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1
Ech, M., S. Yotte, S. Morel, D. Breysse, and B. Pouteau. "Qualification of wearing course material surface evolution after durability test." Construction and Building Materials 35 (October 2012): 313–20. http://dx.doi.org/10.1016/j.conbuildmat.2012.02.081.
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2
Sarsam, Saad Issa. "Influence of Surface Texture on Interface Bond Shear Strength of Asphalt Concrete." Civil Engineering Beyond Limits 1, no. 3 (April 21, 2020): 8–14. http://dx.doi.org/10.36937/cebel.2020.003.002.
Повний текст джерелаАнотація:
The bonding strength provided by the tack coat between asphalt concrete layers at the interface is considered as an essential issue in the performance of the flexible pavement throughout its service life. However, the surface texture of the pavement surface exhibits another essential issue in the bond strength. In this investigation, three layers of asphalt concrete (base, binder and wearing) courses with (25, 19, and 12.5) mm of nominal maximum size of aggregates have been prepared using roller compactor. Rapid curing cutback RC-70 and cationic medium setting emulsion CMS have been implemented as tack coats with three application rates. The slab specimens were subjected to mean texture depth determination using sand patch method. Core specimens of 102 mm diameter were obtained from the prepared slab samples and subjected to interface bond strength test with the aid of a special manufactured mold. Test results were analyzed and compared. It was concluded that when RC-70 tack coat was implemented, asphalt concrete binder course laid on base course exhibited the highest shear strength of 1600 kPa at an application rate of 0.33 liter/m2 when compared to other application rates. Asphalt concrete wearing course laid on binder course exhibited the highest shear strength of 1515 kPa at an application rate of 0.15 liter/m2 when compared to other application rates. When CMS tack coat was implemented, asphalt concrete binder course laid on base course exhibited the highest shear strength of 1620 kPa at an application rate of 0.23 liter/m2 when compared to other application rates. Finally, the asphalt concrete wearing course laid on binder course exhibited the highest shear strength of 2272 kPa at an application rate of 0.23 liter/m2 when compared to other application rates.
3
Pietrzak, Karol, and Zbigniew Tokarski. "Ocena wpływu warunków atmosferycznych na poziom hałasu komunikacyjnego dla wybranej autostrady w Holandii." Przegląd Naukowy Inżynieria i Kształtowanie Środowiska 27, no. 3 (September 20, 2018): 319–27. http://dx.doi.org/10.22630/pniks.2018.27.3.31.
Повний текст джерелаАнотація:
There are many innovative highway surfaces. One it is the surface from porous asphalt. The purpose of construction this pavements is to absorb rainwater and to reduce the noise of the wearing course. The evaluation of the effectiveness of these features can be carried out by various methods including statistical method, CPX, or equivalent noise measurement. During exploitation, the following is assessed: the impact of factors as air humidity, wind, or intensity and the structure of road traffi c during the period of exploitation. This study presents an analysis of measurement results and methods for assessing the impact of these factors, which can be used to plan the reconstruction of porous wearing course.
4
Fullová, Daša, and Daniela Đurčanská. "Laboratory Measurements of Particulate Matter Concentrations from Asphalt Pavement Abrasion." Civil and Environmental Engineering 12, no. 2 (December 1, 2016): 94–102. http://dx.doi.org/10.1515/cee-2016-0013.
Повний текст джерелаАнотація:
Abstract The issue of emissions from road traffic is compounded by the fact that the number of vehicles and driven kilometres increase each year. Road traffic is one of the main sources of particulate matter and traffic volume is still increasing and has unpleasant impact on longevity of the pavements and the environment. Vehicle motions cause mechanical wearing of the asphalt pavement surface - wearing course by vehicle tyres. The contribution deals with abrasion of bituminous wearing courses of pavements. The asphalt mixtures of wearing courses are compared in terms of mechanically separated particulate matter. The samples of asphalt mixtures were rutted in wheel tracking machine. The particulate matter measurements were performed in laboratory conditions. The experimental laboratory measurements make it possible to sample particulates without contamination from exhaust emissions, abraded particles from vehicles, resuspension of road dust and climate affects. The contribution offers partial results of measurements on six trial samples of asphalt mixtures with different composition. It presents particulate matter morphology and the comparison of rutted asphalt samples in terms of PM mass concentrations and chemical composition.
5
Gardziejczyk, W., and M. Wasilewska. "Assessment of Skid Resistance of Asphalt Mixtures in Laboratory Conditions." Archives of Civil Engineering 58, no. 4 (December 1, 2012): 521–34. http://dx.doi.org/10.2478/v.10169-012-0028-6.
Повний текст джерелаАнотація:
AbstractThe aggregate applied for the wearing course has a significant influence on skid resistance of road surfaces. However, it is difficult to evaluate the behaviour of road surface in use on the basis of the Polished Stone Value (PSV) determined for the aggregate according to the so called ‘British method’. The British method, which is currently used in many countries, does not allow to determine the influence of neither the grain size of the aggregate nor the type of the wearing course on skid resistance of road surface. The present paper suggests a method for evaluation of the British Pendulum Number (BPN) for road surfaces in laboratory conditions. The authors assumed the BPN for polished slabs, made from asphalt mixtures, as the criterion. The index was measured with the British Pendulum Tester. The simulation of the process was conducted on research stand (called slab polisher) built at Bialystok University of Technology (BUT). The results of laboratory tests indicate that surfaces from asphalt concrete (AC) have slightly higher values of BPN in comparison with the values determined for surfaces made from stone mastic asphalt (SMA).
6
Hrůza, Petr, Tomáš Mikita, and Přemysl Janata. "Monitoring of Forest Hauling Roads Wearing Course Damage using Unmanned Aerial Systems." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 64, no. 5 (2016): 1537–46. http://dx.doi.org/10.11118/actaun201664051537.
Повний текст джерелаАнотація:
Currently, a large part of the forest roads that were built using the bituminous surface technology in the second half of the last century have been worn out. This means that forest owners and forest managers urgently need to determine the amount and extent of this damage and establish a suitable repair plan, which demands both time and staff. The aim of the study is to verify whether it is possible, and with what precision, to detect the damage of the wearing course by means of unmanned aerial systems, which would facilitate and accelerate this process and possibly make it cheaper. A 3D model of a forest road was created using photos of the current state of a damaged part of a forest road. The aerial photographs were taken by an unmanned aircraft. To verify the accuracy of the model, cross sections of the road surface were surveyed tachymetrically and compared with the cross sections created in the 3D model in ArcMap, from photogrammetric pointcloud using aerial photographs from the unmanned aircraft. The RMSE of the values of the control points in the 3D model cross sections compared to the values of the points in the tachymetric measurement of the cross sections reached to within 0.0198 m. The results of the tested road section showed that the unmanned aerial systems can be used to detect the forest road surface damage with the difference in accuracy being up to 2 cm compared with the accuracy of the current tachymetric methods. Based on the results we can conclude that the used method is appropriate for detailed monitoring of the condition of the asphalt wearing course of forest roads and allows for a precise and objective localization and quantification of damage.
7
Thompson, R. J., and A. T. Visser. "Selection parameters for mine haul road wearing course materials." International Journal of Surface Mining, Reclamation and Environment 14, no. 1 (January 2000): 1–17. http://dx.doi.org/10.1080/13895260008953294.
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8
Irali, F., A. Kivi, S. L. Tighe, and C. Sangiorgi. "Tire–pavement noise and wearing course surface characteristics of experimental Canadian road pavement sections." Canadian Journal of Civil Engineering 42, no. 10 (October 2015): 818–25. http://dx.doi.org/10.1139/cjce-2014-0424.
Повний текст джерелаАнотація:
An evaluation of the acoustic and surface characteristics of different Canadian pavement types was carried out in 2013 at the test track of the Centre for Pavement and Transportation Technology at the University of Waterloo. Noise testing was performed to determine the coefficient of noise absorption on cored samples and noise emissions in the field using the close proximity and the on-board sound intensity methods. Wearing course characteristics were evaluated with field testing, including visual condition surveys, evaluation of frictional properties with the British Pendulum tester, mean texture depth measurements, and surface profile and roughness evaluation with a walking profiler. As of the time of testing, the noise testing results indicate comparable acoustic properties in both flexible and rigid pavement sections, despite differences in the initial pavement materials, mixes, and surface finishing. With increasing pavement age, the amount of noise emissions increases as the pavement surface is worn down. Comparable friction values are also observed in all pavement sections, in line with the noise testing results. However, this is largely based on the initial construction values. Surface distresses are also not uniformly distributed: they are more severe in the oldest sections and more frequent in the loaded lane, which carries the heaviest traffic loads.
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Czech, Krzysztof Robert, and Wladyslaw Gardziejczyk. "Dynamic Stiffness of Bituminous Mixtures for the Wearing Course of the Road Pavement—A Proposed Method of Measurement." Materials 13, no. 8 (April 23, 2020): 1973. http://dx.doi.org/10.3390/ma13081973.
