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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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    <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>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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      <title>Performance damage evolution of asphalt mixture under large/quick humidity-temperature fluctuation cycles</title>
      <link>https://trid.trb.org/View/2577395</link>
      <description><![CDATA[The humidity-temperature effect has been recognized as a major cause of asphalt pavement failure in southern regions of China. To study the characteristics of asphalt pavement materials under frequent high-temperature/cloudburst/high-temperature (large/quick humidity-temperature fluctuation cycles, HTF cycles) conditions, Abaqus and ArcGIS software were used to determine the parameters for HTF cycles laboratory test. Simulated tests were conducted on three-layer rutting specimens/Marshall specimens using a self-designed HTF cycles environment chamber. Finally, the specimens were subsequently sectioned, and performance tests were conducted using uniaxial compression tests, flexural creep tests, and indirect tensile fatigue tests (stress ratios were 0.3, 0.4, and 0.5). Based on the test results, curve fitting and fatigue performance damage models were established. The study indicated that a rainfall intensity of 30 mm/h and a pavement surface temperature of 70 ℃ should be set as the parameters for HTF cycles test. The mechanical properties and high-temperature performance of asphalt mixtures were significantly reduced under these conditions, with a more severe impact observed in middle layer materials (dense-graded asphalt concrete with a maximum nominal aggregate size of 20 mm, AC-20). In contrast, the fatigue performance of upper layer materials (stone matrix asphalt with a maximum nominal aggregate size of 13 mm, SMA-13) was more notably degraded. After 50 cycles of HTF cycles, the flexural tensile strength and compressive strength of the AC-20 mixture exhibited reductions of 61.2 % and 51.7 %, respectively. Meanwhile, the fatigue life of the SMA-13 mixture decreased by 74.3 % under a controlled stress ratio of 0.5. The correlation analysis reveals that the influence of HTF cycles loses prominence under conditions of a high-stress ratio to fatigue performance. The coefficient of determination of the established equation for predicting fatigue performance exceeded 0.9 and has good predictive accuracy. The findings offer practical guidelines for material selection and pavement design for the southern coastal regions of China.]]></description>
      <pubDate>Thu, 31 Jul 2025 09:25:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2577395</guid>
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    <item>
      <title>Robust Methods for UHPC Early-Strength Determination and Quality Control for ABC</title>
      <link>https://trid.trb.org/View/2534054</link>
      <description><![CDATA[Overall, this research showed that the maturity method is applicable for ultra-high performance concrete (UHPC) at early ages and can lead to a good strength prediction when proper guidelines as presented in this thesis are adopted. However, the results show that the current existing ASTM C1074 maturity method procedures and recommendations are ineffective in predicting UHPC strength for ages of one day and less. Also, the 4"×4"×4" cubes showed better strength predictions than the 3"×6" cylinders at ages less than one-day. Moreover, the Arrhenius method has slightly better results than the Nurse-Saul. Finally, new maturity constants were proposed, the lab breaking points' ages were determined, and new curve fitting equations were developed and proposed to predict the UHPC strength with minimal errors. Furthermore, cubes showed better strength predictions than the cylinders, and since cylinders require surface preparation, this consumes time and makes the quality control results sensitive to the specimens’ preparation procedure especially for early age. Thus, the second part of this research focuses on using cubes as an alternative to cylinders. For such, the size effect of the cubes and cylinders with different sizes and various strength levels from less than 1 ksi to over 20 ksi was studied. Furthermore, other factors were considered such as different fiber content and curing regimes. The mentioned factors helped study the size effect effectively and propose robust conversion factors and functions between specimen shapes and sizes.]]></description>
      <pubDate>Mon, 14 Apr 2025 17:07:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/2534054</guid>
