<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <title>Research in Progress (RIP)</title>
    <link>https://rip.trb.org/</link>
    <atom:link href="https://rip.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
    <description></description>
    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Research in Progress (RIP)</title>
      <url>https://rip.trb.org/Images/PageHeader-wTitle-RIP.jpg</url>
      <link>https://rip.trb.org/</link>
    </image>
    <item>
      <title>Evaluation of Adhesive Anchors in Concrete Pavement Applications</title>
      <link>https://rip.trb.org/View/2420093</link>
      <description><![CDATA[The research team will perform a comprehensive evaluation of adhesive anchors used in concrete pavement applications, particularly full-depth repairs. The research team will investigate the effects of sustained and cyclic loading on long term stiffness of the bond between the concrete, the adhesive grout, and the steel anchor. The potential benefits will lie in the suitability of adhesive anchors to perform in concrete pavement applications in addition to the development of recommendations for the use of adhesive anchors to minimize premature failures and to extend pavement service life by maintaining the stiffness of a repair made using drilled adhesive anchors.
]]></description>
      <pubDate>Fri, 23 Aug 2024 11:40:51 GMT</pubDate>
      <guid>https://rip.trb.org/View/2420093</guid>
    </item>
    <item>
      <title>Design of Anchors for Rapid and Durable Strengthening of Bridges with Externally Bonded Carbon Fiber Reinforced Polymer Composites—Phase 2</title>
      <link>https://rip.trb.org/View/1907230</link>
      <description><![CDATA[The beams tested in Phase 1 had sufficient steel stirrup shear reinforcement, which allowed the research team to evaluate the effectiveness of U-wraps in anchoring the longitudinal CFRP reinforcement. However, in practice, an RC beam deficient in flexure may also be deficient in shear, requiring both vertical (shear) and longitudinal (flexural) CFRP reinforcement. Due to the lack of experimental data, the current ACI 440.2R design guidelines do not permit to count on shear U-wrap reinforcement to provide anchorage for the longitudinal CFRP. Thus, the specific objectives of the proposed research program are to determine how effective U-wraps are in:
i. enhancing the shear capacity of shear-deficient RC beams, AND
ii. increasing strain utilization of longitudinal CFRP reinforcement in shear-deficient RC beams.
The primary expected outcome of this work will be more economical FRP strengthening. This will be accomplished by allowing the designer to limit the required area of longitudinal CFRP reinforcement through improved strain utilization (provided by the U-wrap anchorage) while, the same time, being able to consider U-wrap anchors as shear reinforcement.
]]></description>
      <pubDate>Tue, 01 Feb 2022 16:08:41 GMT</pubDate>
      <guid>https://rip.trb.org/View/1907230</guid>
    </item>
    <item>
      <title>RES2020-14: Design Considerations and Limitations of Rock Dowels/Anchors 
Loaded in Shear</title>
      <link>https://rip.trb.org/View/1851967</link>
      <description><![CDATA[In Tennessee, cut rock slopes with exposed discontinuities are often reinforced with grouted steel anchors
installed across the discontinuity to stabilize the system by immobilizing the rock material above the sliding
surface. These elements resist shear loading rather than function in tension. Yet, the steel bar may bend in cases
where the discontinuity is sufficiently large. The purpose of this study was to investigate the performance of
simulated un-tensioned dowel-jointed rock block systems subjected to shear loading and evaluate whether bending
likely occurred as well as its contribution to the reduction in dowel capacity. Variables studied were aperture size
(joint spacing), dowel diameter, and dowel angle of inclination with respect to the joint normal. Physical
experiments were conducted using large concrete blocks to simulate the jointed rock material, steel rebars to
simulate the dowels, and tested in a large-scale direct shear apparatus. A numerical model was developed to extend
the dowel size and joint thickness. A dowel shear capacity design chart was also developed. The chart identifies
the threshold between the pure shear capacity and the reduced capacity due to bending effects as a function of joint
thickness and bar size. Conclusions from this study include (1) rebar double bending phenomenon was inferred
from strain gage data in the case of a large aperture size, (2) bending starts at an aperture size relative to bar
diameter and strength, and reduces the dowel shear capacity by a quantity related to bar size and aperture size, (3)
all results from physical and numerical analyses show sufficient agreement with the governing equations for
theoretical dowel shear and bending conditions to warrant the conservative use of the developed design chart (4)
dowel inclination angle had little influence on ultimate shear resistance, and (5) free and fixed dowel placement
show no significant difference in resistance.]]></description>
      <pubDate>Tue, 11 May 2021 18:22:21 GMT</pubDate>
      <guid>https://rip.trb.org/View/1851967</guid>
    </item>
    <item>
      <title>Confinement Effect of Narrow Baseplates or Reaction Area on Anchor Breakout, Part 2
</title>
      <link>https://rip.trb.org/View/1849173</link>
      <description><![CDATA[The primary objectives of this research project are: (1) Review and identify the effect of confinement of narrow baseplates or reaction area on screw anchors breakout resistance. (2) Determine the effect of anchor groups and configurations on the anchor breakout resistance. (3) Determine the failure mechanism and appropriate confinement modification factor of screw anchors used in various applications. (4) Determine the screw anchors' performance under cyclic loads. (5) Develop new Florida Department of Transportation (FDOT) Structures Design Guidelines criteria for screw anchors with confinement effects. (6) Develop modified FDOT Structures Design Guidelines criteria for adhesive anchors with confinement effects if necessary.
]]></description>
      <pubDate>Mon, 26 Apr 2021 15:52:49 GMT</pubDate>
      <guid>https://rip.trb.org/View/1849173</guid>
    </item>
    <item>
      <title>NCHRP Implementation Support Program. Implementing Products from NCHRP Research on Adhesive Anchor Systems</title>
      <link>https://rip.trb.org/View/1499619</link>
      <description><![CDATA[With the adoption of its eighth edition, the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications, Section 5.13, Anchors, is noted as being applicable to headed studs, headed bolts, certain hooked bolts, adhesive anchors, post installed expansion anchors, and post installed undercut anchors. The design specification references American Concrete Institute (ACI) 318-14, ACI 355.2, and ACI 355.4. These documents cover structural design of anchors and qualification testing for mechanical and adhesive anchors. Many design, materials, and construction engineers in state departments of transportation (DOTs) and the transportation industry may not be familiar with these ACI documents or the proper application of these documents and other related documents for design, specification, procurement, or inspection of the various anchor types.
 