Повний текст джерелаАнотація:
Stiffness is an important mechanical characteristic of asphalt mixtures used in the wearing course. It is one of the determining factors in the generation of tyre/road noise. The dynamic stiffness of the upper layer of the road surface depends on the physical and mechanical properties of the materials it is composed of, and traffic load. Determination of dynamic stiffness, both in laboratory conditions and in situ, requires consideration of many other factors. Tests of dynamic properties of road surfaces in field conditions are most often conducted with the help of modal hammers. Impulse excitation results are usually less accurate than those in the application of modal exciters. The test stand was constructed, comprising a tripod, 32-channel and 24-bit data acquisition system, exciter, signal amplifier, impedance head, single-axis piezoelectric accelerometers and a stinger. The test stand and the proposed method of measuring dynamic stiffness do not require the determination of the resonance frequency of the tested specimen and can be used both on various types of bituminous mixtures of varying shape and dimensions, as well as directly on the upper surface of the wearing course of bituminous pavements. The test results showed that the type of bituminous mixture used in the wearing course significantly affects its dynamic stiffness. The dynamic stiffness level of asphalt concrete, stone mastic asphalt and porous asphalt layers was determined to be similar. The addition of rubber granulates significantly reduced its rigidity, which is very beneficial from the point of view of reducing the tyre/road noise.
10
Budirahardjo, Slamet, and Setyoningsih Wibowo. "ANALISA LABORATORIUM SIFAT CAMPURAN POOR GRADED ASPHALT CONCRETE WEARING COURSE (ACWC)." Teknika 16, no. 1 (March 4, 2021): 17. http://dx.doi.org/10.26623/teknika.v16i1.3174.
Повний текст джерелаАнотація:
<p>Susunan lapisan perkerasan jalan mempunyai fungsi untuk menopang dan mendistribusikan beban lalu lintas dengan tujuan tidak menimbulkan kegagalan konstruksi atau kerusakan yang berarti terhadap konstruksi jalan yang sudah terbentuk. Berkaitan dengan kinerja lapis permukaan perkerasan jalan (<em>surface course</em>) yang berpegang pada prinsip <em>long life performance</em>, maka guna mewujudkan hal tersebut dibuatlah suatu rancangan campuran rencana (<em>Design Mix Formula, </em>DMF) sesuai dengan fungsi jalan. Tujuan penelitian adalah menganalisa nilai stabilitas dan fleksibilitas terhadap nilai porositas campuran aspal panas akibat <em>poor graded</em> campuran AC-WC spesifikasi teknik PU Bina Marga Tahun 2010 yang menyimpang dari rancangan campuran rencana optimum berdasarkan pengujian di laboratorium dengan menggunakan metode Marshall. Berdasarkan target awal gradasi campuran agregat beton aspal Laston AC-WC sesuai spesikasi teknis Bina Marga Tahun 2010 diperoleh nilai Kadar Aspal Optimum (KAO) sebesar 6,1%. Penyimpangan target gradasi campuran agregat mengakibatkan perubahan sifat campuran panas beton aspal Laston AC-WC. Penyimpangan sifat campuran beton aspal Laston AC-WC kondisi KAO = 6,1% terbesar terjadi pada target gradasi senjang campuran agregat tipe 2 terhadap target gradasi awal campuran agregat Laston AC-WC.</p>
11
Worobets, Jay T., Fausto Panizzolo, Steve Hung, John W. Wannop, and Darren J. Stefanyshyn. "Increasing Running Shoe Traction can Enhance Performance." Research Journal of Textile and Apparel 18, no. 2 (May 1, 2014): 17–22. http://dx.doi.org/10.1108/rjta-18-02-2014-b003.
Повний текст джерелаАнотація:
The outsole of a running shoe must provide enough traction for the athlete to avoid slipping during running. What is unknown is whether there is any point to designing running shoe outsoles with traction above this minimum required traction. The purpose of this study was to investigate whether performance could be enhanced by increasing the outsole traction of a running shoe. A commercially available running shoe (Control) was compared against the same shoe model with the outsole modified with a higher traction rubber (High Traction). The available traction of each shoe was measured with a traction testing system. Twenty male athletes completed a maximal effort timed running course in both shoes on two different surfaces. When wearing the Control running shoe, the athletes were able to complete the course on an asphalt road surface at maximal effort without slipping. When completing the same course wearing the High Traction shoe, the subjects were able to perform the course even faster. Therefore, the results show that the role of running shoe outsole traction is not to merely provide adequate traction to avoid large scale slips, but can also help athletes enhance performance of high-traction tasks such as accelerations and changes in direction.
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Uhlmeyer, Jeff S., Kim Willoughby, Linda M. Pierce, and Joe P. Mahoney. "Top-Down Cracking in Washington State Asphalt Concrete Wearing Courses." Transportation Research Record: Journal of the Transportation Research Board 1730, no. 1 (January 2000): 110–16. http://dx.doi.org/10.3141/1730-13.
Повний текст джерелаАнотація:
For years, pavement engineers within the Washington State Department of Transportation (WSDOT) have observed that longitudinal and fatigue (multiple-interconnected) cracks in their thicker asphalt concrete (AC) pavements appeared to crack from the top of the wearing course downward. Often, the cracks stop at the interface between the wearing course and the underlying bituminous layers (a depth of about 50 mm). Studies done elsewhere in the United States and internationally have reported similar results. The results of extensive coring that WSDOT routinely collects in its pavement rehabilitation process were compared in a study. WSDOT normally cores AC pavements to determine thickness for use in mechanistic-empirical design. In addition to coring for AC thickness, specific information noting surface-initiated (top-down) cracking with the crack depth or full-depth cracking was noted. WSDOT observed top-down cracking occurring in the thicker sections, with thinner sections cracking full depth. Top-down cracking generally started within 3 to 8 years of paving for pavement sections that were structurally adequate and were designed for adequate equivalent single-axle loads.
13
Mikita, Tomáš, Dominika Krausková, Petr Hrůza, Miloš Cibulka, and Zdeněk Patočka. "Forest Road Wearing Course Damage Assessment Possibilities with Different Types of Laser Scanning Methods Including New iPhone LiDAR Scanning Apps." Forests 13, no. 11 (October 26, 2022): 1763. http://dx.doi.org/10.3390/f13111763.
Повний текст джерелаАнотація:
Forests make up 34.1% of the Czech Republic total area and forest roads account for nearly the same length (47,465 km) as all other roads administered by the state and its regions (55,738 km). Forest roads are not as intensively used as other roads. On the other hand, as logging trucks carry the maximum permitted load on roads and forests create a specific microclimate, forest roads are subject to rapid wear. A road wearing course is generally designed for 20 years of service and for a maximum damage level of 25% before they are supposed to be reconstructed. To ensure this life cycle is adhered to, more efficient, faster, and more flexible surface damage detection adaptable for forest environment is needed. As smartphones and their optical devices, i.e., new iPhones with LiDAR sensors, become more advanced, the option arises to perform laser scanning on road surfaces using smartphones applications. This work aimed to test this technology and its precision applicability to assessing damage to a forest wearing course and compare it with another hand-held personal laser scanner (PLShh), represented in this study by GeoSLAM ZEB Horizon scanner, and more precise terrestrial laser scanning (TLS) technology, represented in this study by Faro Focus 3D laser scanner, which have started to replace tacheometric wearing course damage surveying thanks to their greater precision. So, this study involved a comparison of three alternative laser scanning methods focused especially on these, which are implemented in new iPhones for tacheometric surveying. First, a Faro Focus 3D laser scanner was used for the TLS method. Second, the PLShh method was tested on a GeoSLAM ZEB Horizon scanner. Third, another PLShh method using an iPhone 13 Pro with applications 3D Scanner and Polycam was evaluated. If we are comparing positional height accuracy of PLShh to tacheometric surveying on reference cross position height coordinates, ZEB Horizon achieved devXY and devZ RMSE 0.108 m; 0.025 m; iPhone 13 Pro with 3D Scanner app devXY and devZ RMSE 0.185 m; 0.021 m, and with Polycam app devXY and devZ RMSE 0.31 m; 0.045. TLS achieved the best results with devXY RMSE 0.049 and devZ RMSE 0.0077. The results confirm that only the TLS scanner achieves precision values in height differences applicable for an assessment of forest road wearing course damage measurement comparable with tacheometric surveying. Surprisingly, comparing the PLShh scanners to the TLS technology, they achieved interesting results, comparing their transverse profiles and 3D objects as digital surface models (DSM) of the road to TLS in height position. In transverse profiles, ZEB Horizon achieved devZ RMSE 0.032 m; iPhone 13 Pro with 3D Scanner app devZ RMSE 0.017 m, and with Polycam app devZ RMSE 0.041 m compared to the TLS method measured using a Faro Focus 3D static laser scanner. Comparing forest road DSM to Faro Focus 3D, ZEB Horizon achieved devZ RMSE 0.028 m; iPhone 13 Pro with 3D Scanner app devZ RMSE 0.018 m and with Polycam devZ RMSE 0.041 m. These results in height differences show that the height accuracy of PLShh achieves precision, which is applicable to determining the current shape of forest road wearing course compared to the required roof shape gradient. However, further testing provided the insight that such a kind of PLShh measurement is still only possible to use for the identification of a transverse profile shape, as in length measurement the length error increases. All PLShh are able to capture the current shape of forest road cross profile, but still they cannot be used for any design or calculation of material measurement needed for wearing course repair.
