Road Surface Characteristics and Skidding Resistance

1967 ◽  
Vol 40 (3) ◽  
pp. 684-693 ◽  
Author(s):  
Barbara E. Sabey
Keyword(s):  
Large Scale ◽  
High Pressures ◽  
Water Film ◽  
Surface Characteristics ◽  
Road Surface ◽  
Dominant Factor ◽  
Fine Scale ◽  
The Road ◽  
Drainage Channels ◽  
On The Road

Abstract When roads are wet their skidding resistance is reduced by the lubricating action of the film of water on the road. Under some circumstances this reduction may be substantial and the extent of it is largely dependent on the characteristics of the road surface. The first requirement for a good skidding resistance on wet roads is to facilitate break through of the water film in order to establish areas of dry contact between the road and the tire. Drainage channels, provided by the large scale texture of the road or by a pattern on the tire, assist in getting rid of the main bulk of water and are of increasing importance the higher the speed. The penetration of the remaining water film can be achieved only if there are sufficient fine scale sharp edges in the road on which high pressures (about 1000 lb/in2) are built up. The existence of such fine scale sharpness gives the surfaces a harsh feel. When vehicles are travelling at speeds of about 30 mph the fine scale texture of the road is the dominant factor determining skidding resistance. However, as they travel faster, it becomes increasingly difficult to penetrate the water film in the time available, however harsh the surface. At high speeds the requirements for a good skidding resistance are therefore different. The resistance to skidding arises to a larger extent from energy losses in the rubber of the tire as the surface of the tread is deformed by projections in the road surface and, although the physical properties of the tread rubber are important in this respect, it is essential to have sufficiently large and angular projections in the road surface to deform the tread, even though a water film may still be present on the surface. At higher speeds the coarseness of texture becomes as important as its harshness.

scholarly journals THE EXPERIMENTAL STUDY OF SHALLOW FLOWS OF LIQUID ON THE AIRPORT RUNWAYS AND AUTOMOBILE ROADS

Transport ◽  
2010 ◽  
Vol 25 (4) ◽  
pp. 394-402 ◽  
Author(s):  
Andrey Beljatynskij ◽  
Olegas Prentkovskis ◽  
Julij Krivenko
Keyword(s):  
Experimental Study ◽  
Traffic Safety ◽  
Water Film ◽  
Reynolds Numbers ◽  
Road Surface ◽  
Moving Vehicle ◽  
The Road ◽  
Shallow Flows ◽  
On The Road ◽  
Effective Water

Hydroplaning or aquaplaning is associated with the complete loss of the grip of a tyre because of the presence of a water film between the tyres of a moving vehicle (an automobile, an airplane, etc.) and the road surface. In this case, a vehicle becomes uncontrollable. Hydroplaning (aquaplaning) occurs when the speed of a vehicle reaches the critical value, when the wheel does not have time enough for water compulsion, which leads to the formation of a permanent water film between it and the road surface. The higher the depth of the water on the road surface under the tyre, the higher the risk of hydroplaning (aquaplaning). In other words, hydroplaning (aquaplaning) is the floating of the wheel on the water wedge. In physical terms, it is the loss of the ability of a tyre of the effective water compulsion from the contact area with the road. As a result, a water film of several millimeters is formed under the wheel, and a vehicle actually floats up. The article presents the results obtained in the experimental study of the flows of liquid, whose depth is comparable with that of depressions and cambers of rough roadway pavement. It is stated that the relationships used for calculating surface flows should be corrected for shallow flows, taking into account the actual roughness of road covering. Shallow flows are mostly laminar. The transition Reynolds numbers are about 3000. The relationships used for calculating shallow flows may be determined more accurately by test pouring of water on the surface of roadway pavement, with further generalization of the data. The experimental research performed is closely related to the study of the problems of aquaplaning and traffic safety of various means of transport.

scholarly journals Effects of Speeds and Weights of Travelling Vehicles on the Road Surface Temperature

2021 ◽  
pp. 100077
Author(s):  
Samim Mustafa ◽  
Hidehiko Sekiya ◽  
Aya Hamajima ◽  
Iwao Maeda ◽  
Shuichi Hirano
Keyword(s):  
Surface Temperature ◽  
Road Surface ◽  
The Road ◽  
Road Surface Temperature ◽  
On The Road

scholarly journals STUDI KERUSAKAN JALAN DITINJAU DARI FAKTOR SETEMPAT (STUDI KASUS RUAS JALAN BLANGKEJEREN – LAWE AUNAN)

