U.S. Department of Transportation
Federal Highway Administration
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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
This magazine is an archived publication and may contain dated technical, contact, and link information.
|Publication Number: FHWA-HRT-13-005 Vol. 77 No. 1 Date: July/August 2013|
Publication Number: FHWA-HRT-13-005 Vol. 77 No. 1
Date: July/August 2013
Below are brief descriptions of communications products recently developed by the Federal Highway Administration’s (FHWA) Office of Research, Development, and Technology. All of the reports are or will soon be available from the National Technical Information Service (NTIS). In some cases, limited copies of the communications products are available from FHWA’s Research and Technology (R&T) Product Distribution Center (PDC).
When ordering from NTIS, include the NTIS publication number (PB number) and the publication title. You also may visit the NTIS Web site at www.ntis.gov to order publications online. Call NTIS for current prices. For customers outside the United States, Canada, and Mexico, the cost is usually double the listed price. Address requests to:
Requests for items available from the R&T Product Distribution Center should be addressed to:
R&T Product Distribution Center
Szanca Solutions/FHWA PDC
13710 Dunnings Highway
Claysburg, PA 16625
For more information on R&T communications products available from FHWA, visit FHWA's Web site at www.fhwa.dot.gov/research/library (or email email@example.com), or the National Transportation Library at ntl.bts.gov (or email firstname.lastname@example.org).
Publication Number: FHWA-HRT-11-040
This report documents the results of crash data analyses to assess the potential safety benefits of vehicle-to-infrastructure (V2I) communication applications. It provides estimates of the frequency, characteristics, and costs of crashes that would be targeted by proposed V2I applications. Further, the document evaluates precrash scenarios not addressed by those applications.
Researchers investigated V2I applications concerning intersection safety, speed management, vulnerable road users, and other safety areas. They conducted a primary analysis using the National Automotive Sampling System’s General Estimates System database, which weights a sample of crashes to estimate the total number of crashes nationwide. The researchers also used other databases, including the Highway Safety Information System and the Fatality Analysis Reporting System. They associated precrash scenarios with V2I application areas and then totaled crash frequencies and associated costs within each application area to determine potential safety benefits.
The analyses aimed to estimate the magnitude of the crash problem (the number of crashes, fatalities, and injuries; the amount of property damage; and the cost of the crashes) that could be avoided with the help of currently identified V2I communications for safety applications. The researchers also sought to characterize roadway locations by crash types, precrash scenarios, and contributing factors. In addition, they identified other significant crash types, precrash scenarios, and contributing factors, including currently identified and unidentified application areas that might be suitable for solutions involving V2I connectivity. Finally, they assessed the relative potential safety benefits of currently identified and alternative V2I communications for safety application areas.
The report is available to download at www.fhwa.dot.gov/publications/research/connectedvehicles/11040/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-12-066
FHWA’s Office of Safety Research and Development (R&D) helps reduce highway crashes and related fatalities and injuries by developing and implementing safety innovations through a program of nationally coordinated research and technology development. Within the Office of Safety R&D, the Safety Management, Human Factors, and Roadway teams conduct this research. This fact sheet features highlights from this broad research portfolio.
The Safety Management team supports decisions about resource allocation through consistent, high-quality data collection and analysis, development of analytical tools to transform data into actionable information, and formal evaluations of the effectiveness of potential safety improvements.
Studying human factors helps researchers better understand transportation user needs and limitations. By taking into account driver capabilities when designing roadways, researchers can help minimize human errors and enhance public safety, ultimately decreasing crashes and fatalities. Human factors research supports many of the projects and programs undertaken within other R&D focus areas.
The Roadway Safety Research Program emphasizes two fundamental objectives: keeping vehicles on the road and minimizing the consequences of a vehicle leaving the roadway. Researchers are conducting safety studies in five focus areas: roadway departure, speed management, intersection safety and design, visibility, and intelligent transportation systems.