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Malikov, Vladimir, Nikolay Tihonskii, Victoria Kozlova, Lilia Shevtsova, and Alexey Ishkov. "Modification of a metal surface with detonation diamond nanoparticles." Journal of Physics: Conference Series 2373, no. 3 (December 1, 2022): 032024. http://dx.doi.org/10.1088/1742-6596/2373/3/032024.
Повний текст джерелаАнотація:
Abstract Friction between metal surfaces in various mechanisms is an actual problem in modern engineering. Friction causes wearing of the rubbing parts. For reducing the coefficient of friction, it is proposed to treat the surfaces of rubbing parts with a suspension having a high (more than 20%) content of ultradispersed detonation diamond (UDD). In the course of treatment, nanodiamond particles penetrate into the substance being treated and create a thin surface layer (up to 1000 nm, depending on the degree of part processing), which leads to smoothing the effect of microsliding, due to which the reduction of the friction coefficient. The resulting surface layer consists of a metal matrix with diamond nanoparticles embedded in it. The paper shows the study of the steel part surface with the use of the optical and X-ray methods, and provides information on the change in the coefficient of friction of steel parts.
15
Georgiou, Panos, and Andreas Loizos. "Characterization of Sustainable Asphalt Mixtures Containing High Reclaimed Asphalt and Steel Slag." Materials 14, no. 17 (August 30, 2021): 4938. http://dx.doi.org/10.3390/ma14174938.
Повний текст джерелаАнотація:
Policymakers are implementing the transition to a circular model in all economic sectors to drastically mitigate the effects of climate change. In this regard, the producers of paving products should promote the reuse and recycling of solid waste in the design of sustainable asphalt materials. This study evaluated the performance-based properties of three highly recycled mixtures for wearing courses of asphalt pavements containing steel slag and varying amounts (25, 40, and 50%) of fractionated reclaimed asphalt (RA). In addition, the mixtures incorporated a warm mix asphalt (WMA) organic additive to lower production temperatures compared to a reference hot mix asphalt (HMA). Based on the experimental results, the warm recycled asphalt mixtures show equivalent or better performance compared to HMA in terms of moisture susceptibility, stiffness, rutting and fracture resistance, and surface macrotexture. Therefore, the combined incorporation of RA and steel slag with WMA was proven to be an effective option in designing environmentally friendly and high-performance wearing course mixtures.
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P, Praveen Kumar, and Dr Kiran Kumar B V. "Performance Evaluation of Bituminous Mixes with Modified Binders using Roller Compactor cum Rut Analyzer (RCRA)." International Journal for Research in Applied Science and Engineering Technology 10, no. 4 (April 30, 2022): 1502–7. http://dx.doi.org/10.22214/ijraset.2022.41551.
Повний текст джерелаАнотація:
Abstract: In India majority of roads are being constructed by flexible pavements. But the performance of the pavement largely depends on quality and type of materials used, construction methodology adopted, temperature, climatic conditions etc. Because of these variations in these parameters, pavements undergo distress/ failure. The different types of failure in flexible pavement are Rutting, Shovelling, Edge breaks, Cracks, Slippage etc. Rutting is a common phenomenon which occurs in flexible pavement surface due to overloading of vehicles and repeated application of wheel load. Rutting is defined as channelized depression in the pavement surface along wheel path due to heavy repetitive traffic load. Design of bituminous paving mixes greatly effects the performance of pavements. In the present laboratory research work, conventional bitumen is used in wearing/ surface course and Modified Bitumen is used in binder course of the layer. Pavement layers are constructed/casted in an Indigenously designed, developed and fabricated equipment called Roller Compactor cum Rut Analyzer (RCRA) and Rutting test is performed. The Rutting test is carried out on wearing course of bituminous layer (BC Gr-II with VG-30) and by adopting Binder course layer namely DBM Gr-II prepared with two different types of binders namely VG-30, SBS-70. The overall objective is to compare the Marshall properties of the conventional and Modified Bituminous mix and to study the rutting performance of these bituminous mixes.. Results shows that bituminous mixes prepared with Modified Bitumen/Binders (SBS-70) has a very high Marshall Strength and offers greater resistance to rutting. Keywords: Modified Bitumen, Bituminous Concrete (BC), Dense Bituminous Macadam (DBM) , Marshall Stability, Roller Compactor cum Rut Analyzer (RCRA), Styrene-Butadiene-Styrene (SBS).
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AKBULUT, Hüseyin, and Lale ATILGAN GEVREK. "Investigation of Stress Occurring in the Wearing Layer in Cases of Embedded Pipes in Different Layers in Asphalt Pavements with Hydronic Heating System." Afyon Kocatepe University Journal of Sciences and Engineering 22, no. 2 (April 30, 2022): 324–31. http://dx.doi.org/10.35414/akufemubid.1004772.
Повний текст джерелаАнотація:
In order to prevent snow accumulation and ice formation on asphalt concrete roads, the use of a hydronic heating system embedded in the pavement is recommended as an alternative to traditional snow and ice fighting applications. Hydronic heating systems circulate a heated liquid through a pipe network placed under the pavement layer to melt the snow and ice accumulated in the pavement layer, thus preventing the road surface from icing. Various parameters need to be evaluated for a reliable and economically viable hydronic snowmelt system. In this study, the stresses that occur as a result of traffic load in flexible pavements where hydronic heating systems are used and the stresses that occur as a result of traffic load in flexible pavements without hydronic heating system are compared using finite element software. Evaluations were made using five different air temperatures and three different inlet water temperatures. In the study, the stresses occurring in the surface course were investigated when buried pipes are located in the surface course, binder course, asphalt base course and gravel base layer. In addition, the stresses that occur as a result of traffic load in pe-x pipes used in the system were also evaluated.
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Caroline, Jenny, and Maritha Nilam Kusuma. "Optimizing Performance Asphalt Concrete Hot Rolled Sheet– Wearing Course (HRS-WC) Using Chitosan Powder." UKaRsT 6, no. 1 (April 30, 2022): 130. http://dx.doi.org/10.30737/ukarst.v6i1.2545.
Повний текст джерелаАнотація:
Road quality is also affected by temperature and weather, leading to surface pavement deformation. It is necessary to improve the quality of the road pavement so that the quality of the road becomes more durable and stable. Hot Rolled Sheet – Wearing Course (HRS-WC) is flexible and has high durability. The natural mineral has been used as the filler for pavement construction. However, further research is necessary to obtain alternative and more sustainable materials. This study will discuss portland cement filler as a reference to compare filler replacement with chitosan powder (shellfish) based on the general specifications of the 2018 highway revision 3 division 6. Chitosan powder contains calcium oxide of 3.04% and silica oxide of 17.98%, which are similar to cement fillers. The composition of chitosan powder are 100%: 0%, 50%: 50%, 25%: 75%, and 0%: 100%. performance analysis is done through the marshall test. The results showed that the comparison of the use of the best chitosan powder was at the asphalt content of 7.3 with 50% : 50% with a marshall test value of 993.4 kg, flow 3.20 %, VMA 18.36%, VFB 72.01%, VIM 5.14, MQ 301.440 kg/mm. From the result which meets the requirement, the filler has shown quality improvement as an additional mixture according to (SNI 03-6723-2002). Hence still not optimal to replace portland cement because, from the value of the marshall test, portland cement has a higher marshall value than chitosan.
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Yuniarti, Ratna, Desi Widianty, Rohani Rohani, and Hasyim Hasyim. "Tinjauan Terhadap Durabilitas Campuran Asphalt Concrete Wearing Course Menggunakan Aspal Tua Dengan Berbagai Bahan Peremaja." JURNAL SAINS TEKNOLOGI & LINGKUNGAN 6, no. 2 (December 31, 2020): 132. http://dx.doi.org/10.29303/jstl.v6i2.141.
Повний текст джерелаАнотація:
Asphalt concrete wearing course is laid on the top of road pavement so that directly exposed to ultra violet light and other environment impact. The higher temperature at the pavement surface and exposure to atmospheric oxygen accelerated aging cause asphalt to stiffen and become brittle. This aging result decrease the binding of asphalt and aggregate leads various damage of pavement. The aged asphalt rejuvenated and recycled with rejuvenating agent has been developed to reduce the use of virgin material for road maintenance. This article aims to review durability of asphalt concrete wearing course using waste cooking oil, epoxy resin, kerosene and waste engine oil as asphalt rejuvenators. Aging asphalt was prepared by heating in an oven at 85 oC for 120 hours (long term oven aging). Durability was assessed from the value of Marshall immersion which represent the resistance of asphalt mixture at water immersion. Relation between Marshall immersion and voids in mix (VIM), voids in the mineral aggregate (VMA), voids filled with bitumen (VFB) and density are also evaluated. From the analysis, it can be concluded that the use of waste cooking oil, epoxy resin, kerosene and waste engine oil as asphalt rejuvenators increase the durability of asphalt mixture containing the aged asphalt.
