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    <title>Transport Research International Documentation (TRID)</title>
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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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    <item>
      <title>DEM Modelling of Unbound Granular Materials for Transport Infrastructures : on soil fabric and rockfill embankments</title>
      <link>https://trid.trb.org/View/1876027</link>
      <description><![CDATA[Unbound granular materials (UGM) are widely used as load-bearing layers and for embankment construction within transport infrastructures. These play a significant role on operation and maintenance of transportation systems. However, pavement and railway engineering still today rely heavily on empirical models based on macroscopic observations. This approach results in limited knowledge on the fundamentals at particle scale dictating the macroscopic response of the material. In this sense, the discrete element method (DEM) presents a numerical alternative to study the behaviour of discrete systems with explicit consideration of processes at particulate level. Additionally, it allows obtaining information at particulate level in a way that cannot be matched by traditional laboratory testing. All of this, in turn, can result in greater micromechanical insight.This thesis aims at contributing to the body of knowledge of the fundamentals of granular matter. UGM for transport infrastructures are studied by means of DEM in order to gain insight on their response under cyclic loading. Two main issues are considered: (1) soil fabric and its effect on the performance of coarse-fine mixtures and (2) modelling of high rockfill railway embankments. Among the main contributions of this research there is the establishing of a unified soil fabric classification system based exclusively on force transmission considerations that furthermore correlates with performance. In particular, fabrics characterized by a strong interaction between the coarse and fine fractions resulted in improved performance. A soil fabric type with a potential for instability was also identified. Regarding embankments, DEM modelling shows that traffic induced settlements accumulate on the top layers and therefore seem to be unaffected by embankment height above a certain value. A marked influence of degradation, even considering its nearly negligible magnitude, was observed, largely resulting in increased settlements.]]></description>
      <pubDate>Wed, 01 Sep 2021 14:27:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/1876027</guid>
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    <item>
      <title>Monitoring und Analyse des Grobstaubvorkommen </title>
      <link>https://trid.trb.org/View/1508285</link>
      <description><![CDATA[Internationale Studien aus den letzten Jahren lassen eine deutliche Klimaveraenderung in den kommenden Jahrzehnten erwarten. Klimamodelle prognostizieren zunehmende regionale Starkwind- und Sturmereignisse. Diese koennen die Verkehrssicherheit durch Aufwirbelung und Verfrachtung von lockerem Bodenmaterial gefaehrden. Darueber hinaus kann ein temperaturbedingter Anstieg von Reifen-Abriebspartikeln dazu fuehren, dass die Massenkonzentration im Bereich der Partikelfraktion 2,5 bis 10 µm deutlich zunimmt und zu PM10-Grenzwertueberschreitungen fuehren kann. Neben der Gefaehrdung der Verkehrssicherheit und den moeglichen Ueberschreitungen der Luftschadstoffgrenzwerte koennen mit dem Klimawandel einhergehende extreme Wetterereignisse auch dazu fuehren, dass die Lebensdauer vom Bauwerk Strasse erheblich beeintraechtigt wird und ein erhoehter Strassen-Oberflaechenabrieb stattfindet. Es wurde ein Langzeitmonitoring realisiert werden, das den Einfluss des Klimawandels auf die Grobstaubentwicklung an Verkehrswegen quantitativ und qualitativ erfasst, und mit dessen Ergebnissen ein entsprechendes Gefaehrdungspotenzial sowie geeignete Vermeidungsmassnahmen eruiert werden koennen. ABSTRACT IN ENGLISH: International studies of recent years indicate a marked change in climate in the coming decades. Climate models predict a rise in regional strong wind and storm events. They can endanger traffic safety by raising and transporting loose soil material. A temperature-related rise in tyre abrasion particles can also lead to a distinct increase in mass concentration in the particle fraction range from 2.5 to 10 µm and to the overstepping of PM10 thresholds. In addition to endangering traffic safety and exceeding air pollutant thresholds, climate change-related extreme weather events can also mean that the useful life of road structures is impaired considerably and the road surface abrasion increased. Long-term monitoring will be implemented to quantitatively and qualitatively record the influence of climate change on the development of coarse dust on traffic routes. A corresponding hazard potential and suitable avoidance measures can be determined from the results. ]]></description>
