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Search results for: asphalt pavement structures, fatigue performance, s-vecd, hima, sma 16
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Accurate rolling resistance Rolling resistance measurements can be influenced by a number of factors
PublicationTire rolling resistance is one of the most difficult-to-measure parameters of the tire/ pavement interface, especially if road measurements are required. First of all, it is necessary to measure a fairly small force in the system that is heavily loaded by other forces and subjected to many adverse effects causing measurement errors. The second problem is related to the fact that tire rolling resistance depends on many factors,...
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FEM modelling of stress and strain distribution in weld joints of steel sandwich panels
PublicationThe development of laser welding technology has enabled the mass production of thin-walled structures, including steel sandwich panels. The technology of joining plating panels with stiffeners by welding allows us to create joints with a specific geometry and material properties. In comparison with other types of joints, laser welds are characterized by their specific behaviour under cyclic load and, as a consequence, a different...
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The Influence of Selected Parameters of Numerical Modelling on Strains and Stresses at Weld Toe Notch
PublicationLatest development in the field of welding technology and prefabrication enabled massive production of thin-walled sandwich structures. Multi-layered sandwich structures are fabricated with the use of high-power CO2 lasers, friction welding, arc welding, hybrid welding, or other technique designed for the special purpose. Steel or aluminium alloy plates with thickness between 1 and 5 mm are connected by internal stiffeners. Strength...
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Methods of deep modification of low-bearing soil for the foundation of new and spare air runways
PublicationAfter analyzing the impact of aircraft on the airport pavement (parking spaces, runways, startways), it was considered advisable to consider the problem of deep improvement or strengthening of its subsoil. This is especially true for low-bearing soil. The paper presents a quick and effective method of strengthening the subsoil intended for the construction of engineering structures used for civil...
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Quasistatic and fatigue behavior of an AISI H13 steel obtained by additive manufacturing and conventional method
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Energy-based fatigue failure characteristics of materials under random bending loading in elastic-plastic range
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Experimental investigations and damage growth modeling of EN‐AW 2024 aluminum alloy under LCF loading accounting creep pre‐deformation
PublicationThis article presents the results of experimental tests of creep rupture and of low-cycle fatigue (LCF) of EN-AW 2024 aluminum alloy devoid of damage and having preliminary damage. The preliminary damage was dealt in the process of creep at elevated temperature 100C, 200C, and 300C until achievement of two different strain values at each temperature. Samples with preliminary damage were subjected to fatigue tests at room temperature....
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Quasistatic and fatigue behavior of an AISI H13 steel obtained by additive manufacturing and conventional method
PublicationThis work aims to compare the mechanical behavior of an AISI H13 steel obtained by additive manufacturing with that obtained by conventional manufacturing methods. The average values of the ultimate tensile strength (UTS) and ductility obtained for the specimens produced by the conventional method were equal to 658 MPa and 18%, respectively, which compares with 503 MPa and 0.75% registered for the selective laser melting (SLM)...
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Ocena odporności na pękanie podbudów drogowych z mieszanek mineralno-cementowo-emulsyjnych (MCE)
PublicationPodbudowy z mieszanek mineralno-cementowo-emulsyjnych (MCE) są jednym z wielu materiałów stosowanych do wykonywania warstw nawierzchni w ramach przebudów dróg w Polsce. Mieszanki MCE pozwalają na maksymalne powtórne wykorzystanie istniejących warstw konstrukcyjnych do budowy lub przebudowy nawierzchni. Do wykonania podbudów z MCE stosuje się materiał pochodzący z rozbiórki istniejących warstw (destrukt) bitumicznych, warstw związanych...
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Lightweight structures in architecture: scenarios for the future
PublicationLightweight structures - structures with a reduced weight, which otherwise retain the qualities necessary for the building performance, ensuring a proper durability and strength, safety, indoor environmental quality and energy efficiency; stuctures which strive for the optimization of structural systems - are in tune with current trends and socio-economic, environmental and technological factors. The growing interest in the lightweight...