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Zhu, Shiyu, Xiaoping Ji, Zhengming Zhang, Dongye Shao, Hangle Li, and Chen Yun. "Evolution characteristics of the surface texture of the wearing course on asphalt pavement based on accelerated pavement polishing." Construction and Building Materials 333 (May 2022): 127266. http://dx.doi.org/10.1016/j.conbuildmat.2022.127266.
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Wang, Tengda, Liqun Hu, Xiaodong Pan, Song Xu, and Di Yun. "Effect of the Compactness on the Texture and Friction of Asphalt Concrete Intended for Wearing Course of the Road Pavement." Coatings 10, no. 2 (February 24, 2020): 192. http://dx.doi.org/10.3390/coatings10020192.
Повний текст джерелаАнотація:
Maintaining good friction performance of highway pavement is important for road safety. The friction is affected by many factors, and the present study investigates the effect of the compactness on the texture and friction of asphalt concrete during the polishing process. Two three-dimensional (3D) texture parameters and the mean texture depth (MTD) were used to characterize the surface texture of AC-13 asphalt concrete. The differences of surface texture are then being analyzed among the pavement in the field, rutting slabs with 97% compactness (RS-97), rutting slabs with 100% compactness (RS-100), and rutting slabs with 103% (RS-103). The rutting slabs were polished by a circular vehicle simulator (CVS). The 3D surface topography, British pendulum number (BPN), and MTD were obtained during the polishing process. Test results show that the surface of the rutting slab can be smoother as the compactness increased from 97% to 103%. During the whole polishing process, the rutting slab with smaller compactness had higher value of the MTD. The impact of compactness on the BPN is insignificant during the polishing process, but rutting slabs with smaller compactness had better friction at high speed as the result of the higher MTD.
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Destrée, Alexandra, Stefan Vansteenkiste, Tine Tanghe, and Joëlle De Visscher. "Reliable Laboratory Tests: A Prerequisite for the Design of High-Quality Slurry Surfacing Mixtures." Advances in Materials Science and Engineering 2022 (April 22, 2022): 1–20. http://dx.doi.org/10.1155/2022/7157233.
Повний текст джерелаАнотація:
Surface treatment with slurry surfacing is a quick and cost-effective technique to restore the condition and performance of a road surface, compared with the replacement of the wearing course. It is therefore not surprising that cities and municipalities, faced with increasingly tight budgets, choose slurry surfacing to maintain their roads. A slurry surfacing with good performance and a long service life requires, above all, a well formulated mixture and a good control of the execution quality. Slurry surfacing could then even be considered for ultrathin wearing courses on new pavements. From 2016 to 2020, the Belgian Road Research Centre (BRRC) was engaged in a 4-year research project called BeP2S (Better Performing Slurry Surfacing) financially supported by the Belgian Bureau for Standardization (NBN). The project focussed on laboratory testing, gathering data and field experience, assessing the link between laboratory and field performance, and the mix design process. This paper is dedicated to the European test methods of the EN 12274 series (“Slurry surfacing–Test methods”), as well as some alternative test methods, which were evaluated (complexity, relevance for the mix design process, …) and improved in terms of test conditions, precision, and discriminating power. Five performance-related tests proved to have sufficient ability to discriminate between mixtures with variations in mix design. Recommendations were made for the ranges within which the laboratory test results should fall in order for the slurry surfacing to perform well.
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Wasilewska, Marta. "Analysis of skid resistance of road pavements in the initial period of its life." Budownictwo i Architektura 13, no. 4 (December 11, 2014): 285–92. http://dx.doi.org/10.35784/bud-arch.1858.
Повний текст джерелаАнотація:
Changes of microtexture and macrotexture significantly influence skid resistance of road pavements. It takes place especially during the initial period of pavement life. Binder on the coarse aggregate is removed and then surface of grain is polished by traffic. The intensity of changes of a skid resistance coefficient depends on the type of wearing course, traffic load and sites (straight, intersection, curved segments). In this paper, skid resistance of different pavements surface based on BPN (British Pendulum Number) and MTD ( Mean Texture Depth) is compared. The study was conducted on test sections of asphalt concrete and SMA pavements during the reconstruction of the national road No. 8 km 614 +850 - 639 +365 for three months from putting into traffic.
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Putra, K. H., M. Firdausi, and M. Rubbyanto. "The Effect of Coal Powder Addition to Asphalt Concrete - Wearing Course (AC-WC) Mixture to Increase Road Surface Hardness Quality." IOP Conference Series: Materials Science and Engineering 462 (January 8, 2019): 012026. http://dx.doi.org/10.1088/1757-899x/462/1/012026.
Повний текст джерела
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NAPIÓRKOWSKI, Jerzy, Magdalena LEMECHA, and Łukasz KONAT. "EFFECT OF EXTERNAL LOAD ON THE PROCESS OF STEEL CONSUMPTION IN A SOIL MASS." Tribologia 273, no. 3 (June 30, 2018): 111–17. http://dx.doi.org/10.5604/01.3001.0010.6146.
Повний текст джерелаАнотація:
This paper presents the results of a study on the effect of external load on the course and intensity of Hardox Extreme hardness steel wear in sandy soil. The research was conducted under laboratory conditions using a rotating bowl machine. The abrasive was composed of two types of soil: light and medium. External pressure applied to the sample surface had the following values: 13.08, 39.24, and 65.04 [kPa]. On the basis of the results from the analysis of variance, a significant effect of external load on the values of wear on a differentiated level for particular soil masses was found. The analysis of friction surfaces complements the study. Furrows and micro-cuts prevail in the wearing process, and their intensity depends on the cohesion force between the soil grains.
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Andika, Rindi Sekar, and Ari Widayanti. "Analisis Kerusakan dan Perbaikan Jalan Beraspal pada Lapisan Asphalt Concrete-Wearing Course (AC-WC) di Kota Surabaya." Proceedings Series on Physical & Formal Sciences 1 (October 31, 2021): 163–70. http://dx.doi.org/10.30595/pspfs.v1i.149.
Повний текст джерелаАнотація:
AC-WC asphalt layer is a surface layer of flexible pavement construction that bears a direct load from the vehicle wheels. The increase in the number and load of traffic that occurs every year impacts road conditions and can cause damage. This requires analysis, repair and maintenance of roads for roads to function properly. The purpose of this study was to analyze road damage and provide alternative treatments for each road based on the type and level of damage that occurs. The method used was literature study, observation, documentation, and analysis with the PCI method. Observations were made on roads with class III flexible pavement in South Surabaya City. The results obtained were that the most dominant type of damage was crack damage, the level of road damage varies (low, medium, high severity) and there were different types of damage at the same point. The highest percentage and value of the damage were on Kembang Kuning Road and Pakis Tirtosari III Road. Based on the PCI method, the condition value of Dukuh Kupang XX Road was the lowest, at 25 (very poor). On Kembang Kuning Road and Pakis Tirtosari III Road maintenance work was needed, while Dukuh Kupang Road required road repairs.
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Wang, Kechen, Xiangyu Chu, Jiao Lin, Qilin Yang, Zepeng Fan, Dawei Wang, and Markus Oeser. "Investigation of the Formation Mechanism and Environmental Risk of Tire—Pavement Wearing Waste (TPWW)." Sustainability 13, no. 15 (July 21, 2021): 8172. http://dx.doi.org/10.3390/su13158172.
Повний текст джерелаАнотація:
Tire—pavement interaction behaviours result in large amounts of wearing waste matter, which attaches to the surface of the pavement and is directly exposed to the surrounding environment. This kind of matter imposes a great challenge to the environment of the road area. The current study is devoted to carrying out a comprehensive investigation of the formation mechanism of tire—pavement wearing waste (TPWW), as well as the resulting environmental risks. A self-developed piece of accelerated polishing equipment, the Harbin advanced polishing machine (HAPM), was employed to simulate the wearing process between vehicle tires and pavement surfaces, and the TPWW was collected to conduct morphological, physical, and chemical characterisations. The results from this study show that the production rate of TPWW decreases with the increase in polishing duration, and the coarse particles (diameters greater than 0.425 mm) account for most of the TPWW obtained. The fine fraction (diameter smaller than 0.425 mm) of the TPWW comprises variously sized and irregularly shaped rubber particles from the tire, as well as uniformly sized and angular fine aggregates. The environmental analysis results show that volatile alkanes (C9–C16) are the major organic contaminants in TPWW. The Open-Graded Friction Course (OGFC) asphalt mixture containing crumb rubber as a modifier showed the highest risk of heavy metal pollution, and special concern must be given to tire materials for the purpose of improving the environmental conditions of road areas. The use of polyurethane as a binder material in the production of pavement mixtures has an environmental benefit in terms of pollution from both organic contaminants and heavy metals.
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S, Manjunatha, and Dr B. V. Kiran Kumar. "Performance Based Testing on Bituminous Mixes using Roller Compactor cum Rut Analyser (RCRA)." International Journal for Research in Applied Science and Engineering Technology 10, no. 4 (April 30, 2022): 1631–35. http://dx.doi.org/10.22214/ijraset.2022.41622.
