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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>
    <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>IMPROVEMENT IN THE DAY AND NIGHT VISIBILITY OF SIGNALLING DEVICES. APPLICATIONS OF PHOTOMETRY AND COLORIMETRY</title>
      <link>https://trid.trb.org/View/180407</link>
      <description><![CDATA[This study comes within the scope of the research described in research project IRRD 500733.  Its aim is to widen the knowledge of the efficiency of signalling devices thanks to a better approach to their photometric and colorimetric properties.  It deals with traffic signals and reflecting devices.  Measurements were made of the light intensity, colour and ghosting effect of the different types of traffic signals used in France.  Based on a bibliographic analysis of the visual efficiency of traffic signals and a comparison of measurement results with draft recommendations by the CIE (International Commission for Lighting), elements are proposed for the drafting of future standards.  A measuring method was developed for determining the variation in the light intensity of flashing lights as a function of time for flashes which last approximately 100 microseconds.  It is then possible to calculate their effective light intensity by the Blondel-Rey method.  Their colour is defined using the trichromatic coordinates of the filter.  Among reflecting devices, a special study was conducted of carriageway markings, reflecting studs and reflectorized films.  The values characterizing the photometric and colorimetric properties of this equipment are defined together with methods of measuring them in the laboratory. (TRRL)]]></description>
      <pubDate>Fri, 30 Jul 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/180407</guid>
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    <item>
      <title>THE VIBREX - INFLUENCE OF THE PARAMETERS OF A VIBRATING ROLLER ON COMPACTION EFFICIENCY</title>
      <link>https://trid.trb.org/View/174628</link>
      <description><![CDATA[On an unstabilized, fully crushed, well-graded 0/20 quartzite gravel, compacted in a 30 cm layer, were tested approximately fifty vibrating rollers fitted to an experimental compacting machine: the vibrex.  Each parameter: mass per unit of length of vibration generator, suspended mass/vibrating mass ratio, eccentric moment, vibration frequency, can be varied independently within a wide range of values.  The results show that: (1) the mass ratio must be considered as a design parameter which does not have a marked influence on efficiency, but which must be taken into account for the selection of vibration parameters; (2) a higher value of the mass per unit of length of the generator would enable a high quality of average state of compaction to be reached more rapidly; (3) the higher theoretical amplitude when empty would enable a given requirement of compaction at the bottom of the layer to be reached more quickly; (4) vibration frequency is a parameter that can be of great importance vis-a-vis the efficiency of a machine.  The relative influence of these different parameters was quantified, and a classification of the equipment was established on the basis of the quality it reaches when used at the same limit rate of efficiency, beyond which evolution in quality becomes lower than a given threshold.  Some compactors reach their limit of efficiency in a "useful" number of passes, which varies from one machine to the next, in a relative range of approximately 1 to 2; but it was also observed that over the whole range of the rollers tested, very satisfactory qualities of compaction can be obtained with reduced values of the "useful" number of passes.  (TRRL)]]></description>
      <pubDate>Tue, 30 Mar 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/174628</guid>
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    <item>
      <title>REPAIR OF CRACKED CONCRETE STRUCTURES BY MEANS OF EPOXY BINDER INJECTION</title>
      <link>https://trid.trb.org/View/160991</link>
      <description><![CDATA[Part 1 of the report recalls data on organic binders, mainly epoxy binders.  Criteria are given for the selection of products before use.  Part 2 is a study of the effectiveness of the repair as regards the thermodynamics of the interface - the adhesion of the binder to the support is ensured by the wetting of the concrete surface by the different binder components, then by the binder itself.  An additional study of capillary phenomena shows that the binder advances in the cracks mainly thanks to hydrostatic pressure.  The previous results are compared to those of a mechanical study on a reinforced concrete model: a cracked beam in circular bending is treated under load (open cracks) by injection and subjected to a second flexural test.  It appears that the behaviour of the repaired beam is improved under small loads, but that with greater loads the value of the modulus of elastic is too low and injection defects appear.  Lastly the old cracks reappear completely when the elastic modulus of the reticulated binder is too low.  In the case of incomplete repair it is at the location of badly filled or unfilled cracks that cracking reappears.  When injection is carried out satisfactorily and if the elastic modulus of the reticulated binder is sufficiently high the mechanical behaviour under flexural stress is very near that of the initial beam before cracking. (TRRL)]]></description>
      <pubDate>Wed, 28 Oct 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/160991</guid>
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    <item>
