Investigating the Relation among British Pendulum Number, Mean Texture Depth and Asphalt Content in Hot Mix Asphalt (original) (raw)
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Characterization of the Skid Resistance and Mean Texture Depth in a Permeable Asphalt Pavement
IOP Conference Series: Materials Science and Engineering
Road pavements need a deep characterization of the surface layer, with which the vehicles have direct contact and, therefore, must provide security to the users. The use of permeable asphalt pavements (PAP) with porous layers has provide obvious advantages in reducing runoff and the rainwater infiltration into the soil or for storage. However, the study of the interaction between the pavement surface layer and the tire rubber requires additional tests in terms of texture and friction, since they are important parameters for the design, construction, management, maintenance and roads safety. Considering the application of a PAP in a parking lot, the study objective was to characterize in the field the pavement surface in terms of mean texture depth (MTD) and skid resistance (Pendulum test value, PTV). The methods used were the volumetric technique by the patch test and the pendulum test, according to EN 13036-1 and EN 13036-4, respectively. The double layer porous asphalt (DLPA) at the surface is characterized by having a structure with high voids content that led to results of clearly rougher macrotexture and good skid resistance. The normalized limit values were met, however, a very strong correlation between MTD and PTV was not observed. A comparison was also made with porous surfaces of other studies and it was found that porous asphalt has a good behaviour at the start of construction which may tend to improve in the long term. From the study, it is concluded that the PAP presents good performance of the surface layer, providing road safety to users.
Asphalt pavements surface texture and skid resistance — exploring the reality
Canadian Journal of Civil Engineering, 2012
Wet pavement skidding due to inadequate surface texture or friction contributes to 20% to 35% of all wet weather crashes. Many of the past studies of pavement surface texture and friction have deficiency in selecting the model forms or variables and interpreting the models and (or) the findings or have recommended further investigation. These pose a challenge for the highway agencies in selecting the appropriate surface layer and (or) measuring tools. This study was undertaken to re-examine some of the pavement surface texture and skid resistance related issues and aid the highway agencies in this area. Pavement surface texture and skid resistance aspects were carefully examined using the data collected from nine asphalt concrete (AC) surfaces. Pavement surface texture was measured using the sand patch method and a high speed texture laser. Skid resistance was measured using a British Pendulum and a skid trailer. The analysis has reinstated that aggregate quality is the predominant factor for AC surface skid resistance. Both texture depth and ribbed tire skid resistance was shown to increase with an increase in coarse aggregate (CA) content proving their interdependency. Neither the voids in mineral aggregate (VMA) or air voids (AV) contents showed a meaningful or statistically significant correlation with the surface texture or skid resistance. Fairly good correlations were found among the British Pendulum number (BPN), ribbed tire skid number (SN) and mean texture depth (MTD) rejecting the hypothesis that BPN is a measure of only surface microtexture and ribbed tire skid number is insensitive to surface texture.
rodoviasverdes.ufsc.br
The greatest emphasis in pavement performance has been done in structural design components. However, the pavement friction is also important and is one of the factors that determining pavement safety. The wet skidding crashes are largely reduced when friction between a vehicle tire and pavement is high. Skid resistance and texture are important safety characteristics which need to be considered when pavement mixes are tested in laboratory. The objective of this study was to evaluate the skidding based on macrotexture and microtexture used in the International Friction Index (IFI). This study was conducted in asphalt mixtures compacted slab produced in laboratory. Two different mixtures grading (dense and gap) were produced using conventional asphalt and asphalt rubber. The characterization of the macrotexture and microtexture of asphalt pavements surfaces was obtained by the following tests: (i) British pendulum; (ii) Volumetric Method. IFI values were calculated by the pair of the parameters Sp and F60. The results showed that the mixture with gap grading had higher texture in comparison of mixtures with a dense grade gradation. The asphalt rubber mixtures improved the skid resistance compared to conventional mixtures.
Skid Resistance of Asphalt Pavements
Skid resistance of a road pavement surface is the force developed when tyre is prevented from rotating slides along the pavement sur-face. This property comes from the combination of the macro- and micro-texture of pavement. The skid resistance of an asphalt pave-ment is an important parameter influencing driving safety on a road, since there is a proven relationship between skid resistance and accident parameters. The paper deals with the measurement principle of pavement skid resistance (surface friction) including longitudinal and transverse friction. A high number of measuring devices of skid resist-ance are also introduced highlighting their advantages and limitations. Besides, the measurement policies in the European Union and in Hun-gary are outlined. Pavement surface texture is investigated dealing with the levels of surface tex-ture, the most common measuring tech-niques, the macro-texture features of asphalt types, as well as the Hungarian regulation in the field. As a rela...
Threshold value of skid resistance and texture depth for Malaysia road
IOP Conference Series: Materials Science and Engineering
Skid resistance is an important pavement characteristic for roads, which determines the friction between the road surface and vehicle tyres. The level of friction is largely influenced by the pavement surface aggregates micro texture, macro texture, and drainage attributes. The objective of this paper is to present the findings of the research and analysis conducted on Skid Resistance Value (SRV), Mean Texture Depth (MTD) and Skid Number (SN) obtained from the data collected on federal roads over the years since 2008. This research also attempted to determine the appropriate limiting values for SRV (microtexture), MTD (macrotexture) and SN for the federal roads. The result of analysis indicated that the average value of SRV at the locations of wet surface accident is 52.31 + 8.54. While for MTD, the accident risk is higher when MTD value is below the average of 0.45 + 0.025. The SRV and MTD results were correlated to each other and it can be concluded that accident risk increases significantly when SN value is below the average value of 31.49 + 7.87. Based on these findings, it is concluded that the minimum desirable values for SRV and SN for Malaysia's Federal roads to be 55 and 30 respectively.