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Eco-friendly modification of bitumen: The effects of rubber wastes and castor oil on the microstructure, processability and properties
PublicationThe bitumen industry in the European Union is facing several difficulties, including rising demand, unstable oil supply, rising prices for synthetic polymer modifiers, and a focus on lowering carbon footprint. Bitumen modification with crumb rubber (CR) is one of the most promising solution to these challenges. However, CR-modified bitumen have poor processability and low storage stability. To overcome these flaws we are introducing...
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Optimal retrofit strategy using viscous dampers between adjacent RC and SMRFs prone to earthquake‑induced pounding
PublicationNowadays, retrofitting-damaged buildings is an important challenge for engineers. Finding the optimal placement of Viscous Dampers (VDs) between adjacent structures prone to earthquake-induced pounding can help designers to implement VDs with optimizing the cost of construction and achieving higher performance levels for both structures. In this research, the optimal placement of linear and nonlinear VDs between the 3-story, 5-story,...
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The Influence of Binding Agents on Stiffness of Mineral-cement-emulsion Mixtures
PublicationThis paper attempts to determine the behavior of mineral-cement-emulsion mixture (MCE) under load, whether is it similar to asphalt mixtures (viscoelastic behavior) or to cement treated materials (elastic behavior). To answer this question nine mineral- cement-emulsion mixtures with different combinations of cement and emulsion content were tested in laboratory using Simple Performance Test (SPT). For each mixture stiffness moduli...
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Recycled Polyethylene terephthalate (PET) as Construction Material in Civil Engineering: A Review
PublicationIn general, the quantity of plastics of all types consumed annually all over the world has been growing in a phenomenal way. The manufacturing processes, service industries and municipal solid wastes (MSW) generate numerous waste plastic materials. The increasing awareness about the environment has tremendously contributed to the concerns related with disposal of the generated wastes. It is believed that the management of solid...
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COMPARISON OF INVESTMENT PERFORMANCE MEASURES USING THE EXAMPLE OF SELECTED STOCK EXCHANGES
PublicationIn the following paper, the main objective is to examine whether the selection of the performance measure influences the evaluation of individual investments and the performance rankings generated on that basis. This study presents the values of 16 performance indicators along with their detailed descriptions. All calculations were made using the R program, and the source code can be found at the end of the article. Nine selected...
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Phototransformation of Amlodipine: Degradation Kinetics and Identification of Its Photoproducts
PublicationNowadays, monitoring focuses on the primary compounds and does not include degradation products formed during various biological and chemical processes. Transformation products may have the same effects to human health and the environment or sometimes they can be more toxic than the parent compound. Unfortunately, knowledge about the formation of degradation products is still limited, however, can be very important for the environmental...
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Road texture influence on tyre rolling resistance
PublicationTyre performance, one of the critical factors for vehicle users, is strongly related to theroad surface characteristics, most notably to the pavement texture. Phenomena that occur at the tyre/road interface affect tyre friction (skid resistance), rolling resistance, tyre wear and tyre/road noise. This article deals with relationship between surface texture and rolling resistance of light and heavy vehicle tyres. Mean profile depth...
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The Application of Granulated Expanded Glass Aggregate with Cement Grout as an Alternative Solution for Sub-Grade and Frost-Protection Sub-Base Layer in Road Construction
PublicationThe purpose of the research was to assess the possibility of using granulated expanded glass aggregate (GEGA) with cement grout as a replacement of a sub-grade and frost-protection layer, made of natural fine aggregates (NATU), stabilized with a hydraulic binder. Instead of traditional parts of the road construction, such as the sub-grade and frost-protection layer with the application of fine aggregate, stabilized with cement,...
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Azo and azoxythiacrown ethers: synthesis and properties
PublicationA series of 16- and 18-membered azo- and azoxythiacrown ethers have been synthesized by reductive macrocyclization of the respective bis(nitrophenoxy)oxaalkanes. The aromatic residues located in the polyether region of the molecule were introduced to macrocyclic skeletons and their affinities toward different groups of metal cations in ion-selective electrodes were described. X-ray structures for one dinitropodand and one azoxybenzothiacrown...