      <pubDate>Tue, 22 May 2018 03:24:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1508285</guid>
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    <item>
      <title>THE COMPACTION OF AGGREGATES IN MARSHALL SAMPLES WITH RESPECT TO PARTICLE COMPOSITION, THE WIDTH OF THE GRADATION AREA AND THE SAMPLE SIZE</title>
      <link>https://trid.trb.org/View/1063899</link>
      <description><![CDATA[FOR MANY YEARS THE CHARACTERISTIC VALUES OF THE MARSHALL SAMPLE HAVE REPRESENTED THE CRITERIA FOR EVALUATING THE SUITABILITY AND QUALITY OF BITUMINOUS MIXTURES.  THE BULK DENSITY OF THE MARSHALL SAMPLE GIVES THE REFERENCE  VALUE FOR EVALUATING THE LAYING OF ROLLED ASPHALT COURSES (DEGREE OF COMPACTION).  THE PROBLEM LIES IN THE PRODUCTION OF THE MARSHALL SAMPLE FOR COARSE-GRAINED BITUMINOUS MIXTURES, AND IN PARTICULAR THOSE CONTAINING COARSE CHIPPINGS (GAP GRADING).  THE OBJECT OF THE STUDY IS TO FIND REASONS FOR THE DECREASE IN THE COMPACTION OF THE SAMPLE IN THE CASE OF COARSE-GRAINED OR GAP-GRADED MIXTURES, AND THE EFFECT OF THE VOIDS FILLING H (INDEX A), WHICH DECREASES WITH PARTICLE SIZE, ON THE COMPACTION PROPERTIES OF THE BITUMINOUS MIXTURES.]]></description>
      <pubDate>Sun, 21 Nov 2010 08:47:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1063899</guid>
    </item>
    <item>
      <title>WATER PERMEABILITY AND FILTER PROPERTIES OF SOLID POROUS BODIES</title>
      <link>https://trid.trb.org/View/1050574</link>
      <description><![CDATA[IN THIS DOCUMENT A DESCRIPTION IS GIVEN OF BASIC TESTS FOR DETERMINING THE PERMEABILITY WITH RESPECT TO WATER AND FILTER PROPERTIES OF THIN FILTER PLATES (10 CM DIAMETER, 2 CMS HIGH) MADE OF SYNTHETIC RESIN BOUND BROKEN STONE MATERIAL.  FILTERS WERE PERMEATED BY SUSPENSIONS WITH SOIL MATERIAL CONSISTING OF FINE SAND OR COARSE SILT WITH A HYDRAULIC GRADIENT OF 1 : 1 TO 1 : 4.  THE PERMEABILITY WAS DETERMINED IN RELATION TO THE HYDRAULIC GRADIENTS, THE DEGREE OF WATER SATURATION, THE VOID CONTENT, THE AIR CONTENT AND THE PHYSICAL PROPERTIES OF THE WATER, ALL OF WHICH WERE STUDIED AND EMPIRICAL EQUATIONS FOR THE RELATIONSHIPS BETWEEN THE VARIABLES WERE ESTABLISHED.  FURTHERMORE, THE CONDITIONS FOR THE PARTICLE TRANSPORTATION OF THE FINE FRACTIONS OF THE SUSPENSION IN THE FILTER WERE STUDIED.  WITH UNIFORM  HYDRAULIC GRADIENTS FLUSHING OUT OF THE FINE FRACTIONS FROM THE FILTER HARDLY EVER OCCURRED, ALTHOUGH IT DID HAPPEN WHERE THERE WAS FREQUENT CHANGE IN THE PRESSURE LEVELS.  WITH A RATIO U = 4 OF THE MEAN PORE DIAMETER DPM TO THE LARGEST PARTICLE SIZE D MAX OF THE FINE FRACTIONS, ALMOST ALL FINE GRAINS WERE FLUSHED OUT.  ON THE OTHER HAND, WITH A RATIO U = 1, ALMOST ALL THE FINE FRACTIONS REMAINED IN THE FILTER AND CLOGGED IT.  THE TERZAGHI FILTER RULE WAS CONFIRMED AS CORRECT.]]></description>
      <pubDate>Sun, 21 Nov 2010 01:46:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/1050574</guid>
    </item>
    <item>
      <title>LASER AND ULTRASONIC SYSTEMS FOR THE AUTOMATION OF ROAD PAVEMENT MACHINES</title>
      <link>https://trid.trb.org/View/1004884</link>
      <description><![CDATA[El primer sistema automatico de nivelacion instalado en Espana fue en la Autovia Andujar-Villa del Rio en una motoniveladora CAT-16G.  En dicha obra existia un problema con el suelo seleccionado.  Era una zahorra de buena calidad, pero con abundancia de material grueso.  Obtener la rasante definitiva en el extendido, compactacion y refino dentro de las condiciones exigidas era realmente dificil.  La obtencion de la rasante geometrica del suelo seleccionado era muy costosa y practicamente imposible.  Consecuencia de ello, se procedio a la instalacion en una motoniveladora CAT-16G de equipos automaticos de ultrasonidos.  De esta forma, se fueron aprobando geometricamente la capa de material seleccionado y mejorando tanto los rendimientos como la calidad, personal, trabajo topografico, coste, etc.  Titulo en frances: "Systemes laser et ultrasons pour l'automatisation des machines sur chaussees".  Ver ficha general IRRD 401001.]]></description>
      <pubDate>Sat, 20 Nov 2010 02:16:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1004884</guid>
    </item>
    <item>
      <title>QUALITY CONTROL OF EMBANKMENTS. PROPOSAL OF NEW METHODS</title>