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    <item>
      <title>Prüfung und Bewertung der Dauerhaftigkeit „zeitweise fließfähiger und selbstverdichtender Verfüllbaustoffe (ZFSV)“ im Unterbau von Verkehrsflächen</title>
      <link>https://trid.trb.org/View/2516279</link>
      <description><![CDATA[Zeitweise fließfähige, selbstverdichtende Verfüllbaustoffe (ZFSV) sind Baustoffe, die in der Regel aus einem Basismaterial (zum Beispiel Bodenaushub, rezyklierte oder industrielle Gesteinskörnungen), Zement, Tonmehl, Wasser und eventuell Zusatzstoffen bestehen und im Einbauzustand in flüssiger Konsistenz vorliegen. Durch Zusatzstoffe wie zum Beispiel Beschleuniger und Plastifikatoren können die Eigenschaften des Gemisches angepasst werden. Die Endprodukteigenschaften können mit den in der Bodenmechanik üblichen Kennwerten für die Scherfestigkeit (Reibungswinkel und Kohäsion) und die Steifigkeit beschrieben werden. Je nach Anwendungsbereich sind unterschiedliche Anforderungen an die zeitlich veränderlichen mechanischen und rheologischen Eigenschaften von ZFSV zu stellen, die durch die Wahl geeigneter Mischverhältnisse erzielt werden können. ZFSV sind vergleichsweise neue Baustoffe und werden deswegen nur teilweise im erdbautechnischen Regelwerk berücksichtigt. Die "Zusätzlichen Technischen Vertragsbedingungen und Richtlinien für Erdarbeiten im Straßenbau (ZTVE-StB 17)" geben lediglich vor, dass die Übereinstimmung der Baustoffeigenschaften mit den vorab festgelegten Anforderungen an das zulässige Größtkorn, die Fließfähigkeit, die Tragfähigkeit, die Druckfestigkeit, sowie die Volumen- und Raumbeständigkeit nachzuweisen sind. In den "Hinweisen für die Herstellung und Verwendung von zeitweise fließfähigen, selbstverdichtenden Verfüllbaustoffen im Erdbau (H ZFSV)" werden nur geeignete Baustoffe zur Herstellung von ZFSV und Prüfverfahren zur Bestimmung der Frisch- und Endprodukteigenschaften genannt. Die Frostbeständigkeit sowie die Beständigkeit gegenüber Trocken-Feucht-Wechsel von ZFSV wurde bisher vereinzelt anhand von Prüfverfahren, die für Beton beziehungsweise bindemittelbehandelte Böden entwickelt worden sind, untersucht. Dabei stellte sich jedoch heraus, dass die Versuche insbesondere bei Frostbeanspruchung frühzeitig abgebrochen werden mussten, da die Proben zumeist zu stark beansprucht wurden und bereits während der Versuchsdurchführung zerfielen. Im Projekt wurden ZFSV aus drei unterschiedlichen Basismaterialien (Bodengruppen SE, TL und SU nach DIN 18196) hinsichtlich ihrer Dauerhaftigkeit untersucht. Dabei wurde ein reiner Portlandzement als Bindemittel und Na-Bentonit als Additiv verwendet. Zunächst wurden im Rahmen der Vorversuche Dauerhaftigkeitsversuche in Anlehnung an bestehende nationale und internationale Prüfverfahren für Boden-Bindemittel-Gemische an einem ZFSV aus dem grobkörnigen Basismaterial durchgeführt. Dabei stellte sich heraus, dass diese Verfahren für ZFSV nicht geeignet sind. Die Prüfverfahren wurden dann stufenweise angepasst, bis ein geeignetes Verfahren zur Prüfung der Dauerhaftigkeit von ZFSV gegenüber Frost-Tau-, Trocken-Feucht-Wechsel und Wasserlagerung entwickelt wurde. Im Rahmen weiterer Untersuchungen wurden die drei Prüfverfahren an zwei weiteren ZFSV aus einem feinkörnigem Basismaterial und an drei ZFSV aus dem gemischtkörnigen Basismaterial erfolgreich angewendet. Die Ermittlung des CBR-Wertes war immer möglich, selbst an stark beschädigten Proben (zum Beispiel an einem ZFSV aus dem feinkörnigen Basismaterial mit hohem Ausgangswassergehalt nach drei Frost-Tau-Zyklen). Es war deshalb nicht erforderlich, die im Rahmen der Vorversuche entwickelten Prüfverfahren zu ändern beziehungsweise anzupassen. Für die drei entwickelten Verfahren zur Prüfung der Dauerhaftigkeit von ZFSV gegenüber Frost-Tau- beziehungsweise Trocken-Feucht-Wechsel und Wasserlagerung wurde ein Entwurf für eine Prüfvorschrift in Anlehnung an die "Technischen Prüfvorschriften für Boden und Fels im Straßenbau (TP BF-StB)", Teil B 7.1 formuliert. Im Entwurf sind nicht nur die Prüfverfahren ausführlich beschrieben, sondern es wird auch auf die Probenherstellung und die -lagerung eingegangen. Abschließend wurden unterschiedliche Kriterien zur Bewertung der Dauerhaftigkeit von ZFSV auf Grundlage der Ergebnisse der Dauerhaftigkeitsversuche an den neun untersuchten ZFSV vorgeschlagen. ABSTRACT IN ENGLISH: Controlled low-strength materials (CLSM) are materials that usually consist of a base material (e.g. excavated soil, recycled or industrial aggregates), cement, clay powder, water and possibly additives and have a liquid consistency at the moment of installation. The properties of the mixture can be adjusted by adding additives such as accelerators and plasticizers. The end-product properties can be described with the