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Decreasing CO2 Emissions By Reducing Tire Rolling Resistance
PublicationThe first motor vehicle was built by Nicolas Cugnot almost 250 years ago and since then there has been a continuous process of motor vehicles’ improvements, as well as development of new road pavements. The fuel crisis of the 70s of the 20th century made it clear to vehicle builders that measures should be taken to reduce vehicle fuel consumption and it contributed to an increased interest in electric vehicles. Although significant...
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One year performance evaluation of low volume road with cold recycled base course on the basis of FWD and Dynamic Modulus tests
PublicationArticle presents results of assessment of performance of trial section of flexible pavement with cold recycled base constructed on low volume road within typical contract conditions. Performance evaluation was made based on Falling Weight Deflectometer (FWD) test performed during construction stage – 2 times on the top of cold recycled base course – 28 and 180 days after compaction of base course and 2 times on the top of the wearing...
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Application of unmanned USV surface and AUV underwater maritime platforms for the monitoring of offshore structures at sea
PublicationThe operation of offshore structures at sea requires the implementation of advanced systems for their permanent monitoring. There is a set of novel technologies that could be implemented to deliver a higher level of effective and safe operation of these systems. A possible novel solution may be the application of a new maritime unmanned (USV) surface and underwater vehicles/platforms (AUV). Application of such vehicles/platforms...
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Application of Multivariate Analysis Methods in Welding Engineering
PublicationPhenomena and processes taking place during welding are usually very complex and, for this reason, should be described using multivariate methods. The article discusses the methodological basis and selected application areas as regards the solving of welding problems using statistical multivariate methods. In addition, the article presents exemplary applications of the design of experiment, multiple regression analysis, cluster...
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Introduction to the ONDM 2022 special issue
PublicationThis JOCN special issue contains extended versions of selected papers presented at the 26th International Conference on Optical Network Design and Modeling (ONDM 2022), which took place 16–19 May 2022 at Warsaw University of Technology, Warsaw, Poland. The topics covered by the papers represent trends in optical networking research: application of machine learning to network management, cross-layer network performance optimization,...
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Design of Jack-up Platform for 6 MW Wind Turbine: Parametric Analysis Based Dimensioning of Platform Legs
PublicationThe article presents the results of the research conducted within the framework of the project entitled WIND-TU-PLA (ERA-NET, MARTEC II), the general aim of which was to design and analyse supporting structures for wind turbines intended for operation on the South Baltic area. The research part described in the article aimed at developing a preliminary design for a jack-up platform which can operate on water areas with depth of...
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Enhancing seismic performance of buckling-restrained brace frames equipped with innovative bracing systems
PublicationNowadays, to improve the performance of conventional bracing systems, in which, buckling in the pressure loads is the main disadvantage, the buckling-restrained brace (BRB) is introduced as a solution. In this study, the performance of the BRB system was improved with innovative lateral-resisting systems of double-stage yield buckling-restrained brace (DYB), and a combination of DYB improved with shape memory alloy (SMA) materials...
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Preliminary study of linear viscoelasticity limits of cold recycled mixtures determined in Simple Performance Tester (SPT)
PublicationThe publication presents methodology developed for determination of linear viscoelasticity limits for cold recycled mixtures with cement and bituminous emulsion using Simple Performance Tester (SPT). Methodology was verified on reference materials (PCV and steel dummy specimens, cement concrete and asphalt concrete) to comply with elasticity and viscoelasticity theory. The developed methodology enabled determination of linear viscoelasticity...
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Sub-national structures matter when evaluating physical activity promotion: Lessons from Germany
PublicationBackground Public policies are increasingly acknowledged as important part of promoting physical activity (PA). However, especially in states with sub-national administrative structures such as Germany, national and sub-national approaches differ considerably. In Germany, sport for all (SfA) promotion is mostly organized at sub-national level, which is usually not covered in national evaluations. Knowledge of these structures helps...
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Performance of organic coatings upon cyclic mechanical load
PublicationA number of engineering structures fail due to the fatigue damage resulting from cyclic mechanical stress. However, as far as organic coatings are concerned this degradation factor remains underestimated. In the paper the authors propose a methodology combining global electrochemical impedance spectroscopy and local atomic force microscopy measurements for evaluation of coating resistance to an impact of repetitive mechanical stress. Typical...
