The Relationship Between Texture and Pavement Friction

1978 ◽  
Vol 6 (4) ◽  
pp. 215-232 ◽  
Author(s):  
J. J. Henry
Keyword(s):  
Standard Test ◽  
Skid Resistance ◽  
Side Force ◽  
Force Coefficients ◽  
Speed Dependence ◽  
The Relationship ◽  
Pavement Friction ◽  
Slip Method

Abstract The transient slip method is shown to be a useful technique to evaluate the speed dependence of pavement friction. From the results of transient slip tests with a standard test tire, it is possible to predict skid resistance, speed gradients, and side force coefficients. Transient slip data can be predicted from wet pavement macro-texture and microtexture and, therefore, skid resistance-speed gradients and side force coefficients can be predicted from texture measurements.

Wet Skid Resistance of Car and Truck Tires

1974 ◽  
Vol 2 (2) ◽  
pp. 102-116 ◽  
Author(s):  
A. Dijks
Keyword(s):  
Surface Texture ◽  
Road Surface ◽  
Skid Resistance ◽  
Test Results ◽  
Side Force ◽  
Force Coefficients ◽  
Truck Tires ◽  
Braking Force ◽  
Wet Skid Resistance

Abstract Two test trailers for measuring tire characteristics are described. One of the trailers is specially built for testing car tires and can steer, camber, and brake the test tire. This trailer is provided with a five component measuring hub. The second trailer, for testing truck tires, is restricted to braking only. Braking forces are measured with a dynamometer. The determination of peak and locked wheel braking force coefficients is discussed. In addition, for car tires, a method for obtaining side force coefficients is given. Test results are given for both car and truck tires showing the influence of road surface texture, speed, and tread depth on skid resistance, and the results are compared.

ELASTOMERIC NANOPARTICLES: EFFECTIVE ADDITIVE FOR HIGH PERFORMANCE RUBBER NANOCOMPOSITES

2020 ◽  
pp. 000-000 ◽  
Author(s):  
Xiang Wang ◽  
Jinliang Qiao ◽  
Zhifeng Zhou ◽  
Jianming Gao ◽  
Guicun Qi ◽  
...  
Keyword(s):  
Automobile Industry ◽  
High Performance ◽  
Rolling Resistance ◽  
Skid Resistance ◽  
Rubber Composites ◽  
Wear Life ◽  
Important Challenge ◽  
The Relationship ◽  
Wet Skid Resistance

ABSTRACT The “magic triangle” is the most important challenge to rubber composites for the automobile industry. According to the magic triangle, it is difficult to improve the rolling resistance (energy saving), wet skid resistance (safety), and wear (life) of a tire simultaneously. However, ∼5% decrease of rolling resistance, >20% increase of wet skid resistance, and 15% decrease of wear were achieved after adding a small amount of elastomeric nanoparticle (ENP). The effect of ENP on the performances of rubber composites was expounded by characterization of the dispersion of filler and the relationship between filler and rubber. The main difference between ENPs and other nanoparticles was that ENPs acted as not only a part of filler but also as a part of rubber in rubber composites.

scholarly journals Identifikasi Pemahaman Konsep Usaha dan Energi Calon Guru Fisika

2019 ◽  
Vol 7 (2) ◽  
pp. 157
Author(s):  
Muhammad Reyza Arief Taqwa
Keyword(s):  
Kinetic Energy ◽  
Conceptual Understanding ◽  
Standard Test ◽  
Multiple Choice Questions ◽  
Descriptive Research ◽  
Basic Physics ◽  
Mathematical Equations ◽  
Relationship Of ◽  
The Relationship ◽  
Mathematical Operations

This study aims to reveal the students' conceptual understanding on the concept of work and energy. In this study focused on discussing the ability of students to understand the concept of kinetic energy. To achieve this goal, 5 reasoned multiple choice questions were used. The question is a standard test of basic physics lectures at UM. This research is a descriptive research. The study was conducted on 50 students in the "Physics Content and Its Pedagogic I" course. The results showed that only 13 (26%) students correctly answered the relationship of K(x) from the F(x) graph and 10 (20%) students who correctly answered the K ratio of the two objects driven by the same force and displacement. Students' difficulties when solve the questions are more likely to be caused by the habits of students using mathematical equations without understanding their physical meaning, in addition students also have weaknesses in mathematical operations.

Simulation of Flow Around a Cube at Moderate Reynolds Numbers Using the Lattice Boltzmann Method

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Majid Hassan Khan ◽  
Atul Sharma ◽  
Amit Agrawal
Keyword(s):  
Reynolds Number ◽  
Drag Coefficient ◽  
Lattice Boltzmann Method ◽  
Steady Flow ◽  
Flow Regime ◽  
Lattice Boltzmann ◽  
Reynolds Numbers ◽  
Side Force ◽  
Force Coefficients ◽  
Boltzmann Method

