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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <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>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Seismic performance of piers reinforced with GFRP/steel bars and double spiral stirrups</title>
      <link>https://trid.trb.org/View/2563207</link>
      <description><![CDATA[Conventional hybrid-reinforced piers have unresolved issues of seismic-induced shear failure and steel bar corrosion. To solve these problems, a corrosion-resist pier structure reinforced with GFRP/steel bars and double spiral stirrups is proposed. Eight piers were tested and compared under horizontal quasi-static reciprocating loading. The influence of parameters on the seismic performance of the piers was investigated, including the reinforcement configuration, spiral core diameter, core longitudinal bar diameter and shear span ratio. The test results show that all the specimens had a flexural failure. The double spiral stirrups configuration provides multiple confinements on concrete, improves the bearing and energy dissipation capacity of piers, and avoids the shear failure in piers. At the same time, corrosion of steel bars is prevented because the outer steel bars are replaced by GFRP bars. While the peak loads of the hybrid-reinforced piers were a little smaller than those of the steel-reinforced piers, their ductility, ultimate displacement and plastic hinge length improved significantly. A parameter analysis of finite element models was made to determine the influence of the spiral core diameter, core longitudinal bar diameter, concrete strength and outer GFRP longitudinal bar diameter on the peak load of the piers. The results show that increasing the outer and interior longitudinal bar diameters and spiral core diameter can improve the structural stiffness and bearing capacity of the piers effectively. This study provides reference for the safety design of bridge substructures under offshore earthquake actions.]]></description>
      <pubDate>Tue, 08 Jul 2025 09:56:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2563207</guid>
    </item>
    <item>
      <title>Experimental and Analytical Investigation of Shear Behavior and Strength of Haunched Beams Reinforced with Basalt Fiber–Reinforced Polymer Rebars</title>
      <link>https://trid.trb.org/View/2464460</link>
      <description><![CDATA[Tapered beams are characterized by varying moments of inertia along their span, commonly the pier cap configuration used in bridge construction. This study presents the shear behavior of tapered beams reinforced with basalt fiber–reinforced polymer (BFRP) bars through experiments and analyses. Eight BFRP beams were tested to explore the influence of changing inclination angles and the presence of BFRP stirrups. These beams were divided into two groups, each consisting of four beams: one control straight beam and three tapered beams with different tapered angles. The first group was without shear reinforcement, while the second group was reinforced with BFRP stirrups. Results revealed that increasing tapered angles decreased the shear strength of BFRP tapered beams without stirrups but increased it in beams with BFRP stirrups. The analytical part proposed equations to estimate the shear strength of BFRP tapered beams, with findings indicating conservative estimations consistent with experimental data trends.]]></description>
      <pubDate>Mon, 27 Jan 2025 15:11:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2464460</guid>
    </item>
    <item>
      <title>Design Criteria for Overhanging Ends of Bent Caps</title>
      <link>https://trid.trb.org/View/2427466</link>
      <description><![CDATA[A program of 36 bent cap sections of 36 in. depth was tested in an investigation primarily directed to the bond and shear strengths which should be used in design. Intermediate, A432, and A431 grade steels were used. Even though the final failures were often classified as bond or shear only 8% of the specimens failed at less than the calculated f sub y steel stress. The average f sub s developed was between 1.15 f sub y and 1.20 f sub y. In shear it was found that an ultimate v much higher than allowed by current specifications was feasible for loads placed between 0.5d and 1.2d from the support. Vertical stirrups added no perceptible strength but horizontal web steel was effective. In bond it was found that the nominal bond stress in the length between load and support was not important, but that an end anchorage distance beyond the load was essential. With an end anchorage of 15 in. for #11 bars or 12 in. for #8 bars, there seemed to be no problem in developing a 75 ksi steel. The width of web cracks was only slightly less than that of flexural cracks on the tension face and suggested the desirability of using horizontal stirrups in these cantilever ends.]]></description>
