<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>Efficacy, Advancement, and Monitoring of Carbon Fiber Composite Cable (CFCC)</title>
      <link>https://rip.trb.org/View/2724770</link>
      <description><![CDATA[Carbon Fiber Composite Cable (CFCC), and the Carbon Fiber Reinforced Polymer (CFRP) materials are being used for prestressing
applications in Michigan bridge rehabilitation and replacement projects with the most recent generation of CFCC is a 0.7-inch strand
configuration. The quantity of stands is similar to conventional strands, and concomitant updated design criteria. Determining the
efficacy of the new 0.7-inch CFCC strand long-term behavior is essential for future design and construction considerations.
Monitoring the CFCC elements in newly constructed bridges (with 0.7-inch strands) and some prior construction (from OR14-039)
will provide an understanding of the long-term behavior and realizations of recommendations on future designs, and continued
considerations of field deployment.]]></description>
      <pubDate>Tue, 07 Jul 2026 10:05:57 GMT</pubDate>
      <guid>https://rip.trb.org/View/2724770</guid>
    </item>
    <item>
      <title>Full-Scale Performance Evaluation of a Modular, Lightweight, UHPC Panel System for Repair of Corrosion-Damaged Steel H-Piles</title>
      <link>https://rip.trb.org/View/2695941</link>
      <description><![CDATA[This project directly supports the mission of the Center for Healthy and Durable Transportation (CHDT) by advancing innovative, implementable solutions to extend the service life of aging bridge infrastructure. The research focuses on developing and validating a modular, lightweight ultra-high-performance concrete panel system (UHPC-PS) for rehabilitating corrosion-damaged steel H-piles—critical substructure elements in United States bridges. By integrating advanced materials such as fiber-reinforced UHPC and carbon fiber reinforced polymer (CFRP) grids with practical field deployment strategies and full-scale performance validation under realistic service and seismic loading, the project enhances infrastructure durability, constructibility, long-term performance, and public safety, directly benefiting transportation agencies.]]></description>
      <pubDate>Thu, 23 Apr 2026 16:26:18 GMT</pubDate>
      <guid>https://rip.trb.org/View/2695941</guid>
    </item>
    <item>
      <title>Interfacial Shear Transfer for Concrete Elements with Non-Corrosive Composite Reinforcement </title>
      <link>https://rip.trb.org/View/2646936</link>
      <description><![CDATA[This project will investigate a novel approach to enhance the dowel resistance of Glass Fiber Reinforced Polymer (GFRP) bars when used as shear reinforcement construction of concrete bridges. Fiber reinforced polymer is known to be resistant to corrosion with potential benefits in bridge construction. However, it has low dowel action resistance, which can jeopardize the integrity of the composite action between precast/prestressed concrete and cast-in-place bridge deck slabs, which can lead to failure of the bridge girder system. Improving the dowel action resistance of GFRP stirrups will eliminate a barrier to wider adoption of non-corrosive GFRP bars in bridge construction. The objective of this project is to explore a novel approach whereby GFRP dowels will be placed at an angle to the shear interface between the precast beam and the cast-in-place deck for enhancing the horizontal shear resistance of fiber reinforced polymer dowels for the purpose of ensuring composite action in bridges built with non-corrosive reinforcement.  

The scope of the project is limited to GFRP bars, which is the most widely used rebar alternative due to its lower cost and acceptable properties compared to other types of fiber reinforced polymer bars. The contribution of the GFRP bars to the mechanism of shear transfer will be evaluated by using push-off specimens that have been successfully used for studying dowel action of steel bars. Push-off specimens with non-orthogonal GFRP dowels at two angles and two spacings are proposed to be tested experimentally along with a control specimen. The proposed specimens will explore the effect of different angles and dowel spacing on the interfacial shear resistance between concrete elements with GFRP dowls. ]]></description>
      <pubDate>Mon, 05 Jan 2026 22:26:37 GMT</pubDate>
      <guid>https://rip.trb.org/View/2646936</guid>
    </item>
    <item>
      <title>Externally Bonded FRP 
Construction Specifications for KYTC</title>
      <link>https://rip.trb.org/View/2593936</link>
      <description><![CDATA[The Kentucky Transportation Cabinet (KYTC) now specifies the use of fiber reinforced polymer (FRP) material to repair and strengthen concrete structures. This material has a high strength-to-weight ratio, is lightweight, and can be installed easily with minimal labor costs. Although the performance and durability of FRP repairs hinges on using proper construction practices, KYTC currently lacks specifications for the surface preparation and application of FRP material.]]></description>
      <pubDate>Thu, 28 Aug 2025 11:32:33 GMT</pubDate>
      <guid>https://rip.trb.org/View/2593936</guid>
    </item>
    <item>
      <title>Durability and Cost-Benefit Assessment of Innovative Materials for Bridge Deck Maintenance and Construction</title>
      <link>https://rip.trb.org/View/2543852</link>
      <description><![CDATA[The South Carolina Department of Transportation (SCDOT) manages one of the largest state transportation networks in the US, including over 9400 bridges. For existing and newly built bridges, concrete decks are the primary area of concern for durability due to aging, increased load demands, and direct exposure to corrosive environments, especially throughout the coastline and the Lowcountry. As a result, excessive cracking (e.g., due to aging, shrinkage, overloads, exposure to chloride salts) and corrosion-related damage (e.g., concrete spalling, loss of reinforcing material) are all-too-common conditions that hinder safety, reduce capacity, and negatively affect user satisfaction.

