Recent Publications

Public Roads, Nov, 1999 by Zac Ellis

Calcium Magnesium Acetate at Lower Production Cost: Production of CMA Deicer From Biomass Publication No. FHWA-RD-98-055

The purpose of this project was to demonstrate the technical and economic feasibility of producing calcium magnesium acetate (CMA) from solid waste by gasification/fermentation. Bench-scale fermentation experiments were conducted with synthesis gases typical of those from gasification of various residues. Fast reaction rates and high yields were obtained; and phase contaminants, such as chlorides, metals, and sulfur gases in concentrations expected in syngas, were not found to affect the fermentation. The production of CMA by reacting lime and magnesium oxide with acetic acid extracted from the fermentation broth was optimized in bench-scale experiments. Procedures for using cheap grades of lime and magnesium oxide were developed. Ice melting and penetration tests, as well as analytical results, showed the laboratory CMA to be of a comparable (or better) quality than that of the industry product.

The NTIS number is PB99-142747; the cost is $41 for a paper copy or $17 for the report on microfiche.

Development of the Bicycle Compatibility Index: A Level of Service Concept, Final Report Publication No. FHWA-BD-98-072

This research effort was undertaken to develop a methodology for deriving a bicycle compatibility index (BCI) that could be used by practitioners to evaluate the capability of specific roadways to accommodate both motorists and bicyclists. The BCI methodology was developed for urban and suburban roadway segments (i.e., midblock locations that are exclusive of major intersections) and it incorporated those variables that bicyclists typically use to assess the "bicycle-friendliness" of a roadway (e.g., curb lane width, traffic volume, and vehicle speeds). The developed tool will allow practitioners to evaluate existing facilities to determine what improvements may be required as well as to determine the geometric and operational requirements for new facilities.

The NTIS number is PB99-146771; the cost is $29.50 for a paper copy or $17 for the report on microfiche.

The Bicycle Compatibility Index: A Level-of-Service Concept: Implementation Manual Publication No. FHWA-RD-98-095

This report focuses on the application of the BCI methodology and the use of the Microsoft Excel workbook, which comes on a disk with the report. The report includes a brief summary of the model development, data requirements for using the model, a detailed discussion of the workbook, and numerous examples applied to real-world development. In addition to this implementation manual, there is also a final report (FHWA-RD-98072) containing a complete discussion of the research methodology, data collection procedures, data analysis, and model development.

The NTIS number is PB99-146789; the cost is $27 for a paper copy or $12 for the report on microfiche.

Design and Construction of PCC Pavements, Volume III: Improved PCC Performance Models Publication No. FHWA-RD-98-113

Researchers conducted this study to evaluate and analyze portland cement concrete (PCC) pavements and to develop recommendations for designing and constructing long-lived concrete pavements. It involved a detailed evaluation and analysis of the PCC pavement data in the Long-Term Pavement Performance (LTPP) database using a variety of methods to determine the design features and practices that have beneficial effects on long-term performance. Emphasis was placed on identifying those specific design features that can be included during design to improve the performance of PCC pavements under various combinations of environmental and traffic loading conditions, and for different subgrade support conditions. The study focused on developing practical recommendations that can be implemented by highway agencies to increase pavement life.

This volume describes and provides information on improved pavement distress and roughness prediction models that were developed as part of the study. A key focus was to develop distress and roughness prediction models that incorporate mechanistic principles, but are still practical for use by state highway agencies.

Corrosion Evaluation of Epoxy-Coated, Metallic-Clad, and Solid Metallic Reinforcing Bars in Concrete Publication No. FHWA-RD-98-153

This report describes the work conducted from 1993 to 1998 to develop cost-effective "new breeds" of organic, inorganic, ceramic, and metallic coatings, as well as metallic alloys that can be used on or as reinforcement for embedment in PCC. As part of the study, 12 different bar types were tested in concrete: black bars, three bendable and three nonbendable epoxies, Types 304 and 316 stainless steel, copper-clad, galvanized, and spray metallic-clad reinforcing. Measurements of macrocell voltages, half-cell potentials, electrical impedance spectroscopy, linear polarization, and mat-to-mat resistances were used in conjunction with visual observations to determine the effectiveness of each system. The research supports the continued use of epoxy-coated reinforcing bars as a corrosion-protection system. As in all cases, the corrosion rates of the epoxy-coated bars were less than that observed for the black bars.