      <pubDate>Mon, 16 Sep 2024 10:31:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2427466</guid>
    </item>
    <item>
      <title>Contribution of Stirrups to Shear Resistance</title>
      <link>https://trid.trb.org/View/2235583</link>
      <description><![CDATA[While the parallel chord truss model is a universally accepted model for evaluating the contributions of stirrups to the shear capacity of slender beams, codes-of-practice provide very different mean of evaluating the angle of diagonal compression of the struts in this truss model. This angle controls the contribution of shear reinforcement as the number of stirrups "n" to be counted as lifting the diagonal compressive force up a vertical tie in the truss is proportional to the cotangent of the angle of diagonal compression relative to the longitudinal axis of the beam. ACI318-08 assumes that this angle of diagonal compression is 45 degrees, while the AASHTO LRFD Bridge Design Specifications and EuroCode2 allow much flatter angles of diagonal compression to be used. The effect is that the contribution of in-place stirrups in a particular beam by one approach can be close to 3 times that calculated by another approach. The basis and appropriateness of different approaches are explored.]]></description>
      <pubDate>Mon, 24 Jun 2024 09:31:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/2235583</guid>
    </item>
    <item>
      <title>Shear behavior of externally prestressed ultra-high-performance concrete (UHPC) T-beams without stirrups</title>
      <link>https://trid.trb.org/View/2166786</link>
      <description><![CDATA[Externally prestressed ultra-high-performance concrete (UHPC) beams without stirrups (EPUBs-WS) that simplify the reinforcement design and construction procedure are becoming a competitive option in bridge engineering. To investigate the shear behavior of EPUBs-WS, five specimens were designed and tested considering several critical parameters, such as the shear span-to-depth ratio (λ), shear stirrups, and longitudinal reinforcement ratio. The EPUBs-WS exhibits diagonal tension failure as the fibers pull out and the specimen shears off into two parts along the critical diagonal crack. However, the beam with λ = 3.67 exhibited flexural failure due to the large λ. The stiffness, shear-cracking strength, and shear strength of EPUBs-WS decrease as λ increases. Stirrups enhance the shear resistance of EPUBs but result in a more brittle shear failure mode. A higher reinforcement ratio augments the dowel action in EPUBs-WS, which contributes to a ductile shear failure mechanism. The web-shear cracking force accounts for 46% to 87% of the shear capacity, implying that the shear-cracking strength is a significant factor in the design of EPUBs-WS. An equation for predicting the shear-cracking strength of prestressed UHPC beams is proposed and validated using a database of experimental results reported in the literature. A parametric analysis is performed using 40 available specimens to investigate the effects of compressive strength, λ, reinforcement ratio, fiber reinforcing index, and prestressing level on the shear strength of prestressed UHPC beams without stirrups. By considering the key parameters, equations for estimating the shear strength are proposed and exhibit good accuracy.]]></description>
      <pubDate>Wed, 28 Jun 2023 16:29:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2166786</guid>
    </item>
    <item>
      <title>Influence of stirrup ratio on vehicular impact resistance of double-column RC bridge piers</title>
      <link>https://trid.trb.org/View/2174026</link>
      <description><![CDATA[Vehicular collision is a typical lateral consecutive impact process. Under such an impact process, reinforced concrete (RC) bridge piers commonly suffer shear failure or punching-shear breakage, which could further cause the collapse of the bridges, especially for the simply-supported double-column RC bridges. The current work experimentally and numerically investigates the influence of stirrup ratio on the lateral consecutive impact resistance of double-column RC bridge piers (DCBPs). Firstly, a scaled lateral consecutive impact test is conducted on three DCBP specimens (containing impacted pier, adjacent pier and bent cap) to examine the influence of stirrup ratio on the dynamic behaviors at component level. Then, finite element (FE) models of the impact test are established and validated against the experimental results. Finally, refined numerical simulations of light, medium and heavy trucks colliding with a prototype simply-supported double-column RC bridge are performed at structural level to analyze the influence of stirrup ratio on dynamic shear capacity and deformation of the impacted RC piers, and anti-collapse performance of the bridges. The results derive