U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
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-11-006 Date: September/October 2011|
Publication Number: FHWA-HRT-11-006
Issue No: Vol. 75 No. 2
Date: September/October 2011
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:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Toll-free number: 800–553–NTIS (6847)
Web site: www.ntis.gov
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, the National Transportation Library’s Web site at http://ntl.bts.gov, or the OneDOT information network at http://dotlibrary.dot.gov.
Publication No. FHWA-HRT-11-022
The use of modular bridge deck components has the potential to produce higher quality, more durable bridge decks. However, the materials used to connect the precast bridge deck components often prove lacking, resulting in less than desirable overall system performance. Advanced cementitious composite materials, such as ultra-high performance concrete (UHPC), present an opportunity to enhance the performance of field-cast connections significantly. This TechBrief highlights the results of an FHWA study to evaluate the performance of field-cast UHPC connections linking precast concrete bridge deck components.
Through its Structural Concrete Research Program, FHWA recently completed an experimental study focused on the performance of field-cast UHPC deck-level connections between precast modular bridge components. Researchers fabricated and tested bridge deck components simulating both longitudinal and transverse connections, and then subjected them to repeated traffic loadings.
During the loadings, the researchers assessed three critical behaviors. First, cyclic loading below the cracking load enabled researchers to assess the cracking performance of the field-cast UHPC and its bonding to the precast concrete. Second, cyclic loading that generated stresses above the static cracking stress on the specimen enabled researchers to evaluate whether any uncontrolled, progressive cracking or interface debonding occurred between the UHPC and precast concrete. Finally, the researchers assessed the static overload performance of the system.
The results of the study, in combination with experience gained through deployments of field-cast UHPC-filled connections, have demonstrated the viability of this connection system.
The document is available at www.fhwa.dot.gov/publications/research/infrastructure/structures/11022/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-11-038
The exceptional mechanical and durability properties of UHPC present potential solutions to highway infrastructure deterioration, repair, and replacement issues. This TechNote provides an introduction to UHPC and discusses practical considerations. The document includes information on UHPC applications; availability; mixing and casting; curing procedures; testing procedures; sample preparation and extraction; structural design, analysis, and modeling; and inspection information.
Since it became commercially available in 2000, UHPC has been used in three prestressed concrete girder simple span bridges in the United States. Many more departments of transportation are considering using UHPC for a wide variety of highway infrastructure applications. The concrete's high compressive and tensile strengths enable the redesign and optimization of structural elements, while its enhanced durability properties can extend design life. Enhanced durability also enables potential use as thin overlays, claddings, or shells.
Researchers have determined that UHPC can facilitate the development of innovative solutions to existing challenges, for example, advancing accelerated construction, lengthening span ranges, and rehabilitating substandard infrastructure. According to the TechNote, a decade of research and deployment efforts demonstrates that UHPC is a material both capable of and poised for future deployment in infrastructure-scale applications.
The document is available at www.fhwa.dot.gov/publications/research/infrastructure/structures/11038/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-11-025
Pavement-shoulder dropoffs can pose challenges to drivers attempting to return their vehicles safely to the road when recovering from a roadway departure. This report, Safety Evaluation of the Safety Edge Treatment, examines the effectiveness of a pavement edge sloped at a 30-degree angle to minimize the impacts on vehicles entering and exiting the shoulder. The document describes an FHWA evaluation of the Safety Edge treatment in three States, safety effectiveness analysis and results, treatment costs, benefit-cost analysis and results, and recommendations.
Using data from Georgia, Indiana, and New York, researchers completed a 3-year study of sites that were resurfaced and treated with the Safety Edge (treatment sites), sites that were resurfaced but not treated with the Safety Edge (comparison sites), and sites that were similar to the treatment and comparison sites but were not resurfaced (reference sites).
Researchers found that for all two-lane highway sites in Georgia and Indiana, the effectiveness of the Safety Edge treatment is a reduction in total crashes of approximately 5.7 percent. While this result is not statistically significant, the Safety Edge treatment is so inexpensive that its application under most conditions appears to be highly cost effective. The report concludes that the treatment is suitable for use by highway agencies under a broad range of conditions on two-lane highways.
The document is available at www.fhwa.dot.gov/publications/research/safety/hsis/11025/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-11-031
The Highway Safety Information System (HSIS), developed and maintained by FHWA, is a roadway-based system that houses quality data on a large number of crash, roadway, and traffic variables collected from State departments of transportation. HSIS aims to bolster the FHWA safety research program and provides input for policy decisions. This brochure, HSIS: The Essential Information System for Making Informed Decisions About Highway Safety, highlights key information about HSIS, including participating States, available data, a related laboratory, a Web site, and related tools including guidebooks, data element tables, and summary reports.
The HSIS database contains basic files on crashes, roadway inventories, and traffic volumes from California, Illinois, Maine, Michigan, Minnesota, North Carolina, Ohio, Utah, and Washington. Information also is available on supplemental data such as intersections, interchanges, horizontal curves, and vertical grades from some of the States. Safety analysts, researchers, and other highway safety professionals can request and receive data in various formats such as Microsoft® Excel® and Access®, dBaseTM, SAS®, American Standard Code for Information Interchange (ASCII), or convert the data to a format for sharing and for use in a statistical analysis system.
The HSIS Web site is accessible at www.hsisinfo.org. The brochure is available at www.fhwa.dot.gov/publications/research/safety/hsis/11031/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-11-027
Geosynthetic Reinforced Soil (GRS) technology consists of closely spaced layers of geosynthetic reinforcement and compacted granular fill material. The GRS Integrated Bridge System is a fast, cost-effective method of bridge support that blends the roadway into a superstructure to create a jointless interface between the bridge and the approach. This report is the second in a two-part series to provide engineers with basic knowledge of GRS technology and its fundamental characteristics as an alternative to other construction methods.
The application of the Integrated Bridge System has several advantages. According to the report, the system is easy to design and economical to construct. It can be built in variable weather conditions and can easily be modified in the field. FHWA found that this method has significant value when employed for small, single-span structures. Further, FHWA selected the technology for promotion under the Every Day Counts Initiative (www.fhwa.dot.gov/everydaycounts), which aims to accelerate implementation of proven, market-ready technologies.
The Geosynthetic Reinforced Soil Integrated Bridge System Synthesis Report is available at www.fhwa.dot.gov/publications/research/infrastructure/structures/11027/index.cfm. Printed copies are available from the PDC.
Publication No. FHWA-HRT-11-026
The Geosynthetic Reinforced Soil Integrated Bridge System Interim Implementation Guide outlines the state of the art and recommended practice for designing and constructing GRS technology for the application of the Integrated Bridge System. The procedures presented in the manual are based on 40 years of State and Federal research focused on GRS technology as applied to abutments and walls. FHWA developed the interim implementation guide to assist deployment of this technology as part of the Every Day Counts Initiative.
FHWA developed the implementation manual to provide engineers with background knowledge of GRS technology and its fundamental characteristics as an alternative to other construction methods. The manual presents step-by-step guidance on the design of GRS Integrated Bridge Systems and provides analytical and empirical design methodologies in both the Allowable Stress Design and Load and Resistance Factor Design formats. The guide also provides material specifications and detailed construction guidance along with methods for the inspection, performance monitoring, maintenance, and repair of GRS Integrated Bridge Systems. Quality assurance and quality control procedures also are covered.
The document is available at www.fhwa.dot.gov/publications/research/infrastructure/structures/11026. Printed copies are available from the PDC. Copies are also available from NTIS under order number PB2011107390.