The condition of the State’s bridge decks is reflected in the National Bridge Inventory. In 2018, for the first time, the number of bridges rated as ‘Fair’ (4855, over 50% of the total) surpassed those rated as ‘Good’. This trend shows what bridge inspectors are well aware of—that the rate of deterioration exceeds the rate of rehabilitation and replacement. The outlook is that a ‘State of Good Repair’ is increasingly challenging, despite the SCDOT’s growing maintenance efforts.

In fact, the cost and impact on mobility of bridge maintenance and new construction put a premium on accelerating the transition to innovative deck materials that offer unprecedented durability and cost benefits. Compelling examples are ultra-high performance concrete, specialty admixtures (e.g., shrinkage-control, nano-amendment), cementitious-matrix overlays, externally bonded fiber-reinforced polymer (FRP) systems, galvanized steel bars, and noncorrosive glass FRP (GFRP) bars whose cost is now on par with black steel.

In addition to bridge deck research, the proposed research will also focus on developing standard repair procedures for various bridge components. An emphasis will be placed on developing procedures that are relatively easy to perform by maintenance forces with commonly available equipment.

The proposed research aims to bridge the gap between state-of-the-art and field implementation. Doing so requires addressing a lack of familiarity by practitioners, a difficulty with assessing cost benefits, and a limited availability of SCDOT provisions and tools for design, and life-cycle cost analysis (LCCA) for asset management.

]]></description>
      <pubDate>Mon, 28 Apr 2025 09:09:57 GMT</pubDate>
      <guid>https://rip.trb.org/View/2543852</guid>
    </item>
    <item>
      <title>A Durable Composite Bridge Deck System for Accelerated Bridge Construction Comprising FRP Stay in Place Form and UHPC Overlay</title>
      <link>https://rip.trb.org/View/2536274</link>
      <description><![CDATA[Prefabricated deck panels have also been implemented in new constructions and redecking of existing bridges as part of the Accelerated Bridge Construction technique which offers numerous advantages such as rapid construction, enhanced safety, and reductions in traffic disruptions. A composite deck is proposed in this project comprising fiber-reinforced polymer (FRP) stay-in-place (SIP) forms as bottom reinforcement, the inner concrete core which could be made from a variety of materials to meet different strength and sustainability requirements and is to be reinforced with conventional steel bars, and ultra-high-performance concrete (UHPC) as a top overlay. The system is envisioned to be suitable for both prefabricated jointed and jointless field-cast applications, and applicable for new bridge constructions as well as redecking projects. The FRP SIP forms integrate the advantages of both SIP forms such as reduced construction costs, shorter timelines, enhanced safety; and FRP reinforcement including high strength, lightweight, and immunity to corrosion. The exceptional mechanical and durability characteristics of UHPC enable protection of the inner core and its steel reinforcement against environmental stressors and contribute to structural performance. The primary objective of this research is to evaluate the design, construction, and performance of the proposed deck system under service and ultimate conditions. Specific objectives include: (a) developing final designs including geometric, material, and reinforcement details of the deck and deck connections for prefabricated systems; (b) conducting experimental and analytical investigations to evaluate the deck and deck joint performance under mechanical loading and assess conformance to the design requirements in bridge design specifications; and (c) developing design, construction, and implementation guidelines for the proposed technology.]]></description>
      <pubDate>Mon, 14 Apr 2025 13:51:24 GMT</pubDate>
      <guid>https://rip.trb.org/View/2536274</guid>
    </item>
    <item>
      <title>Investigating the Performance of Corrosion-Resistant GFRP-Reinforced Bridge Railings with Open Expansion Joints</title>
      <link>https://rip.trb.org/View/2529965</link>
      <description><![CDATA[The test specimen’s structural setup will be adjusted to match the Florida Department of Transportation (FDOT) impact pendulum's universal foundation and simulate an open expansion joint. Efficient structural solutions preventing GFRP reinforcement slippage will be developed and tested. The impactor used in previous tests will be refined to better replicate real-world truck impact conditions in terms of height and width. These adjustments aim to provide valuable insights into enhancing the safety performance and durability (and subsequently resiliency) of corrosion-resistant GFRP reinforcing in bridge railings.]]></description>