      <title>PRESENT POSSIBILITIES OF USING HYPERFREQUENCIES IN CIVIL ENGINEERING - BIBLIOGRAPHIC STUDY</title>
      <link>https://trid.trb.org/View/172454</link>
      <description><![CDATA[This bibliographic compilation regroups known applications up to June 1979.  The first part concerns physics notions which are the basis of the use of hyperfrequencies.  The laws of propagation in different media enable the characteristics of hyperfrequencies to be outlined together with the possible applications to civil engineering.  Data are provided on the guided propagation of electromagnetic waves, and on the generation and amplifying of hyperfrequencies.  These general data lead to familiarization with the specific terminology and technology.  Part 2 reviews present applications found after searching the IRRD and ASE data bases.  These applications are classified into 2 categories according to the physical characteristics used.  Chapter 1 deals with applications related to propagation characteristics.  These characteristics could bring fresh solutions to various problems such as detection of structural defects, measurement of thickness or geometric characterization of surfaces.  Chapter 2 outlines applications connected to radiation - matter interaction phenomena.  Possibilities exist for measuring the moisture content or temperature of materials.  Numerous energy-related applications of micro-waves are mentioned in fields such as the melting of bitumen compounds, the drying or embrittlement of materials. An annex deals with problems arising from the use of hyperfrequencies, electromagnetic pollution, safety vis-a-vis radiation, and appertaining legislation.  (TRRL)]]></description>
      <pubDate>Wed, 28 Oct 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/172454</guid>
    </item>
    <item>
      <title>FLINDERS UNIVERSITY ELECTRIC RESEARCH VEHICLE</title>
      <link>https://trid.trb.org/View/91930</link>
      <description><![CDATA[The Flinders electric vehicle was designed to meet the urgent requirement for a functional electrical vehicle in the urban environment.  Conventional electric vehicles have proved unable to meet requirements for an urban commuter vehicle.  Vehicles presently available are excessively heavy, due to the battery requirement, and their range in stop-start city traffic is low.  The Flinders concept differs radically from the conventional electric vehicle. The battery current requirements are greatly reduced, resulting in a much lighter, more efficient battery.  No electrical control is used to govern either power as the printed-armature motor determines its own requirement from the battery when used in this concept. /Author/TRRL/]]></description>
      <pubDate>Tue, 29 Sep 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/91930</guid>
    </item>
    <item>
      <title>CONCRETE PAVEMENTS. REVIEW OF TECHNIQUES USED FOR REPAIR</title>
      <link>https://trid.trb.org/View/160332</link>
      <description><![CDATA[In the first part of the report the author analyzes the deterioration process of a rigid pavement with a view to determining on which parts of the pavement work must start to bring the pavement back to its initial conditions.  Part 2 examines the different techniques used in various countries.  In part 3 an attempt is made to summarize the results of the two previous parts and to propose solutions susceptible to be applied to the motorway network in France, particularly to relief motorways in the Paris region. (TRRL)]]></description>
      <pubDate>Thu, 21 May 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/160332</guid>
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    <item>
      <title>ROCK FALLS ON ROADS - MAPPING METHOD</title>
      <link>https://trid.trb.org/View/154740</link>
      <description><![CDATA[The "mapping" committee of the study group for cliffs has developed a method of grading the risks arising from stone and rock falls on roads.  This method is based on a previous survey among road operators and on an analysis of the various parameters determining stability: topography, discontinuities, vegetation, existing protecting devices, hydrology, morphological indices.  It is shown how to combine these different factors to deduce several risk levels (low, medium, high, very high) shown on maps, to which are added short term particularly dangerous spots. Those maps also give indication, on the nature of the risk run, that is determined according to a volumetric classification: mass rock falls, falls of blocks of rock, falls of stones.  Concrete examples are appended.  (TRRL) research project IRRD no 500593.]]></description>
      <pubDate>Fri, 06 Feb 1981 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/154740</guid>
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    <item>
      <title>DENSITY AND MOISTURE CONTENT LOGGING - FIRST GENERATION OF NUCLEAR PROBES</title>
      <link>https://trid.trb.org/View/154330</link>
      <description><![CDATA[This report summarizes laboratory studies of nuclear logging probes for measuring the in-situ bulk density and moisture content in boreholes.  The measurement of bulk density is effected by means of gamma rays and the moisture content by thermalization of rapid neutrons. To develop the probes the authors used the principle of double detection.  By combining data from two sensors, it is possible to partly ignore the irregularities of the borehole diameter.  The first part of the report deals with the development of the bulk density measuring probe which uses gamma rays: definition of the radio-element sensors used, source-sensor distance, mechanical filters and discrimination thresholds, calibration method.  Part 2 is devoted to the development of the moisture content measuring probe which uses the thermalization of rapid neutrons and facilitates study of the influence of the source-sensor distance and borehole diameter, and the calibration method.  The prototype developed from those tests is presented.  The importance of measurement conditions is examined for the two devices. (TRRL)]]></description>
