May/June
2001
RECENT
PUBLICATIONS
Compiled
by Zac Ellis of FHWA's Office of Research and Technology Services
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.tfhrc.gov, 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,
peter.kopac@fhwa.dot.gov, and it can also be downloaded at www.tfhrc.gov/pavement/pccp/pavespec/pavespec.htm.
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.tfhrc.gov/safety/ihsdm/ihsdm.htm.
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:
- FHWA-RD-99-138,
Volume I: An Introduction to the Deep Mixing Methods as Used in
Geotechnical Applications
- FHWA-RD-99-167,
Volume III: The Verification and Properties of Treated Ground
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.