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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: Date: May/June 2001|
Issue No: Vol. 65 No. 3
Date: May/June 2001
Below are brief descriptions of reports recently published by the Federal Highway Administration's (FHWA) Office of Research, Development, and Technology. All of the publications are available from the National Technical Information Service (NTIS). In some cases, limited copies of the publication are available from the Research and Technology (R&T) Report Center.
When ordering from NTIS, include the NTIS PB number (or publication number) and the publication title. You may also 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
Telephone: (703) 605-6000
Toll-free number: (800) 553-NTIS (6847)
Expanded Sales Desk Hours: 8 a.m. to 8 p.m. EST, Mon.-Fri.
Requests for items available from the R&T Report Center should be addressed to:
R&T Report Center, HRTS-03
Federal Highway Administration
9701 Philadelphia Court, Unit Q
Lanham, MD 20706
Telephone: (301) 577-0906
Fax: (301) 577-1421
For more information on research and technology publications coming from FHWA, visit the Turner-Fairbank Highway Research Center's (TFHRC) Web site at www.fhwa.dot.gov/research/tfhrc/, 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/.
Laboratory and Test-Site Testing of Moisture-Cured Urethanes on Steel in Salt-Rich Environment
Publication No. FHWA-RD-00-156
Three 3-coat moisture-cured (MC) urethane commercial products formulated for protecting new steel (SSPC-SP 10) and power tool-cleaned steel (SSPC-SP 3) surfaces against corrosion were evaluated; the total coating film thickness was about 75 microns. Zinc-rich MC-urethane primers were used for SSPC-SP 10 steel surfaces, whereas the primers for SSPC-SP 3 surfaces contained zero or a small amount of zinc; the same midcoats and topcoats were used for both steel surfaces. Sealers with film thickness of 25 microns were also studied for any potential effect on the coating performance of the coating systems for power tool-cleaned surfaces.
The FHWA-developed cyclic testing method was conducted to compare the performance of these coating systems. The test included freeze, ultra-violet light/condensation, and salt-fog/dry-air cycles. An aggressive outdoor marine exposure at Sea Isle City, NJ, was also performed for all the coating systems as a comparison. Several physical and chemical properties of the MC-urethanes were examined to study their effect on coating performance.
Improved Prediction Models for PCC Pavement Performance-Related Specifications, Volume I: Final Report and Volume II: PaveSpec 3.0 User's Guide
Publication Nos. FHWA-RD-00-130 and 131
The current performance-related specifications (PRS) methodology has been under development by FHWA for several years and has now reached a level at which it can be implemented by state highway agencies. PRS for highway pavements depend heavily on performance prediction models to determine the impact of varying levels of construction quality. This study focused on the improvement of the key distress and smoothness prediction models used in the PRS for jointed plain concrete pavement. Performance models for transverse joint faulting, transverse slab cracking, transverse joint spalling, and smoothness (International Roughness Index) were evaluated and then improved substantially. Performance model calibration guidelines were also developed so that a state can calibrate any of these models specifically to its pavement performance data.
The PaveSpec PRS demonstration software was upgraded to Version 3.0 under this study. Some of the specific improvements incorporated in PaveSpec 3.0 include: (1) improved distress indicator models, as well as the ability to calibrate or modify the default models; (2) sensitivity analysis capabilities; (3) expected pay charts; and (4) online help. Appendix A of this report contains a complete updated PaveSpec User's Guide.
The PaveSpec 3.0 software is available on CD-ROM from Peter Kopac, (202) 493-3151, email@example.com, and it can also be downloaded at www.fhwa.dot.gov/publications/research/infrastructure/pavements/pccp/pavespec/. Printed copies of both volumes of the report are available from NTIS. The NTIS numbers are PB2001-102161 (Volume I) and PB2001-102162 (Volume II).
