<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>Synthesis and Verification of Link Slab Practices for Jointless Bridge Decks in Accelerated Bridge Construction (ABC)</title>
      <link>https://rip.trb.org/View/2744923</link>
      <description><![CDATA[Bridge deck expansion joints are among the most maintenance-intensive
components of highway bridges, often leading to premature deterioration,
increased repair costs, and reduced service life. Link slabs provide an effective
alternative by enabling jointless deck configurations, improving durability, and
reducing long-term maintenance demands. Despite their proven benefits,
inconsistencies in design methodologies particularly regarding the need for deck
debonding and the use of advanced materials such as Ultra-High-Performance
Concrete (UHPC) have limited their broader adoption in Accelerated Bridge
Construction (ABC) applications. Early studies recommended partial debonding
near girder ends, while more recent large-scale investigations, such as SHRP2
R19A, concluded that debonding may not be required. At the same time, UHPC-based link slabs have demonstrated excellent crack control and durability, yet
remain without standardized design guidance. This project aims to synthesize
existing research, field applications, state DOT practices, and emerging material
innovations to establish practical best practices for link slab design. To this end,
the current study will (1) compile and evaluate past research and
implementations, (2) compare conventional and UHPC-based link slab
approaches, (3) conduct analytical and limited experimental verification to resolve
conflicting recommendations, and (4) develop design provisions and example
details suitable for ABC applications. The proposed work will produce a
comprehensive synthesis report, validated guidance, and actionable
recommendations for DOTs and practitioners. By clarifying design assumptions,
addressing uncertainties in debonding requirements, and evaluating the role of
UHPC, this study will promote the consistent and reliable use of link slabs in
jointless bridge decks.]]></description>
      <pubDate>Fri, 07 Aug 2026 08:21:45 GMT</pubDate>
      <guid>https://rip.trb.org/View/2744923</guid>
    </item>
    <item>
      <title>Implementation of Semi-integral Bridges in Texas</title>
      <link>https://rip.trb.org/View/2342165</link>
      <description><![CDATA[The research team will validate predicted semi-integral bridge performance against actual semi-integral bridge performance; particularly regarding backfill placement requirements. In particular, the geotextile-confined backfill will be monitored to assess its impact on (1) the lateral earth pressures induced due to cycles of temperature-induced backfill movements and (2) the settlements of the backfill material. The new approach, developed in research project 0-6936, is expected to reduce lateral earth pressures and decrease settlements. This validation of field performance will facilitate the development of a standard detail and commentary for the Bridge Design Manual as well as the compilation of additional design and construction guidelines. The research team will also monitor the semi-integral bridge at China Creek, in the Wichita Falls District using the wireless field monitoring system installed during research project 0-6936.]]></description>
      <pubDate>Tue, 20 Feb 2024 15:49:50 GMT</pubDate>
      <guid>https://rip.trb.org/View/2342165</guid>
    </item>
    <item>
      <title>Performance Assessment of Jointless Abutments in Virginia</title>
      <link>https://rip.trb.org/View/1635525</link>
      <description><![CDATA[Since the early 1980’s, the Virginia Department of Transportation (VDOT) has been developing, evaluating, modifying, and incorporating bridge abutments that eliminate deck joints. More than 35 years later, VDOT’s Structure and Bridge Division has asked the Virginia Transportation Research Council to assess the performance of the various jointless abutments by visiting a representative sample of bridges constructed with these abutment and approach types. The goal of this project will be to assess the effect of various geometrical parameters on the long-term performance of various jointless abutments. This study may serve as the first in a potentially multi-phase effort that, ultimately, could expand the number of new bridges that can be constructed using more economical jointless abutments and approaches that also lead to lower life-cycle costs and fewer disruptions to the traveling public.]]></description>
      <pubDate>Thu, 04 Jul 2019 10:11:40 GMT</pubDate>
      <guid>https://rip.trb.org/View/1635525</guid>
    </item>
    <item>
      <title>Development of ABC Course Module: Design of Link Slabs</title>
      <link>https://rip.trb.org/View/1596199</link>
      <description><![CDATA[This project builds on the findings from a former accelerated bridge construction (ABC) UTC-sponsored research project on link slabs and develops a short course module to provide the design guidelines and practical recommendations necessary to properly implement a link slab in jointless bridges.]]></description>
      <pubDate>Sat, 30 Mar 2019 14:28:33 GMT</pubDate>
      <guid>https://rip.trb.org/View/1596199</guid>
    </item>
    <item>
      <title>Design and Performance of Micropile Supported Integral Abutment Bridges</title>
      <link>https://rip.trb.org/View/1498118</link>
      <description><![CDATA[There is little to no guidance on the design of micropiles (or end-bearing variation thereof) supporting fully integral abutment bridges (IABs), and no known performance data. A design methodology for the structural and geotechnical design of micropile-supported IABs is needed. Specific guidance is sought on (1) the acceptability of plastic hinges, which current H-pile supported IAB design practices permit, and (2) geotechnical resistance for an end-bearing variation of the micropile. The objective is to demonstrate micropiles satisfy strength and stability requirements for IAB applications when shallow bedrock is present, and adhere to the American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications. This work will include: Literature search and review of structural and geotechnical design requirements for micropiles in Sections 5, 6 and 10 of the AASHTO LRFD Bridge Design Specifications; analytical/numerical analyses of micropiles in conjunction with loadings and demands of IABs; confirmation and/or refinement of numerical analyses through field instrumentation to verify adequacy of micropiles in IAB applications.