2018 ◽  
Vol 1 (3) ◽  
pp. 667-678
Author(s):  
Mulyadi Mulyadi ◽  
Muhammad Isya ◽  
Sofyan M. Saleh
Keyword(s):  
Traffic Safety ◽  
Condition Index ◽  
Road Surface ◽  
Primary Data ◽  
Soil Conditions ◽  
Pavement Condition ◽  
Local Factors ◽  
The Road ◽  
Pavement Condition Index ◽  
On The Road

Abstract: Blangkejeren - Lawe Aunan road conditions overall is on the slopes of the mountains which is strongly influenced by local environmental factors such as drainage, topography, soil conditions, material conditions and vehicle load conditions across the road. It should be noted in order to avoid a decrease in the road quality due to road surface damage that can affect the traffic safety, comfort and smoothness.. Therefore, it is necessary to study the evaluation of the condition of the damaged road surface and the local factors that affect the damage in order to avoid a decrease in the roads quality. This study took place on Blangkejeren - Lawe Aunan roads started from Sta. 529 + 700 - Sta. 535 + 206. Generally, the condition of roads in this segment were found damage that disturb the comfort, smoothness and safety of the roads users. In this study, the primary data obtained by actual surveys in the form of data field length, width, area, and depth of each type of damage as well as local factors that lead to such damage. Actual field surveys conducted along the 5.506 km, with the distance interval of each segment is 100 m. The secondary data obtained from the relevant institutions and other materials related to this research. This study analyzed the PCI method (Pavement Condition Index) to obtain the level of damage in order to know how to handle, while for the identification of the damage done by observation factors descriptively appropriate observation in the field such as the number of damage points. The results of this study found that the type of damage caused to roads is damage to the cover layer, a hole, and curly. This type of damage that commonly occurs on the road Blangkejeren - Lawe Aunan is damage to the edges with a percentage of 87.30%. The local factors that greatly affect drainage on the percentage of damage is 62.00%. PCI average value is 13.47 which indicates a very bad condition (very poor) and requires maintenance or improvement of reconstruction.Abstrak: Kondisi jalan Blangkejeren – Lawe Aunan secara keseluruhan berada di lereng pegunungan sangat dipengaruhi oleh faktor lingkungan setempat seperti drainase, topografi, kondisi tanah, kondisi material dan kondisi beban kendaraan yang melintasi jalan tersebut. Hal ini perlu diperhatikan agar tidak terjadi penurunan kualitas jalan akibat kerusakan permukaan jalan sehingga dapat mempengaruhi keamanan, kenyamanan, dan kelancaran dalam berlalu lintas. Oleh karena itu, perlu dilakukan penelitian evaluasi terhadap kondisi permukaan jalan yang mengalami kerusakan serta faktor setempat yang mempengaruhi kerusakan tersebut agar tidak terjadi penurunan kualitas jalan. Penelitian ini mengambil lokasi di ruas jalan Blangkejeren – Lawe Aunan yang dimulai dari Sta. 529+700 - Sta. 535+206. Umumnya kondisi ruas jalan pada segmen ini banyak ditemukan kerusakan-kerusakan yang dapat mengganggu kenyamanan, kelancaran, dan keamanan pengguna jalan. Dalam penelitian ini data primer diperoleh dengan melakukan survei aktual lapangan yaitu berupa data panjang, lebar, luasan, dan kedalaman tiap jenis kerusakan serta faktor setempat yang mengakibatkan kerusakan tersebut. Survei aktual lapangan dilakukan sepanjang 5,506 km, dengan jarak interval setiap segmen adalah 100 m. Adapun data sekunder diperoleh dari lembaga terkait dan bahan lainnya yang berhubungan dengan penelitian ini. Penelitian ini dianalisis dengan metode PCI (Pavement Condition Index) untuk mendapatkan tingkat kerusakan agar diketahui cara penanganannya, sedangkan untuk identifikasi faktor kerusakannya dilakukan dengan pengamatan secara diskriptif sesuai hasil pengamatan di lapangan berupa jumlah titik kerusakan. Hasil penelitian ini didapatkan bahwa jenis kerusakan yang terjadi pada ruas jalan adalah kerusakan lapisan penutup, lubang, dan keriting. Jenis kerusakan yang umum terjadi pada ruas jalan Blangkejeren – Lawe Aunan adalah kerusakan tepi dengan persentase 87,30 %. Faktor setempat yang sangat mempengaruhi kerusakan adalah drainase dengan persentase 62,00%. Nilai PCI rata-rata yaitu 13,47 yang menunjukkan kondisi sangat buruk (very poor) dan memerlukan pemeliharaan peningkatan atau rekonstruksi.

