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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Modernization and Updates to the AASHTO Guide Specifications for Highway Construction</title>
      <link>https://rip.trb.org/View/2709240</link>
      <description><![CDATA[The American Association of State Highway and Transportation Officials (AASHTO) Guide Specifications for Highway Construction (Guide Specs) provides an important national resource for transportation agencies by promoting consistency in construction specifications, methods of measurement, basis of payment, and testing procedures. The technical content of the Guide Specs was last updated and published in 2020 through NCHRP Project 20-07, which primarily focused on adding new sections rather than performing a comprehensive revision. The previous full edition was published in 2009. Since that time, significant changes have occurred in highway construction technology, safety, contracting methods, and regulatory practices.

Many contracting options beyond the traditional design-bid-build method are increasingly being used. At the same time, technological advances such as integrated digital workflows and digital ticketing are becoming more common, and performance-related specifications such as balanced mix design, performance engineered mixes, and nondestructive testing (NDT) acceptance procedures are continuing to evolve. As these technologies and practices advance, it is imperative that the Guide Specs be modernized to ensure they remain technically accurate, relevant, and compatible with current industry practices.

 OBJECTIVE: The objective of this research is to comprehensively update and expand the AASHTO Guide Specs. ]]></description>
      <pubDate>Wed, 03 Jun 2026 11:43:53 GMT</pubDate>
      <guid>https://rip.trb.org/View/2709240</guid>
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      <title>SPR-4631: Evaluation of the Potential Benefits of Implementing the AASHTO Guide Specifications for the Analysis and Identification of Fracture Critical Members and System Redundant Members</title>
      <link>https://rip.trb.org/View/1869559</link>
      <description><![CDATA[In 2018, The AASHTO Committee on Bridges and Structures (COBS) approved the AASHTO Guide Specifications for the Analysis and Identification of Fracture Critical Members and System Redundant Members and the AASHTO Guide Specifications for Internal Redundancy of Mechanically-fastened Built-up Steel Members. This project will conduct an exploratory study on a set of bridges in the state of Indiana where both the IRM and SRM Guide Specifications are evaluated for implementation within the state. ]]></description>
      <pubDate>Thu, 29 Jul 2021 16:28:43 GMT</pubDate>
      <guid>https://rip.trb.org/View/1869559</guid>
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      <title>Correlation of Shear Design between AASHTO LRFD Bridge Design Specifications and the AASHTO Guide Specifications</title>
      <link>https://rip.trb.org/View/1324978</link>
      <description><![CDATA[The American Association of State Highway and Transportation Officials (AASHTO) Guide Specifications for the Seismic Design of Bridges was developed to provide a displacement-based approach to the design and construction of conventional bridges.  These specifications can apply to all levels of seismic shaking.  States like Nevada have not officially adopted the Guide Specifications but use it as part for their designs.  The specifications were a result of the performance of bridges during the 1989 Loma Prieta and 1994 Northridge earthquakes.  These earthquakes specifically showed vulnerability of reinforced concrete columns to inadequate transverse reinforcement for longitudinal confinement and shear reinforcement.  The Guide Specifications works to ensure good shear performance by specifying details that are calculated to provide sufficient displacement/ductility capacity.  There have been many experiments and studies that have focused the flexural/bending aspects of column design.  The number of studies that investigated shear capacity is substantially less, but they have been used to develop shear equations that are ductility based.  The purpose of the project is to investigate the shear capacity of reinforced concrete columns using both the Guide Specifications and the load and resistance factor design (LRFD) Specifications for various levels of axial load, transverse reinforcement and longitudinal reinforcement to determine how the two specifications compare both within the plastic hinge zone and outside the plastic hinge zone for areas throughout Nevada, Arizona and New Mexico.  Outside the plastic hinge region, the Guide Specifications permits the designer to use the LRFD Specifications or equations within the Guide Specifications with predetermined values. In order to develop a comprehensive understanding of shear behavior, in addition to examining conventional ASTM A706 and ASTM A615 Grade 60 reinforcement comparison will also be conducted on high strength reinforcement.  Experimental data is limited for high strength reinforcement but will provide some test points to compare with the models.  The addition of high strength reinforcement enables a consistent examination of shear, plus adds a tool for the designer to use in increasing safety and improving sustainability. As part of the range of the specimens that will be compared, predictions will also be made of the shear capacities of experimental columns given in the PEER Structural Performance Database [Eberhard and Berry].  This will allow not only a comparison between the two methods but also a better understanding their accuracy.]]></description>
      <pubDate>Wed, 01 Oct 2014 02:16:23 GMT</pubDate>
      <guid>https://rip.trb.org/View/1324978</guid>
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      <title>KDOT Column Expert: Ultimate Shear Capacity of Circular Columns using the Modified Compression Field Theory</title>
      <link>https://rip.trb.org/View/1286096</link>
      <description><![CDATA[The extreme event requirement as a limit state set by AASHTO LRFD makes it necessary to develop the actual capacity of concrete sections to accurately design them to withstand the extreme load events. For confined sections subjected to combined axial force and uniaxial bending moment, the actual ultimate flexural capacity is found using the earlier versions of Kansas Department of Transportation (KDOT) Column Expert. Accordingly, it is necessary to develop a computer program that evaluates the section capacity in shear by generating accurate shear-moment interaction diagrams for each level of axial force and compares them to the available experimental results. This analysis can prove useful to estimate the existing capacity of damaged bridge piers when subjected to truck impacts. It is also desirable to have a reliable analysis tool that can be used to assess the actual shear capacity of the pier when developing a repair action. Experimental evidences have shown that the modified compression field theory can capture the actual shear capacity of the section very accurately. In addition, the dowel action of the longitudinal bars acting in tension can contribute to increasing the shear capacity, a factor often neglected by design codes of practice. The nonlinear axial load-strain and uniaxial moment-curvature response of reinforced concrete circular section combined with shear forces is very involved. It is important to note that accurate results are guaranteed when the axial load and bending moments are proportional since loading path dependence is avoided. Rasheed and Abd El Fattah have developed a framework for columns that imposes proportional axial force and uniaxial bending moment on circular sections and iterates to obtain the corresponding deformation parameters. However, this procedure needs to be extended to the general case of shear-moment-axial force interaction.]]></description>
      <pubDate>Thu, 16 Jan 2014 01:00:16 GMT</pubDate>
      <guid>https://rip.trb.org/View/1286096</guid>
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