      <pubDate>Fri, 28 Mar 2025 08:24:10 GMT</pubDate>
      <guid>https://rip.trb.org/View/2529965</guid>
    </item>
    <item>
      <title>A Novel Constrained Layer Damper for Wind-Induced Vibration Mitigation of High-Mast Illumination Poles</title>
      <link>https://rip.trb.org/View/2505729</link>
      <description><![CDATA[This project will develop a novel Constrained Layer Damper (CLD) for retrofitting High-Mast Illumination Pole (HMIP) structures to mitigate wind-induced vibrations. Work in Stage 1 will focus on mechanical characterization of viscoelastic (VE) materials, and the subsequent numerical modeling and optimization of the CLD. A series of axial tests and shear relaxation tests will be performed to obtain the hyperelastic and viscoelastic properties of candidate VE materials using relevant standards. A small-scale tubular cantilever beam will be designed and modeled in Abaqus. The model will be used to perform parametric studies to optimize the thicknesses of the constraining layer and the VE layer. In addition, both steel and carbon fiber-reinforced polymers (CFRP) will be investigated for the constraining layer. The result will guide the small-scale laboratory validation in Stage 2. To estimate damping enhancement, a static loading will be applied to the numerical models, which will be then removed to generate free-vibration responses. A full-scale HMIP structure will be selected from KDOT’s inventory and modeled in Abaqus to perform parametric studies similar to those performed earlier in Stage 1. In addition to optimizing the thicknesses of the constraining and VE layers, an additional study will analyze the impact of the handhole detail, which the CLD must avoid covering. In Stage 2, laboratory and field validations will be carried out for the developed CLD technology. Small-scale tubular cantilever beam will be fabricated and the proposed CLD will be implemented according to the numerically optimized parameters (e.g., thicknesses of the VE and constraining layers). Free vibration tests will be conducted with the tubular cantilever beam before and after the CLD is installed. Free vibration responses will be recorded using an accelerometer to extract damping ratios. Full-scale HMIP will be instrumented with wireless accelerometers, and pluck tests will be carried out to obtain the intrinsic damping of the HMIP. The optimized CLD design will be installed on the HMIP. Particular attention will be paid to proper anchorage of the constraining layer at the bottom of the CLD to ensure full development of shear strain in the VE layer. This will be followed by pluck tests to assess the level of damping enhancement by the CLD.  The final report will include all relevant data, results, and conclusions. ]]></description>
      <pubDate>Mon, 03 Feb 2025 22:13:46 GMT</pubDate>
      <guid>https://rip.trb.org/View/2505729</guid>
    </item>
    <item>
      <title>Use of Fiber-Reinforced Polymer (FRP) Bars in Seismic Design of Building Structures (NDOT 280-24-803)</title>
      <link>https://rip.trb.org/View/2502109</link>
      <description><![CDATA[Fiber reinforced polymer (FRP) has emerged as an alternative for producing reinforcing bars (rebars) for reinforced-concrete (RC) structures. FRP rebars are noncorrosive and provide a suitable solution for construction of RC structures in highly corrosive environments, e.g., salt storage structures as envisioned by the Nevada Department of Transportation (NDOT). Since mechanical behavior of FRP is different from steel, unique procedures for the analysis, design, and construction of RC structures with FRP rebars are necessary. Design and construction guidelines for FRP-reinforced concrete (FRP-RC) structures have been established in other countries. In the U.S., ACI 440 provides general information and guidelines for the design and construction of structural concrete members reinforced with FRP bars, based on the worldwide state-of-knowledge. This guide, however, is limited to non-seismic applications. It, therefore, eliminates FRP-RC applications in most of the western U.S., including most of Nevada, due to the high seismicity of the region. There is a need to advance research and to provide engineering guidelines that will enable application of FRP rebars in seismic design of RC structures. The objective of this study is to develop new design approaches which can be used for the employment of FRP bar in structures which are designed to sustain seismic loading. ]]></description>
      <pubDate>Mon, 03 Feb 2025 12:12:49 GMT</pubDate>
      <guid>https://rip.trb.org/View/2502109</guid>
    </item>
    <item>
      <title>UHPC for Durable and Post-Earthquake Functional Recovery Bridge Piers</title>
