Nemzetközi szemle: Október
Az aszfalt teljesítményének javítása grafén alapú bitumen nanokompozitokkal
Enhancement of Asphalt Performance by Graphene-Based Bitumen Nanocomposites
Szerző(k): S. Moghtadernejad, E. Barjasteh, R. Nagata, H. Malabeh
Mineta Transportation Institute USA
Terjedelem: 43 oldal
As the State of California continues to grow, demand for enhanced infrastructure such as roadways and highways escalates. In view of the current average highway lifespan of 15–20 years, the improvement of asphalt binders leads to material sustainability by decreasing required maintenance and increasing the lifespan of roadways. In the present investigation, enhancement of asphalt binder properties was achieved by different methods of mixing varying compositions of graphene nanoparticles with an SBS polymer and asphalt binder. Additionally, experimental evaluation and comparison of the rheological and mechanical properties of each specimen is presented. Graphene nanoparticles have attracted great curiosity in the field of highway materials due to their incredible rigidity, even in small quantities. Addition of as little as 1.0% nanoparticles in combination with polymers in an asphalt binder is expected to increase the rigidity of the material while also maintaining the beneficial polymer characteristics. Evaluation of the effect of the mixing design established that the methods for application of graphene to the polymer-modified asphalt binder are critical in the improvement of a roadway, resulting in resistance to premature aging and strain from constant road operation.
Közlekedési létesítmények alap tervezésének történeti és jövőbeni távlatai
History and Future Perspectives on Foundation Design for Transportation Structures
Szerző(k): Transportation Research Board USA
Terjedelem: 154 oldal
This engineering E-Circular is celebrating the Transportation Research Board (TRB) Centennial Anniversary in the year 2020, and its support and influence on the history and standard of practice for foundation design of transportation structures. Much like the many branches of civil engineering, within the topic of foundations of bridges and other structures there are many branches and areas of specialization. Bridge foundations vary from spread foundations to piles, and multiple varieties within pile types such as precast concrete or steel piles, cast-in-place piles, or varieties such as cast and steel shell. However, including foundation type there are hundreds if not thousands of variables to consider in foundation design, which require coordination between civil, structural, and geotechnical engineers as well as state departments of transportation (DOTs), environmental planners, and other stakeholders, and require knowledge of the many design codes and constantly emerging research and design guidance.
Útmutató fejlesztése a biztonság és a költség-hatékonyság integrálásához az újra burkolási, helyreállítási és rehabilitációs (3R) projektekbe
Developing Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects
Szerző(k): D.W. Harwood, D.J. Cook, R. Coakley, C. Polk
MRIGLOBAL, CH2M HILL, USA
Terjedelem: 166 oldal
This report presents the results of research to develop improved design guidelines for resurfacing, restoration, and rehabilitation (3R) projects. The guidelines were developed based on the results of a literature review, a highway agency survey, discussions with design and safety practitioners, and review of the results of benefit–cost analysis results for design improvement type typically included in 3R projects.
Útmutató a biztonság és a költség-hatékonyság integrálásához az újra burkolási, helyreállítási és rehabilitációs (3R) projektekbe
Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects
Szerző(k): D.W. Harwood, D.J. Cook, R. Coakley, C. Polk
MRIGLOBAL, CH2M HILL, USA
Terjedelem: 237 oldal
NCHRP Research Report 876 presents a rational approach for estimating the cost-effectiveness of including safety and operational improvements in a resurfacing, restoration, or rehabilitation (3R) project. The approach uses the performance of the existing road in estimating the benefits and cost-effectiveness of proposed design improvements. The guidelines are accompanied by two spreadsheet tools, one for analyzing a single design alternative and one for comparing several alternatives or combinations of alternatives.
Az európai közlekedés dekarbonizációja – az előttünk álló út
Decarbonising Transport in Europe – The Way Forward
Szerző(k): International Transport Forum, OECD
Terjedelem: 13 oldal
This paper summarises the findings of the project “Decarbonising Transport in Europe”. Initiated, funded and supported by the European Commission, the DTEU project developed a suite of advanced models of transport activity in Europe that provide detailed quantitative evidence on the actual impact of CO2 mitigation measures. These allows European decision makers to identify and assess realistic pathways towards decarbonising transport to 2050 and to help the European Union to achieve its CO2 reduction ambitions for the transport sector.