NCHRP Project 20-07/Task 255, “Development of a Test Method to Determine the Ability of Adhesive Anchors to Resist Sustained Tensile Load,” and NCHRP Project 04-37, “Long-Term Performance of Epoxy Adhesive Anchor Systems,” conducted extensive research on adhesive anchor systems.
 
NCHRP Project 20-07/Task 255 (published as NCHRP Report 639: Adhesive Anchors in Concrete Under Sustained Loading Conditions) provided an initial basis for developing AASHTO standards for sustained loads on adhesive anchors in response to recommendations from the National Transportation Safety Board to the FHWA, AASHTO, and the state DOTs.
 
NCHRP Project 04-37 (published as NCHRP Report 757: Long-Term Performance of Epoxy Adhesive Anchor Systems) resulted in a draft specification for design and construction of adhesive anchor systems. NCHRP Report 757 includes a draft workflow process chart to aid agencies in the appropriate selection and specification of adhesive anchors. The report also contains appendices with draft AASHTO standards pertaining to the use of adhesive anchors in concrete including: (1) Test methods and specifications and material specifications and commentary for inclusion in the AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing, (2) Design guidelines, (3) Design specifications and commentary for inclusion in the AASHTO LRFD Bridge Design Specifications, (4) Quality assurance guidelines, and (5) Construction specifications and commentary for inclusion in the AASHTO LRFD Bridge Construction Specifications.
 
These testing and material specifications made reference to the extensive and well-vetted testing program found within ACI 355.4 with a proposed exception for sustained-load testing. Design provisions for adhesive anchors in tensile loading were developed for AASHTO under given limitations. For cases that fall outside those restrictions, the designer was referred to ACI 318-11. Construction specifications were drafted for incorporation into the existing Section 29 “Embedment Anchors” of the AASHTO LRFD Bridge Construction Specifications, which previously addressed adhesive anchors. Quality assurance guidelines were drafted to orient construction and inspection personnel to adhesive anchor installation.
 
The objective of this research was to develop and execute a plan for dissemination and successful application of research products presented in NCHRP Reports 639 and 757 through a series of pilot workshops and national webinars.]]></description>
      <pubDate>Tue, 30 Jan 2018 09:40:56 GMT</pubDate>
      <guid>https://rip.trb.org/View/1499619</guid>
    </item>
  </channel>
</rss>