Tire-pavement Contact Area Research Articles

A New Approach for Determining Rubber Enveloping on Pavement and Its Implications for Friction Estimation

The depth to which the pavement texture is enveloped by the tire tread rubber (d) is an important parameter related to contact performance. This study presents a new method (S-BAC), which relies on the ratio between the real contact area and the nominal tire-pavement contact area (S) and the bearing area curve (BAC), to measure the depth on pavements. The tire-pavement contact was simulated by contact between a non-patterned rubber block and pavement specimens. After analyzing the affecting factors, the new method was compared with previous methods by the d values and the application on the relationship between pavement texture parameters and friction. The results reveal that though there is a linear regression between the d obtained with the S-BAC and previous methods, the d values obtained with different methods differ. Applying the S-BAC method can strengthen the relationship between texture parameters and friction more than other methods.

Promoting the pavement skid resistance estimation by extracting tire-contacted texture based on 3D surface data

The pavement skid resistance is of vital importance for road safety and maintenance. The existing studies mainly calculates various parameters of pavement texture to evaluate the skid resistance. However, most researchers mainly calculate the whole texture parameters, but rarely consider which part of the texture is actually involved in the friction. This paper studies the measurement and calculation of the tire-pavement contact area and its influence on the skid resistance prediction. In this study, we proposed a set of methods to predict the rubber-contacted pavement area percentage and to extract the rubber-contacted texture. Besides, the skid resistance prediction models based on high-resolution three-dimensional (3D) surface data of the whole and the contacted texture are built and compared. The results show that when the rubber-contacted percentage is set at 20% or ̃% (the predicted percentages), the accuracy of the prediction model is higher. It is demonstrated that the performance of the skid resistance prediction will be improved by extracting the contacted texture. Also, the amount of data can be considerably reduced, which will effectively relieves computational cost.

Thermomechanical Coupling of a Hyper-viscoelastic Truck Tire and a Pavement Layer and its Impact on Three-dimensional Contact Stresses

A thermomechanical coupling between a hyper-viscoelastic tire and a representative pavement layer was conducted to assess the effect of various temperature profiles on the mechanical behavior of a rolling truck tire. The two deformable bodies, namely the tire and pavement layer, were subjected to steady-state-uniform and non-uniform temperature profiles to identify the significance of considering temperature as a variable in contact-stress prediction. A myriad of ambient, internal air, and pavement-surface conditions were simulated, along with combinations of applied tire load, tire-inflation pressure, and traveling speed. Analogous to winter, the low temperature profiles induced a smaller tire-pavement contact area that resulted in stress localization. On the other hand, under high temperature conditions during the summer, higher tire deformation resulted in lower contact-stress magnitudes owing to an increase in the tire-pavement contact area. In both conditions, vertical and longitudinal contact stresses are impacted, while transverse contact stresses are relatively less affected. This behavior, however, may change under a non-free-rolling condition, such as braking, accelerating, and cornering. By incorporating temperature into the tire-pavement interaction model, changes in the magnitude and distribution of the three-dimensional contact stresses were manifested. This would have a direct implication on the rolling resistance and near-surface behavior of flexible pavements.

Determination of rutting performance of asphalt pavements considering realistic tire-pavement contact area

In the conventional pavement design procedure using multilayer elastic theory, tire loading equal to tire inflation pressure and traditional circular contact area are assumed. Therefore, the area of contact is extremely overestimated and the contact stress is significantly underestimated. Rotary Compactor and Wheel Tracker (RCWT) equipment was designed and fabricated with three different functionalities. The RCWT captures the realistic contact areas of pneumatic tires, simulates the field compaction process, and conducts simulative laboratory wheel tracking test. This study was conducted to determine relative damage of realistic tire-pavement contact area with respect to the traditional contact area. Based on the obtained footprint results, 63 percent difference exists between traditional and effective contact areas. Furthermore, it was found that based on the thickness of asphalt layer, vehicle tire was 2.5 to 1.5 times more damaging than full circular contact area. Moreover, realistic contact area causes about 50 percent reduction in pavement operational life.