]]></description>
      <pubDate>Mon, 22 Jan 2018 10:51:15 GMT</pubDate>
      <guid>https://rip.trb.org/View/1498118</guid>
    </item>
    <item>
      <title>Alternative ABC Connections Utilizing UHPC</title>
      <link>https://rip.trb.org/View/1410735</link>
      <description><![CDATA[Two major questions are asked by bridge owners when specifying use of accelerated bridge construction (ABC) in bridge projects - durability and cost. Past experiences in bridge design, construction and maintenance indicates that one of the key elements in enhancing the service life of bridges is to eliminate “Joints” where possible. ABC projects on other hand, incorporate many “Joints”. As a result there is an urgent need for addressing the durability and service life of ABC projects through developing connections details that will have even have higher durability and service life.
Ultra High Performance Concrete (UHPC) provides an excellent opportunity to develop generic connection details for superstructure and substructure bridge elements with superior durability and service life performances. Within this project several ABC connection details that provides challenges during construction will be identified and combination of experimental and numerical studies will be carried out to develop alternative ABC connection details that are user friendly and have superior durability characteristics.
Researchers at Florida International University (FIU) has carried out preliminary work and have demonstrated that it is very much feasible to develop alternate ABC connections using UHPC with superior characteristics.
It is expected that this project will result in development of information that will significantly help to promote use of ABC in many bridge projects.
Close collaboration with stakeholders will be maintained to assist in quick implementation of the research results.]]></description>
      <pubDate>Wed, 08 Jun 2016 17:11:35 GMT</pubDate>
      <guid>https://rip.trb.org/View/1410735</guid>
    </item>
    <item>
      <title>Finite Element Analysis of Concrete Approach Slab on Soil Embankment</title>
      <link>https://rip.trb.org/View/1230340</link>
      <description><![CDATA[Current AASHTO specifications for structural design of bridge approach slabs do not take into account the interaction of slabs with the underlying soil. Consequently, the slabs experience a distress primarily in the form of cracking, also known as "the bump at the end of the bridge" because they are not designed to sustain the effects of differential settlements. Passing of large heavy vehicles over distressed slabs generates impact loads that cause further damages to bridges and pavements and may become a safety concern. In addition, the accumulation of settlement over time necessitates frequent maintenance, thus increasing the whole life cycle costs of bridges and incurring additional costs due to the associated traffic disruptions. While several different suggestions have been proposed for the alleviation of this problem (Stark et. al., 1995; Monley and Wu, 1993; Helwany et al., 2003) none of them have been widely accepted or implemented. It is because of a sheer number of bridges, including 25,620 in Kansas alone, and 590,111 in the U.S. that the current design approach negatively affects the resilience, durability, safety and economy of transportation infrastructure. Kansas has the fourth largest number of bridges, following Texas, Ohio and Illinois. In addition, according to Bakeer et al. (2005) Kansas was also the second state to build the integral bridge in 1935. Today Kansas has about 1,000 integral bridges. This type of a bridge is more sustainable choice than its non-integral counterpart because it boasts multiple advantages. However, the bridge approach settlement in integral bridges is even more significant due to a complex soil-structure interaction. Significant differential settlements occur below the approach slab because integral bridges accommodate thermal expansions and contractions of the deck through the cyclic deformation in the adjacent soil. Devising a design that will enable the approach slabs to sustain larger differential settlements will directly contribute to the increased resilience, longevity, safety and economy of transportation lifelines, thus increasing their overall sustainability rating.]]></description>
      <pubDate>Thu, 03 Jan 2013 13:58:31 GMT</pubDate>
      <guid>https://rip.trb.org/View/1230340</guid>
    </item>
  </channel>
</rss>