Peak Friction Prediction Model Based on Surface Texture Characteristics

2015 ◽  
Vol 2525 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Pietro Leandri ◽  
Massimo Losa
Keyword(s):  
Surface Characteristics ◽  
Concrete Surface ◽  
Exponential Model ◽  
Asphalt Pavements ◽  
Vehicle Speed ◽  
In Situ Tests ◽  
Antilock Brake System ◽  
Texture Characteristics ◽  
Friction Prediction ◽  
New Formulation

This paper proposes a new model for predicting the speed gradient of peak friction values on asphalt pavements on the basis of surface characteristics. The innovative feature of the proposed model is the reliable estimation of peak friction values experienced by vehicles equipped with an antilock brake system at a certain vehicle speed. To define the experimental model, several types of dense asphalt concrete surface layers with various surface characteristics were analyzed by in situ tests. Friction was measured with the Skiddometer BV11 and the British pendulum tester, and texture properties were measured with a laser profilometer. The Rado model was used to predict peak friction values at three vehicle speeds, and these data were used to determine the gradient of peak friction values for each pavement section. The spectral analysis of pavement profile data was used to define a texture parameter negatively correlated with peak friction values; this parameter was introduced in a new formulation of the speed number Sp* that was a measure of the influence of pavement macrotexture on peak friction values. The speed number Sp* was used in the new exponential model proposed for defining the gradient of peak friction values. The results show that the model is highly reliable; because the model allows identification of texture characteristics to be modified to optimize peak friction values, it is particularly useful for optimization of the mix design and maintenance of pavement surfaces.

Lateral coefficient of friction for characterizing winter road conditions

2016 ◽  
Vol 43 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Sahar Salimi ◽  
Somayeh Nassiri ◽  
Alireza Bayat ◽  
Don Halliday
Keyword(s):  
Field Experiments ◽  
Surface Friction ◽  
Concrete Surface ◽  
Snow Accumulation ◽  
Frictional Heat ◽  
Vehicle Speed ◽  
Test Road ◽  
Winter Road ◽  
Friction Measurements ◽  
The University

Real Time Traction Tool (RT3)-Curve was used in this study to evaluate the effect of ice and snow on tire–road lateral friction coefficient, herein referred to as the Halliday Friction Number (HFN). The field experiments for the study were performed in winter 2012–2013 on the University of Alberta’s test road facility in Edmonton, Alberta. Each run was repeated at three target speeds under varied road conditions, bare dry, dry with ice patches, ice, and three levels of snow accumulation. No considerable correlation was found between vehicle speed and the friction measurements for bare dry, ice- and snow-covered conditions. Expectedly, the bare dry asphalt concrete surface had the highest HFN, the presence of ice reduced the dry surface friction by 55%. The accumulation of snow on the dry surface reduced the HFN further than ice, by 69, 75, and 81% for light, moderate, and heavy snow, respectively. A falling trend was observed for friction as more snow accumulated on the ground. Analysis of the effect of number of truck passes over ice at −3.5 and −5 °C showed that ice can become more slippery after each pass of traffic. A similar analysis for snow revealed that more passes over moderate snow will compact the fresh snow into a slippery surface. For light snow, even at low temperatures (<−10 °C), passes of traffic will melt the snow through frictional heat and result in higher friction values.

scholarly journals Effects of Anti-Graffiti Protection on Concrete Durability

2014 ◽  
Vol 634 ◽  
pp. 517-526 ◽  
Author(s):  
Elsa Neto ◽  
Ana Souto ◽  
Aires Camões ◽  
Arlindo Begonha ◽  
Paulo Cachim
Keyword(s):  
Water Absorption ◽  
Atmospheric Pressure ◽  
Surface Characteristics ◽  
Concrete Surface ◽  
Experimental Program ◽  
Concrete Durability ◽  
Protection Systems ◽  
Before And After ◽  
Paint Removal ◽  
Durability Of Concrete

The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti, a form of vandalism that causes a major social and economic impact on society. Concrete is a porous material sometimes deteriorated over the years, and the interactions between the inks and the substrate and removal methods sometimes deteriorate or alter the concrete surface, especially if it is necessary to repeat the removal process. The anti-graffiti products are applied on the surface of the concrete, hindering the adhesion of paints or preventing its penetration into the pores of concrete, which in turn facilitates their removal. However, it appears that many of the existing protective products on the market may also alter the surface characteristics of the concrete irreversibly. Considering that the durability of concrete depends on the composition and characteristics of the surface, it is essential to know the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes in durability indicators and surface properties that protect concrete from deterioration (i) concrete without protection before and after application of spray paint, (ii) concrete with protection before and after application of spray paint and (iii) after paint removal were studied. Two anti-graffiti products were evaluated: a permanent and a sacrificial one. Effects of the anti-graffiti systems on the concrete durability are investigated and the tests performed include: water absorption by capillary and immersion at atmospheric pressure. The results of the water absorption tests show that the graffiti protection reduces the water absorption into the concrete and facilitates the removal of the graffiti without affecting negatively the characteristics of the surface and thus contributing to improve its durability.