that, (i) The impacted piers exhibit shear failure at the impact location, and the damage degree is significantly reduced with increasing stirrup ratio. However, the damage degree of adjacent piers and bent caps is not obviously influenced by the change of stirrup ratio; (ii) A higher stirrup ratio effectively achieves less stiffness degradation and smaller lateral deformation of the impacted piers under the first impact, that allows DCBPs to resist a higher second impact force; (iii) The deformation shape of the impacted piers is changed from the localized deformation to the global deformation with the increase of stirrup ratio, while such a variation does not occur to the adjacent piers; (iv) As the stirrup ratio increasing, the simply-supported double-column RC bridge can withstand a higher dynamic shear demand induced by vehicular collisions, and therefore decreases the global damage and collapse probability, especially when subjected to heavy truck collisions.]]></description>
      <pubDate>Wed, 28 Jun 2023 16:29:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/2174026</guid>
    </item>
    <item>
      <title>Fatigue safety assessment of longitudinal and transverse reinforcements for concrete girder bridge designs</title>
      <link>https://trid.trb.org/View/2058594</link>
      <description><![CDATA[Highway concrete bridges are subjected to fatigue, with stress cycles from the traffic defining the fatigue lives of reinforcement and concrete. Most existing studies on fatigue reliability of bridges address bending, ignoring the fatigue effect on stirrups. This paper evaluates the service life and reliability indexes, from the fatigue point of view, of longitudinal and transverse reinforcements of several concrete girders (prestressed and reinforced) for new bridge designs. Traffic loads are considered as measured by a high-speed weigh-in-motion system at an important highway in Brazil. It is found that reliability indexes for longitudinal reinforcements tend to decrease with the increase of “span length/girder height” ratio and reliability indexes for stirrups tend to increase with the introduction of intermediate crossbeams. Safety levels of stirrups are usually found to be lower than those of longitudinal rebars and tendons, especially for reinforced girders. It is found that deterministic fatigue live estimates lower than 50 years correspond to unsatisfactory reliability indexes (probabilistic analysis).]]></description>
      <pubDate>Wed, 30 Nov 2022 16:56:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2058594</guid>
    </item>
    <item>
      <title>Understanding Reinforcement Behavior Using Distributed Measurements of Shear Tests</title>
      <link>https://trid.trb.org/View/1854323</link>
      <description><![CDATA[The use of distributed fiber-optic strain sensors (FOS) has the potential to allow for reinforced concrete behavior to be quantified and understood with a new level of detail. In this investigation, three large reinforced concrete (RC) beams—JP-1, JP-2, and JP-3—with varying percentages of transverse reinforcement, were tested in three-point bending. Distributed FOS were installed on the longitudinal and transverse reinforcement bars, enabling identification and quantification of a number of behavioral mechanisms. These included stirrup demands at all depths and locations in the member, variations in longitudinal bar strain at the support based on shear demand, and bending of longitudinal bars from stirrup hook anchorage. After longitudinal bar yielding, the development and growth of a plastic hinge was monitored in specimen JP-3 under increasing plastic rotation. Simultaneously, the stirrup strains increased despite being subjected to a near-constant shear force, especially near the critical section for shear.]]></description>
      <pubDate>Wed, 30 Jun 2021 12:00:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/1854323</guid>
    </item>
    <item>
      <title>Basic Installations for Reinforced Concrete Arch Pipe</title>
      <link>https://trid.trb.org/View/1759347</link>
      <description><![CDATA[Beginning in 2018, the precast concrete pipe producers of the Minnesota Concrete Pipe Association (MnCPA) worked with the Minnesota Department of Transportation (MnDOT) to update the standards for reinforced concrete arch pipe. The MnDOT standard plates include steel reinforcement areas for both circumferential steel and transverse steel (stirrups) where required. The latest MnDOT standards include pipe classes in accordance with American Association of State Highway and Transportation Officials (AASHTO) M206 (or ASTM C506) as well as some larger sizes and higher strength classes that are not included in the AASHTO standard. The reinforcement designs for these larger sizes were performed in accordance with the 8th Edition of the AASHTO LRFD Bridge Design Specifications and were formulated to encompass the worst of either the loads from the field installation, or the testing loads in three-edge bearing. The three-edge bearing test requirements tended to govern the required steel area for transverse reinforcement. However, the field conditions governed the extent to which the transverse reinforcement needs to extend out from the invert of the pipe.]]></description>