      <pubDate>Mon, 27 Oct 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/154330</guid>
    </item>
    <item>
      <title>DETERMINATION OF THE WATER CONTENT OF AGGREGATES AND FRESH CONCRETE BY A NEUTRON METHOD</title>
      <link>https://trid.trb.org/View/154332</link>
      <description><![CDATA[This report is divided into two parts, each of which corresponds to a particular application of the neutron method.  (1)Measurement of humidity of aggregates stored in bins: following a study of an apparatus designed for measuring simultaneously the humidity from the deceleration of neutrons and the density by gamma diffusion of materials stored in a bin, the author describes the results obtained under concrete mixing plant conditions using a prototype device.  Provided there is standardization on the site itself, the precision of measurement is plus or minus 0.3% of the absolute value of humidity by weight.  The volume of measurement is quite significant and represents 350 kg in the case of sand, a considerable proportion of the quantity used for the making of a cubic metre of concrete.  (2) the neutron humidity measurement device for fresh concrete: it is important to have available a device for determining rapidly, on site, the water content of fresh concrete.  An apparatus is being designed to carry out this measurement on a sample of concrete of 16 litres.  This apparatus is easily transportable on site; the precision is estimated at plus or minus 0.3% of the absolute value of humidity by weight.  The device has been applied to materials other than concrete.  A synthesis of all the results obtained to date is presented. (TRRL)]]></description>
      <pubDate>Mon, 27 Oct 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/154332</guid>
    </item>
    <item>
      <title>LOSS OF STRESS OF THERMAL ORIGIN DURING MANUFACTURE OF PRETENSIONED PRESTRESSED ELEMENTS SUBJECTED TO HEAT TREATMENT</title>
      <link>https://trid.trb.org/View/146878</link>
      <description><![CDATA[This paper follows research project 10-11-7 (see IRRD 500214).  Loss of stress, due to hindered thermal expansion of reinforcement restrained between two points, is given by the expression representing the maximum value of loss induced by one thermal cycle characterised by the difference between working temperature and initial temperature.  This value can be reduced by the steel-concrete bond during temperature rise; the resulting bonding induces a different stress evolution for the length of concrete-covered reinforcement relative to the free lengths between the moulds.  The loss is then created by a mechanism which can be described schematically as partial premature prestressing of the constituents made of still very deformable concrete, induced by the constraint exerted by the reinforcement on the expansion of concrete.  The very numerous parameters influencing the loss of thermal origin are taken into account in complex analytical formulae.  It is shown however that these expressions can be very notably and validly simplified to take account of the predominant role played by two physical factors derived from the analysis of the mechanisms: the temperature at which the adhesion of the reinforcement due to setting becomes sufficient to suppress the possibility of slip of concrete along the reinforcement and the value of the longitudinal deformation modulus of concrete at that time and its evolution up to the time the working temperature is reached.  The validity of these formulae is proved experimentally in certain cases studied in the laboratory.  Finally a computer program allows the influence of all the parameters to be simulated. /TRRL/]]></description>
      <pubDate>Tue, 22 Apr 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/146878</guid>
    </item>
    <item>
      <title>APPLICATION OF THE CAMBRIDGE UNIVERSITY ELASTOPLASTIC MODELS TO THE BEHAVIOUR OF A TRIAL EMBANKMENT ON SOFT SOIL</title>
      <link>https://trid.trb.org/View/147701</link>
      <description><![CDATA[The Cambridge University model of the behaviour of clays is needed by computer programs for computers with a small main utilised for predicting the long term behaviour of one of many equation systems; details are also given of an the Laboratoires des Ponts et Chaussees at Cubzac-les-Ponts requires a minimum main memory, eliminating the limitation computer program Rosalie: see IRRD abstracts nos 900002 and study is divided into 4 parts: (1) current tendencies in method.  The paper shows the introduction of the modified structural design program for minicomputers; (3) description of the calculation parameters, the results and their Appendix a comprises a list of sub-routines written in months after construction.  /TRRL/ Appendix B briefly describes the electronic equipment used. /TRRL/]]></description>
      <pubDate>Tue, 15 Jan 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/147701</guid>
    </item>
    <item>
      <title>THE BEHAVIOUR OF BITUMINOUS MIXES IN SIMPLE TENSION</title>
      <link>https://trid.trb.org/View/147706</link>
