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    <title>Transport Research International Documentation (TRID)</title>
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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>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Interpretation of very long-term basic creep tests of concrete</title>
      <link>https://trid.trb.org/View/1899478</link>
      <description><![CDATA[The prediction of very long-term delayed deformation of concrete is particularly important for prestressed structures. This deformation has a number of components, one of which is basic creep, which is the deformation of the concrete under loading, in the absence of any exchange of water with the environment. Analysis of experimental results shows that this component can be expressed as a logarithmic function of time. However, some very long-term tests seem to show a deviation from this trend. The aim of this article is to demonstrate that these deviations can be explained by experimental artefacts (either parasitic drying or leaching of the concrete).]]></description>
      <pubDate>Tue, 21 Dec 2021 16:46:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899478</guid>
    </item>
    <item>
      <title>Modeling Long-term Delayed Strains of Prestressed Concrete with Real Temperature and Relative Humidity History</title>
      <link>https://trid.trb.org/View/1899363</link>
      <description><![CDATA[The prediction of delayed strains is very important in prestressed concrete structures.  Temperature and relative humidity of concrete structures are two important parameters for this prediction and, on site, are varying over time. Based on model code 2010 and superposition principle, we propose an analytical method to take into account these varying temperature and relative humidity. The coupling between delayed strain of concrete and relaxation of stress in prestressing bars are also considered. We validate the proposed method against in-situ measurement on the mockup of VeRCoRs which is a 1/3 scale mockup of a biaxially prestressed confining building. In the end, we discuss the importance of taking into account the coupling between delayed strain and relaxation of stress, the influence of varying temperature on delayed strain of concrete and also the value of Poisson's ratio of drying creep.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:39:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899363</guid>
    </item>
    <item>
      <title>Prediction of the basic creep of concrete with high substitution of Portland cement by mineral additions at early age - Basic creep of concrete with high slag content</title>
      <link>https://trid.trb.org/View/1899297</link>
      <description><![CDATA[The present work analyses the basic creep of concrete compositions for which 75% of Portland cement is substituted by limestone filler and/or blast furnace slag. Compressive creep tests are performed during and after the peak of hydration of the slag in order to track the effect of the slag on the development of the creep properties. An adapted version of the Model Code 2010 (MC2010) is used to model basic creep. It is observed that the high substitution rate of cement by limestone filler and/or slag leads to a significant change in the evolution of the viscoelastic properties of concrete till a significant degree of reaction of slag is reached. It corresponds to the end of the second peak of hydration due to slag. After the slag peak of hydration, the basic creep is similar to ordinary Portland cement concrete with equivalent water-to-binder ratio. For very early age, a new model is developed and is composed of two terms which consider the hydration of (i) Portland cement and (ii) slag in the aging of the specific creep function.]]></description>
      <pubDate>Tue, 21 Dec 2021 16:36:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/1899297</guid>
    </item>
    <item>
      <title>Time evolutions of non-aging viscoelastic Poisson's ratio of concrete and
implications for creep of C-S-H</title>
      <link>https://trid.trb.org/View/1491808</link>
      <description><![CDATA[The viscoelastic Poisson's ratio of concrete is an essential parameter to study creep and loss of prestress in biaxially prestressed structures. Here we first aim to scrutinize the various existing definitions of this ratio. We then analyze all creep data of concrete available in literature that make it possible to compute the evolutions of this viscoelastic Poisson's ratio, which, for mature concrete, is found to remain roughly constant or slightly decrease over time, such as to reach a long-term value always comprised between 0.15 and 0.2. Then, the long-term viscoelastic Poisson's ratio of concrete is downscaled to the level of calcium silicate hydrates (noted C-S-H) with micromechanics. The long-term viscoelastic Poisson's ratio of the C-SH gel is found to range between 0 and 0.2. Finally, the identification of this range is used to discuss various potential creep mechanisms at the level of the C-S-H particles.]]></description>
