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:

Requests for items available from the R&T Report Center should be addressed to:

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/.

This report presents the following three recent projects on load testing of geosynthetic-reinforced soil (GRS) bridge abutments and piers:

(1) A full-scale bridge-pier load test conducted by FHWA's Turner-Fairbank Highway Research Center in 1996 (referred to as the Turner-Fairbank pier).

(2) A full-scale, long-term load test of a bridge abutment and a bridge pier conducted by the Colorado DOT and the University of Colorado at Denver from 1996-1997 (referred to as the Havana Yard piers and abutment).

(3) A production bridge abutment load test conducted by Yenter Companies in Black Hawk, Colorado, in 1997 (referred to as the Black Hawk abutment).

All of the bridge supporting structures were instrumented to measure their performance during the load test. The effect of pre-loading was also investigated in the Turner-Fairbank pier and the Black Hawk abutment. The report describes each of the projects in detail, presents the measured test results and discussion of the results, and offers recommendations on the applications of the GRS bridge abutments and piers.

The NTIS publication number is PB2001-103487.

Methods for determining the workability of freshly mixed portland cement concrete with slumps less than 51 mm (2 in) were investigated. Four potential methods to determine the workability of concrete were proposed for evaluation and development. The methods included two moving-object methods, one free-orifice method, and a vibrating-slope method. The report outlines modifications to these existing techniques and equipment to permit the measurement of rheological properties at two or more shear rates. The vibrating-slope apparatus (VSA) was selected for further development.

The NTIS publication number is PB2001-105681.

The Strategic Highway Research Program (SHRP) H-106 maintenance experiment and the FHWA Long-Term Monitoring (LTM) of Pavement Maintenance Materials Test Sites project studied the repair of potholes in asphalt-surfaced pavements. Many different repair materials and methods were investigated between 1991 and 1996 through test sites installed at eight locations in the United States and Canada. The findings of these combined studies have been merged with standard highway agency procedures to provide the most useful and up-to-date information on the practice of repairing potholes.

This manual of practice is an updated version of the 1993 SHRP Pothole Repair Manual. It contains the latest information pertaining to the types and performance characteristics of repair materials and methods, as well as the proper ways of planning, designing, constructing, and monitoring the performance of pothole repair projects. It also details how the cost-effectiveness of pothole patch types can be determined and provides an updated partial listing of materials and equipment manufacturers.

The manual is intended for field and office personnel within highway maintenance agencies and contracted maintenance firms. It contains valuable information for supervisors and foremen in charge of individual patching operations, engineers in charge of planning and overseeing many patching projects, and managers in charge of establishing pothole repair policies and standards.

The NTIS publication number is PB2000-103415.

The same SHRP H-106 maintenance experiment and FHWA LTM project also studied the repair of partial-depth spalls in concrete pavements. Many different repair materials and methods were investigated between 1991 and 1998 through test sites installed at four locations in the United States. This manual of practice is an updated version of the 1993 SHRP Spall Repair Manual. It contains the latest information pertaining to the performance of repair materials and methods; the availability and relative costs of repair materials; and the proper ways of planning, designing, constructing, and monitoring the performance of partial-depth spall repair projects. It also provides an updated partial listing of materials and equipment manufacturers.

The manual is intended for field and office personnel within highway maintenance agencies and contracted maintenance firms. It contains valuable information for supervisors and foremen in charge of individual spall repair operations, engineers in charge of planning and overseeing many spall repair projects, and managers in charge of establishing repair policies and standards.

The NTIS publication number is PB2000-103414.

The SHRP H-106 maintenance experiment and FHWA LTM project also studied the treatment (sealing and filling) of cracks in asphalt-surfaced pavement. Many different treatment materials and methods were investigated between 1991 and 1998 through test sites installed at five locations in the United States and Canada. The manual of practice is an updated version of the 1993 SHRP Crack Sealing and Filling Manual. It contains the latest information pertaining to the performance of treatment materials and methods, the availability and relative costs of sealant/filler materials, and the proper ways of planning, designing, constructing, and monitoring the performance of crack treatment projects. It too contains an updated partial listing of materials and equipment manufacturers.

The manual is intended for field and office personnel within highway maintenance agencies and contracted maintenance firms. It contains valuable information for supervisors and foremen in charge of individual crack treatment operations, engineers in charge of planning and overseeing many crack treatment projects, and managers in charge of establishing crack treatment policies and standards.

The NTIS publication number is PB2000-103845.

The SHRP H-106 maintenance experiment and FHWA LTM project also studied the resealing of joints in concrete pavements. Many different sealant materials and resealing methods were investigated between 1991 and 1998 through test sites installed at five locations in the United States. This manual of practice is an updated version of the 1993 SHRP Joint Seal Repair Manual. It contains the latest information pertaining to the performance of sealants and resealing methods; the availability and relative costs of sealant materials; and the proper ways of planning, designing, constructing, and monitoring the performance of joint resealing projects. It also provides an updated partial listing of materials and equipment manufacturers.

The manual is intended for field and office personnel within highway maintenance agencies and contracted maintenance firms. It contains valuable information for supervisors and foremen in charge of individual resealing operations, engineers in charge of planning and overseeing many joint resealing projects, and managers in charge of establishing resealing policies and standards.

The NTIS publicationnumber is PB2001-103412.

This report presents the first world-wide tire/pavement contact-stress model based on the artificial neural networks (ANN) developed by the authors at the Pennsylvania Transportation Institute at Pennsylvania State University.

These models represent the first mathematical representation of real, measured contact stress at wide ranges of vertical loads and inflation pressures for two types of tires. The developed ANN model has the capability of generating such complex stress distribution patterns under a tire at any given load and inflation pressure for a specific tire type used for the ANN training. The information given in this report is considered to be an important contribution to the ongoing efforts to improve tire/pavement contact-stress modeling and analysis. The neural network representation of a tire contact-stress distribution is called "Neuro-Patch Model."

The neural network models have been trained using precise, measured, three-dimensional contact-stress distribution patterns obtained from low-speed rolling tire tests conducted by the University of California at Berkeley, and data has been supplied by FHWA. In this study, two types of tires, namely Goodyear 11R22.5 radial-ply and Goodyear 10.00X20 bias-ply truck tires, were modeled at different inflation pressures ranging from 520 to 920 kPa and vertical loads ranging from 26 to 56 kN.

The NTIS publication number is PB2001-103488.