      <link>https://rip.trb.org/View/2440290</link>
      <description><![CDATA[This research will advance recent material technology breakthroughs to enhance the resilience, durability, and functional recovery of bridge piers for TI subject to seismic hazard. A new type of bridge piers will be investigated that possesses very high resistance to damage and cracking, ultra-high strength, high compressive ductility, excellent corrosion resistance, and self-centering capabilities when subjected to large earthquake displacement reversals. The proposed bridge pier is developed using an innovative design concept that fully utilizes the unique mechanical behavior of ultra-high-performance  concrete (UHPC), as well as high-strength non-corrosive fiber-reinforced polymer (FRP) rebars or corrosion-resistant high-strength low-carbon chromium steel rebars.]]></description>
      <pubDate>Sun, 13 Oct 2024 11:33:29 GMT</pubDate>
      <guid>https://rip.trb.org/View/2440290</guid>
    </item>
    <item>
      <title>Design and Assessment of Concrete Bridge Substructure Disturbed Regions Utilizing Fiber Reinforced Polymers</title>
      <link>https://rip.trb.org/View/2414054</link>
      <description><![CDATA[As the North Carolina Department of Transportation (NCDOT) explores the use of fiber reinforced polymers (FRP) in its structures, there is a need to further investigate the use of FRP in substructure components that are considered disturbed regions, such as bent caps and footings. When these substructure components are constructed with conventional steel reinforcement, they can corrode, leading to early and costly repairs or replacement, particularly in coastal environments. The use of internal FRP reinforcement in substructure components eliminates the need for costly interventions resulting from steel corrosion and can greatly increase the service-life of these structures. This proposal will focus on developing design and assessment procedures for concrete bridge substructure disturbed regions utilizing FRP. In the design and analysis of reinforced concrete deep beams, such as bridge bent caps and footings, the use of sectional design methods results in unnecessarily conservative structures. The application of strut-and-tie methods often results in more efficient structural designs that better represent the load carrying mechanisms of the members. However, these procedures are based on various implicit assumptions that did not originally contemplate the use of longitudinal and/or transverse FRP reinforcement. Additionally, existing American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO LRFD) methods for the design of deep beams using strut-and-tie methods are general in nature, and not tailored to the structural typologies typically used by NCDOT. The proposed research will investigate the use of internal FRP for both longitudinal and transverse reinforcement, and will develop recommended design procedures for typical bridge substructure components in North Carolina. 
The overall research objective is to develop recommendations and procedures for the design and assessment of deep FRP reinforced concrete substructure components in North Carolina. The following is a detailed list of research objectives: (1) Identify candidate bridge substructure components that the NCDOT uses, are classified as deep beams, and are strong candidates for implementing internal FRP reinforcement. (2) Conduct several large-scale experiments to investigate the response of deep members designed using FRP (CFRP and GFRP) for both the longitudinal and transverse reinforcement. (3) Conduct nonlinear finite element modelling to supplement experimental results. (4) Develop procedures for the design of FRP reinforced deep beams based on the AASHTO LRFD strut-and-tie method. (5) Provide recommendations that can be implemented into the NCDOT workflow for the design of bridge substructure components with FRP reinforcement. 
These anticipated research products will result from completion of the proposed tasks: 
(1) Procedures to conduct strut-and-tie design and analysis of deep FRP reinforced bridge substructure components for candidate and common structures identified. (2) Nonlinear finite element analysis results for FRP reinforced substructure component designs including predicted performance at service and ultimate loads. (3) Results from large-scale experiments of representative component designs. (4) Recommendations for changes to the Structure Management Unit Design Manual and overall Structures Management Unit policies. (5) Guidance and documentation for the implementation of the developed procedures into existing NCDOT workflows. (6) Design examples and associated workshops to explain the procedures and processes developed. 