      <link>https://trid.trb.org/View/1000439</link>
      <description><![CDATA[Las operaciones de control de calidad de terraplenes se basan normalmente en la determinacion de densidades in situ y en la realizacion de placas de carga, cuando las densidades son dificiles de realizar. Por otra parte, la normativa actual exige unas cualidades a los terraplenes en cuanto a clasificacion de materiales y solo cita la densidad como ensayo de control in situ.  Ante la gran variedad de terrenos que pueden utilizarse y las escasas especificaciones que actualmente estan disponibles se propone un sistema de control de calidad basado en las siguientes premisas: La clasificacion de terraplenes, suelos mixtos y pedraplenes ha de estar claramente delimitada.  En terraplenes y suelos mixtos, o sea suelos con materiales gruesos, los criterios de aceptacion o clasificacion se tienen que basar en: granulometria, plasticidad, CBR y materia organica y ademas en nuevos criterios que hagan intervenir: humedad, variacion del CBR con la humedad, y alterabilidad.  Los ensayos propuestos tienen como objetivo completar estos criterios de aceptacion o clasificacion, mediante una propuesta concreta de metodos. Los ensayos de control in situ se basan principalmente en la densidad pero es necesario hacer intervenir tambien humedad y capacidad de soporte.  Los ensayos propuestos de control de calidad in situ completan estos criterios mediante una propuesta de metodos que incluye sistemas de aplicacion de penetrometros dinamicos y placas de carga.  El conjunto del trabajo presentado puede considerarse como una propuesta de norma de control de calidad para la ejecucion de terraplenes y explanaciones.  Se incluyen graficos y tablas con resultados de ensayos realizados.  Ver ficha general IRRD 401692.]]></description>
      <pubDate>Sat, 20 Nov 2010 00:01:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/1000439</guid>
    </item>
    <item>
      <title>TREATMENT OF A SUBGRADE IN THE BOTTOM OF A CUTTING</title>
      <link>https://trid.trb.org/View/1000426</link>
      <description><![CDATA[Se presenta una serie de medidas aplicadas para aumentar la capacidad portante en desmontes que se encuentran anegados en agua.  En primer lugar se realiza un drenaje profundo para rebajar el nivel freatico de la explanacion y, en segundo lugar, aumentar la capacidad portante de dicha explanada. Para ello el sistema puesto en obra consiste en: colocacion de un geotextil, extendido de arena de rio lavada, extendido y compactacion de material grueso, colocacion de otro geotextil, y extendido de un suelo seleccionado que constituira la coronacion de la explanada.  Se incluyen figuras y graficos con resultados de ensayos de suelos realizados: analisis granulometrico, CBR, proctor, etc.  Ver ficha general IRRD 401692.]]></description>
      <pubDate>Sat, 20 Nov 2010 00:00:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/1000426</guid>
    </item>
    <item>
      <title>EMPLOYMENT AND BEHAVIOUR OF GYPSIFEROUS MATERIALS IN BACKFILLS</title>
      <link>https://trid.trb.org/View/1000423</link>
      <description><![CDATA[Se analizan los distintos tipos litologicos en que se presenta el yeso en la naturaleza, con especial atencion al comportamiento deformacional del yeso masivo de cara a su empleo en pedraplenes o rellenos, teniendo en cuenta la resistencia de la roca matriz y las condiciones granulometricas de puesta en obra, asi como la presencia de otros materiales inertes en rellenos tipo todo-uno.  Se comenta la influencia de las propiedades reologicas del yeso sobre los asientos diferidos y se discute el comportamiento de algunos terraplenes construidos en la zona de Aragon en donde se han medido importantes asientos postconstructivos.  Se indican algunas recomendaciones respecto a las condiciones de empleo de estos materiales en futuros pedraplenes y rellenos. Se incluyen graficos.  Ver ficha general IRRD 401692.]]></description>
      <pubDate>Sat, 20 Nov 2010 00:00:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1000423</guid>
    </item>
    <item>
      <title>INFLUENCE OF GRANULOMETRY AND THE MAXIMUM SIZE ON THE SHEARING STRENGTH OF ROCKFILLS</title>
      <link>https://trid.trb.org/View/1000422</link>