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Dynamic mechanical properties and flexing fatigue resistance of tire sidewall rubber as function of waste tire rubber reclaiming degree
PublicationA stepwise downsizing method of gel particles in reclaimed rubber to a micro-nano scale and its excellent dynamic performance in tire sidewall were introduced by this work. The results showed that the size of gel particles decreased from several micrometers to micro-nanometers with the increase of reclaiming degree, accompanied by reduced molecular weight and widened molecular weight distribution of sol fraction. The addition of...
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The long-term properties of mineral-cement-emulsion mixtures
PublicationThis publication presents evaluation of long-term behavior of mineral-cement-emulsion (MCE) mixtures. MCE mixtures are among the major products of cold recycling of old asphalt pavements. They are composed by binding of the old materials reclaimed from the pavement and new mineral aggregate using two different binding agents – cement and bituminous emulsion. While bituminous emulsion dissolutes and binds materials quite fast, it...
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Tyre/road noise reduction by a poroelastic road surface
PublicationLow noise road surfaces of existing types may in favourable cases and in new conditions provide up to 7 dB of noise reduction. For higher noise reductions, innovative solutions must be sought. Poroelastic road surfaces (PERS) may be such a solution, which currently is studied in the EU project PERSUADE. This paper presents results of trials with a PERS version prefabricated by one of the project partners. Tests were made in a laboratory...
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Patch size setup and performance/cost trade-offs in multi-objective EM-driven antenna optimization using sequential domain patching
PublicationPurpose This paper aims to assess control parameter setup and its effect on computational cost and performance of deterministic procedures for multi-objective design optimization of expensive simulation models of antenna structures. Design/methodology/approach A deterministic algorithm for cost-efficient multi-objective optimization of antenna structures has been assessed. The algorithm constructs a patch connecting extreme Pareto-optimal...
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Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
PublicationThe performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to...
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Investigating the effects of structural pounding on the seismic performance of adjacent RC and steel MRFs
PublicationAn insufficient separation distance between adjacent buildings is the main reason for structural pounding during severe earthquakes. The lateral load resistance system, fundamental natural period, mass, and stiffness are important factors having the influence on collisions between two adjacent structures. In this study, 3-, 5- and 9-story adjacent reinforced concrete and steel Moment Resisting Frames (MRFs) were considered to investigate...
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Modern GFRP Composite Footbridges
PublicationApplication of GFRP composites in civil engineering is still not large but already noticeable. Advantages of this material, such as: low volume weight, relatively high stiffness and strength, well fatigue resistance, easiness in shaping, high material damping and high environmental resistance, make it attractive for bridge and in particular foot-bridge designers. It is estimated that nowadays in the world there are realized hundreds...
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Evaluation the P-Delta Effect on Collapse Capacity of Adjacent Structures Subjected to Far-field Ground Motions
PublicationIn urban areas, adjacent structures can be seen in any insufficient distance from each other, because of economic reasons and refusal of acquired minimum separation distance according to seismic previsions. Collapse capacity assessment of structures is one of the important objectives of performance-based seismic engineering. The purpose of this study is to consider the pounding phenomenon and P-Delta effect in seismic collapse...
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Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
PublicationThe performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to...
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Research on GNSS satellite navigation systems
PublicationThis article contains results of research on two GNSS systems, i.e. GPS and GLONASS. Architectures, signal structures and navigation messages of both systems have been described. Some selected investigation results, concerning receiver performance in presence of interference, have been presented.
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EM‐driven constrained miniaturization of antennas using adaptive in‐band reflection acceptance threshold
PublicationNumerical optimization of geometry parameters is a critical stage of the design process of compact antennas. It is also challenging because size reduction is constrained by the necessity of fulfilling imposed electrical performance requirements. Furthermore, full‐wave electromagnetic (EM) analysis needs to be used for reliable performance evaluation of the antenna structure, which is computationally expensive. In this paper, an...
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Influence analysis of selected parameters on the ASON/GMPLS control plane performance
PublicationThe paper regards the problem of ASON/GMPLS performance. The authors present influence analysis of selected parameters on the ASON/GMPLS control plane performance represented in mean Connection Set-up Time E(CST) and mean Connection Release Time E(CRT). The selected parameters are: offered traffic, request intensity and proportion of requests class. The influence analysis is performed with simulation method by using OMNeT++ discrete-event...