Útmutató tervezet a visszanyert műanyag hulladék felhasználására a helyi önkormányzati utak felület kezelési megoldásaiban
Interim Guidelines for the Use of Recycled Waste Plastic in Local Government Road Surfacing Applications
Szerző(k): A. Remtulla, S. Halligan
(letölthető ingyenes regisztrációval)
Terjedelem: 63 oldal
As a result of the ban on the export of recycled waste plastic, there is increasing interest in repurposing recycled waste plastic for use in road surfacing applications. There is no guide for this purpose and until such time as a guide is available there is a need for interim guidance about how recycled waste plastic could be used in road surfacing applications. This document provides interim guidance on the types of recycled waste plastic in Australia, what it has been used for in recent times, how it could be incorporated into asphalt or sealing work and flowcharts to assist in procuring products that use recycled waste plastic for road surfacing applications.
A dinamikus vízen csúszás előre becslése és kezelése az utakon
Guidance to Predict and Mitigate Dynamic Hydroplaning on Roadways
Szerző(k): G.W. Flintsch, J.B. Ferris, S. Taheri, S. Katicha, Y. Kang, A. Nazari, E. de Leon Izeppi, K. Velez, F. Battaglia, L.Chen, D. Kibler, K.K. McGhee
Virginia Tech, University of Buffalo, Virginia Department of Transportation, USA
Terjedelem: 135 oldal
This report presents the results of National Cooperative Highway Research (NCHRP) Project 15-55, aimed at enhancing the way we understand and assess hydroplaning on roadways. Hydroplaning is a serious problem that is associated with a relatively small but nonetheless significant number of crashes. Traditionally, hydroplaning potential has been approached as a road geometry design problem; however, as with many other safety-related issues, hydroplaning is a complex phenomenon.
The original experimental work in the 1960s and 1970s resulted in a definition of hydroplaning based on a hydroplaning speed, and hydroplaning research since then has focused on improving the models to predict this hydroplaning speed. This research represents one of the first attempts to significantly upgrade understanding and methods to predict hydroplaning potential since 1970s. Since the road is only one of the relevant factors, which also include the vehicle, the tires, the environment, and the driver, a full understanding requires a multidisciplinary approach.
Innovatív anyagok és fejlett technológiák a fenntartható burkolat infrastruktúráért
Innovative Materials and Advanced Technologies for a Sustainable Pavement Infrastructure
Szerző(k): J.L. Le, M. Marasteanu, L. Zanko, J.M. de Oliveira, T. Calhoon, M. Turos, T. Stricherz, D. Hopstock, V. Hegg
University of Minnesota USA
Terjedelem: 75 oldal
It is widely acknowledged that early detection of material damage and timely rehabilitation can lead to a significant reduction in the life-cycle cost of asphalt pavements. This research investigates the capabilities of damage detection and healing of graphite nanoplatelet (GNP)-taconite modified asphalt materials. The first part of the research is concerned with the application of GNP-taconite modified asphalt materials for damage detection using electrical conductivity. It is shown that, as compared to conventional asphalt materials, the GNP-taconite modified asphalt materials exhibit an improved electrical conductivity due to the electron hopping mechanism. Based on the mathematical analogy between the elastostatic field and the electrostatic field, a theoretical model is derived to relate the change of electrical conductivity to the damage extent of the material. Although, in principle, the material damage can be accessed using the electrical conductivity, the practical application of this method is complicated by the fact that the conductivity is influenced by the moisture content. The second part of the research investigates the damage healing capability of GNP-taconite modified asphalt materials heated by microwave. GNP-taconite modified asphalt materials can effectively absorb the heat generated by the microwave, and the rising temperature can effectively heal the microcracks in the binder. This damage-healing mechanism is verified by a set of semi-circular beam tests. Finally, microwave heating technology is applied to the tack coat system. It is shown that, with microwave heating, the GNP-taconite modified asphalt material can effectively improve the bond strength of the interface of the tack coat system.