]]></description>
      <pubDate>Thu, 08 Aug 2024 10:59:49 GMT</pubDate>
      <guid>https://rip.trb.org/View/2414054</guid>
    </item>
    <item>
      <title>Role Of Grout And GFRP Slip Liner On The Circumferential Behaviour Of Retrofitted Corroded Metal Culverts </title>
      <link>https://rip.trb.org/View/2404267</link>
      <description><![CDATA[For any aging infrastructure, its probability of failure increases with time. There are a multitude of ways to repair and rehabilitate deteriorating pipes, and as the infrastructure system continues to age, it is important to understand and promote the use of effective and durable materials for retrofit. Fiber reinforced polymer (FRP) composites have shown to offer an attractive alternative to replace the deteriorating steel in structural corrugated metal pipes (CMPs). FRP composites have significantly improved durability characteristics compared to steel, which will reduce maintenance costs and improve lifecycle costs. Other materials such as HDPE slip liners for retrofit are in existence but their durability and improvement to load carrying capacities is under question. Past experimental work has shown GFRP to be a suitable material for developing composite action with corroded steel using a polymer grout. Longitudinal testing of corroded CMP with glass fiber reinforced polymer (GFRP) slip liners has garnered interest of the New Mexico DOT. However, field conditions are more circumferential dominant behaviors, and no data exist on this performance measure for CMPs with GFRP slip liners. The proposed work will help evaluate the parameters obtained from circumferential bending necessary to develop design for field implementation using GFRP slip liners with different grouts for corroded culvert retrofit. ]]></description>
      <pubDate>Sun, 21 Jul 2024 14:59:54 GMT</pubDate>
      <guid>https://rip.trb.org/View/2404267</guid>
    </item>
    <item>
      <title>Design and Detailing of Anchorages for Externally Bonded CFRP - Phase 2</title>
      <link>https://rip.trb.org/View/2353877</link>
      <description><![CDATA[The results of this research will investigate improving the process and efficiency of repairing bridge girders that have insufficient shear capacity with CFRPs. This could result in fewer bridges needing replacement due to insufficient capacity, allowing a more optimized design, and reducing the construction time of the repair. The primary objective of this research is to evaluate the performance of the proposed details and to compare the performance of various anchoring methods.]]></description>
      <pubDate>Mon, 03 Jun 2024 14:48:10 GMT</pubDate>
      <guid>https://rip.trb.org/View/2353877</guid>
    </item>
    <item>
      <title>Extraction and Physio-Mechanical Testing of FRP Reinforcing Bars from 5-year-old Seawater Concrete Test Blocks on Halls River Bridge Bulkhead</title>
      <link>https://rip.trb.org/View/2377933</link>
      <description><![CDATA[The primary objective is to review the limitation of using BFRP rebar in submerged conditions, as currently stated in the Structures Manual Volume 4 by extracting concrete test blocks containing FRP reinforcing bars from the Halls River Bridge bulkhead cap, and performing tests as indicated in this scope on BFRP and GFRP bars, and CFRP strands embedded in the test blocks.]]></description>
      <pubDate>Mon, 03 Jun 2024 14:31:29 GMT</pubDate>
      <guid>https://rip.trb.org/View/2377933</guid>
    </item>
    <item>
      <title>Investigating the Long-Term Durability of CFRP Repairs for Bridges Under Environmental Conditions (4.16)</title>
      <link>https://rip.trb.org/View/2373993</link>
      <description><![CDATA[Carbon fiber-reinforced polymers (CFRP) have been widely used for bridge repair and
strengthening because of their high strength-to-weight ratio, corrosion resistance, and ease of installation. However, the long-term durability of CFRP repairs under harsh environmental conditions remains unclear. Accumulated damage resulting from mechanical loading and environmental degradation, such as moisture, freezing, and thermal aging, may cause unpredictable damage to the infrastructure. To address this issue, this project aims to investigate the combined effects of fatigue and environmental aging on the durability of CFRP. The project employs a range of theoretical and computational methods to explore the impact of these factors on the mechanical properties of CFRP repairs. These methods multi-scale modeling of environmentally and mechanically conditioned samples to simulate the effects of moisture and temperature changes. The project results are expected to provide valuable insights into the long-
term durability of CFRP repairs, which can help ensure the safety and reliability of bridges that have been repaired with CFRP. The project outcomes may have practical implications for bridge design and maintenance as well as for the wider adoption of CFRP as a repair and strengthening material in civil infrastructure.]]></description>
      <pubDate>Thu, 09 May 2024 13:59:25 GMT</pubDate>
      <guid>https://rip.trb.org/View/2373993</guid>
    </item>
  </channel>
</rss>