Abstract This article reports flow behavior around a suspended cube obtained using three-dimensional (3D) lattice Boltzmann method (LBM)-based simulations. The Reynolds number (Re) range covered is from 84 to 770. Four different flow regimes are noted based on the flow structure in this range of Re: steady axisymmetric (84 ≤ Re ≤ 200), steady nonaxisymmetric (215 ≤ Re ≤ 250), unsteady nonaxisymmetric in one plane and axisymmetric in the other plane (276 ≤ Re ≤ 300), and unsteady nonaxisymmetric in streamwise orthogonal planes (339 ≤ Re ≤ 770). Recirculation length and drag coefficient follow inverse trend in the steady flow regime. The unsteady flow regime shows hairpin vortices for Re ≤ 300 and then it becomes structureless. The nature of force coefficients has been examined at various Reynolds numbers. Temporal behavior of force coefficients is presented along with phase dependence of side force coefficients. The drag coefficient decreases with increase in Reynolds number in the steady flow regime and the side force coefficients are in phase. Drag coefficients are compared with established correlations for flow around a cube and a sphere. The side force coefficients are perfectly correlated at Re = 215 and they are anticorrelated at Re = 250. At higher Reynolds numbers, side force coefficients are highly uncorrelated. This work adds to the existing understanding of flow around a cube reported earlier at low and moderate Re and extends it further to unsteady regime at higher Re.

scholarly journals Evaluation of Pavement Skid Resistance Using Surface Three-Dimensional Texture Data

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 162 ◽  
Author(s):  
Yuanyuan Wang ◽  
Xingyu Lai ◽  
Fei Zhou ◽  
Jinshun Xue
Keyword(s):  
Friction Coefficient ◽  
Evaluation Model ◽  
Three Dimensional ◽  
Detection Methods ◽  
Driving Safety ◽  
Skid Resistance ◽  
Reconstruction Method ◽  
Multinomial Regression ◽  
3D Texture ◽  
The Relationship

Pavement skid resistance is an important guarantee for driving safety. However, it is very difficult to determine the exact friction in a field environment. In order to overcome the limitations of traditional evaluation methods, the effect mechanism of surface 3D (three-dimensional) texture on skid resistance was firstly analyzed. Then the surface 3D texture of pavement was acquired through an improved binocular reconstruction method. Additionally, the relationship between friction coefficient and 3D texture was also analyzed. Subsequently, under the concept of IFI (international friction index) used to harmonize different detection methods of skid resistance, the evaluation model of skid resistance based 3D texture was further established. The results showed that the multiple quadratic multinomial regression model can well describe the relationship between skid resistance and texture indicators. The establishment of an improved evaluation model is simple to operate and implement. It can directly evaluate the skid resistance on pavement surface once the aggregates’ type and 3D texture are known. This evaluation model not only overcomes the challenges of friction coefficient with a strong conditional restriction, but also provides a harmonious approach for different detection methods in the evaluation of pavement skid resistance.

Skid Resistance of Passenger Car Tires on Wet Surfaces

1968 ◽  
Vol 41 (4) ◽  
pp. 780-806 ◽  
Author(s):  
G. Maycock
Keyword(s):  
Road Surface ◽  
Skid Resistance ◽  
Passenger Car ◽  
Force Coefficients ◽  
Potential Value ◽  
Lubricating Film ◽  
High Speeds ◽  
Wide Range ◽  
Road Surfaces ◽  
Braking Force

Abstract This paper reports investigations into the effect of tread pattern, pattern modifications, tread material, and tire casing construction, on skid resistance of passenger-car tires at speeds between 25 and 80 mph on a range of wet road surfaces. The technique was to brake the front wheels of a car until they locked, and to record deceleration of the vehicle. From the deceleration record, both peak and locked-wheel values of braking force coefficients were obtained. The method is described and an assessment of the errors is given. The experiments showed the importance of adequate drainage of the region of contact between tire and road, particularly at higher speeds, in order to remove the lubricating film of water. Such drainage can be provided either by a tread pattern or a coarse road surface. The results indicate the importance of each and their inter-relation. Results of various modifications to a standard tread pattern are given; these show that on smooth surfaces worthwhile increases in wet road adhesion at high speeds can be obtained by suitable design of tire tread patterns. Magnitude of increases in friction due to changes in tread material are given for both peak and locked-wheel coefficients. Ratios of peak to locked-wheel coefficients have been calculated over a wide range of surface and tire combinations. They show the potential value of devices enabling a vehicle to make use of these high coefficients.

Skid-Resistance and Noise-Reducing Characteristics of Exposed-Aggregate Cement Concrete Pavement

2014 ◽  
Vol 1052 ◽  
pp. 352-357 ◽  
Author(s):  
Jiu Peng Zhang ◽  
Guo Qiang Liu ◽  
Peng Zhi Wang
Keyword(s):  
Traffic Noise ◽  
Concrete Pavement ◽  
Skid Resistance ◽  
Cement Concrete ◽  
Pavement Surface ◽  
Index Variation ◽  
Cement Concrete Pavement ◽  
New Type ◽  
The Relationship ◽  
Resistance Value

EACCP is a new-type cement concrete pavement with better skid-resistance and less traffic noise. In this paper, skid-resistance and noise-reducing performance of EACCP are tested and analyzed by laboratory and outdoor tests. The results indicate that the relationship between BPN and EAD is followed the parabola variation laws. With the increase of EAD, TD decreases. And skid-resistance value exists the extremum. If BPN is targeted as skid-resistance optimization goal for pavement surface features, the optimized EAD is existed and approximately to 40~60. The relationship between BPN and TD is also followed the parabola variation laws which also suggests the existence of the optimized TD scope approximately to 0.8~1.0mm.The relationship between TD and EAD can be simulated by index variation laws. With the increase of EAD, TD decreases, which proves the evident noise-reducing performance of EACCP. And the reduction amplitude of noise increases with vehicular acceleration.

The relationship between the chemical structure of s-triazines and fungitoxicity to Sclerotium rolfsii

1973 ◽  
Vol 19 (3) ◽  
pp. 329-334 ◽  
Author(s):  
C. D. Ercegovich ◽  
R. L. Chrzanowski ◽  
H. Cole ◽  
N. Herendeen ◽  
S. Witkonton
Keyword(s):  
Mycelial Growth ◽  
Chemical Structure ◽  
Sclerotium Rolfsii ◽  
Standard Test ◽  
Highly Active ◽  
Level Of Activity ◽  
Apparent Correlation ◽  
Test Concentration ◽  
Absolute Correlation ◽  
The Relationship

Thirty eight substituted s-triazine and three dialkyl biguanide analogs were tested for their effects on mycelial growth and the formation of sclerotia by Sclerotium rolfsii. None of the chemicals were fungicidal to the organism at a test concentration of 100 μg/ml in potato dextrose agar. One of the chemicals, ipazine, was highly fungistatic, and 11 others demonstrated a significant but lower degree of activity against mycelial growth. The formation of sclerotia was completely inhibited in the presence of only one s-triazine, 2-amino-4-chloro-6-n-propylamino-s-triazine. Eight other s-triazines were as active as atrazine, the standard test chemical, in inhibiting the formation of sclerotia, and 10 more of the s-triazines were significantly effective but at a lower level of activity than atrazine. N1,N5-bis(ethyl)biguanide was the only chemical which caused a significant increase in the number of sclerotia formed. No absolute correlation was observed between biological activity and chemical structure although in certain instances there was an apparent correlation between toxicity and the overall electron withdrawing character of the non-alkylamino substituent on the s-triazine ring, or to the steric effects caused by the configuration of the alkylamino substituents. Only those chemicals which were highly active as herbicides were significantly effective in inhibiting mycelial growth and sclerotia formation; however, not all of the herbicidally active compounds were effective in this regard.

Relationship between Test Results of the ACSIRO and ASTM C1202 Methods

2006 ◽  
Vol 302-303 ◽  
pp. 567-571 ◽  
Author(s):  
Wei Wen Li ◽  
Fa Guang Leng ◽  
Xiong Zhou Yuan
Keyword(s):  
Standard Test ◽  
Total Charge ◽  
Test Results ◽  
Additional Test ◽  
Simple Modification ◽  
Concrete Quality ◽  
The Difference ◽  
Astm C1202 ◽  
The Relationship

The ASTM C1202 method is observed that the total electric charge passed is not an ideal indicator for classification of concrete quality when different binders are considered. Considering the drawback of the ASTM 1202 method, a simple modification to the ASTM C1202 method is recommended. The modification involves an additional test using curing water as electrolyze solution. The difference in the total charge passed obtained between standard test and test performed in curing water is suggested as an indicator for concrete quality. The test results show that there exists a good correlation between the ACSIRO and the ASTM C1202 methods. The relationship can be formulated as a linear function.

scholarly journals Investigation on Acoustic Versus Functional Characteristics of Porous Asphalt

2021 ◽  
Vol 16 (4) ◽  
pp. 212-239
Author(s):  
Filippo Giammaria Praticò ◽  
Rosario Fedele ◽  
Paolo Giovanni Briante
Keyword(s):  
Input Data ◽  
Error Function ◽  
Theoretical Background ◽  
Mix Design ◽  
Asphalt Pavements ◽  
Porous Asphalt ◽  
Measured Resistivity ◽  
Acoustic Spectra ◽  
The Relationship ◽  
Pavement Friction

The theoretical background, standards, and contract requirements of pavement friction courses involve functional (e.g., permeability) and acoustic (e.g., resistivity) characteristics. Unfortunately, their relationship is partly unknown and uncertain. This affects the comprehensiveness and soundness of the mix design of asphalt pavements. Based on the issues above, the goals of this study were confined into the following ones: 1) to investigate the relationship between acoustic and functional properties of porous asphalts; 2) to investigate, through one-layer (1L) and two-layer (2L) models, the effectiveness of the estimates of acoustic input data through mixture volumetric- and permeability-related characteristics. Volumetric and acoustic tests were performed and simulations were carried out. Equations and strategies to support a comprehensive approach were derived. Results demonstrate that even if the measured resistivity is very important, permeability-based estimates of resistivity well explain acoustic spectra. Furthermore, the distance between observed and estimated peaks of the absorption spectrum emerges as the best error function.

Sign in / Sign up

Export Citation Format

Share Document