On the Road to Large-Scale 3D Monocular Scene Reconstruction using Deep Implicit Functions

2021 ◽  
Author(s):  
Thomas Roddick ◽  
Benjamin Biggs ◽  
Daniel Olmeda Reino ◽  
Roberto Cipolla
Keyword(s):  
Large Scale ◽  
Scene Reconstruction ◽  
Implicit Functions ◽  
The Road ◽  
On The Road

scholarly journals Road Surface Condition Forecasting in France

2009 ◽  
Vol 48 (12) ◽  
pp. 2513-2527 ◽  
Author(s):  
L. Bouilloud ◽  
E. Martin ◽  
F. Habets ◽  
A. Boone ◽  
P. Le Moigne ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Initial Conditions ◽  
Meteorological Data ◽  
Surface Condition ◽  
Road Surface ◽  
Snow Layer ◽  
Surface Conditions ◽  
The Road ◽  
Road Surface Temperature ◽  
On The Road

Abstract A numerical model designed to simulate the evolution of a snow layer on a road surface was forced by meteorological forecasts so as to assess its potential for use within an operational suite for road management in winter. The suite is intended for use throughout France, even in areas where no observations of surface conditions are available. It relies on short-term meteorological forecasts and long-term simulations of surface conditions using spatialized meteorological data to provide the initial conditions. The prediction of road surface conditions (road surface temperature and presence of snow on the road) was tested at an experimental site using data from a comprehensive experimental field campaign. The results were satisfactory, with detection of the majority of snow and negative road surface temperature events. The model was then extended to all of France with an 8-km grid resolution, using forcing data from a real-time meteorological analysis system. Many events with snow on the roads were simulated for the 2004/05 winter. Results for road surface temperature were checked against road station data from several highways, and results for the presence of snow on the road were checked against measurements from the Météo-France weather station network.

Influence of Silica Sand Particles on Disc Brake Squeal Noise

2013 ◽  
Vol 471 ◽  
pp. 81-85 ◽  
Author(s):  
Ahmad Razimi Mat Lazim ◽  
Abd Rahim Abu Bakar ◽  
Mohd Kameil Abdul Hamid ◽  
Izzat Mohd Asri
Keyword(s):  
Surface Condition ◽  
Surface Characteristics ◽  
Silica Sand ◽  
Brake Pad ◽  
Brake Squeal ◽  
The Road ◽  
Film Distribution ◽  
Before And After ◽  
Sand Particles ◽  
On The Road

Researchers in recent years begin to explore on tribological behavior of automotive brake squeal phenomena which covers the morphology, chemical composition, friction and wear, phase composition and third body or friction film distribution. However less effort has been made to study the tribological on the influence of small particles on brake squeal. During braking condition, both rotor and pads are exposed to road environmental particle which may affect pads surface condition. In order to assess the influence of this particle on brake squeal a series of squeal tests were performed. Silica sand grit particles with a size range between 400 to 200 μm which most available on the road surface were used in this experiment. Brake pad and disc surface characteristics were analyzed before and after squealing condition using Scanning Electron Microscope (SEM) and Energy dispersive X-ray analysis (EDX). The result shows that the silica sand particles had influence the squeal and surface behavior of the brake pad.