Повний текст джерелаАнотація:
Abstract: In India majority of roads are being constructed by flexible pavements. But the performance of the pavement largely depends on quality of materials used, Equipment’s used, construction methodology adopted, temperature and climatic conditions at the area etc. Because of these variations in the mentioned parameters, pavements undergo distress/ failure. The different types of failure in flexible pavement are Rutting, Shovelling, Edge breaks, Cracks, Slippage etc. Rutting is a common phenomenon which occurs in flexible pavement surface due to overloading of vehicles and repeated application of wheel load. Design of bituminous paving mixes greatly effects the performance of pavements. In the present laboratory research work, Bitumen grade VG-30 & VG-40 are used in wearing/ surface course and VG-30 is used in binder course of the layer to study the properties of Marshall Stability. An indigenously developed equipment called Roller Compactor cum Rut analyser (RCRA) is used to study the performance of these bituminous mixes against Rutting. Keywords: Job Mix Formula (JMF). Marshal Method, Bituminous Concrete (BC), Dense Bituminous Macadam (DBM) Roller Compactor cum Rut Analyser (RCRA).
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Iwański, Marek, and Grzegorz Mazurek. "Rheological properties of the bituminous binder extracted from SMA pavement with hydrated lime." Baltic Journal of Road and Bridge Engineering 11, no. 2 (June 27, 2016): 93–101. http://dx.doi.org/10.3846/bjrbe.2016.11.
Повний текст джерелаАнотація:
The durability of pavement layers depends on the type of bitumen and changes in its material structure during service life. In 1999, while rebuilding and modernizing road infrastructure in Kielce (Poland), a stone mastic asphalt wearing coarse layer with hydrated lime was placed on one of the town’s main streets. Stone mastic asphalt mixture contained 6.2% of D70 bitumen (currently 50/70) and 4% SBS polymer under the trade name Kraton 1101 CM. The hydrated lime was dosed into the stone mastic asphalt mixture to replace 30% of the filler mass. Pavement surface condition after 12 years of service life was very good. In 2011, bitumen samples were extracted from stone mastic asphalt and tested. The tests were performed on the samples that contained fatty amine and hydrated lime as adhesive agents, obtained from stone mastic asphalt wearing course layer in the rut paths and from between the area limited by rut paths. The hydrated lime additive was found to have a positive effect on rheological properties of the recovered bitumen providing resistance to the water and frost.
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Akin, Michelle, Laura Fay, and Xianming Shi. "Friction and Snow–Pavement Bond after Salting and Plowing Permeable Friction Surfaces." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 11 (September 13, 2020): 794–805. http://dx.doi.org/10.1177/0361198120949250.
Повний текст джерелаАнотація:
Open graded, ultrathin, and permeable friction course surfaces (collectively referred to as PFSs) have been successfully used by many transportation agencies in several countries as a wearing surface to help reduce water splash and spray, reduce potential for hydroplaning, increase friction, and reduce noise. Despite these advantages, when used in colder climates PFSs tend to freeze more rapidly, transport deicing/anti-icing chemicals from the road surface, clog from sands and other debris, and retain snow and ice for a longer period of time. Most of the reported difficulties with PFSs are at near-freezing temperatures (28°F–35°F). Laboratory tests were conducted using samples of traditional dense graded pavement (DGP), cores from new and old in-service open graded friction course pavements, and ultrathin friction course samples made from hot mix asphalt collected from paving operations. The tests were conducted in a walk-in environmental chamber at 28°F. Snow–pavement bond strength and static friction were measured to determine the effectiveness of anti-icing with salt brine and deicing with dry and pre-wet solid salt. The test results revealed that compacted snow bonds more strongly to PFSs, yet friction of PFSs was significantly greater than DGPs after snow removal, even without the use of salt. The PFSs appeared more white and snowy, and this appearance may be contributing to unnecessarily high application rates of salt by practitioners. Field testing is recommended to better understand the frictional behavior of PFSs during a variety of winter storm conditions and deicer application strategies.
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Izevbekhai, Bernard Igbafen, Lev Khazanovich, and Vaughan R. Voller. "Deployment of the Next Generation Concrete Surface in Minnesota." Transportation Research Record: Journal of the Transportation Research Board 2640, no. 1 (January 2017): 95–103. http://dx.doi.org/10.3141/2640-11.
Повний текст джерелаАнотація:
Development of a quiet diamond grinding configuration commenced in an initial laboratory effort at Purdue University, followed by research iterations from 2007 to 2010 at the pavement test track research facility (MnROAD) of the Minnesota Department of Transportation (DOT). This paper catalogues the stages in the development and deployment of the Next Generation Concrete Surface (NGCS) from the configuration development at MnROAD, coupled with the simultaneous development of a tire–pavement noise predictive model deployed on Interstate 94 near Saint Cloud, Interstate 35 in Duluth, and Interstate 394 in Minneapolis, Minnesota. NGCS in these projects caused noise reduction of 3 to 6 dB, representing 50% to 75% sound intensity reduction. Diamond grinding was performed on the preexisting textures: burlap drag on Interstate Highway 94 near Saint Cloud, transverse tining on Interstate Highway 35 in Duluth, and Ultra-Thin Bonded Wearing Course (UTBWC) on Interstate 394, Minnesota DOT exceeded the goal of not increasing the pregrind tire–pavement noise level by these rehabilitations. The predictive tire–pavement interaction noise model was validated in these deployments, including on Interstate 394, where the full acoustic benefit of NGCS had been attenuated by the anomalous effect of undulations reminiscent of the previous concrete–UTBWC interface, which had inadvertently conferred a background configuration to the new diamond-ground surface.
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Rajczyk, Jarosław. "New Material Solutions for Road Surface Construction Made of WMA." Advanced Materials Research 1020 (October 2014): 811–16. http://dx.doi.org/10.4028/www.scientific.net/amr.1020.811.
Повний текст джерелаАнотація:
The need for modernization and adjustment of existing road infrastructure to European Union requirements will result in the need for processing thousands tones of waste. The amount of waste received from road repairs and road demolitions, as well as technological by-products in Poland may be estimated at the level over 2.5 million tones, which is almost 2% of all waste production. Construction waste recycling is truly justified in this case, together with waste management according to the provisions of national and international law. One of such products is dust generated as a side effect of stone processing in a Casey mine in Ireland. Laboratory tests of the new material compositions with the use of waste from this mine not only realize the general aims of economic and ecological assumptions, but also allow increasing quality of a new product which is an asphalt-concrete composite. In order to check the properties of the use of a filler in a form of Hornfels Ireland powder there was conducted a series of special tests on the asphalt concrete testing the wearing course. Hornfels Ireland powder produced as a waste material of an aggregate processing in Cassey Quarry is a useful material, which may be successfully used as a component in a process of WMA production.
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Rosyidi, Sri Atmaja P., Indra Ariani, and Siti Isnaini K. Djaha. "Korelasi Empirik antara Kecepatan Gelombang Permukaan terhadap Kepadatan dan Kekakuan pada Campuran Laston – WC." Semesta Teknika 17, no. 1 (November 25, 2015): 1–9. http://dx.doi.org/10.18196/st.v17i1.414.
Повний текст джерелаАнотація:
Density and stiffness of asphaltic mixture are important parameter used for pavement design and construction. These parameter measure the required thickness of pavement.The aim of this study is to investigate the empirical relationship between pavement density and stiffness of Asphalt Concrete-Wearing Course (AC-WC) and surface wave velocity. Surface wave velocity is obtained from the seismic test set up in laboratory. A high frequency of impact source is employed in order to produce the high frequency waves propagating in mixture samples.The wave displacement is measured by accelerometer receivers connected to the computer for signal processing and spectrum analysis. In this study, AC-WC mixture is prepared with 35×,50×, 75× and 100× blows for providing sample with different density. From the results, it shows that the surface wave velocity is able to detect the various density of samples. Higher density of sample produces higher velocity and vice versa. Some empirical correlations between surface wave velocity with density and stiffness are also produced with significant statistical measures. This study shows the surface wave velocity is potential parameter employed for mixture assessment in pavement design and evaluation.
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Kotek, Peter, Matúš Kováč, and Martin Decký. "The Skid Resistance Evaluation on the Longterm Monitored Road Sections." Civil and Environmental Engineering 10, no. 2 (December 1, 2014): 66–72. http://dx.doi.org/10.2478/cee-2014-0013.
Повний текст джерелаАнотація:
Abstract The article deals with the analysis of the skid resistance results measured at the long-term monitored road sections in Slovakia in perspective of the possibility of the deterioration functions determination for the purposes of the pavement management system. There were 11 road sections evaluated, on which have been surface characteristics measured since 1998. The focus was on the evaluation of the longitudinal friction coefficient Mu measured by device Skiddometer BV11, which is the property of the Slovak Road Administration. Beside the Mu parameter, the test conditions were observed and evaluated, as well (measured speed, air and surface temperature, type of asphalts of the wearing course, traffic load, and the season (spring, autumn, respectively) in which the skid resistance measurements were performed. In conclusion, there was reviewed a presumption of the possibility to determine a deterioration functions for skid resistance in point of view the quality of the data, which have been collected on the Slovak long-term monitored road sections.
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Springis, Guntis, Janis Rudzitis, Eriks Gerins, and Natalija Bulaha. "Theoretical Approach of Wear for Slide-Friction Pairs." Solid State Phenomena 260 (July 2017): 202–11. http://dx.doi.org/10.4028/www.scientific.net/ssp.260.202.