      <description><![CDATA[A simple tensile test is proposed for the determination of characteristics which would facilitate the design of pavements from the point of view of failure, or the study and control of the materials from the viewpoint of a specific use.  The author examines first different mechanisms of deformation of granular media with bituminous binders in order to have a more comprehensible base for the establishment and the interpretation of a non-linear law of behaviour.  This law was established in the case of refined tests which make it possible to define the standards.  On the basis of relatively extensive studies carried out on a group of very different formulae, the author has defined a procedure for simplified tests.  He also seeks to establish a multiple linear correlation between fatigue tests and tension tests where use is made particularly of a factor of non-linearity serving as a measure of damage in the test with a single loading.  The different formulae are compared within the framework of a model of a two course pavement or a sub-grade and the external stresses are invariable; the modulus and the allowable deformation in fatigue make it possible to calculate the thickness of the surfacing.  The tensile test is then applied to the study of some formulation parameters.  /TRRL/]]></description>
      <pubDate>Tue, 15 Jan 1980 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/147706</guid>
    </item>
    <item>
      <title>STABILIZATION OF FISSURED ROCK MASSES BY GROUTED STEEL BARS</title>
      <link>https://trid.trb.org/View/146761</link>
      <description><![CDATA[The practical use of passive steel rock bolts grouted along their entire length for the consolidation of fissured rock masses has made it possible to demonstrate the effectiveness of such a procedure.  The aim of the study described in this report was to arrive at a better understanding of the mechanism of operation of this type of anchorage.  Initially a study is made of the behaviour under shear of the surfaces of discontinuity of rock masses, which constitutes basic data for the stability of these masses.  A description is given of an experimental study carried out in the laboratory on the model of a joint reinforced with a passive anchorage, in which the following parameters were varied: mechanical characteristics of the steel used for the anchorage; characteristics of the grouting material; compressive strength of the rock; the inclination of the bar at the joint; surface conditions of the discontinuity.  This study makes it possible to develop methods for the evaluation of the additional strength gained with a passive anchorage placed perpendicularly to a smooth joint.  /TRRL/]]></description>
      <pubDate>Sat, 29 Dec 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/146761</guid>
    </item>
    <item>
      <title>FATIGUE OF WELDED METAL ENGINEERING STRUCTURES. INTRODUCTORY REPORT TO A RESEARCH PROGRAMME</title>
      <link>https://trid.trb.org/View/91928</link>
      <description><![CDATA[The first chapter of this bibliographic study presents the general aspects of the problem of fatigue in welded metal structures.  Chapter 2 recalls the mathematical or physical damage theories, while notions of life time and strength of members subjected to fatigue are defined together with fatigue test principles and procedures.  Test results are utilized according to probabilistic statistical methods which can be expressed in analytical mathematical laws, if simplifying assumptions are accepted.  Chapter 3 describes the parts of a metal structure under traffic, which are most exposed to risks of damage due to fatigue.  Chapter 4 studies the influence of the characteristics of welded joints on the fatigue behaviour of couplings.  These characteristics are either of geometric origin, including porous spots, blisters and defects due to lack of fusion or of metallurgical origin.  Means of improving the fatigue behaviour of welded joints are outlined.  In conclusion remarks are made on the representativeness of tests on samples in a study conducted to forecast the fatigue behaviour of a structure. /TRRL/]]></description>
      <pubDate>Sat, 29 Sep 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/91928</guid>
    </item>
    <item>
      <title>CONTRIBUTION TO THE STUDY OF THE CATIONIC INTERFACIAL ACTIVITY OF ROAD BITUMENS</title>
      <link>https://trid.trb.org/View/81009</link>
      <description><![CDATA[The first part of this report presents general data on the use of bitumens in road construction, their manufacture, their physico-chemical characteristics and their structure. The influence of interfacial properties on the coating of solid materials and on the properties of composite materials where they are used as binders.  Part 2 shows the role played by acid and basic compounds on interfacial properties such as interfacial tension vis-a-vis aqueous phases and the wetting of solids. These polar compounds show an anionic and cationic interfacial behaviour.  A comparison is made between the behaviour of polar compounds extracted from bitumen as nitrogen bases and that of surface-active agents used as adhesion agents.  Part 3 deals with cationic interfacial activities.  A comparison is made of five bitumens and two reference amines: n-dodecylamine and cyclododecylamine.  Their interfacial activity was shown to be the same as that of cyclododecylamine.  But it is not possible to completely simulate the behaviour of a bitumen by that of an amine of this type: indeed it seems that non-interfacial active compounds in bitumen can modify the interfacial absorption conditions of the cationic surface-active agent.  /TRRL/]]></description>
      <pubDate>Wed, 28 Mar 1979 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/81009</guid>
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