Backcalculation of Layer Parameters for LTPP Test Sections, Volume I: Slab on Elastic Solid and Slab on Dense-Liquid Foundation Analysis of Rigid Pavements
Publication No. FHWA-RD-00-086
This report documents the results of backcalculation of layer material properties for rigid pavements included in the Long Term Pavement Performance (LTPP) program in the United States and Canada using deflection testing data. The study backcalculated the layer material properties for rigid pavements using the slab on elastic solid foundation and the slab on dense-liquid foundation procedures. The "best fit" algorithm was used after consideration of alternative methods of backcalculation. Pre-processing and post-processing utility software were developed to facilitate data handling. The backcalculation analysis was conducted for all General Pavement Studies, Special Pavement Studies, and Seasonal Monitoring Program test sections. Data tables that include backcalculation parameters were developed for inclusion in the LTPP Information Management System.
The report is available from NTIS. The NTIS number is PB2001-103071.
Prediction of the Expected Safety Performance of Rural Two-Lane Highways
Publication No. FHWA-RD-99-207
This report presents an algorithm for predicting the safety performance of a rural two-lane highway. The accident prediction algorithm consists of base models and accident modification factors for both roadway segments and at-grade intersections on rural two-lane highways. The base models provide an estimate of the safety performance of a roadway or intersection for a set of assumed nominal or base conditions. The accident modification factors adjust the base model predictions to account for the effects on safety for roadway segments of lane width, shoulder width, shoulder type, horizontal curves, grades, driveway density, two-way left-turn lanes, passing lanes, and roadside design, and the effects on safety for at-grade intersections of skew angle, traffic control, exclusive left- and right-turn lanes, sight distance, and driveways.
The accident prediction algorithm is intended for application by highway agencies to estimate the safety performance of an existing or proposed roadway. The algorithm can be used to compare the anticipated safety performance of two or more geometric alternatives for a proposed highway improvement.
The report is available from NTIS. The NTIS number is PB2001-102166. It is also available on FHWA's Web site: www.fhwa.dot.gov/research/tfhrc/projects/safety/comprehensive/ihsdm/index.cfm. Limited printed copies are also available from Mike Griffith, FHWA, at (202) 493-3316.
An Introduction to the Deep Mixing Methods as Used in Geotechnical Applications, Volume II: Appendices
Publication No. FHWA-RD-99-144
The Deep Mixing Method (DMM) is an in situ soil treatment technology whereby the soil is blended with cementitious and/or other materials. This report first traces the historical development of the various proprietary DMM methods and provides a structural summary of applications. It also compares the applicability of DMM with other competitive forms of ground treatment and improvement. The bulk of the report constitutes a description of the individual methods, focusing on the equipment, the procedures, and the properties of the treated soil. The report continues by describing the nature of the market in North America, Japan, and Scandinavia, while observations are also made on the various potential barriers to further growth in the United States. This report incorporates some factual data from an earlier FHWA draft report (1996), but follows a different structure and philosophy.
This volume is the second in a series. The other volumes in the series, which were published earlier, are:
Portable Instrumentation for Real-Time Measurement of Scour at Bridges
Publication No. FHWA-RD-99-085
Portable scour-measuring systems were developed to meet the requirements of three different applications: bridge inspections, limited-detail data collection, and detailed data collection. A portable scour-measuring system consists of four components: (1) the instrument(s) for making the measurement, (2) a system for deploying the instrument(s), (3) a method to identify and record the horizontal position of the data collected, and (4) a data storage device. Commercially available instruments were evaluated for use in measuring scour at bridges during floods. The systems developed consist primarily of commercially available instruments, which were modified and interfaced to achieve the required functionality.
The bridge-inspection system is intended for use by bridge inspectors to measure the streambed elevation around piers and abutments to ensure the stability of bridge foundations. The system developed and described here uses a low-cost echo sounder to measure the water depth and a tethered float to deploy the transducer around the bridge piers and abutments.
The report is available from NTIS. The NTIS number is PB2001-102040.