Повний текст джерелаАнотація:
A number of different mechanisms and devices in mechatronic systems may involve sliding-friction surfaces. The issues of service life and its prediction for the details of such surfaces have always been of particular importance. Having studied the wear process prediction theories that have been developed in the course of time, which can be classified by dividing them in definite groups based on similar theoretical approach one can state that each of them has different shortcomings, which might affect the result precision, when essential basic parameters have been disregarded, as well as create a need for useless additional practical experiments, as a result of which theoretical calculation becomes unnecessary. [4] The article determines the most suitable wear calculation model that allows considering the set of parameters necessary for calculating slide-friction pair. Wearing usually proceeds in three stages: the running-in stage, the normal wear stage, and the intensive wear stage. The proposed model is provided for normal wear stage calculations. The proposed model for wear calculation is based on the application of theories from several branches of science to the description of 3D surface micro-topography in accordance with random field theory, assessing the material’s physical and mechanical characteristic quantities, substantiating the regularities in creation of material particles separated during the wear process and taking into consideration definite service conditions of fittings. Since the wear process is variable and many-sided, it is influenced by numerous different parameters, for example, surface geometry (roughness, waviness, form deviation, etc.), physical and mechanical conditions of the upper layer, material components, wear regime, wear temperature, etc. Based on the regularities stated in the article one can propose the following wear calculation sequence [4]:1) Initial data should be stated which will be further necessary in calculations: constructive-kinematic characteristic quantities (rated area Aa of wearing component, load P, gliding movement speed v, movement time t), fatigue characteristic of friction component material (friction coefficient f (f≤0,1) and material fatigue destruction parameters (m, σ-1, N0), mechanical characteristic quantities of material (E, μ);2) Parameters should be stated after attachment: surface roughness parameters (Sa, Sm1, Sm2, Sm2a), initial wear Up and corresponding time Tp, tolerated wear Umax.
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P, Praveen Kumar, and Dr Kiran Kumar B V. "Performance Evaluation of Flexible Pavements with Modified Bitumen Binders." International Journal for Research in Applied Science and Engineering Technology 10, no. 4 (April 30, 2022): 1496–501. http://dx.doi.org/10.22214/ijraset.2022.41537.
Повний текст джерелаАнотація:
Abstract: In India majority of roads are being constructed by flexible pavements. But the performance of the pavement largely depends on quality and type of materials used, Construction methodology adopted, temperature, climatic conditions etc. Because of these variations in the mentioned parameters, pavements undergo distress/ failure. The different types of failure in flexible pavement are Rutting, Shovelling, Edge breaks, Cracks, Slippage etc. Rutting is a common phenomenon which occurs in flexible pavement surface due to overloading of vehicles and repeated application of wheel load. Rutting is defined as channelized depression in the pavement surface along wheel path due to heavy repetitive traffic load. Design of bituminous paving mixes greatly effects the performance of pavements. In the present laboratory research work, conventional bitumen is used in wearing/ surface course and Modified Bitumen is used in binder course of the layer. Pavement layers are constructed/casted in an Indigenously designed, developed and fabricated equipment called Roller Compactor cum Rut Analyzer (RCRA) and Rutting test was performed. The overall objective is to compare the Marshall properties of the conventional and Modified Bituminous mix and to study the rutting performance of these bituminous mixes. Results shows that bituminous mixes prepared with Modified Bitumen/Binders has a very high Marshall Strength and offers greater resistance to rutting Keywords: Modified Bitumen, Bituminous Concrete (BC), Dense Bituminous Macadam (DBM), Marshall Stability, Roller Compactor cum Rut Analyzer (RCRA), Crumb Rubber Modified Bitumen (CRMB)
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Gong, Ya Dong, Yue Ming Liu, Ting Chao Han, and Jun Cheng. "The Designing and Wear Simulation of the Wheel Used in Super-High Speed Point Grinding." Solid State Phenomena 175 (June 2011): 177–82. http://dx.doi.org/10.4028/www.scientific.net/ssp.175.177.
Повний текст джерелаАнотація:
The application of the wheel used in super-high speed point (SHSP) grinding is introduced in detail, depicting the applied rang of the wheel, through designing the wheel body and the layer of CBN in the wheel. The designed principle is inferred according to the specific shape, the grinding productivity is analyzed in the course grinding zone and the finished grinding zone, introducing the angle of course grinding zone, which affects the grinding parameters in SHSP grinding, the value of the angle is designed to be suited to the point grinding, and manufacturing the wheel, introducing the changed state of chip flowing grinding used in the new wheel, the micro-surface of the wheel is observed through microscope, whose the ratio of air hole and the layer of CBN are analyzed, simulating the wear trend of the new wheel, the conclusions about super hard abrasives and wearing are drawn at last, the application of SHSP grinding is related to designing and manufacturing of the wheel, which provides the equipment for realizing high precision and productivity processing and offers the referred basis for the theoretical research.
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Kunz, Bethany K., Nicholas S. Green, Janice L. Albers, Mark L. Wildhaber, and Edward E. Little. "Use of Real-Time Dust Monitoring and Surface Condition to Evaluate Success of Unpaved Road Treatments." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 52 (October 9, 2018): 195–204. http://dx.doi.org/10.1177/0361198118799167.
Повний текст джерелаАнотація:
Fugitive dust from unpaved roads creates human health hazards, degrades road surfaces, and increases the cost of road maintenance. As a result, many different chemical treatments are applied to unpaved roads in an attempt to control dust and stabilize the wearing course. However, investigations of the effectiveness of these treatments have often been poorly planned or executed. The objective of this study was to use a combination of real-time dust monitoring and objective road condition evaluations to assess the success of two chemical treatments for a period of 19 months post-application, to provide quantitative information in support of road management decisions. Dust production from road sections treated with calcium chloride-based durablend-C™ or the synthetic fluid EnviroKleen® was monitored on five dates using a vehicle-mounted particulate matter meter. Both products reduced dust by up to 99% relative to an untreated control section during the monitoring period, and quantitative data from the meter were consistent with qualitative observations of dust conditions. Linear models of dust production indicated that road treatment and humidity explained 69% of the variation in dust over time. Road sections treated with either product developed less rutting and fewer potholes than the untreated control. Overall, the combination of real-time dust monitoring and surface condition evaluation was an effective approach for generating quantitative data on endpoints of interest to road managers.
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Hadiwardoyo, Sigit Pranowo, Raden Jachrizal Sumabrata, and Puspita Jayanti. "Contribution of Short Coconut Fiber to Pavement Skid Resistance." Advanced Materials Research 789 (September 2013): 248–54. http://dx.doi.org/10.4028/www.scientific.net/amr.789.248.
Повний текст джерелаАнотація:
The use of synthetic and natural fibers in composite materials has been proven to increase strength and reduce required amounts of basic building materials. Previous research has determined that fibers have a high tensile strength and the potential to increase the cohesive and tensile strengths of asphalt mixtures. Additionally, previous research suggests that skid resistance is influenced by changes in the asphalt penetration grade. Short decorticated and pulp coconut fibers were used as additives in this study. Short coconut fibers measuring 0.5-1.25 cm were mixed with pen 60/70 asphalt to yield fiber contents of 0%, 0.75% and 1.5%. The fibrous asphalt was mixed with asphalt-concrete-wearing-course-grade aggregate. The asphalt concrete mixture was molded and compacted with a wheel tracking compactor using an 8.16-ton standard vehicle axle load. Specimens were subsequently tested with a British pendulum tester at temperatures of 26 oC, 30 °C, 35 °C, 40 °C, 45 °C, and 50 °C. Skid resistance decreased with an increase in pavement surface temperature. The inclusion of 0.75% coconut fiber in the asphalt mixture improved skid resistance but did not improve resistance to increased road surface temperatures.
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Lane, Ben, Paul Sherratt, Hu Xiao, and Andy Harland. "Characterisation of ball impact conditions in professional tennis: Matches played on hard court." Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology 230, no. 4 (August 1, 2016): 236–45. http://dx.doi.org/10.1177/1754337115617580.
Повний текст джерелаАнотація:
To assess ball performance for research and development purposes requires greater understanding of the impact conditions a tennis ball experiences in professional tournament play. Ball tracking information taken from three consecutive years of an ATP 250 tour event played on hard court was analysed. The frequency of first serves, second serves, racket impacts and surface impacts was assessed per game and extrapolated to show how many impacts a single ball is subjected to. Where applicable the pre- and post-impact velocities and angles were found, and the distribution of each was analysed. In total, data from 65 matches comprising 1505 games were analysed. On average, each game contained 70.26 (±16.23) impacts, of which 9.23%, 3.16%, 37.78% and 49.83% were first serves, second serves, racket impacts and surface impacts, respectively. As a result, assuming all balls in play are used evenly, a single ball is expected to be subjected to 105 (±24) impacts over the course of the nine games that it is in play. The results of the investigation could be used to design a wear protocol capable of artificially wearing tennis balls in a way that is representative of professional play.