Evaluating the asphalt pavement's surface characteristics by field testing
Revista de la construcción, 2020
Pavement management systems are crucial because of monitoring the current pavement condition to supply safe, efficient, comfortable and durable riding surface for vehicles. Driving safety is the most important issue, which is closely related to pavement surface texture. The texture of the pavement surface and its ability to resist the polishing effect of heavy traffic is an important parameter in providing necessary skidding resistance during the service life. In this study, 4 different asphalt pavement sections located in Izmir/TURKEY with having different traffic characteristics were investigated every three months for two years aiming to evaluate the effect of traffic volume on the surface textural and frictional properties of the pavement. The textural properties were evaluated using sand patch test (SPT) and a 3D Laser Scanning System (LSS), while Dynamic Friction Tester (DFT) was employed to assess the frictional properties. As a result, lower Mean Texture Depth (MTD) and Mean...
Experimental-based model for predicting the skid resistance of asphalt pavements
International Journal of Pavement Engineering, 2013
The skid resistance of asphalt pavement is a major characteristic of road safety. This study aimed at the development of a model that expresses skid resistance as a function of mixture gradation, aggregate texture and traffic level. The model was developed based on comprehensive measurements and analysis of asphalt mixture surface characteristics (friction, texture and skid resistance) in the laboratory and the field. In addition, aggregates were characterised using the aggregate imaging system after different polishing intervals in the Micro-Deval. The aggregate gradation was described using the twoparameter cumulative Weibull distribution function. The developed model provides an estimate of the skid number in the field. Consequently, this model can be used by engineers to select different combinations of aggregate types and mixture designs such that the desired level of skid resistance at a given traffic level is achieved.
Contract, 2005
The proposed Mechanistic-Empirical Pavement Design Guide (MEPDG) procedure is an improved methodology for pavement design and evaluation of paving materials. Since this new procedure depends heavily on the characterization of the fundamental engineering properties of paving materials, a thorough material characterization of mixes used in Virginia is needed to use the MEPDG to design new and rehabilitated flexible pavements. The primary objective of this project was to perform a full hot-mix asphalt (HMA) characterization in accordance with the procedure established by the proposed MEPDG to support its implementation in Virginia. This objective was achieved by testing a sample of surface, intermediate, and base mixes. The project examined the dynamic modulus, the main HMA material property required by the MEPDG, as well as creep compliance and tensile strength, which are needed to predict thermal cracking. In addition, resilient modulus tests, which are not required by the MEPDG, were also performed on the different mixes to investigate possible correlations between this test and the dynamic modulus. Loose samples for 11 mixes (4 base, 4 intermediate, and 3 surface mixes) were collected from different plants across Virginia. Representative samples underwent testing for maximum theoretical specific gravity, asphalt content using the ignition oven method, and gradation of the reclaimed aggregate. Specimens for the various tests were then prepared using the Superpave gyratory compactor with a target voids in total mix (VTM) of 7% ± 1% (after coring and/or cutting). The investigation confirmed that the dynamic modulus test is an effective test for determining the mechanical behavior of HMA at different temperatures and loading frequencies. The test results showed that the dynamic modulus is sensitive to the mix constituents (aggregate type, asphalt content, percentage of recycled asphalt pavement, etc.) and that even mixes of the same type (SM-9.5A, IM-19.0A, and BM-25.0) had different measured dynamic modulus values because they had different constituents. The level 2 dynamic modulus prediction equation reasonably estimated the measured dynamic modulus; however, it did not capture some of the differences between the mixes captured by the measured data. Unfortunately, the indirect tension strength and creep tests needed for the low-temperature cracking model did not produce very repeatable results; this could be due to the type of extensometers used for the test. Based on the results of the investigation, it is recommended that the Virginia Department of Transportation use level 1 input data to characterize the dynamic modulus of the HMA for projects of significant impact. The dynamic modulus test is easy to perform and gives a full characterization of the asphalt mixture. Level 2 data (based on the default prediction equation) could be used for smaller projects pending further investigation of the revised prediction equation incorporated in the new MEPDG software/guide. In addition, a sensitivity analysis is recommended to quantify the effect of changing the dynamic modulus on the asphalt pavement design. Since low-temperature cracking is not a widespread problem in Virginia, use of level 2 or 3 indirect tensile creep and strength data is recommended at this stage.
Skid Resistance and Texture Depth Analysis of Stone Mastic Asphalt
2001
I would like to thank the Ministry of Science, Technology, and the Environment, that has enabled me to complete the study without encountering any financial difficulties. I am also indebted to the technical and administrative staff of Civil-Engineering Department especially Haji Razali Mohd Amin for his patience and assistance throughout my study at Road Safety Research Center (RSRC). Thanks to all lectures of civil engineering for their help in diverse ways. Last but not least, I would like to express my deep gratitude and great indebtedness to my younger brother Abuker Ali for his emotional support and continual encouragement during my study. I pray that Almighty God may bless Vlll all that have contributed in whatever way to the success of my studies at Universiti Putra Malaysia but have not mentioned here. IX I certify that an Examination Committee met on 22 th January 2001 to conduct the final examination of Abdullahi Ali Mohamed on his Master of Science thesis entitled "Skid Resistance and Texture Depth Analysis of Stone Mastic Asphalt" in accordance with Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulations 1981. The Committee recommends that the candidate be awarded the relevant degree. Members of the Examination Committee are as follows: