Nemzetközi szemle: November
Az aszfalt kötőanyagok fáradási jellemzőinek és az aszfalt keverékek fáradási teljesítményének összefüggései
Relationships Between the Fatigue Properties of Asphalt Binders and the Fatigue Performance of Asphalt Mixtures
Szerző(k): Donald W. Christensen and Nam Tran;
Transportation Research Board USA
Terjedelem: 221 oldal
Asphalt mixture fatigue response is a complex function of various parameters. As modulus increases, strain capacity decreases which decreases fatigue life. At the same time, increasing modulus will result in a decreasing phase angle which will increase the fatigue exponent, increasing fatigue life. Healing is probably a significant factor in asphalt mixture fatigue performance, with increasing phase angles correlating to better healing and improved fatigue life for non-polymer-modified binders; for polymer-modified binders, the relationship between rheology and healing is unclear. To further complicate matters, in real pavement systems softer binders and mixes will in general exhibit higher failure strains but will also tend to result in higher strains in situ, at least partly offsetting the beneficial effects of lower modulus values.
A helyszíni hideg újrahasznosítás és a keverőtelepi hideg újrahasznosítás gyakorlata és teljesítménye
Practice and Performance of Cold In-Place Recycling and Cold Central Plant Recycling
Szerző(k): M. Stroup-Gardiner
Transportation Research Board USA
Terjedelem: 145 oldal
Cold in-place recycling (CIR) is a process in which 3 to 4 in. (75 to 100 mm) of the existing asphalt pavement layers are pulverized, mixed with a recycling agent, and repaved in place. Cold central plant recycling (CCPR) is similar to CIR, but it can recycle thicker pavement layers and the recycling operation occurs at a nearby, usually mobile, plant location. CCPR can use reclaimed asphalt pavement (RAP) obtained from the roadway under construction, a mixture of RAP from various nearby projects, or previously stockpiled RAP. Neither CIR nor CCPR is used to modify the underlying base and subgrade materials, so roadways need to be structurally sound with good drainage. The objective of this synthesis is to document how projects suitable for CIR and CCPR processes are selected, considered in the pavement design phase, constructed, and evaluated. Three methods were used to accomplish this objective: (1) an online agency survey, (2) a literature review, and (3) interviews to collect agency experiences for case examples.
Hálózati szintű értékelési eszköz fejlesztése az ITS infrastruktúra menedzsmenthez
Development of a Network-Level Evaluation Tool for Managing ITS Infrastructure
Szerző(k): S. Van Hecke, M. Gallagher, K. Jeannotte, D. Krechmer, G. Leao
Cambridge Systematics, SRF, USA
Terjedelem: 70 oldal
The research team developed a methodology and implementation tool for the evaluation of Intelligent Transportation System (ITS) projects. The tool enables users to define packages of ITS improvements and provides a planning-level benefit/cost analysis output based on roadway data (such as delay and safety).
Repülőtéri beton burkolatok gyors táblajavítása és táblacseréje
Rapid Slab Repair and Replacement of Airfield Concrete Pavement
Szerző(k): J. Stempihar, J. Medina, T. Van Dam, L. Pierce, J. Bruinsma, K. Smith, D. Peshkin
Nichols Consulting Engineers, Chtd., Applied Pavement Technology, Inc., USA
Terjedelem: 134 oldal
Whether in a commercial service or general aviation airport, the closure of a critical pavement asset has a significant impact on operations, especially if that asset is the runway at a single-runway airport. ACRP Research Report 234: Rapid Slab Repair and Replacement of Airfield Concrete Pavement will assist airport personnel in planning, designing, and constructing appropriate rapid slab repair and replacement (RSRR) activities to cost-effectively minimize the impact of pavement-related closures. Airports can benefit from guidance on these activities, since their execution can differ from traditional pavement repair and replacement.
A nehéz járművek közúti reformját megalapozó adatok
Data to Support the Heavy Vehicle Road Reform
Szerző(k): U. Ai, G. O’Connor, T. Martin, B. Eastwood, E. Dann, W. Hore-Lacy, Y. Li
(letölthető ingyenes regisztrációval)
Terjedelem: 388 oldal
This is the final report for the three-year project AAM6068 Data to Support the Heavy Vehicle Road Reform, which has investigated a number of different aspects of the requirements, gaps, and opportunities for supplying infrastructure data suitable for supporting a future heavy vehicle cost recovery and investment process. It has continued the work of the previous project (AT1920) and represents a total of seven years of work from 2013 to 2020. The Parts of the report are as follows: Part A – Project Summary, Part B – Heavy Vehicle Infrastructure Rating, Part C – National Road Asset Register, Part D – Infrastructure Base Map and Data Alignment Guidance, Part E – Traffic Data Analysis, Part F – Alignment of Expenditure Reporting Data, Part G – Stocktake of Pavement Deterioration Modelling, Part H – Investigation of Maintenance Data Records.
Az utazási idő megbízhatóságának elemzési és előre becslési módszerei az USA államközi autópálya hálózatán
Methods to Analyze and Predict Interstate Travel Time Reliability
Szerző(k): X. Zhang, M. Zhao, J. Appiah, M.D. Fontaine
Virginia Transportation Research Council, USA
Terjedelem: 73 oldal
The Moving Ahead for Progress in the 21st Century Act (MAP-21) defined requirements for system reliability performance measures. Under MAP-21, state departments of transportation are responsible for reporting travel time reliability and for setting targets and showing progress toward those targets. In order to know how to improve travel time reliability and what to expect from investments in transportation infrastructure, these agencies need a better understanding of the factors that affect travel time reliability and methods to predict future travel time reliability. The purpose of this study was to quantify the factors influencing travel time reliability and investigate how to account for these factors in setting reliability targets and communicating progress.
Napenergia termelés zajvédő falakon és hóvédműveken
Harnessing Solar Energy Through Noise Barriers and Structural Snow Fencing
Szerző(k): M. Yang, Y. Yu, D, Cao
North Dakota University, USA
Terjedelem: 169 oldal
This research studied the possibility of harnessing solar energy through right-of-way associated structures, such as noise barriers and snow fences. A detailed survey was conducted of the general public, farmers, and utility companies to determine their acceptance of such an initiative. A large percentage of the general public, farmers, and utility companies welcomed the idea of harnessing power using right-of-way associated structures. Furthermore, a detailed structural design for the solar noise barrier and snow fence were created. The effects of the solar panels installed on noise barriers or snow fences in terms of noise reduction, glaring, impact and crash responses, and snow-drift responses were studied, and the potential influence on traffic safety was summarized. To make the generated energy usable, a convenient connection with the power grid through modularized controllers and inverters was developed and tested in a lab setting. It was verified through the lab testing that such a prototype can realize the proposed functionalities very well.
Útmutató a „Szuper 2” folyosók (előzési sávok) megvalósításához Texas államban
Guidelines for Implementing Super 2 Corridors in Texas
Szerző(k): Marcus A. Brewer
The Texas A&M University System, USA
Terjedelem: 42 oldal
Multiple research projects on Super 2 passing lanes for rural two-lane highways have produced guidance for practitioners on the design and implementation of those passing lanes. In addition, guidance documents such as the Texas Department of Transportation Roadway Design Manual and the Texas Manual on Uniform Traffic Control Devices provide recommendations for practitioners. This guidebook combines information on key topics from those documents into a single location, providing a primary source for practitioners seeking information on the implementation of Super 2 corridors in Texas. References to research and guidance documents are provided for the practitioner to obtain more detailed information.