Analysis of the Actual Contact Surface of Selected Aircraft Tires with the Airport Pavement as a Function of Pressure and Vertical Load

The contact surface of the wheel with the airport surface is important for the safety of flight operations in the ground manoeuvring area. The area of the contact surface, its shape and stress distribution at the pavement surface are the subject of many scientists’ considerations. However, there are only a few research studies which include pressure and vertical load directly and its influence on tire-pavement contact area. There are no research studies which take into account aircraft tires. This work is a piece of an extensive research project which aims to develop a device and a method for continuous measurement of the natural airport pavement’s load capacity. One of the work elements was to estimate the relationship between wheel pressure and wheel pressure on the surface, and the area of the contact surface. The results of the research are presented in this article. Global experience in this field is cited at the beginning of the article. Then, the theoretical basis for calculating the wheel with the road surface contact area was presented. Next, the author’s research views and measurement method are presented. Finally, the obtained test results and comments are shown. The tests were carried out for four types of tires. Two of them were airplane tires from the PZL M28 Skytruck/Bryza and Sukhoi Su-22 aircraft. Two more came from the airport ASFT (airport surface friction tester) friction tester-one smooth ASTM; the other smooth retreaded type T520. The tires were tested in a pressure range from 200 to 800 kPa. The range of vertical wheel load on the pavement was 3.23–25.93 kN for airplane tires, and 0.8–4.0 kN for friction tester tires. The tests proved a significant influence of the wheel pressure value and wheel pressure on the surface on the obtained contact surface area of the wheel with the surface. In addition, it was noted that the final shape and size of the contact surface is affected by factors other than wheel pressure, tire pressure and dimensions.

Dynamic friction coefficient between tire and compacted asphalt mixtures using tire-pavement dynamic friction analyzer

This study proposes a newly developed real-time testing system, namely, a tire-pavement dynamic friction analyzer (TDFA), to measure the dynamic friction coefficient between tire and pavement. Based on the self-developed TDFA, the friction coefficient between tire and pavement can be measured in real-time in the lab. A number of working conditions of tires were mimicked and tested. Subsequently, the effect of parameters such as tire load, tire pressure, actual tire-pavement contact area, tire speed, and slip ratio on pavement friction were investigated. It is found that there is a closely linear correlation between the actual tire-pavement contact area and the dynamic friction coefficient (DFC), and such correlation differs with the variation of pavement types. DFC usually has a negative linear relationship to tire speed. As slip ratio varies from 0% to 100%, the strongest correlation between DFC and Mean profile depth (MPD) can be found at the interval of 10%–15% slip ratio, which indicates that the pavement macrotexture also plays a role in the peak value of friction coefficient for the asphalt pavement. This testing method is very promising for the estimation of friction properties of pavement in the phase of lab mix design. It may also be used in the materials selection for pavement design.

Tire⁻Pavement Contact-Aware Weight Estimation for Multi-Sensor WIM Systems.

Accurately estimating the weight of a moving vehicle at normal speed remains a challenging problem due to the complex vehicle dynamics and vehicle–pavement interaction. The weighing technique based on multiple sensors has proven to be an effective approach to this task. To improve the accuracy of weigh-in-motion (WIM) systems, this paper proposes a neural network-based method integrating identification and predication. A backpropagation neural network for signal classification (BPNN-i) was designed to identify ideal samples acquired by load sensors closest to the tire-pavement contact area. After that, ideal samples were used to predict the gross vehicle weight by using another backpropagation neural network (BPNN-e). The dataset for training and evaluation was collected from a multiple-sensor WIM (MS-WIM) system deployed in a public road. In our experiments, 96.89% of samples in the test set had an estimation error of less than 5%.