This document describes research specific to the Highway Safety Information System; the Interactive Highway Safety Design Model; the Evaluation of Low-Cost Safety Improvements Pooled Fund Study and Develop-ment of Crash Modification Factors; motorcycle crash causation; geographic information system tools for safety analyses; driving simulation and human factors field investigations; signs and markings; pedestrian safety; roadway safety; and vehicle-to-infrastructure technology development.
The fact sheet is available to download at www.fhwa.dot.gov/publications/research/safety/12066/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-13-024
Many highway agencies have adopted standard tests in their specifications for qualification and acceptance of concrete mixtures. The following tests serve as a means of indirectly assessing the permeability of concrete mixes: the American Association of State Highway and Trans-portation Officials’ (AASHTO) Standard Method of Test for Rapid Determination of the Chloride Permeability of Concrete, AASHTO T277, and the American Society for Testing and Materials’ (ASTM) Standard Test Method for Electrical Indication of Concrete’s Ability to Resist Chloride Ion Penetration, ASTM C1202. These tests are commonly known as the rapid chloride permeability test (RCPT).
Studies have shown that the surface resistivity test is a promising alternative to the RCPT. Some agencies are interested in replacing the RCPT with the surface resistivity test and have started implementing it. However, none of the studies have included high-volume fly ash mixtures or mixtures containing fly ash and fine limestone powder. This TechBrief discusses a study focused on investigating the correlation of the surface resistivity test with the widely used RCPT in evaluating the ability of concrete to resist chloride penetration, including high-volume fly ash mixtures.
Researchers used 25 plain, binary, and ternary (a mixture containing three parts) concrete mixtures containing up to 55 percent of Class F or Class C fly ashes -- and, in some cases, fine limestone powder with different aggregate types and maximum sizes -- to evaluate the correlation between the RCPT and the surface resistivity test. They found that the surface resistivity test results are highly correlated with the RCPT, even for high-volume fly ash mixtures and ternary mixtures with finely ground limestone. The researchers then proposed a correlation curve. The surface resistivity test was easier and faster to run compared to the RCPT and did not require any specimen preparation. It also presented lower variability than the RCPT.
This TechBrief is available to download at www.fhwa.dot.gov/publications/research/infrastructure/pavements/13024/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-13-042
Concepts for construction of prefabricated bridge elements and systems frequently rely on field-cast grouts to complete the connections between discrete precast concrete elements. A variety of grouts is available, each with unique performance attributes. This TechBrief discusses a study on the performance of a representative sample of grouts in terms of relevant material properties.
The study reports on the performance of eight specific grouts representing five different types of grout. Although many of these grouts could be used in a post-tensioned connection system, the tests investigated their performance in a non-post-tensioned condition. Researchers examined properties including compressive strength, shrinkage, splitting tensile bond strength, and freeze/thaw resistance. The tests focused on characterizing basic mechanical, dimensional stability, and bond properties for field-cast grouts that could be used in connecting precast concrete bridge components. The results demonstrate that material characteristics, practical construction considerations, and costs can vary widely.
For accelerated construction projects requiring high compressive strengths within 1 day, an epoxy grout and an ultra-high-performance concrete displayed acceptable properties. The ultra-high-performance concrete also displayed appropriate strength gain, was comparatively dimensionally stable, and had good workability, high tensile strength, and high modulus of elasticity. An alternative for this type of project and for other projects requiring exceptionally rapid strength gain is a magnesium phosphate grout.
The control concrete performed as well as the three conventional grouts in most cases. The conventional grouts shrank more, had only modestly higher compressive and bond strengths, cracked earlier, and cost substantially more.
This document is a technical summary of the unpublished FHWA report, Material Characterization of Field-Cast Connection Grouts. The TechBrief is available to download at www.fhwa.dot.gov/publications/research/infrastructure/structures/bridge/13042/index.cfm. Printed copies are available from the PDC.