characteristic values for shear strength (frictional angle and cohesion) and stiffness commonly used in soil mechanics. Depending on the field of application, there are different requirements for the time-varying mechanical and rheological properties of CLSM, which can be achieved by selecting suitable mixing ratios. CLSM are comparatively new materials and are therefore only partially considered in the earthworks regulations. The "Zusätzliche Technische Vertragsbedingungen und Richtlinien für Erdarbeiten im Straßenbau (ZTVE-StB 17)" only specify that the conformity of the material properties with the predefined requirements for the maximum allowed grain size, flowability, load-bearing capacity, compressive strength, volume, and space stability must be demonstrated. The "Hinweise für die Herstellung und Verwendung von zeitweise fließfähigen, selbstverdichtenden Verfüllbaustoffen im Erdbau (H ZFSV)" only specify suitable materials for the preparation of CLSM and test methods for determining the fresh and end product properties. The frost resistance as well as the resistance against wetting-drying cycles of CLSM has been investigated in separated cases using test methods developed for concrete or binder-treated soils. In all cases it turned out that the tests had to be interrupted before end, especially in the case of frost action, because the specimens were too heavily stressed and already disintegrated during the test execution. Within the scope of the research project, CLSM made of three different base materials (soil groups SE, TL and SU according to DIN 18196) were investigated with regard to their durability. A Portland cement was used as binder and Na-bentonite as additive. First of all, durability tests were carried out on a CLSM made from the coarse-grained base material following the existing national and international test methods for soil-binder mixtures. It was found that these methods were not suitable for CLSM. The test methods were then gradually adapted until a suitable method for testing the durability of CLSM against freeze-thaw, wetting-drying cycles and water storage was developed. In further investigations, the three test methods were successfully applied to two additional CLSM made with a fine-grained base material and to three CLSM made with the mixed-grained base material. The determination of the CBR value was always possible, even on severely damaged specimens (e.g. after three freeze-thaw cycles on a CLSM with the fine-grained base material with high initial water content). Therefore, it was not necessary to modify or adapt the test procedures that were developed during the preliminary tests. For the three methods developed for testing the durability of CLSM against freeze-thaw or dry-moist cycles and water storage, a draft for a test procedure was formulated based on "Technische Prüfvorschriften für Boden und Fels im Straßenbau (TP BF-StB)" part B 7.1. The draft does not only describe the test methods in detail, but also presents the sample preparation and storage. Finally, different criteria for the evaluation of the durability of ZFSV are proposed on the basis of the results of the durability tests performed on the nine CLSM.]]></description>
      <pubDate>Wed, 26 Feb 2025 09:09:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/2516279</guid>
    </item>
    <item>
      <title>Influence of Sand and Fiber Type on the Fiber-Bridging Properties of Metakaolin-Based Engineered Geopolymer Composites</title>
      <link>https://trid.trb.org/View/2387005</link>
      <description><![CDATA[This study investigates the physical, mechanical, matrix, and fiber-bridging properties of metakaolin-based engineered geopolymer composites (EGCs) using conventional river sand (RS), or microsilica sand (MS) and polyvinyl alcohol fiber, or ultrahigh molecular weight polyethylene (UHMWPE) fiber. The research evaluated the effects of aggregate type, fiber type, and fiber length (i.e., 10 or 12?mm UHMWPE fiber). Results from compressive strength and single crack tensile tests indicated that the effects of aggregate type, fiber type, and fiber length were statistically similar. All EGC materials manufactured outperformed regular concrete’s compressive strength (30?MPa) by approximately 31%–58% while having densities about 21%–24% lower than that of regular concrete (2.3?g/cm3). The three-point bending test on the notched geopolymer mortars showed that RS specimens exhibited a lower crack tip matrix toughness (Jtip) value than MS, favoring multiple cracking behavior. All EGC specimens displayed promising pseudo-strain-hardening (PSH) behavior, with PSH strength and energy indices exceeding 1.3 and 2.7, respectively. RS-based composites displayed a more robust PSH behavior compared to those with MS. Notably, the study determined that the tensile strain capacity was more influenced by the PSH energy index than by the strength index, with a coefficient of determination of 0.77 supporting this correlation. The standout composite, incorporating RS and 0.8 vol.% 12?mm UHMWPE fiber, achieved exceptional tensile strain capacities of up to 8%. This performance level is comparable to Grade 60 steel reinforcement, highlighting the potential of EGCs as a sustainable and high-strength alternative for civil infrastructure projects.]]></description>
      <pubDate>Wed, 12 Jun 2024 11:09:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/2387005</guid>
    </item>
    <item>
      <title>Behaviour and confinement mechanism of circular concrete-filled aluminum alloy tubular stub columns under axial compression</title>
      <link>https://trid.trb.org/View/2354136</link>
      <description><![CDATA[Concrete-filled steel tubes are widely applied in offshore structures, which often being exposed to aggressive ocean climate. This has recently led to the introduction of concrete-filled aluminum alloy tubular (CFAT) columns, of which aluminum alloy tube is used as a superior anti-corrosion metal material. However, limited research has led to the design of CFAT columns not being included in the current design specifications, limiting their engineering applications. Accordingly, in this paper, an experimental program including 9 CFAT specimens was launched to further investigate the compressive behavior of CFAT short columns and to clarify the confinement mechanism in such columns. The test results indicate that the ultimate capacity of CFAT short columns is improved with the increase of concrete strength or the decrease of tube diameter-to-wall thickness ratio. Based on the experimental results, the finite element model (FEM) was established, and then used to clarify the confinement mechanism of CFAT columns and investigate the effects of the salient parameters on the behavior of such columns. By comparing with the existing experimental results, the accuracy of current strength calculation formulas for CFAT columns was assessed, and the conclusion indicates that there is an unexpected deviation in the prediction results. To this end, a simplified strength prediction formula for CFAT columns was proposed, which successfully introduced a novel confinement factor that well reflects the confinement effect of the concrete core. This confinement factor considers the effects of proof stress, concrete strength, and tube diameter-to-wall thickness ratio. Finally, compared with other formulas, the proposed formula has better performance in predicting results.]]></description>
      <pubDate>Thu, 25 Apr 2024 09:41:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/2354136</guid>
    </item>
    <item>
      <title>Evaluating the Effect of the Compressive Strength Development Factor on Concrete Creep Deformation in Bridge Construction</title>
      <link>https://trid.trb.org/View/2127020</link>
      <description><![CDATA[Excessive midspan deflection is often observed in large-span prestressed concrete girder bridges. In particular, the deformation caused by shrinkage and creep of concrete is an important part of deflection that often exceeds expectations. To achieve creep deformation control, extending the curing time and postponing the loading age are frequently adopted during construction. This article proposed an approach based on creep experiments with prismatic and beam specimens and viscoelastic model-based finite element analyses to evaluate the effect of the concrete strength development factor on the ultimate creep coefficient in the  Comité Euro-International du Béton-Fédération internationale de la précontrainte (CEB-FIP) model. The concrete strength development factor ξcc(t/tu) is defined as the ratio of the mean compressive strength at the loading time to the maximum mean compressive strength obtained in the test. The strategies for targeted regulation and control of ξcc(t/tu) were discussed by establishing an artificial neural networks model for strength prediction from a database provided in the authors' previous work. Uniaxial compressive prismatic specimens and pure bending beam specimens with a span of 5.0 m were used in the experiment for creep behavior observation. A viscoelastic finite element analysis (FEA) model was established based on solidification theory. The FEA model results were verified with measured data for capturing the creep behavior under ambient conditions to obtain reliable long-term creep deformation predictions. Finally, the proposed method was validated with the Xincheng bridge construction for the optimistic loading age determination, and the results indicated good feasibility in girder deflection control.]]></description>
      <pubDate>Tue, 28 Mar 2023 09:56:59 GMT</pubDate>
      <guid>https://trid.trb.org/View/2127020</guid>
    </item>
    <item>
      <title>Axial compressive behavior of stainless steel tube confined concrete column piers</title>
      <link>https://trid.trb.org/View/1852588</link>
      <description><![CDATA[The steel tube confined concrete (STCC) column piers of marine structures have been proposed in recent years. The main advantages of STCC piers include the convenient construction process and improved core concrete strength. This research presents an experimental investigation on stainless steel tube confined concrete (SSTCC) column piers subjected to axial loading. Thirty two specimens were prepared and tested. Test variables included section shape, steel tube thickness, and concrete strength. Failure modes, axial ultimate compressive strength, strain characteristics, rigidity, confinement effect, and ductility were comprehensively investigated. Test results demonstrated that the main failure modes for circular and square specimens were concrete shear failure and steel tube fracture caused by concrete deformation, respectively. The axial compressive ultimate strength was affected by the tube thickness and concrete strength. The ultimate strength increased with the increase in the confinement factor, and the increasing ratio of the circular specimens was five times to that of square specimens. The differences in axial ultimate compressive strength of SSTCC column piers, carbon steel tube confined concrete column piers, and concrete filled steel tube column piers were also analyzed. Increasing tube thickness could increase the ductility and rigidity of the specimens. Moreover, axial ultimate compressive strengths were calculated and discussed based on different calculation models.]]></description>
      <pubDate>Thu, 24 Jun 2021 16:40:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/1852588</guid>
    </item>
    <item>
      <title>Poisson’s Ratio Assessed from Ultrasonic versus Load Test</title>
      <link>https://trid.trb.org/View/1692597</link>
      <description><![CDATA[Fifty-three cored specimens from block samples of partially cemented soil (caliche), collected from the Las Vegas valley, were tested for their Unconfined Compressive Strength (UCS). Deformations of sixteen of these samples were recorded using a compressometer as well as Linear Variable Displacement Transducers (LVDTs). The compressometer, which is more commonly used on concrete cylinder samples, has the advantage in rock sample testing that lateral as well as axial deformation can be measured. Consequently, the equivalent linear secant Poisson’s ratio can be evaluated (μ = -εL / εa) with increasing stress level over the course of the UCS test. All samples were subjected to ultrasonic wave velocities determination prior to UCS tests. Compressional (V‫‫‫p) and shear (Vs) wave velocities were measured using a commercial Ultrasonic Pulse Wave Transducer. The lab velocities were obtained in order to compare with field values from geophysical tests on site. However, from these lab wave velocities, the Poisson’s ratio at zero strain/load were computed and compared with the variation in Poisson’s ratio with increasing stress level based on deformation measurements from the UCS test. Such comparison is the subject of this paper.]]></description>
      <pubDate>Thu, 02 Apr 2020 09:42:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1692597</guid>
    </item>
    <item>
      <title>Evaluation of Sulfate Resistance of Concrete with Recycled and Natural Aggregates</title>
      <link>https://trid.trb.org/View/1483789</link>
      <description><![CDATA[The paper deals with the results of sulfate resistance of eight concrete mixtures with coarse recycled concrete aggregate/natural aggregate, CEMI/CEMIII and two different water-to-cement ratios (w/c). These concretes were immersed in 5% Na2SO4 or 5% MgSO4 solutions for 90, 180 and 365 days. The evaluation of sulfate resistance was done by determination of compressive strength and length change. Concrete specimens submerged in both solutions up to 365 days, containing recycled concrete aggregate, CEM III and both w/c ratios, showed good resistance to sulfate attack. Characteristics related to microstructure (SEM, BSE-EDS, XRD and FTIR) were analysed on the concrete which was not sulfate resistant.]]></description>
      <pubDate>Thu, 30 Nov 2017 09:53:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/1483789</guid>
    </item>
    <item>
      <title>Development of a Mortar Abrasion Test for Fine Aggregates and Wear Resistance of Concrete Pavements - Paper</title>
      <link>https://trid.trb.org/View/1434845</link>
      <description><![CDATA[The cost-effective design of a rigid pavement with exposed Portland cement concrete (PCC) must take into consideration the on-going life cycle costs of maintaining adequate macrotexture and microtexture characteristics, which are essential in providing surface friction. The longevity and durability of the pavement’s surface texture depends on the ability of the selected aggregates to resist polishing and of the total mix to resist abrasion. In PCC pavements, the composition and characteristics of the fine aggregate are a key component in controlling its ability to resist polishing and retain good microtexture. Macrotexture is imparted during construction, e.g., tining, dragging, or through scheduled maintenance, e.g., grinding and grooving. Macrotexture retention in PCC pavements will depend on a number of factors including aggregate type, mix design, and workmanship, e.g., depth of tining, curing.  Currently, there is insufficient development of an adequate test to directly measure the abrasion resistance of concrete as a function of the fine aggregate component and the retention of macrotexture which are directly related to the frictional performance of concrete pavements. Aggregate tests such as acid Insoluble Residue (IR) that evaluates carbonate mineral content and micro-Deval abrasion (MDA) that measures relative durability of fine aggregates are indirectly related to microtexture and macrotexture retention in concrete materials.  This paper presents the development and results of a testing program utilizing equipment originally designed for measuring the Aggregate Abrasion Value (AAV) of coarse aggregates according to British Standards BN ES 1097-8. Mortar coupons were tested on a mechanical wheel lap rotating at 30 revolutions per minute for a total of 500 revolutions while a dry abrasive charge was fed onto the lap at a rate of 800 g per minute in front of each specimen. The average mass loss of four specimens is reported as the mortar abrasion value (MAV). A total of thirty concrete fine aggregates from sources across Ontario were evaluated.  The abrasion loss for each fine aggregate mortar mix was determined at the ages of 7 and 28 days. Results were compared with the compressive strength, insoluble residue, micro-Deval abrasion loss and mineralogy of the aggregates. The determination of the mortar’s resistance to abrasion was dependent on the degree of hydration and bond strength of the cement as demonstrated in comparing 7 day vs 28 day test results. Test results show that sensitivity to abrasion was minimized due to the selected water:cement ratio of the mortar. As a result, with increased curing time, variation in MAV test values was reduced with respect to aggregates of different mineral hardness. Test results show that there was little correlation established between the MAV and the various other parameters tested.]]></description>
      <pubDate>Tue, 15 Nov 2016 16:51:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1434845</guid>
    </item>
    <item>
      <title>Evaluation of Physical and Durability Characteristics of New Headed Glass Fiber–Reinforced Polymer Bars for Concrete Structures</title>
      <link>https://trid.trb.org/View/1419885</link>
      <description><![CDATA[This paper presents the results of a collaborative research project between Quebec’s Ministry of Transportation and Ontario’s Ministry of Transportation, which aimed at characterizing a new type of headed glass fiber-reinforced polymer (GFRP) reinforcing bar and evaluating its suitability as internal reinforcement for concrete structures. To achieve these objectives, the project was implemented in three stages: (1) evaluation of the physical and mechanical properties; (2) determination of the pullout behavior in concrete; and (3) characterization of the long-term durability of the headed GFRP bars. A total of 57 specimens embedded in a 200-mm concrete cube were tested with the direct pullout test to investigate the effect of confinement, bar size, concrete compressive strength, and exposure conditions on the pullout behavior of the headed GFRP bars. Simultaneously, microstructural analyses and measurements of the physicochemical and mechanical properties were carried out on conditioned and unconditioned headed GFRP bars. The results show that the materials, geometry, and interface configuration of the head provided very good mechanical interlocking to the GFRP bars. Up to 63 and 53% of the guaranteed tensile strength of the straight GFRP bars were achieved for 15.9- and 19-mm diameter bars with headed ends, respectively. Scanning electron microscopy and differential scanning calorimetry showed no material changes in the head and bars after exposure to alkaline solution and freeze-thaw cycling. Exposure to the alkaline solution under sustained loading had the most detrimental effect, with the bar retaining 79.4% of its pullout strength. The results indicate that the tested headed GFRP bar has suitable mechanical and durability properties for use as reinforcement in concrete bridge components.]]></description>
      <pubDate>Mon, 29 Aug 2016 11:08:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1419885</guid>
    </item>
    <item>
      <title>Hysteretic behavior of special shaped columns composed of steel and reinforced concrete (SRC)</title>
      <link>https://trid.trb.org/View/1357966</link>
      <description><![CDATA[This paper describes a series of experimental investigations on seventeen specimens of steel reinforced concrete special shaped (SRCSS) columns under low cyclic reversed loading using parallel crosshead equipment. Nine T-shaped SRC columns, four L-shaped SRC columns and four +-shaped SRC columns were tested to examine the effects of shape steel configuration, loading angle, axial compressive ratio and shear-span ratio on the behavior (strength, stiffness, energy dissipation, ductility, etc.) of SRCSS column specimens. The failure modes and hysteretic performance of all the specimens were obtained in the tests. Test results demonstrate that the shear-span ratio is the main parameter affecting the failure modes of SRCSS columns. The specimens with small shear-span ratio are prone to shear failure, and the primary failure planes in SRCSS columns are parallel to the loading direction. As a result, there is a symmetry between positive and negative loading directions in the hysteretic curves of the SRCSS columns. The majority of displacement ductility coefficients for all the specimens are over 3.0, so that the SRCSS columns demonstrate a better deformation capacity. In addition, the equivalent viscous damping coefficients of all the specimens are greater than 0.2, indicating that the seismic behavior of SRCSS columns is adequate. Finally, the superposition theory was used to calculate the limits of axial compressive ratio for the specimens, and it is found that the test axial compressive ratio is close to or smaller than the calculated axial compressive ratio limit.]]></description>
      <pubDate>Fri, 26 Jun 2015 13:42:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1357966</guid>
    </item>
    <item>
      <title>Structural Assessment of "D" Regions Affected by Premature Concrete Deterioration: Technical Report</title>
      <link>https://trid.trb.org/View/1350687</link>
      <description><![CDATA[The current study is a continuation of the earlier study that investigated the effects of Alkali Silica Reaction (ASR) and Delayed Ettringite Formation (DEF) induced deterioration on the D-Regions of structures. Of the four near full-scale C-Beam specimens that were constructed, and conditioned over time as part of the earlier study, the last specimen (Specimen 3), which was field conditioned through the Texas heat along with supplemental water for a period of five years, is the main focus of this study. With time, additional cracks caused by ASR/DEF swelling were observed in addition to the load induced cracks. Based on the deterioration data collected and observations made on Specimen 3, it was classified to show heavy damage due to ASR/DEF deterioration. The experimental test of Specimen 3 which resulted in a brittle shear failure through the beam-column joint, showed a similar failure mechanism to the other three C-Beam specimens. The heavy deterioration caused by ASR/DEF deterioration also did not seem to have any effect on the load carrying capacity of the specimen. However, the response of the specimen was considerably stiffer and less ductile than the earlier tested C-Beam specimens with no, slight, and moderate amounts of deterioration. This is due to the restraint offered to ASR/DEF swelling strain by the reinforcement, which causes tensile strains in the reinforcement. This effectively put the concrete under a state of active prestress. Although no signs of corrosion are observed in the specimen during the deterioration phase, in terms of concrete cover spalling or rust stains in concrete, a considerable amount of corrosion was observed on the reinforcement bars once the cover concrete was removed. A minimalist semi-empirical analysis technique is developed to model the expansion strains caused by ASR/DEF expansion in reinforced concrete. The proposed model takes into account the effects of compressive and tensile prestrains on the expansion strains caused by ASR/DEF, in addition to the daily variations in temperature and humidity. This enables the model to capture the expansion strains in reinforced concrete structures that are exposed to environmental conditions. The model is validated and applied to simulate the expansion strains observed for the C-Beam specimens. Considering the complex nature of the ASR/DEF phenomena, the nature of the structure considered, and the variability in the field recorded data, the model simulates the expansion strains quite well. The Compatibility Strut-and-Tie Modeling (C-STM) technique, which was developed and verified in Phase I of this report, is used to model the force-deformation behavior of C-Beam Specimen 3. The expansion strains that are obtained from the ASR/DEF model is used to compute the prestress loads to be applied in the C-STM technique to account for the effects of ASR/DEF expansion in the model. The C-STM simulates the overall force-deformation and the internal behavior of the structure quite well.]]></description>
      <pubDate>Fri, 24 Apr 2015 10:24:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1350687</guid>
    </item>
    <item>
      <title>Slab Replacement Maturity Guidelines</title>
      <link>https://trid.trb.org/View/1307345</link>
      <description><![CDATA[This study investigated the use of maturity method to determine early age strength of concrete in slab  replacement application. Specific objectives were (1) to evaluate effects of various factors on the compressive maturity-strength relationship of concrete at early age, (2) to develop appropriate test procedures for applying maturity method to predict early age strength of concrete, and (3) to validate the accuracy of the prediction of maturity method using the proposed test procedures.  The maturity method using the Arrhenius maturity function was found to be quite reliable and convenient for use in predicting the early-age compressive strength of concrete in replacement slab application. Some limitations of maturity-strength prediction, such as the strength loss due to high curing temperature and insufficient moisture, supply were observed in the laboratory studies. However, these limitations were observed at the later age of the concrete when the compressive strength reached around 3,000 to 3,500 psi, and thus the observed limitations did not have any negative effect on the early-age-strength prediction of the concrete in the replacement slab.  Using the strength of the protection specimens as strength determination of the in-place concrete is unreliable and may result in over-prediction of its strength. The maturity method using the Arrhenius maturity function is recommended for use to estimate the early-age compressive strength of concrete in slab replacement application. A testing protocol for the generation of maturity-strength curve for prediction of early-age compressive strength of concrete was recommended. The concrete used in the replacement lab must have exactly the same water-cement ratio, mix ingredients, and fresh concrete properties as those of the laboratory concrete used to develop the maturity curve. In the event that differences in fresh concrete properties, with more than ±1 inch in slump and/or ±1 % in air  contents, are observed between the actual concrete used at the project site and the concrete which has been used to develop the maturity-strength curve, the maturity-strength curve should not be used to make strength predictions without proper adjustments of the predicted strengths due to effects of the variations in the fresh concrete properties.]]></description>
      <pubDate>Wed, 28 May 2014 15:26:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1307345</guid>
    </item>
    <item>
      <title>Fluid-Pressured Test to Measure Tensile Strength of Concrete</title>
      <link>https://trid.trb.org/View/1303837</link>
      <description><![CDATA[A fluid-pressured test has been developed as an alternative to measure tensile strength of concrete. This test method covers the determination of the tensile strength of cylindrical concrete specimens with a centered internal hole where a radial internal fluid pressure is applied until failure occurs. This loading condition induces tangential stresses on the specimen; the maximum fluid pressure sustained by the specimen is affected by appropriate geometric factors to obtain a measurement of the tensile strength. Preliminary experimental data suggests that the tensile strength measured with the proposed method is about 17% greater than the tensile strength obtained from splitting tensile tests. Additionally, results of the tensile pressure strength were on average 11% of the compressive strength.]]></description>
      <pubDate>Tue, 22 Apr 2014 16:07:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1303837</guid>
    </item>
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