found in literature review.
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Comparison of Skid Resistance evolutionmodels
2012Co-Authors: Véronique Cerezo, Minh Tan, Malal KaneAbstract:This paper presents results of a research aiming at modeling the evolution of road surface Skid Resistance using statistical and phenomenological approaches. Data are provided by a database composed of measurements collected on French roads during ten years: Skid Resistance values (Sideway Force Coefficient measured by SCRIM machine), macrotexture values (Mean Profile Depth), road geometry, traffic and age. Principal component analyses determine the connection between relevant factors. Analyses of variance enable the selection of independent variables used in the evolution laws. Various types of evolution laws are explored: linear regressions with one to four parameters, non-linear regressions and logarithmic functions. In parallel, model based on the combination of the main factors that can explain the Skid Resistance evolution is developed. This model takes into account both mechanical effect like polishing under traffic and ageing effect (changes in asphalt mix properties due to the weather effect). In a last part of the study, results obtained with the two approaches on a specific database are compared with results based on models found in literature review.
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Effect of Aggregate and Asphalt on Pavement Skid Resistance Evolution
Paving Materials and Pavement Analysis, 2010Co-Authors: Dan Zhao, Malal Kane, Minh TanAbstract:When designing pavement, engineers must optimize some requirements such as user safety (Skid Resistance), environmental impact (noise, rolling Resistance...)... However, this Skid Resistance evolves during the entire pavement life. So it is a common practice to perform laboratory tests to forecast the evolution of Skid Resistance. Previous works done in the French Laboratory of Bridges and Roads (Laboratoire Central des Ponts et Chaussees, LCPC) have identified phenomena such as binder removal, aggregate polishing and seasonnal variations to be responsible of these variations. This paper focuses on the polished stone values of aggregates and the aging of asphalt on the evolution of pavement Skid Resistance. Skid Resistance of different specimens of nude aggregates and asphalt mixes that are submitted to polishing and aging was studied. On Skid Resistance point of view, aging of aggregates can be neglected in comparison to those of asphalt. Rocks with high polishing Resistance offer less variation of Skid Resistance. Aging of asphalt tends to increase Skid Resistance until 12 month and remains this latter constant after.