Tire-Pavement Friction Characteristics with Elastic Properties of Asphalt Pavements

The skid-resisting performance of pavement is a critical factor in traffic safety. Recent studies primarily analyze this behavior by examining the macro or micro texture of the pavement. It is inevitable that skid-resistance declines with time because the texture of pavement deteriorates throughout its service life. The primary objective of this paper is to evaluate the use of different asphalt pavements, varying in resilience, to optimize braking performance on pavement. Based on the systematic dynamics of tire-pavement contact, and analysis of the tire-road coupled friction mechanism and the effect of enlarging the tire-pavement contact area, road skid resistance was investigated by altering the elastic modulus of asphalt pavement. First, this research constructed the kinetic contact model to simulate tire-pavement friction. Next, the following aspects of contact behaviors were studied when braking: tread deformation in the tangential pavement interface, actual tire-pavement contact in the course, and the frictional braking force transmitted from the pavement to the tires. It was observed that with improvements in pavement elasticity, the actual tire-pavement contact area increased, which gives us the ability to effectively strengthen the frictional adhesion of the tire to the pavement. It should not be overlooked that the improvement in skid resistance was caused by an increase in pavement elasticity. This research approach provides a theoretical basis and design reference for the anti-skid research of asphalt pavements.

Comparative Study of Water-Blasting Equipment for Airfield Surface Decontamination

Runway rubber removal is a maintenance function employed to ensure safe landing areas for aviation operations. Rubber deposits accumulate on runway areas where aircraft tires touchdown and braking occurs. This tire-rubber build-up occludes pavement microtexture and macrotexture, causing a significant loss in available skid resistance during wet conditions. Reduction of available pavement microtexture in a wet environment prevents the development of adhesional friction, which can result in viscous hydroplaning. Reduction of pavement macrotexture prevents the removal of bulk water from the tire–pavement contact area and also prevents the development of the hysteresis frictional component. To restore friction to safe levels for aircraft operations, rubber must be periodically removed. Several techniques for rubber removal are available. Water-blasting is a proven surface decontamination technique which employs the use of high-pressure or ultra-high-pressure water (UHPW) to blast rubber deposits from the runway surface. This effort provides a performance-based comparison between three commercially available UHPW water-blasting systems. The evaluation was conducted on an ungrooved portland cement concrete (PCC) runway with heavy rubber contamination along the touchdown and breaking zones. Several types of testing equipment such as a circular track meter (CTM) and dynamic friction tester (DFT) were used to characterize the surface properties of the runway before and after rubber removal. The measurements were used for statistical pairwise comparative analysis of International Friction Index (IFI), speed constant and mean profile depth (MPD). Treatment effect analysis of premeasured and postmeasured data revealed that UHPW systems improved the surface texture properties by at least 40% regardless of the decontamination equipment.

CHARACTERIZATION OF EFFECTIVE TIRE CONTACT AREA FOR VARIOUS TREAD PATTERNS

The effective tire-pavement contact area affects the relative damage of asphalt pavement and should be incorporated in both mechanistic and empirical response analyses of pavements. A new machine called ROTOCOM Wheel Tracker (RCWT) was designed and fabricated to capture the effective tire contact area apart from slab compacting, and conducting simulative laboratory wheel tracking tests. The main focus of this paper is laboratory measurement of effective tire contact areas for various tread patterns. Seven tire treads were selected for the footprint image analyses at five tire loads and four tire inflation pressures. An image processing MATLAB-based program was coded to calculate the contact areas of the 280 imprints obtained from both sides of the RCWT. Factorial analysis indicated significant effects of tire tread, tire load, and inflation pressure on the resulting contact area. Comparison between effective and traditional contact areas indicated that the current pavement design procedure with traditional circular contact area extremely overestimates the actual tire-pavement contact area up to 92%.

Analysis of Perpetual Asphalt Pavement Response under Heavy Loads in Northeast Area of China