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Protsenko, E. S., N. A. Remnyova, and N. V. Panchenko. "The Effect of Tear Film Quality on Protective Properties against SARS-CoV-2 and on Further Risks of Infection in Dry Eye Disease." Ukraïnsʹkij žurnal medicini, bìologìï ta sportu 6, no. 3 (June 26, 2021): 53–64. http://dx.doi.org/10.26693/jmbs06.03.053.
Повний текст джерелаАнотація:
SARS-CoV-2 is a new coronavirus causing global pandemic COVID-19 throughout the world, the clinical manifestations of which may include not only respiratory syndrome and systemic manifestations, but also eye symptoms. The purpose of the study. This study processed and presented to the scientific community the latest scientific evidence from the world literature regarding the effect of tear film quality on protective properties against SARS-CoV-2 and on further risks of COVID-19 infection in dry eye disease. Many studies have proven the presence of ACE2 as well as TMPRSS2 expression in the conjunctival and corneal epithelium and detection of SARS-CoV-2 RNA in the tear fluid of infected patients, which indicates the ocular tissue tropism to the virus and its possible transmission through the ocular surface. The detection of SARS-CoV-2 in conjunctival or tear samples may depend on viral load and secretion, as well as on sampling time during the course of the disease. It has been suggested that SARS-CoV-2 is prone to exist on the surface of the eye in the early stages of conjunctivitis, and the viral load decreases after a few days. However, cases of virus detection without conjunctivitis may indicate that SARS-CoV-2 can cause latent and asymptomatic infection. With the introduction of protective anti-epidemic measures such as protective masks, the rapid increase and progression of dry eye disease has begun, which leads to decreased ocular surface immune mechanisms, and could potentially increase the risks of SARS-CoV-2 virus transmission. The mechanisms of protection of the healthy ocular surface and possible ways to combat SARS-CoV-2 were reviewed. And the potential causes of increased ocular surface infections during a pandemic were also shown. Through wearing of protective masks, there is additional dispersion of air around the eyes and accelerated evaporation of tear fluid with its thinning and rupture, which contributes to the progression of the prevalence of dry eye disease. The information confirmed by research has already appeared in the literature. This ocular surface condition has been defined by the term "MADE" – dry eye associated with wearing a mask. Dry eye disease, in turn, is a multifactorial ocular surface disease that results in tear film instability, hyperosmolar stress, and a cascade of inflammatory responses. This initiates ocular surface damage, impaired immune status, pathological apoptosis of conjunctival and corneal cells, and loss of basic protective function. Conclusion. Thus, given the obvious decrease in the immune defense mechanisms of the ocular surface in dry eye disease, which is a vulnerable place for virus penetration, this area deserves further in-depth study
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Šneideraitienė, Lina, and Daiva Žilionienė. "Assessment of Skid Resistance of Road Pavements." Baltic Journal of Road and Bridge Engineering 15, no. 3 (August 14, 2020): 157–68. http://dx.doi.org/10.7250/bjrbe.2020-15.490.
Повний текст джерелаАнотація:
The quality of the paved road depends not only on the decisions of the road designer and the work carried out but also on the materials used. Most of the aggregates used are imported from other countries. However, the usage of domestic materials reduces the cost of the road pavement and the use of aggregates produced by a special production technology in Lithuania, i.e., dolomite aggregates instead of granite aggregates. Experimental studies were carried out on the skid resistance of the road surface. It was found that the coefficient of skid resistance met the requirements for surface dressing with dolomite aggregate, and the results were analysed with 95% probability. This coefficient partially met the requirements for asphalt concrete, while it did not meet the requirements at all for stone mastic asphalt. The surface roughness, however, met the requirements for road sections where granite aggregates were used instead of dolomite in mixes of surface dressing and asphalt concrete. The analysis was carried out considering the volume of traffic and the service life of the individual road sections. It was determined that it was suitable for a 5-year guarantee period to perform the surface dressing, wearing course of asphalt concrete and stone mastic asphalt with dolomite aggregate where part of heavy vehicles is less than 20% of traffic flow. The use of granite aggregates was justified only in the road where heavy vehicles dominated.
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Martina, Nunung, Muhammad Fathur Rouf Hasan, and Yanuar Setiawan. "Pengaruh Serbuk Ban Bekas Sebagai Campuran Agregat Halus Pada Campuran Aspal Porous." Wahana Teknik Sipil: Jurnal Pengembangan Teknik Sipil 24, no. 2 (December 31, 2019): 144. http://dx.doi.org/10.32497/wahanats.v24i2.1731.
Повний текст джерелаАнотація:
The porous asphalt mixture is a new generation of flexible pavement that is able to pass water in the upper layer (wearing course) both vertically and horizontally. The porous asphalt layer effectively provides more safety, especially when it rains to avoid aquaplaning which causes roughness of the surface to be more rough. Therefore, at this time there are many studies on the use of alternative materials to replace the limited natural materials with materials that can be utilized. The results showed that porous asphalt mixture with used tire crumb as a fine aggregate mixture had an increase in flow value of 6.32% with a decrease in stability value by 27.52% and a decrease Marshall Quotient value at 31.82%. The testing of roughness is increased by 17.71% and Mu-Meter 24.14%. This research is effective in overcoming environmental problems which include processing tire waste of 3.03 tons for 1 km of road pavement construction work.
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Kopynets, Ivan, Mykola Stulii та Tetiana Protopopova. "EUROPEAN PRACTICE OF SOLVING ISSUES OF EFFECTIVE FUNCTIONING OF SURFACE DRESSING OF PAVEMENT. СOMPLIANCE OF SURFACE DRESSING CHARACTERISTICS WITH TECHNICAL CONDITIONS OF DSTU EN 12271:2021 (EN 12271:2006, IDT)". Dorogi i mosti 2022, № 25 (17 березня 2022): 58–76. http://dx.doi.org/10.36100/dorogimosti2022.25.058.
Повний текст джерелаАнотація:
Introduction. The wearing course of a road pavement is in complicated operational conditions in combination with adverse weather and climatic factors that are characteristic of the country for most of the year. These factors make high demands on the wearing course, in particular arranged by the method of a surface dressing. European practice of solving these issues is based on the provisions of a set of standards that can serve to solve the problems of effective functioning of a surface dressing on roads in Ukraine. Problem statement. The introduction of the requirements of the Association Agreement between Ukraine and the EU [1] into the road sector on a new favorable regime for economic relations, improvement of trade and investment are key factors in economic modernization and sustainable development of the country. European realities indicate that one of the prerequisites for the effective functioning of the road network is, first of all, implementation of modern standards. Actually, in our country there is an urgent need for their updating, in particular for the modern practice of solving the issues for the arrangement of surface dressing of the pavement, especially its design and quality control of work. Therefore, for implementation of the requirements of this Agreement, “DerzhdorNDI” SE has prepared a comprehensive set of national standards in this area with an identical degree of compliance with European requirements. Purpose. The purpose of the work is to promote the implementation of national standards with an identical degree of compliance with European requirements for the efficient operation of layers, arranged by the method of surface dressing on the roads in Ukraine. In this regard, at the present stage, only those requirements are considered, which are set out in the DSTU EN 12271: 2021 (EN 12271: 2006, IDT) «Surface dressing. Specifications» which is being prepared for publication by the National Standardization Body of Ukraine. The related standards, which are applied as a whole, will be updated and presented after their entry into force in the following parts of the article for the acquaintance of the road community. These standards are: –– DSTU EN 12272-1:2021 (EN 12272-1:2002, IDT) Surface dressing - Test methods - Part 1: Rate of spread and accuracy of spread of binder and chippings [2]; –– DSTU EN 12272-2:2020 (EN 12272-2:2003, IDT) Surface dressing - Test methods - Part 2: Visual assessment of defects [3]; –– DSTU EN 12272-3:2020 (EN 12272-3:2003, IDT) Surface dressing. – Test method - Part 3: Determination of binder aggregate bonding by Vialit plate shock test method [4]. Materials and methods Analysis of the national standard DSTU EN 12271: 2021_ (EN 12271: 2006, IDT) Surface dressing - Requirements with identical degree of conformity EN 12271: 2006 (version en) Surface dressing - Requirements[5]. Results The requirements of the national standard for the effective functioning of the surface dressing of roads in Ukraine are considered, further use of which provides an opportunity to improve the performance of works for its arrangement. Conclusion.The implementation of the requirements of the standard will contribute to the establishment of scientifically sound standards for surface dressing. The priority approaches proposed in it regarding requirements, design process and quality control can be approved as modern, requiring application in the road industry. In particular, it is appropriate to introduce requirements for the mandatory arrangement of the test site to confirm surface dressing performance (Type Approval Installation Trial (TAIT)), or measures taking into account the specifics of Factory Production Control (FPC). The use of the requirements of the standard will be facilitated by the development of country regulations or practical recommendations based on regional local conditions, and their implementation in order to create the most relevant areas of effective forms of improving the quality of surface dressing.
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Amadi E., Nkama. "Glassphalt Concrete Production Using Stone Dust as a Filler through Trial Mix Design." International Journal of Advanced Research in Engineering 3, no. 4 (December 29, 2017): 1. http://dx.doi.org/10.24178/ijare.2017.3.4.01.
Повний текст джерелаАнотація:
Various studies have shown that waste glass has been crushed and screen and can serve as an alternative replacement of fines and coarse aggregate when mixed with Bitumen to form a glassphalt concrete which can be used in landscaping or non-load bearing walls in a building. This researched work was intended to compare and analyze the hot mix glassphalt (HMG) and the strength of asphalt concrete using trial mix design through investigative of their performances. The mineral fillers with different percentage by total weight of the mixture used in the study were crushed igneous rock that passes from 0.075mm to 200mm sieve sizes. However, this production did not only establish the usage of glassphalt but also analysis grade of bitumen like 60/70, 30/40, 80/100, 180/200 etc, its sustainability for various road uses either for priming eg. MCI, tackcoat eg. RSI, or surface dressing e.g S125. Various tests were conducted like water absorption test, marshal stability test, void ration test etc. using bitumen grade 60/70 which has a flash point of 250oc and a melting point of 48 – 56oc. Different types of glassphalt concrete was classified: Macadam, Binder course and wearing course with experimental design to determining the maximum deformation load that will deform the glassphalt concrete to aid in predicting its design life span and equally makes necessary recommendations.
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Murphy, Daniel T., and John J. Emery. "Modified Cold In-Place Asphalt Recycling." Transportation Research Record: Journal of the Transportation Research Board 1545, no. 1 (January 1996): 143–50. http://dx.doi.org/10.1177/0361198196154500119.
Повний текст джерелаАнотація:
Cold in-place asphalt recycling has been shown to be a technically sound, cost-effective, environmentally friendly method of strengthening and maintaining a wide range of deteriorating asphalt pavements. The overall process combines testing and mix design procedures, milling, processing and mixing units with microprocessor control of emulsion addition, compaction, placement of a wearing surface and quality assurance testing. In laboratory work and a number of Ontario projects during the past 3 years it has been shown that modification of the cold in-place process to incorporate new aggregate results in an improved recycled binder course with closer voids and stability control. These findings address observed conventional cold in-place asphalt recycling problems such as high residual asphalt cement content (flushing), fine mix (high percent passing 4.75 mm and 75 μm), rutting (low initial stability with emulsion system), and adequacy of in-place material thickness. Structural equivalency factors for cold in-place recycled asphalt compared with conventional binder course hot-mix asphalt have been developed. Resilient properties of laboratory and field samples have been determined with the Nottingham asphalt tester and used in standard mechanistic design programs such as BISAR. Future applications of modified cold in-place asphalt recycling to improve flexible pavements will undoubtedly include airports, which will require consideration of special features such as operational constraints.
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Stienss, Marcin, and Cezary Szydlowski. "Influence of Selected Warm Mix Asphalt Additives on Cracking Susceptibility of Asphalt Mixtures." Materials 13, no. 1 (January 3, 2020): 202. http://dx.doi.org/10.3390/ma13010202.
Повний текст джерелаАнотація:
Warm mix asphalt (WMA) has been widely accepted as a future asphalt paving technology. Besides clear advantages, there are still some concerns regarding durability and long-term performance of pavements made with this type of asphalt mixtures. One of the most important issues is low temperature behaviour of WMA because certain additives used for temperature reduction can affect bitumen properties. This paper presents the evaluation of low-temperature properties of laboratory-produced asphalt concrete for wearing course with selected WMA additives. One type of bitumen with paving grade 50/70 and five WMA additives of different nature (organic, surface tension reducer and combination of both) were used in this study. The production and compaction temperature of mixtures containing WMA additives was 25 °C lower in comparison with the temperature of the reference mix. To assess the susceptibility of WMA to low-temperature cracking, Semi-Circular Bending (SCB) and Thermal Stress Restrained Specimen Test (TSRST) were used. Supplementary rating was made by analysing Bending Beam Rheometer (BBR) test results of asphalt binders.
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Hasyir, Huda Alfian Aunur, and Sapto Budi Wasono. "Analysis Mixed Layer Asphalt Surface as Asbuton Ac-Wc Characteristics of Marshall." :: IJIEEB :: International Journal of Integrated Education, Engineering and Business :: 3, no. 2 (October 9, 2020): 132–43. http://dx.doi.org/10.29138/ijieeb.v3i2.1173.
Повний текст джерелаАнотація:
Natural asphalt is asphalt obtained somewhere in nature, and can be used as obtained or with little processing. No natural asphalt obtained in the mountains like asphalt in Buton island called Asbuton. Asphalt Buton island is a mixture of bitumen material with other mineral materials in the form of rocks. Because asbuton is so sajaa material found in nature, the levels of bitumen dikandungnyaa greatly varies from low to high. To overcome this, then asbuton began to be produced in various forms at the processing plant asbuton. To reduce the use of natural asphalt eat more steps to do research on utilizing asbuton with the composition 6%, 8%, 10%. The purpose of this study is 1.) Determine the material characteristics LGA Asbuton can meet the specifications of Highways in 2018 on a mix of AC-WC 2.) Determine the value of Optimum Asphalt Content on asphalt concrete AC-WC (Asphalt Concrete - Wearing Course) with extra material LGA Asbuton 3.) Knowing how the performance of asphalt concrete AC-WC with additional material and bitumen 60/70 Asbuton terms of Marshall Test. The study was conducted with an experimental method through laboratory testing. The expected benefits of this research is the discovery of optimizing the use of Asbuton for at the time of execution of the work of new road construction or road maintenance and provide alternative natural aggregate material consumption to a minimum.The test results for the optimum bitumen content KAO on the composition 1 Asbuton 6% with a variation of bitumen (5.05% 5.55% 6.05% 6.55% 7.05%) of the chart can be found KAO Marshall 6.2%. Composition 2 Asbuton 8% with a variation of asphalt (5.0% 5.5% 6.0% 6.5% 7.0%) on the graph can be found KAO Marshall 6.3%. Composition 3 Asbuton 10% with a variation of asphalt (5.0% 5.5% 6.0% 6.5% 7.0%) on the graph can be found KAO Marshall 6.4%. Variations in the composition of 6%, 8% and 10% meet all the requirements of the properties of hot asphalt mix can specification of Highways in 2018.
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Légère, Glen, and Allan Bradley. "Long-Term Study on the Cost-Effectiveness of Dust Control and Untreated Aggregate-Surfaced Resource Roads." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 12 (September 15, 2019): 710–16. http://dx.doi.org/10.1177/0361198119854090.
Повний текст джерелаАнотація:
A long-term study of treated and untreated aggregate resource roads in Canada was conducted. The objective was to investigate the cost-effectiveness of annual dust control treatments where the hypothesis is that annual applications may prolong aggregate life. Seven sections along two road segments with different traffic levels were studied over five years. A survey of road users revealed that 88% agreed that the treated sections were safer because of the increase in visibility and quicker dust settlement times. Evaluation of surface aggregate indicated some aggregate wear but there were no significant differences between treated and untreated sections. The source and quality of crushed aggregate has an impact on road performance. The condition of the running surface did not indicate any major performance differences between the treated and untreated sections. Regardless of treatment, age, or aggregate sources, a general downward trend in Unsurfaced Road Condition Index was observed, indicating wearing course degradation over time. The study revealed a strong correlation between traffic volume and maintenance intensity. Moderately higher travel speeds were measured on the treated versus untreated sections. When the cost of treatment and maintenance was compared with historical costs, the dust control scenario was more expensive. However, when log hauling cost savings from increased travel speeds were introduced, the dust control was approximately cost neutral in low traffic scenarios and moderately better for high traffic. If non-quantifiable benefits, such as increased safety, were to be considered, application of dust control treatment is recommended.
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RYNIEWICZ, Wojciech, Łukasz BOJKO, Anna M. RYNIEWICZ, Małgorzata PIHUT, and Paweł PAŁKA. "TRI BOLOGICAL STUDIES OF LAYERED BIOMATERIALS FOR PROSTHETIC STRUCTURES BASED ON SUBSTRUCTURES MADE OF DIGITAL TECHNOLOGIES." Tribologia 287, no. 5 (October 31, 2019): 87–99. http://dx.doi.org/10.5604/01.3001.0013.6566.
Повний текст джерелаАнотація:
Modern dental prosthetics uses CAD/CAM in the Computer Aided Design (CAD) of substructures and its Computer Aided Manufacturing (CAM) process. The substructure is subject to appropriate veneering, which determines the functional cooperation. The aim of this study is to investigate the friction coefficient and wear resistance of the veneering layers of the substructures of prosthetic structures. The test materials are dedicated veneering layers on substructures made of factory-made CoCr, TiCP, and Ti6Al4V metal fittings as well as the glass-ceramic material LiSi2 and the ceramic ZrO2. The study was conducted on a Roxana Machine Works tribological machine in the ball-and-3discs system in an artificial saliva environment using a Hitachi S3400 scanning microscope. As a reference biomaterial, enamel-dentin discs were used. The tribological processes that take place under chewing conditions in the presence of saliva depend on the properties and technological parameters of the surface layer of the biomaterial wearing out and on the enamel of opposing teeth in contact, which also wears out. They should reproduce the physiological nature of adjustment wear in the stomatognathic system (SS). The determined values of the friction coefficient and wear resistance allowed differences to be indicated in the course of tribological processes, and microscopic analyses confirmed them.