      <description><![CDATA[Es frecuente efectuar los ensayos de material grueso(como el de escollera que se coloca en el cuerpo de pedraplenes) sobre una granulometria sensiblemente paralela a la original, pero limitando el tamano maximo de la misma.  Para conocer la influencia que tiene el tamano maximo de particulas ensayado en el angulo de rozamiento interno de una escollera, se esta llevando a cabo en el Laboratorio de Geotecnia del CEDEX un estudio al respecto mediante la realizacion de ensayos de resistencia al corte.  Para ello se han efectuado en material inferior a 20 centimetros ensayos granulometricos, diferenciandose tres granulometrias (gruesa, media y fina), sobre las que se han efectuado ensayos triaxiales sobre probetas, tanto en material semisaturado como saturado. Se analizan en este articulo los primeros resultados obtenidos como por ejemplo que existe una pequena diferencia entre ensayar material semisaturado y saturado, y que el angulo de rozamiento disminuye a medida que aumenta la presion confinante.  Se incluyen graficos y tablas con resultados de los ensayos realizados.  Ver ficha general IRRD 401692.]]></description>
      <pubDate>Sat, 20 Nov 2010 00:00:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1000422</guid>
    </item>
    <item>
      <title>Road performance experiment of rock slag mixture</title>
      <link>https://trid.trb.org/View/935022</link>
      <description><![CDATA[Based on the variability of rock property, material gradation and water content of rock slag mixture, several tests are carried out to study compaction, indoor bearing-ratio (CBR), expansion, crash in water and reboundmodulus of rock slag mixture with different gradations and coarse material content.,the biggest dry density almost remains the same; the value of CBR of rock slag mixture is much more than those of common soil,and even ifcoarse material content is 0, the value of CBR still can meet the demandsof specification; rock slag mix-ture is not expansive material, and it has high water stability; with coarse material content becoming more, the value of rebound modulus of rock slag mixture increases.]]></description>
      <pubDate>Thu, 30 Sep 2010 11:09:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/935022</guid>
    </item>
    <item>
      <title>Influence of coarse aggregate on the permeation, durability and the microstructure characteristics of ordinary Portland cement concrete</title>
      <link>https://trid.trb.org/View/769899</link>
      <description><![CDATA[Reinforced concrete structures in marine and similar environmental conditions have to withstand severe exposures. Due to this, the mix design procedures have to be revised to include durability as a primary criterion along with strength and workability. In line with this need, an investigation was carried out at Queen's University Belfast with the financial help of the Department of Environment, Transport and the Regions, UK. The main objective of the research was to understand the influence of mix parameters on workability, strength, durability and microstructure and to propose a new mix design procedure within which durability has a higher priority. The present paper reports part of this study, which investigates the effect of size and grading of the coarse aggregate on the durability and the microstructure characteristics of concrete. The durability tests carried out included air permeability test, freeze-thaw/salt scaling resistance test and an accelerated carbonation test. The microstructure study was carried out using a scanning electron microscope (SEM) and included image analysis of the interfacial transition zone (ITZ) around the coarse aggregate. The results indicated that as the proportion of larger size aggregate increases in the mix, the local porosity at the ITZ increases and the overall durability decreases. It has also been found that reducing the average aggregate size in a mix improves the pore structure and enhances the durability of the concrete. (A) "Reprinted with permission from Elsevier".]]></description>
      <pubDate>Wed, 21 Dec 2005 15:12:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/769899</guid>
    </item>
    <item>
      <title>AN EXPERIMENTAL INVESTIGATION CONCERNING THE COMPREHENSIVE FRACTURE TOUGHNESS OF SOME BRITTLE ROCKS</title>
      <link>https://trid.trb.org/View/217882</link>
      <description><![CDATA[This paper deals with an experimental investigation of comprehensive fracture toughness of syenite and basalt rocks by using a testing procedure which consists of three-point bending, asymmetric three-point bending and four-point shear tests.  The results obtained show that the curve of rock fracture toughness of various modes can be approximated by an empirical quadratic equation.  The experimental data may be correlated with acoustic velocity, as well as with other mechanical parameters such as uniaxial compressive and tensile strength, modulus of elasticity, and so on. The observations from the tests show that the various characteristics of rock fracture such as the critical stress intensity factors, notch displacement, fracture toughness ratio, and fracture angle are found to be dependent upon the petrological composition, grain size etc. Obvious decrease of fracture toughness for syenite rock with coarser grains implies that there is an influence of the mineral components, rock structure, the grain boundary cracks and intergranular cracks.  From this point of view, the relation between the fracture toughness and the physico-mechanical properties of rocks may be understood through the characteristics of the rock microstructure.  (TRRL)]]></description>
      <pubDate>Wed, 25 Aug 2004 02:39:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/217882</guid>
    </item>
    <item>
      <title>IN-SITU ACCELERATED TESTING OF BITUMINOUS MIXTURES</title>
      <link>https://trid.trb.org/View/685482</link>
      <description><![CDATA[The in-service behaviour of a standard Irish Dense Base Coarse Macadam mixture (DBC) was evaluated by using the material to overlay a road section, which was based upon a weak pavement structure. The response of the layer under a fully laden dual axle truck was examined using a series of pressure cells and asphalt strain gauges that were embedded in the test section. The test section was traversed repeatedly until a network of fatigue cracks was observed on the road surface. The transverse horizontal tensile strain was found to be the most critical parameter with respect to crack initiation. When based on in-situ measured strain data, the analytical model that was developed to predict pavement performance on the basis of fundamental laboratory test data, was found to underestimate the in-service fatigue life of the DBC mixture by a factor of 13.5. The underestimation may be attributed to factors that are not accounted for in the analytical models such as material healing, traffic wander and in-situ environmental conditions, which possibly lead to lower fatigue estimates. (A)]]></description>
      <pubDate>Tue, 13 Jan 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/685482</guid>
    </item>
    <item>
      <title>PILOT STUDY INTO THE APPLICATION POSSIBILITIES OF COARSE GRAVEL</title>
      <link>https://trid.trb.org/View/735012</link>
      <description><![CDATA[An assessment has been made of where coarse gravel can be used, which obstacles there are and whether these obstacles can be removed. A distinction was made between obstacles as regards norms and standard regulations, processing, the market and the design. It is possible to use coarse gravel in the following applications: unreinforced and reinforced concrete, lean concrete in road construction, bedding courses of concrete pavements in road construction, ballast material on flat roofs, filling for cribs and garden applications.]]></description>
      <pubDate>Fri, 04 Apr 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/735012</guid>
    </item>
    <item>
      <title>A STUDY OF GROUND COARSE FLY ASHES WITH DIFFERENT FINENESSES FROM VARIOUS SOURCES AS POZZOLANIC MATERIALS</title>
      <link>https://trid.trb.org/View/693868</link>
      <description><![CDATA[The aim of this study is to evaluate the properties of ground coarse fly ashes, from five sources in Thailand, the shapes, sizes, and chemical compositions of which are completely different. Coarse fly ash was fractionated by an air classifier and ground into three different finenesses ranging from median particle sizes of 1.9-17.2 microns. Physical and chemical properties of the Portland cement and the fly ashes were investigated. Mortar cubes of 5 cm were cast with 20% replacement by weight of Portland cement with ground coarse fly ash. The compressive strengths of the fly ash-cement mortars were determined and compared with the control mortar. The results revealed that the degree of pozzolanic reaction, as determined using compressive strength, of coarse fly ash increased when its fineness was increased by grinding. The strength activity indices of the original fly ash-cement mortars at the curing ages of 7 and 28 days were in the range of 69-82% and 76-90%, respectively. When the particle size smaller than 9 microns of ground coarse fly ash was used, the strength activity index achieved was over 100% of that of the control within 28 days. The results also showed that the fineness of fly ash, not the chemical composition, was the major factor affecting the strength activity index of ground coarse fly ash-cement mortar. (A)]]></description>
      <pubDate>Thu, 04 Oct 2001 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/693868</guid>
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