Below are brief descriptions of products recently published online by the Federal Highway Administration's (FHWA) Office of Research, Development, and Technology. Some of the publications also may be available from the National Technical Information Service (NTIS). In some cases, limited copies are available from the Research and Technology (R&T) Product Distribution Center.

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:

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For more information on research and technology publications 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 is the first of a two-part publication entitled Seismic Retrofitting Manual for Highway Structures. Part 1 of this manual draws from previous FHWA publications on this subject, including Seismic Retrofitting Manual for Highway Bridges (FHWA-RD-94-052), published in 1995. Revisions to the 1995 manual include current advances in earthquake engineering, field experience with retrofitting highway bridges, and the performance of bridges in recent earthquakes. The report is the result of several years of research, with contributions from a multidisciplinary team of researchers and practitioners.

In particular, a performance-based retrofit philosophy is introduced similar to that used for the performance-based design of new buildings and bridges. Included are performance criteria for two earthquake ground motions with different return periods, 100 and 1,000 years. In terms of earthquake ground motion, the event with the lower-level motion and short return period requires a higher level of performance than the event with the upper-level motion and longer return period. The publication recommends performance criteria according to bridge importance and anticipated service life, with more rigorous performance required for important, relatively new bridges, than for standard bridges at the end of their useful life.

The report gives minimum recommendations for screening, evaluating, and retrofitting according to an assigned Seismic Retrofit Category. Bridges in Category A need not be retrofitted, whereas those in Category B may be assessed without a detailed evaluation, provided they satisfy certain requirements. Bridges in Categories C and D require more rigorous consideration and retrofitting. The report also describes various retrofit strategies and explains a range of related retrofit measures in detail, including restrainers, seat extensions, column jackets, footing overlays, and soil remediation.

The NTIS order number for this publication is PB2007-109043.

The second of a two-part publication entitled Seismic Retrofitting Manual for Highway Structures, Part 2 includes new procedures for determining the seismic vulnerability of important highway system structures—namely, retaining structures, slopes, tunnels, culverts, and roadways. Guidance provided includes instructions on screening for potential seismic vulnerabilities, conducting a detailed evaluation, and describing strategies for retrofit design. In addition, discussion classifies each structure by type, construction, or expected performance. The discussion benefits transportation personnel because different types of a given structure (e.g., different types of retaining walls) may have different failure modes, requiring somewhat different approaches to seismic vulnerability screening, detailed evaluating, and retrofitting.

The NTIS order number for this publication is PB2007-109044.

Ultra-high performance concrete (UHPC) exhibits exceptional strength and durability characteristics that make it well suited for use in highway bridge structures. This material can exhibit compressive strength of 193 megapascals, MPa (28 kilopounds per square inch, ksi), tensile strength of 9.0 MPa (1.3 ksi), significant tensile toughness, elastic modulus of 52.4 gigapascals, GPa (7.6 ksi), and minimal long-term creep or shrinkage. It also can resist freeze-thaw and scaling conditions with virtually no damage, and it is nearly impermeable to chloride ions.

This report presents the results from a large suite of material characterization tests completed to quantify the behaviors of commercially available UHPC. The characteristics captured within UHPC fall under four different curing regimes. This study focused on strength-based behaviors (e.g., compressive and tensile strength), long-term stability behaviors (e.g., creep and shrinkage), and durability behaviors (e.g., chloride ion penetration and freeze-thaw).

The document is available online at www.fhwa.dot.gov/publications/research/infrastructure/structures/06103/index.cfm. The NTIS order number for this publication is PB2007-101935.

The objectives of this study are to: (1) quantify the effects of frost penetration on pavement performance in climates with deep sustained frost compared to environments with multiple freeze-thaw cycles; (2) investigate the effect that local adaptations have on mitigating frost penetration damage; and (3) estimate the associated cost of constructing and maintaining pavements in freezing climates. The approach consisted of modeling various pavement performance measures using both climatic and nonclimatic input variables and performance data collected as part of the LTPP program.

The publication defines five climatic scenarios in terms of climatic input variables for the models. The study predicts performance measures for each of the climatic scenarios and compares performance at a 95-percent confidence interval to determine statistically significant differences. Participating pooled fund States discussed standard specifications, standard designs, average life expectancies, and construction costs specific to each State highway agency (SHA). These data, along with information acquired through literature review of SHA standard practices, also summarize the mitigation of frost-related damage. Discussion and comparison of the life-cycle cost analysis for each climatic scenario uses predicted performance to determine average life and average agency construction costs for standard pavement sections. The study also includes an explanation of the use of performance models for local calibration as required in the National Cooperative Highway Research Program Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures, along with the possible application of the performance models in pavement management systems.

The document is available online at www.fhwa.dot.gov/pavement/ltpp/pubs/06121/index.cfm. The NTIS order number for this publication is PB2007-103344.