Experimental Research on Dynamic Characteristics of a Rolling Agricultural Tire (Influence of Running Condition)

2013 ◽  
Author(s):  
Katsuhide Fujita ◽  
Takashi Saito ◽  
Mitsugu Kaneko
Keyword(s):  
Natural Frequency ◽  
Dynamic Behavior ◽  
Experimental Research ◽  
Dynamic Characteristics ◽  
Excitation Frequency ◽  
Road Surface ◽  
Natural Mode ◽  
The Road ◽  
On The Road ◽  
Agricultural Machines

When agricultural machines are operated on pavements, the vibration and noise caused by the interaction between the tire lugs and the road surface are inevitable. In conventional studies, it is considered that the dynamic behavior of a rolling agricultural tire is influenced by the vibration characteristics of the tire. Resonance occurs when the lug excitation frequency of the tire, which is defined as the lug number multiplied by the number of revolutions of the tire, becomes equal to the natural frequency of the tire. In other words, the rolling tire shows large vibrations in the direction of the natural mode corresponding to the natural frequency of the tire. However, in the conventional equipment, the diameter of the drum is smaller than that of the tire. Therefore, the real running condition on the road was not realized by the rolling test using the conventional equipment. In this study, a new equipment is produced to realize the running condition in the rolling test. The dynamic and vibratory characteristics of operating agricultural machine are investigated by using this new equipment. The obtained results are compared to the conventional ones and the influence of the running condition on dynamic characteristics of rolling tire is investigated.

Experiment with Reduced Salting of Rural Main Roads in Finland

1996 ◽  
Vol 1533 (1) ◽  
pp. 32-37
Author(s):  
Veli-Pekka Kallberg
Keyword(s):  
Road Surface ◽  
Winter Maintenance ◽  
The Road ◽  
Pine Trees ◽  
Traffic Volumes ◽  
On The Road ◽  
The Cost ◽  
Chloride Concentrations

An experiment was conducted in the road district of Kuopio in the winters of 1992–1993 and 1993–1994 in which the use of salt in winter maintenance on rural main roads was reduced to 1 to 2 T/road kilometer from the approximately 10 T of salt that typically had been used per road kilometer in similar conditions in recent years. On the experimental roads, salting was replaced by sanding. The cost of winter maintenance on the experimental roads increased by 20 percent on average, and the increase was higher on roads with higher traffic volumes. Slippery conditions due to ice and snow on the road surface were twice as frequent (30 to 40 percent of the time) on the experimental roads as on the control roads in the neighboring road district. There were 27 injury accidents on the experimental roads in the first winter and 25 in the second. This was about the same as the average of the five previous winters. Because the accident trend on other roads in the same time was decreasing, it was concluded that the experiment increased the number of injury accidents by approximately 20 percent on most experimental road sections. Reduced salting decreased the sodium and chloride concentrations in the needles of roadside pine trees. There were also indications of decreased sodium and chloride concentrations in groundwater. Three quarters of the population in the area was pleased with the experiment.

High precision and high resolution monitoring of subsurface changes with DAS and airgun

2020 ◽  
Author(s):  
Baoshan Wang ◽  
Xiangfang Zeng ◽  
Jun Yang ◽  
Yuansheng Zhang ◽  
Zhenghong Song ◽  
...  
Keyword(s):  
Large Scale ◽  
Fiber Optic ◽  
Epicentral Distance ◽  
Low Cost ◽  
Fiber Optic Cable ◽  
The Road ◽  
Air Gun ◽  
Distributed Acoustic Sensing ◽  
On The Road ◽  
Road Crossing

<p>Recently large-volume airgun arrays have been used to explore and monitor the subsurface structure. The airgun array can generate highly repeatable seismic signals, which can be traced to more than 200 km. And the airgun source can be ignited every 10 minutes. The airgun source makes it possible to precisely monitor subsurface changes at large scale. The spatial resolution of airgun monitoring is poor subjecting to the receiver distribution. The distributed acoustic sensing (DAS) technique provides a strategy for low-cost and high-density seismic observations. Two experiments combing DAS technique and airgun source were conducted at two sites with different settings. At the first site, a telecommunication fiber-optic cable in urban area was used. After moderate stacking, the airgun signal emerges on the 30-km DAS array at about 9 km epicentral distance. In the second experiment, a 5-km cable was deployed from the airgun source to about 2 km away. About 800-m cable was frozen into the ice above the air-gun, the rest cable was cemented on the road crossing through a fault. And the airgun has been fired continuously for more than 48 hours with one-hour interval. On the stacking multiple shots’ records, the wavefield in fault zone emerges too. These two experiments demonstrate the feasibility of using various fiber-optic cables as dense array to acquire air-gun signal in different environments and to monitor the subsurface changes.</p>

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