Effects of low vehicle speed on the service life time of asphalt pavements

2015 ◽  
pp. 221-226 ◽  
Author(s):  
A Walther ◽  
I Isailović
Keyword(s):  
Service Life ◽  
Life Time ◽  
Asphalt Pavements ◽  
Vehicle Speed

Influence Of Curing On Surface Characteristics Of Concrete

1988 ◽  
Vol 137 ◽  
Author(s):  
M. Sadegzadeh ◽  
R. J. Kettle ◽  
C. L. Page
Keyword(s):  
Abrasion Resistance ◽  
Mercury Intrusion Porosimetry ◽  
Total Pore Volume ◽  
Surface Characteristics ◽  
Concrete Surface ◽  
Cement Matrix ◽  
Mercury Intrusion ◽  
Rolling Wheel ◽  
Curing Regime ◽  
Curing Regimes

AbstractAn experimental assessment is presented of the influence of curing regimes on the abrasion resistance of concrete. Specimens have been produced from several different mix compositions and the abrasion resistance has been measured using a rolling-wheel apparatus. To explore these relationships, microstructural features of the cement matrix components of the surface have been studied by mercury intrusion porosimetry. The results indicate the abrasion resistance of concrete is controlled by the pore structure of the surface matrix. The nature of the curing regime having significantly influenced the pore size distribution and total pore volume of the surface matrix of the concrete surface.

Study on Vehicle Speed in Pore Water Pressure of Rigid Pavement Base Using Poro-Elasticity

2012 ◽  
Vol 178-181 ◽  
pp. 2615-2618 ◽  
Author(s):  
Hai Bin Li ◽  
Yan Ping Sheng
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Base Material ◽  
Concrete Surface ◽  
Base Layer ◽  
External Loading ◽  
Vehicle Speed ◽  
Cement Concrete ◽  
Rigid Pavement

Water in pavement is a major contributor to pavement failure. Fine aggregates are pumped out near the joint of rigid pavement and cause the erosion of the base layer. In order to analyze the phenomenon, a two dimensional model using Finite Element Method (FEM) and Porous elasticity theory is developed to calculate the pore water pressure development in the base layer underneath joints. The model contains three parts, two cement concrete surface plates separated by a joint gap and a base layer with relatively small stiffness and large permeability. The constitutive behavior of porous medium material used in the model is introduced. Nodes along the depth direction of the base layer underneath the joint are analyzed to investigate the erosion of the base. Distributed loading is applied at the part area near the joint to simulate vehicle passing through the rigid pavement surface. Excess pore water pressure along the depth caused by external loading are calculated. The influence of vehicle speed on the base material is analyzed by adding a tire contacting with surface of the cement concrete. The results of the study show that vehicle speed does not only influence the magnitude but also the dissipation of the pore water pressure.

Tire Longitudinal Slip-Ratio Measurement Using a Camera

2014 ◽  
Author(s):  
Theunis R. Botha ◽  
P. Schalk Els
Keyword(s):  
Experimental Tests ◽  
Wheel Speed ◽  
Image Correlation ◽  
Displacement Sensor ◽  
Vehicle Speed ◽  
In Situ Tests ◽  
Similar System ◽  
Slip Ratio ◽  
Ratio Measurement ◽  
Longitudinal Slip

The longitudinal slip-ratio is one of several parameters that govern the magnitude of the longitudinal force generated by a tire and probably the most important. As such, the longitudinal slip-ratio of a tire is an essential measurement required in the construction of longitudinal tire models. In laboratory experimental tests the slip-ratio can typically be controlled by controlling the rotational speeds of two motors. However, in in-situ tests, where the slip-ratio needs to be measured, the slip-ratio is estimated from three other measurements namely the wheel speed, vehicle speed and the rolling radius of the tire. While the wheel speed is fairly inexpensive and easy to measure accurately, the accurate measurement of vehicle speed requires an expensive GPS or similar system. The measurement of the rolling radius is often performed statically and assumed constant or can be measured with an expensive laser displacement sensor. Errors in the all of these measurements are compounded when determining the slip-ratio. This paper proposes a method of measuring the longitudinal slip-ratio by performing image correlation techniques on consecutive images of the tire-road interface obtained from a single inexpensive camera. Since the method makes use of one measurement system the probability of inducing errors in the slip-ratio is reduced.

scholarly journals The Correlation Between the Statistical Pass-By Index Values and the Total Number of Vehicle Passes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Martin Decký ◽  
Eva Remišová ◽  
Matej Brna ◽  
Marek Drličiak ◽  
Matúš Kováč
Keyword(s):  
Asphalt Concrete ◽  
Sound Pressure ◽  
Traffic Noise ◽  
Concrete Surface ◽  
Sound Level ◽  
Asphalt Pavements ◽  
Degradation Model ◽  
Mastic Asphalt ◽  
Sound Levels ◽  
Vehicle Velocity

Abstract In this study, the traffic noise degradation in asphalt pavements was analysed using the ‘Statistical Pass-By method’. The sound levels of two surfaces were monitored during 9 and 12 years of service, respectively. By comparing the dependencies of the maximum A-weighted sound pressure level on logarithm of vehicle velocity, an increase in the sound level was found at all recorded speeds. Following an analysis of sound levels, as combined with the statistical pass-by index (SPBI) calculated versus age (expressed in vehicles), it was determined that the noise is an increasing power function of SPBI values on vehicle passes, based on an approximation of noise level adjustment to a reference temperature of 20 °C (using a coefficient of 0.06 for asphalt concrete surface AC11 and - 0.03 for mastic asphalt SMA11). The adjusted traffic noise degradation model showed that the SMA11 surface has a higher resistance to acoustic degradation than AC11 surface.

Effects of vehicle speed and permeability on pore pressures in hot-mix asphalt pavements

2003 ◽  
pp. 532-536 ◽  
Author(s):  
Marc E. Novak ◽  
Bjorn Birgisson ◽  
Michael McVay
Keyword(s):  
Hot Mix Asphalt ◽  
Asphalt Pavements ◽  
Vehicle Speed ◽  
Pore Pressures

Low-Noise Asphalt Pavements in Urban Areas

2016 ◽  
Vol 858 ◽  
pp. 282-286
Author(s):  
Petr Kozak ◽  
Ondrej Dasek ◽  
Radka Matuszkova ◽  
Michal Radimsky
Keyword(s):  
Asphalt Concrete ◽  
Urban Areas ◽  
Road Traffic ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Low Noise ◽  
Thin Layers ◽  
Asphalt Pavements ◽  
Road Traffic Noise ◽  
Vehicle Speed

Current requirements for the reduction of the noise pollution in inhabited areas are constantly increasing. Acoustic wearing courses represent the real measures how to directly mitigate sources of road traffic noise created by a tire/road contact. Directly reduced noise emissions created by a tire/road contact don't need further mitigation by expensive noise barriers. Noise emissions on two different types of wearing courses of asphalt mixtures (Asphalt concrete for very thin layers and Low-noise stone mastic asphalt) were measured using the specialized device operating on the basis of CPX (Close Proximity method) and compared with the standard mixture of Asphalt concrete. Differences were between 1 dB and 5 dB depending on the wearing course and the vehicle speed. The efficiency of the low-noise asphalt pavements was also compared with the initial costs of the pavements. The economical evaluation confirmed that the initial costs of the acoustic wearing courses are higher than the costs of the standard asphalt concrete mixture. However the noise reduction by 1 dB using the asphalt concrete for very thin layers increases the costs just by 350 USD (considering the same length and width of the road segment), which makes acoustic wearing courses the economically efficient noise reducing measure.

scholarly journals Influence of formwork liners on fresh, mechanical and durability properties of cast concretes

2021 ◽  
Author(s):  
Sunny R Gurbani
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Surface Characteristics ◽  
Concrete Surface ◽  
Chloride Penetration ◽  
Freeze Thaw ◽  
Durability Properties ◽  
Salt Scaling ◽  
Chloride Penetration Resistance ◽  
Scaling Resistance

The following study investigates the influence of formwork liners on fresh, mechanical and durability properties of cast concretes. In order to investigate the influence of formwork liners (Weather Shield, Poligloss and Zemdrain) manufactured by Newark Group on concrete properties, column and other specimens were cast in conventional moulds (steel, wood and plastic) with and without formwork liners. As per ASTM Standards Surface characteristics, compressive strength, water absorption, sorptivity, chloride penetration, freeze thaw and salt scaling tests were conducted and results are analyzed. It is found that by the application of formwork liners Zemdrain and Weather Shield, compressive strength, water absorption, sorptivity, chloride penetration resistance, freeze thaw resistance and salt scaling resistance were improved. By the application of Poligloss, concrete surface was found to be homogenous without any visible blow-holes.

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