Severe rutting, cracks and moisture damage are presented on conventional semi-rigid base asphalt pavements not long after completed in China. This phenomenon indicates that conventional philosophy on pavement design could not meet more and more frequent and heavy vehicle. With high structural capacity for high traffic volume and heavy loads, the Perpetual Asphalt Pavements (PAPs) solve those problems well. Meanwhile they need minimal or no major structural rehabilitation and/or reconstruction exercises in their life, which ensures low user-delay. Three PAPs, including semi-rigid base asphalt pavement, flexible base asphalt pavement, and combined base asphalt pavement, are put forward for the northeast area in China considering its climate, traffic characteristic. Finite element method is utilized to analyze response of PAPs under heavy loads. Two key factors, i.e. tensile horizontal strains at the bottom of asphalt layers and compressive vertical strains are investigated. Also the capacities of the structures on bearing overloading are estimated. Four types of wheel and axle, including single axle and single tire, single axle and dual tires, dual axles and dual tires, and tri axles and dual tires are adopted in finite element models. The shapes of tire-pavement contact area are either circular or rectangular to simulate standard load or overloading respectively. When rectangular shapes are adopted, the contact area sizes and the distribution of pressure are varied. Conventional asphalt concrete and high modulus asphalt concrete are adopted. Simulations are done. The competences of the three pavement structures on fulfilling long lives are evaluated.

Perpetual Asphalt Pavement Response Analysis on under Heavy Loads in Northeast Area of China

Severe rutting, cracks and moisture damage are presented on conventional semi-rigid base asphalt pavements not long after completed in China. This phenomenon indicates that conventional philosophy on pavement design could not meet more and more frequent and heavy vehicle. With high structural capacity for high traffic volume and heavy loads, the Perpetual Asphalt Pavements (PAPs) solve those problems well. Meanwhile they need minimal or no major structural rehabilitation and/or reconstruction exercises in their life, which ensures low user-delay.Three PAPs, including semi-rigid base asphalt pavement, flexible base asphalt pavement, and combined base asphalt pavement, are put forward for the northeast area in China considering its climate, traffic characteristic. Finite element method is utilized to analyze response of PAPs under heavy loads. Two key factors, i.e. tensile horizontal strains at the bottom of asphalt layers and compressive vertical strains are investigated. Also the capacities of the structures on bearing overloading are estimated. Four types of wheel and axle, including single axle and single tire, single axle and dual tires, dual axles and dual tires, and tri axles and dual tires are adopted in finite element models. The shapes of tire-pavement contact area are either circular or rectangular to simulate standard load or overloading respectively. When rectangular shapes are adopted, the contact area sizes and the distribution of pressure are varied. Conventional asphalt concrete and high modulus asphalt concrete are adopted. Simulations are done. The competences of the three pavement structures on fulfilling long lives are evaluated.

Modeling the Effect of Rolling Conditions on Stress Development at Tire-Pavement Contact Patch

The interfacial pressure between tire and pavement is known to exhibit a highly non-uniform distribution over its contact area. This differs significantly from the uniform contact pressure distribution used traditionally in pavement design and analysis. Past research efforts have recognized that the contact stress distributions are dependent on tire type, tire inflation pressure, wheel load, tire tread patterns and vehicle rolling characteristics. This paper discusses the development of a numerical model that is capable of describing the contact stress distributions at the interface between a rolling tire and the pavement. The theoretical development of the finite element-based simulation model is first described. This model is then validated against the experiment data available in the literature and is applied to simulate the stress distributions at the tire-pavement contact area under different rolling conditions.

Modeling the Effect of Rolling Conditions on Stress Development at Tire-Pavement Contact Patch

The interfacial pressure between tire and pavement is known to exhibit a highly non-uniform distribution over its contact area. This differs significantly from the uniform contact pressure distribution used traditionally in pavement design and analysis. Past research efforts have recognized that the contact stress distributions are dependent on tire type, tire inflation pressure, wheel load, tire tread patterns and vehicle rolling characteristics. This paper discusses the development of a numerical model that is capable of describing the contact stress distributions at the interface between a rolling tire and the pavement. The theoretical development of the finite element-based simulation model is first described. This model is then validated against the experiment data available in the literature and is applied to simulate the stress distributions at the tire-pavement contact area under different rolling conditions.

Laboratory Measurement of the Actual Tire-Pavement Contact Pressure Using a Static Test Device

Abstract It is well-known that the tire-pavement contact pressure (TPCP) is hardly circular or uniformly distributed as often assumed. In this study, using a simple but effective static test set-up, numerous actual TPCPs between a loaded wheel-tire and the surface of an asphalt-mix slab were measured in the laboratory. Various TPCP loading conditions were investigated, including varying the tire inflation pressures, varying the load levels, and using different tire types, different tire tread patterns, and tire ages. Analysis of the results indicated that a linear proportional relationship existed between the following variables: (a) Tire inflation pressure and TPCP, (b) load level and the effective tire-pavement contact area, and (c) load level and TPCP. At a fixed constant tire inflation pressure, an increment in the load level significantly impacted the tire edges compared to the middle zone, and at a constant wheel loading, an increase in the tire inflation pressure will result in possibly a 1.5 times increase in the TPCP. This is detrimental to pavements and is undesirable. Furthermore, the TPCP under new tires was observed to be closer to being uniformly distributed than that under the old tires. In other words, in terms of distresses, if all other factors are equal, an old tire will likely cause more damage to an asphalt pavement than a new tire.

Strain Distribution in the Asphalt Layer under Measured 3-D Tire-pavement Contact Stresses

ABSTRACT Most pavement design methodologies assume the tire-pavement contact stress is equal to the tire inflation pressure and uniformly distributed over a circular contact area. However, tire-pavement contact area is not in a circular shape and the contact stress is neither uniform nor equal to the tire inflation pressure. To precisely account for the effect of actual contact stress on pavement response, this study evaluates the horizontal strains at the bottom of the asphalt layer produced by measured 3-D non-uniform stresses applied on the pavement surface. A multi-layer linear-elastic computer program, CIRCLY, was used to estimate horizontal strains in longitudinal direction and transverse direction under a number of combinations of load, tire pressure and asphalt thickness. Results show that the uniform stress model underestimates the longitudinal strains under a combination of thin surface layer and low tire pressure, and underestimates the transverse strains under a combination of thin surfacing, ...

Strain Distribution in the Asphalt Layer under Measured 3-D Tire-pavement Contact Stresses

ABSTRACT Most pavement design methodologies assume the tire-pavement contact stress is equal to the tire inflation pressure and uniformly distributed over a circular contact area. However, tire-pavement contact area is not in a circular shape and the contact stress is neither uniform nor equal to the tire inflation pressure. To precisely account for the effect of actual contact stress on pavement response, this study evaluates the horizontal strains at the bottom of the asphalt layer produced by measured 3-D non-uniform stresses applied on the pavement surface. A multi-layer linear-elastic computer program, CIRCLY, was used to estimate horizontal strains in longitudinal direction and transverse direction under a number of combinations of load, tire pressure and asphalt thickness. Results show that the uniform stress model underestimates the longitudinal strains under a combination of thin surface layer and low tire pressure, and underestimates the transverse strains under a combination of thin surfacing, low tire pressure and high wheel loading.

Mechanistic Comparison of Wide-Base Single versus Standard Dual Tire Configurations

Wide-base tires are gaining renewed interest in the U.S. trucking industry as tire and rim technology and design continue to improve. First introduced in the early 1980s and termed “super-singles,” new generation, wide-base tires have been developed to allow for lower inflation pressures and larger contact areas than their predecessors. Single tires are of interest to freight haulers because with fewer tires and lighter rims, cargo capacity can increase. Early theoretical and physical modeling studies of super-singles largely found them to be more damaging to highway pavement structures than standard dual tire configurations. However, in light of new tire advancements, the impact on pavement response and performance of the wide-base configuration should be reevaluated. In addition, the accuracy of theoretical models in predicting pavement response under the new wide-base tires should be evaluated because models are often used by agencies to determine single-tire weight limits and permitting. A conventional dual tire assembly (275/80R22.5) was evaluated versus a newly developed single wide-base tire (445/50R22.5) at the National Center for Asphalt Technology Test Track. Embedded asphalt strain gauges and earth pressure cells allowed for direct pavement response measurements and comparisons between the two configurations. In addition, theoretical modeling using layered elastic theory was used to evaluate both configurations. The pavement response measurements indicated no statistical difference between the two configurations. The theoretical model tended to overpredict the response under the wide-base configuration. Future studies should attempt to model the tire-pavement contact area precisely to improve accuracy under the wide-base tire.