      <pubDate>Thu, 14 Dec 2017 15:58:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1491808</guid>
    </item>
    <item>
      <title>Long term basic creep behavior of high performance concrete: data and modelling</title>
      <link>https://trid.trb.org/View/1491751</link>
      <description><![CDATA[This paper presents long term creep data from high performance concretes (HPC) sourced from different research programs or civil engineering projects carried out at IFSTTAR's Paris laboratory, France. The authors are now making all this data publicly available through a data archive. The experimental procedures are described in detail, in particular that used to verify the constancy over time of the specimens' compressive stress. It is shown that the majority of the concretes exhibit linear long-term behavior when plotted against log (time). Indeed, the paper describes modelling sourced from the literature, based on a logarithmic function of time which, despite its simplicity, matches the experimental data quite well. Using this modelling, we studied the behavior of HPC prepared from the same set of constituents. We have shown that the logarithmic change in creep is a quasi linear function of the water to cement ratio and aggregate concentration. Finally, the accuracy of the fib MC2010 model code has been tested on IFSTTAR's data bank.]]></description>
      <pubDate>Thu, 14 Dec 2017 15:54:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1491751</guid>
    </item>
    <item>
      <title>Theoretical and practical differences between creep and relaxation Poisson's ratios in linear viscoelasticity</title>
      <link>https://trid.trb.org/View/1460342</link>
      <description><![CDATA[Poisson's ratio is a well-defined parameter in elasticity. For time-dependent materials, multiple definitions based on the ratios between lateral and axial deformations are available. Here, we focus ourselves on the two most widely used definitions in the time domain, which define time-dependent functions that we call relaxation Poisson's ratio and creep Poisson's ratio. Those two ratios are theoretically different, but are linked in an exact manner through an equation we derive. We show that those two functions are equal at both initial and large times and that their derivatives with respect to time also are. Based on simple rheological models for both the deviatoric and volumetric creep behaviors, we perform a parametric study and show that the difference between those two time-dependent Poisson's ratios can be significant. However, based on creep data available in the literature, we show that, for cementitious materials, this difference can be negligible or not, depending on the case.]]></description>
      <pubDate>Fri, 17 Mar 2017 10:38:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1460342</guid>
    </item>
    <item>
      <title>Concrete early age basic creep: Experiments and test of rheological modelling approaches</title>
      <link>https://trid.trb.org/View/1267953</link>
      <description><![CDATA[At early-age, hydration of cement leads to a reduction of volume (caused by the Le Chatelier contraction) which induces autogeneous shrinkage. Besides, hydration is an exothermic reaction and an increase of temperature occurs (followed by a decrease). As autogeneous shrinkage arises only in cement paste and as coefficient of thermal expansion may be different between cement paste and aggregates, strains incompatibilities lead to an internal self-equilibrated state of stress. Depending especially on the concrete mix, initial cracking may occur at the cement paste scale leading to a modification of the global concrete behavior. In this contribution, finite element simulations using a mesoscopic mesh are performed to access to the internal stresses and damage state due to the hydration process. Calculations take into account the autogenous shrinkage of the cement paste and the differential thermal behavior between cement paste and aggregates. Influence of basic creep strains, thermal boundary conditions and concrete mix (by a simplified approach) are studied showing that, for an ordinary concrete, hydration lead to a slight reduction of 'elastic' stiffness and tensile strength when creep is taken into account. On contrary on a high performance concrete, a significant reduction of the 'elastic' stiffness and tensile strength is expected (with respect to the potential tensile strength) even if the creep is taken into account.]]></description>
      <pubDate>Thu, 07 Nov 2013 11:49:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1267953</guid>
    </item>
    <item>
      <title>Innovative experimental device for the
creep characterization of the concrete/FRP adhesive bond</title>
      <link>https://trid.trb.org/View/1262652</link>
      <description><![CDATA[During its life-time, a bonded assembly is subjected to various ageing mechanisms which may induce synergistic effects. In the case of civil structures strengthened by bonded fiber reinforced polymer (FRP), the influence of coupled mechanical/environmental factors is still a matter of investigation. In this context, an innovative experimental device has been designed to study the durability of concrete/FRP interfaces subjected to both sustained load and hydrothermal ageing. This test setup is able to load simultaneously several double shear specimens and can then be installed in a climatic chamber in order to superimpose accelerated ageing conditions to the creep load. Besides, the design of the test-bodies is compatible with an existing single shear method that allows to determine the residual capacity of aged specimens. This paper aims at describing the proposed creep test setup and its instrumentation, as well as the validation stages, including a comparison of preliminary experimental data with simple analytical and finite element modeling approaches.]]></description>
      <pubDate>Tue, 17 Sep 2013 11:42:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1262652</guid>
    </item>
    <item>
      <title>Predictions des deformations permanentes des materiaux de chaussees</title>
      <link>https://trid.trb.org/View/1124419</link>
      <description><![CDATA[Pour etudier les deformations permanentes des enrobes bitumineux, la division SMIT du LCPC a mis au point un essai triaxial thermoregule a pression de confinement constante. Un important travail de mise au point de l'essai et de verification des mesures a ete realise. Une premiere campagne experimentale, portant sur des essais de fluage a contrainte imposee, a permis d'etudier l'influence des parametres pression de confinement, deviateur de contraintes et temperature sur le comportement des enrobes bitumineux sous chargement statique. Ces essais ont, de plus, permis de valider le principe d'equivalence temps temperature en grandes deformations, avec confinement. Un modele elasto-viscoplastique, permettant de prendre en compte l'application d'une pression de confinement, a ete developpe pour simuler les essais de fluage. Son principe est base sur les observations experimentales. Les applications visees sont l'etude de structures bitumineuses telles que les plates-formes industrielles ou aires de stationnement. Une deuxieme campagne d'essais de compression cyclique sinusoidale a ensuite ete menee. L'influence des parametres pression de confinement, temperature et frequence a ete etudiee. Des differences importantes de comportement ont ete mises en evidence entre les essais statiques et cycliques, liees a la variation cyclique des contraintes. (A).]]></description>
      <pubDate>Tue, 13 Dec 2011 08:25:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1124419</guid>
    </item>
    <item>
      <title>Essais de fluage confines et thermo-regules sur enrobes bitumineux : experimentation et modelisation</title>
      <link>https://trid.trb.org/View/1124406</link>
      <description><![CDATA[Pour etudier les deformations permanentes des enrobes bitumineux, un essai triaxial thermo-regule a ete mis au point. Des essais de fluage statique a differents deviateurs, confinements et differentes temperatures ont permis d'etudier l'influence de ces parametres sur le comportement des enrobes. Un modele viscoelastique-viscoplastique a ete developpe et presente de bonnes capacites pour simuler les essais de fluage. (A).]]></description>
      <pubDate>Tue, 13 Dec 2011 08:24:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1124406</guid>
    </item>
    <item>
      <title>Essais de fluage en compression, en traction et en flexion pour l'etude des comportements differes des betons a hauts niveaux de contraintes</title>
      <link>https://trid.trb.org/View/1097455</link>
      <description><![CDATA[Le Laboratoire Central des Ponts et Chaussees (LCPC) a choisi d'investir du temps et des moyens dans la mise en place de campagnes experimentales relatives a l'etude du comportement en fluage des betons. Cette thematique, bien qu'etudiee depuis de nombreuses annees, souffre aujourd'hui encore, d'une meconnaissance des mecanismes physiques a la base de ce phenomene. Apporter des elements nouveaux pour identifier ces mecanismes, sur la base d'experimentations completes et bien maitrisees a ete l'un des objectifs de l'operation de recherche 11P062 sur la « Mesure de l'impact de la fissuration sur le comportement et la durabilite des structures en composites cimentaires ». Le Laboratoire s'est ainsi equipe d'un ensemble de dispositifs experimentaux pour la mise en oeuvre d'essais sous chargements maintenus en compression, en traction et en flexion a differents niveaux de contrainte, dans une ambiance controlee en temperature et en humidite relative. Ce document presente les choix technologiques faits pour la mise en place de ces nouveaux dispositifs. (A).]]></description>
      <pubDate>Wed, 23 Mar 2011 10:16:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/1097455</guid>
    </item>
    <item>
      <title>CRITERE POSSIBLE POUR ANALYSER LE COMPORTEMENT D'ENROBES BITUMINEUX POUR TRAVAUX ROUTIERS, EN EMPLOYANT LA METHODE MARSHALL.</title>
      <link>https://trid.trb.org/View/1081774</link>
      <description><![CDATA[ON ETABLIT DES RAPPORTS ENTRE DIFFERENTES VARIABLES QUI DETERMINENT LE COMPORTEMENT DES ENROBES BITUMINEUX : STABILITE, FLUAGE, POURCENTAGE DE VIDES, TENEUR EN LIANT ET DENSITE. ON EN TIRE DES CONCLUSIONS EN LES COMPARANT  AUX CRITERES LIMITES MARSHALL OU AU RAPPORT STABILITE/FLUAGE. L'ANALYSE EST ILLUSTREE PAR UN EXEMPLE D'APPLICATION PRATIQUE.]]></description>
      <pubDate>Sun, 21 Nov 2010 18:47:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1081774</guid>
    </item>
    <item>
      <title>LA DETERMINATION DES PROPRIETES DES MATERIAUX EN VUE DU DIMENSIONNEMENT DES CHAUSSEES.</title>
      <link>https://trid.trb.org/View/1081478</link>
      <description><![CDATA[POUR LES GRAVES TRAITEES AUX LIANTS HYDRAULIQUES, ON DETERMINE LE MODULE D'ELASTICITE ; LE COMPORTEMENT A LA FATIGUE ; LA FISSURATION DE RETRAIT EST ETUDIEE A PARTIR DE LA DEFORMATION A LA RUPTURE EN TRACTION DIRECTE. POUR LES MATERIAUX BITUMINEUX, ON DETERMINE LES VALEURS DE MODULE PAR ESSAIS DE MODULE COMPLEXE OU ESSAIS DE RELAXATION ; LE COMPORTEMENT A LA FATIGUE EST ETUDIE EN FLEXION A DEFORMATION IMPOSEE ; ON DETERMINE EGALEMENT A L'AIDE D'ESSAIS DE TRACTION DIRECTE LES DEFORMATIONS ET RESISTANCES A LA RUPTURE. ENFIN LA RESISTANCE EST ETUDIEE PAR PASSAGE REPETE D'UNE ROUE CHARGEE, OU PAR L'ESSAI DE FLUAGE EN COMPRESSION.(A)]]></description>
      <pubDate>Sun, 21 Nov 2010 18:38:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/1081478</guid>
    </item>
    <item>
      <title>LES ENROBES AU BITUME.</title>
      <link>https://trid.trb.org/View/1081350</link>
      <description><![CDATA[CETTE MONOGRAPHIE PASSE EN REVUE DANS UNE PREMIERE PARTIE TOUTES LES LOIS  GENERALES AUXQUELLES OBEISSENT LES DIVERS TYPES D'ENROBES ET MASTICS, Y COMPRIS CEUX UTILISES EN CONSTRUCTION ROUTIERE. LA CONNAISSANCE DE CES LOIS GENERALES PERMET, D'APRES L'AUTEUR, DE DETERMINER LES CARACTERISTIQUES D'UN ENROBE DE COMPOSITION DONNEE CONNAISSANT SEULEMENT LA PENETRATION ET LE POINT DE RAMOLLISSEMENT BILLE ET ANNEAU DU BITUME. DES TABLEAUX PERMETTENT DE CONNAITRE LA RESISTANCE ET LA DEFORMABILITE D'UN ENROBE EN FONCTION DE LA DUREE D'APPLICATION D'UNE CONTRAINTE ET DE LA TEMPERATURE. DANS UNE DEUXIEME PARTIE DE L'OUVRAGE L'AUTEUR ETUDIE L'INFLUENCE DES CONDITIONS REELLES DE MISE EN OEUVRE (TYPE DE COMPACTAGE, CONDITIONS METEOROLOGIQUES, ETC) SUR LA RESISTANCE DES REVETEMENTS A DIVERSES SOLLICITATIONS.(A)   (9446 : CHAUSSEES - M. BONNOT)]]></description>
      <pubDate>Sun, 21 Nov 2010 18:34:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1081350</guid>
    </item>
    <item>
      <title>MANUEL DE CALCUL CEB-FIP - EFFETS STRUCTURAUX DES DEFORMATIONS DIFFEREES DU BETON (DEUXIEME PROPOSITION DE REDACTION - FEVRIER 1972).</title>
      <link>https://trid.trb.org/View/1081308</link>
      <description><![CDATA[LE BUT DE CE MANUEL EST D'OFFRIR LES MOYENS D'EVALUER LES EFFETS STRUCTURAUX DU COMPORTEMENT DU BETON DANS LE TEMPS (C'EST-A-DIRE D'EFFECTUER UNE ETUDE DE FLUAGE DU BETON DES OUVRAGES); LE PRINCIPE DE BASE CONSISTE A PRESENTER DES SOLUTIONS MATHEMATIQUES A LA PORTEE DES PROJETEURS. ON TROUVE DANS LE PREMIER CHAPITRE UNE DISCUSSION CRITIQUE DES METHODES DONT ON DISPOSE ACTUELLEMENT POUR LES ANALYSES DE FLUAGE; ON RETIENT POUR LES APPLICATIONS LES METHODES PERMETTANT D'OBTENIR UNE INTERPRETATION SATISFAISANTE DU COMPORTEMENT DU BETON A L'AIDE DE FORMULES MATHEMATIQUES ELEMENTAIRES. ON PREND EN CONSIDERATION DEUX NIVEAUX D'APPROXIMATION. POUR LE PREMIER DEGRE,  ON PRESENTE UNE METHODE BASEE SUR UNE LOI DE FLUAGE SIMPLIFIEE. POUR LE SECOND, ON PROPOSE DEUX METHODES, DONT L'UNE NECESSITE L'UTILISATION D'UN ORDINATEUR. LE SECOND CHAPITRE EST DEVOLU A L'UTILISATION PRATIQUE DES METHODES PROPOSEES ET AUX CHOIX DES VALEURS NUMERIQUES A INTRODUIRE POUR LA RESOLUTION DES EQUATIONS. ON ETUDIE DANS LE TROISIEME CHAPITRE QUELQUES UNS  DES PROBLEMES LES PLUS USUELS DE L'ANALYSE DE FLUAGE ET EN DONNE LES FORMULES DE RESOLUTION SOUS UNE FORME PERMETTANT LEUR APPLICATION DIRECTE.]]></description>
      <pubDate>Sun, 21 Nov 2010 18:33:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/1081308</guid>
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