      <pubDate>Thu, 04 Feb 2021 10:57:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/1759347</guid>
    </item>
    <item>
      <title>Development and testing of precast concrete beam-to-column connections with high-strength hooked bars under cyclic loading</title>
      <link>https://trid.trb.org/View/1710869</link>
      <description><![CDATA[A traditional reinforcing detail—hooked bars anchored in the joint core—for the bottom bars in precast beams was improved by using small-diameter high-strength bars to reduce the steel congestion in the cast-in-place connection zone. Five full-scale beam-to-column connections, including a monolithic specimen, were tested under reversed cyclic loading. The primary test variables were the type of beam longitudinal bars, manner of roughening the inner surface of the precast U-shell, presence or absence of the small-diameter stirrups inside the U-shell, and height of the precast columns. An analysis of the strength, ductility, stiffness, and energy dissipation showed that the proposed connection exhibited a comparable, although slightly inferior, seismic performance relative to the monolithic connection. Among the precast specimens, the existence of additional stirrups slightly improved the total performance. The use of high-strength steel bars as beam top longitudinal bars further decreased the loading capacity and energy dissipation. The air bubble film technique used to roughen the interfaces ensured the structural integrity.]]></description>
      <pubDate>Tue, 23 Jun 2020 12:26:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1710869</guid>
    </item>
    <item>
      <title>Shear behavior degradation and failure pattern of reinforced concrete beam with chloride-induced stirrup corrosion</title>
      <link>https://trid.trb.org/View/1710863</link>
      <description><![CDATA[Reinforcement corrosion exhibits an adverse effect on the shear strength of reinforced concrete structures. In order to investigate the effects of chloride-induced corrosion of reinforcing steel on the shear behavior and failure pattern of reinforced concrete beams, a total of 24 reinforced concrete beams with different concrete strength grades and arrangements of stirrups were fabricated, among which 22 beams were subjected to accelerated corrosion to achieve different degrees of reinforcement corrosion. The failure pattern, crack propagation, load–displacement response, and ultimate strength of these beams were investigated under a standard four-point loading test in this study. Extensive comparative analysis was conducted to investigate the effects of the concrete strength, shear span-to-depth ratio, and stirrup type on the shear behavior of the corroded reinforced concrete beams. The results show that increasing the stirrup yielding strength is more effective in improving the shear strength of corroded reinforced concrete beams than that of concrete compressive strength. In terms of three types of stirrups, the shear strength of the beams with deformed HRB-335 is least sensitive to stirrup corrosion, followed by the beams with smooth HPB-235 and the beams with deformed HRB-400. The effect of the different stirrups on the shear strength depends on the corrosion degree of stirrup and shear span-to-depth ratio of the beam. The predicted results of shear strength of corroded reinforced concrete beams by a proposed analytical model are well consistent with the experimental results.]]></description>
      <pubDate>Tue, 23 Jun 2020 12:26:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1710863</guid>
    </item>
    <item>
      <title>Experimental Investigation on Shear Fatigue Behavior of Reinforced Concrete Beams with Corroded Stirrups</title>
      <link>https://trid.trb.org/View/1570722</link>