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Predicting the seismic collapse capacity of adjacent SMRFs retrofitted with fluid viscous dampers in pounding condition
PublicationSevere damages of adjacent structures due to structural pounding during earthquakes have emphasized the need to use some seismic retrofit strategy to enhance the structural performance. The purpose of this paper is to study the influence of using linear and nonlinear Fluid Viscous Dampers (FVDs) on the seismic collapse capacities of adjacent structures prone to pounding and proposing modification factors to modify the median...
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Application of Extreme Doses of Aluminium for Growth Control of Filmentous Bacteria Microthrix Parvicella in an Activated Sludge System - Laboratory Investigations
PublicationLaboratory investigations of aluminium (PAX-16) application for control of population of filamentous bacteria Microthrix Parvicella in a three-phase bioreactor in lab-scale were performed. Dosing of small aluminium doses (approximately 0.5 mgAl/gMLSS·d) in the period preceding seasonal growth of M.Parvicella failed to prevent mass growth of this microorganism leading to activated sludge bulking phenomenon (SVI-250 ml/gMLSS)...
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Simulator for Performance Evaluation of ASON/GMPLS Network
PublicationThe hierarchical control plane network architecture of Automatically Switched Optical Network with utilization of Generalized Multi-Protocol Label Switching protocols is compliant to next generation networks requirements and can supply connections with required quality of service, even with incomplete domain information. Considering connection control, connection management and network management, the controllers of this architecture...
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Low-cost multi-objective design of compact microwave structures using domain patching
PublicationA good compromise between size and electrical performance is an important design consideration for compact microwave structures. Comprehensive information about size/performance trade-offs can be obtained through multi-objective optimization. Due to considerable electromagnetic (EM) cross-couplings in highly compressed layouts, the design process has to be conducted at the level of high-fidelity EM analysis which is computationally...
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Evaluation of organic coating systems for corrosion protection of industrial equipment using impedance spectroscopy
PublicationThe high economic impact of corrosion can be reduced by enhanced corrosion management and prevention based on appropriate means. This applies in particular to the protection of structures with organic protective coatings. Steel is subject to corrosion that reduces its service life and leads to destruction in most severe cases. The application of paints to metallic objects for corrosion control has been known for a long time and...
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Influence of the notch rounding radius on estimating the elastic notch stress concentration factor in a laser welded tee joint
PublicationIn recent years an increased interest of industry in sandwich-type metal structures can be observed. These structures consist of thin plates of 2.5 mm in thickness separated by stiffeners of different shapes and forms. Welds joining the plates and stiffeners are made on the outer side of the plates using laser welding technique. A locally focused source of heat causes the plate to melt creating a very narrow and elongated joint....
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Rapid Simulation-Driven Multiobjective Design Optimization of Decomposable Compact Microwave Passives
PublicationIn this paper, a methodology for fast multiobjective optimization of the miniaturized microwave passives has been presented. Our approach is applicable to circuits that can be decomposed into individual cells [e.g., compact microstrip resonant cells (CMRCs)]. The structures are individually modeled using their corresponding equivalent circuits and aligned with their accurate, EM simulated...
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Tire/Road Noise On Poroelastic Road Surfaces - Results Of Laboratory Measurements
PublicationTire/road noise is the most important part of traffic noise for medium and high speed driving both in the case of passenger cars and trucks. The potential to make modification of tires that significantly reduce tire/road noise in nearly over, at least for conventional tires so the only promising action is to improve road pavements. One of the innovative solutions is poroelastic road pavement (PERS) that reduces airflow related...
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The application of the Superpave method of climatic zones analysis in Poland with regard to bitumen performance grading
PublicationCurrently in Poland, similarly as in the other EU countries, road bitumens are tested and classified with regard to mainly the penetration value determined at the tempera-ture of 25C. It should be noted that this classification is not correlated with the cli-matic conditions in which the bitumens are to serve in the road pavement. Towards the end of the last century a new system of bitumen grading was developed and im-plemented...