      <description><![CDATA[Stirrups in RC beams are more vulnerable to corrosion than longitudinal steel bars due to the thinner concrete cover, and the shear behavior may deteriorate faster than the flexural behavior under fatigue loading. An experimental study was conducted to investigate the deterioration mechanism of the shear fatigue behavior of RC beams with corroded stirrups. RC beams were corroded by an impressed current before fatigue loading was applied. The fatigue test results showed that all beams failed with fatigue fracturing of the stirrup, and the corrosion of stirrups had a significant influence on the shear fatigue behavior and fatigue life of RC beams. It was observed that fatigue cracks initiated and propagated rapidly around corrosion pits, and the stirrup fractured at the minimum cross section where the corrosion pits had formed. The strains in the stirrups, longitudinal steel bars, and concrete increased with an increase in the number of loading cycles, and a significant increase of the midspan deflection was observed in all beams. With the increasing corrosion degree of stirrups and load amplitude, the stress amplitude of the stirrups increased obviously, especially at the minimum cross section, and the stress concentration at the corrosion pits put the stirrups in a more adverse situation, resulting in faster deterioration of the shear fatigue behavior and a decrease in the fatigue life of RC beams with corroded stirrups.]]></description>
      <pubDate>Thu, 06 Dec 2018 17:24:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1570722</guid>
    </item>
    <item>
      <title>Structural Behavior of Ultra High Performance Concrete Beams Without Stirrups</title>
      <link>https://trid.trb.org/View/1496331</link>
      <description><![CDATA[This paper presents comparative behavior of Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) beams under flexural and shear loading. Four large scale UHPFRC beams with different reinforcement ratios were tested under dominant shear and flexure loading. The beams were not provided with any shear reinforcement in order to take advantage of high tensile strength offered by UHPFRC. Two of the beams were tested under dominant shear loading and remaining two beams were tested under dominant flexural loading. Comparative results indicate that UHPFRC beams, without stirrups, subjected to shear loading did not experience any reduction in either ductility or moment capacity. This enhancement in performance can be attributed to improved tensile cracking resistance, and enhanced shear strength due to bridging effect of fibers in Ultra-High Performance Concrete (UHPC).]]></description>
      <pubDate>Thu, 25 Jan 2018 09:34:04 GMT</pubDate>
      <guid>https://trid.trb.org/View/1496331</guid>
    </item>
    <item>
      <title>Methods for Calculating Shear Capacity on Oblique Section of Bending Members Strengthened with Enlarged Section</title>
      <link>https://trid.trb.org/View/1485855</link>
      <description><![CDATA[The authors infer that several equations currently used to calculate the bearing capacity of an oblique section of a member strengthened with an enlarged section have several mistakes in the specifications for strengthening the design of highway bridges (JTG/T J22—2008). The shear capacity of the oblique section of a bending member strengthened with an enlarged section could be more accurately and safely calculated using contrastive analysis of relevant design specifications and engineering calculation examples. The authors particularly challenged the calculation method in which the new stirrups bear the second increased shear based on the proportion of the section area of all web reinforcements. They proposed two calculation methods which can be applied to the general case of unilateral thickening of the member section and the reinforcement of three sides. The authors also tested an engineering example. The second proposed method, which considered the comprehensive shear capacity of concrete and stirrups, is simple and relatively safe. This method is unified with the design specification of an ordinary bridge component. The proposed method will be adopted in the technical specifications for strengthening of urban bridges which will be enacted soon.]]></description>
      <pubDate>Fri, 29 Dec 2017 09:35:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/1485855</guid>
    </item>
    <item>
      <title>Shear design considering interaction between steel stirrups and carbon fiber-reinforced polymer strips</title>
      <link>https://trid.trb.org/View/1482186</link>
      <description><![CDATA[Conventional shear-strength relations provide conservative estimates for the design strength of new members. However, when members are strengthened with carbon fiber-reinforced polymer (CFRP) vertical strips, the traditional approach of independently summing the concrete, steel, and CFRP contributions to shear strength was found to overestimate the strength increase due to the CFRP material. Thus, modification factors ksF and kfS are proposed to modify the shear-strength equations in ACI 440.2R and account for the interaction between steel and CFRP transverse reinforcement. The proposed factors provide more accurate and less conservative estimates of shear strength of concrete beams, with improved estimates of the strength increase when CFRP materials are added.]]></description>
      <pubDate>Thu, 28 Sep 2017 17:19:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1482186</guid>
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