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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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      <link>https://trid.trb.org/</link>
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    <item>
      <title>INFLUENCE OF SEASONAL VARIATION OF SUBGRADE MOISTURE ON THE DESIGN AND PERFORMANCE OF FLEXIBLE PAVEMENTS</title>
      <link>https://trid.trb.org/View/269938</link>
      <description><![CDATA[Moisture variation in the subgrade below semi-impervious bituminous pavements has a significant influence on the performance of the pavement, depending on soil, environmental and climatic conditions.  This aspect has to be taken into account while deciding on the strength of the subgrade which, in turn, influences pavement thickness design.  The Highways Research Station in Madras undertook detailed studies of the variation in the moisture of pavement subgrades under different climatic and soil conditions in the tamil nadu state.  As many as 34 sites were investigated between 1962 and 1976.  This paper gives a brief review of the research carried out abroad and on the experimental sites.  It is hoped that the results obtained will help to determine the maximum moisture that a compacted subgrade soil would retain from the knowledge of a given site, rainfall and engineering characteristics of the soil. For the covering abstract see TRIS 450968.  (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:57:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/269938</guid>
    </item>
    <item>
      <title>STUDY OF STRENGTH AND CURING OF LIME-STABILISED LATERITE SOIL - PLAIN AND FIBER-REINFORCED</title>
      <link>https://trid.trb.org/View/269937</link>
      <description><![CDATA[This study examined the possibility of establishing a correlation between the dry density and the strength of loam laterite soil specimens stabilized with lime and cured in an oven at 50 degrees C for three days instead of cured at a normal temperature in the laboratory for 15, 30, 45 and 60 days.  The results indicated that 3 days' accelerated curing at 50 degrees C is equivalent to 6 weeks' normal curing for a laterite soil stabilized with 5% lime by weight of air-dried soil, at 95 to 100 per cent maximum modified AASHOU dry density.  The effect of the proportion of lime added for stabilization was also studied.  It seems that at densities up to approximately 95% of maximum modified AASHOU dry density, unconfined compressive strength increases with the addition of lime, but at higher densities, it increases and then tends to fall.  The study further examined the possibility of multiple correlation for estimating compressive strength from the independent variables dry density and number of days of curing with a five percent addition of lime, this proportion being the optimum percentage for maximum improvement.  An investigation was also carried out of the flexural strength of plain and fibre-reinforced mixtures (coconut fibres 2 and 4 cm in length were used).  The results were encouraging.  For the covering abstract see TRIS 450968.  (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:57:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/269937</guid>
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      <title>SOIL ENGINEERING</title>
      <link>https://trid.trb.org/View/269936</link>
      <description><![CDATA[For abstracts of papers contained in this bulletin see TRIS 450969 and 450970.  (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:57:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/269936</guid>
    </item>
    <item>
      <title>COMPARISON OF AGGREGATE GRADINGS FOR HIGHWAYS BASED ON THEIR VOIDS CHARACTERISTICS</title>
      <link>https://trid.trb.org/View/269935</link>
      <description><![CDATA[The grading of aggregates for road construction can differ widely from one agency to the next.  In an effort to identify a specific parameter for the design of gradings, the packing and voids characteristics of aggregates of different sizes were studied.  It was observed that the voids structure in an aggregate mixture depends on the size ratios and volumetric proportions of the aggregates contained in the mixture.  The voids structure was defined as "composite" or "filler" type depending on the size ratios of the components.  The components were further subdivided into "balanced", "abundant in fine aggregate" and "abundant in coarse aggregate".  It was found that aggregate grading can be analysed for its voids structure if the size ratios and proportions of consecutive aggregate size fractions are known.  An experimental investigation was carried out to compare three standard specified gradings with skip gradings possessing the same voids ratios as standard grading, but with their components proportioned at or near the balanced stage.  The Marshall characteristics of such skip-graded mixtures were observed to be superior to those of the standard continuously-graded mixtures.  This shows that the strength characteristics of a pavement mixture are influenced by the voids structure as well as the voids volume.  Aggregate grading can therefore be designed by selecting the sizes of aggregate groups so as not to lose the composite structure and by selecting them in balanced proportions.  For the covering abstract see TRIS 450963. (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:57:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/269935</guid>
    </item>
    <item>
      <title>FRACTURE ENERGY - USEFUL MATERIAL CHARACTERISTIC IN PAVEMENT EVALUATION</title>
      <link>https://trid.trb.org/View/269934</link>
      <description><![CDATA[Energy as material characteristic has been the basic parameter for investigating material behaviour under fatigue.  Such an approach to explain pavement behaviour under traffic has not been commonly adopted so far.  This paper presents the development of the concept of fracture energy as the parameter representing the overall state of a pavement at any stage of its life.  A hypothesis is presented for the application of the energy concept in pavement evaluation.  A mathematical relation between fracture energy and remaining life is also derived.  For the covering abstract see TRIS 450963.  (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:57:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/269934</guid>
    </item>
    <item>
      <title>INFLUENCE OF LIME AND STONE DUST FILLERS ON FATIGUE PROPERTIES OF BITUMINOUS CONCRETE MIXES</title>
      <link>https://trid.trb.org/View/269933</link>
      <description><![CDATA[The aim of the study is to find means of decreasing the bitumen content in a pavement mixture without sacrificing the qualities required of modern roads.  A study is presented of the influence of minerals fillers on bituminous mixtures.  Repetitive loading tests were carried out to examine fatigue in bituminous mixtures, and the effect of this fatigue on pavement deflection.  The role of fillers in this was investigated, and details are given of the experimental equipment, materials used, sample preparation and test procedure.  The results are presented and discussed.  For the covering abstract see TRIS 450965. (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:57:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/269933</guid>
    </item>
    <item>
      <title>DEFORMATION BEHAVIOUR OF SUBGRADE SOIL AND RUTTING IN A FLEXIBLE PAVEMENT</title>
      <link>https://trid.trb.org/View/269932</link>
      <description><![CDATA[The paper discusses the stress conditions that need to be simulated in laboratory testing of subgrade soils so that pavement behaviour may be assessed accurately.  Details are given of repeated loading triaxial tests on the subgrade soil of the Orissa trunk road at in situ moisture content and density to determine the plastic stress-strain characteristics of the soil.  The rut depth was calculated by using the layer-strain approach, taking into account the lateral swelling of the pavement on either side of the wheel path.  For the covering abstract see TRIS 450963.  (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:57:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/269932</guid>
    </item>
    <item>
      <title>RIGID AND FLEXIBLE PAVEMENTS</title>
      <link>https://trid.trb.org/View/269931</link>
      <description><![CDATA[For abstracts of papers contained in this bulletin see TRIS 450964-450967. (TRRL)]]></description>
      <pubDate>Fri, 27 Aug 2004 21:57:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/269931</guid>
    </item>
    <item>
      <title>REGIONAL TRANSFERABILITY OF BRAZIL SPEED AND FUEL MODELS</title>
      <link>https://trid.trb.org/View/375844</link>
      <description><![CDATA[This paper describes the work done by the Indian Central Road Research Unit on the applicability to India of the Brazil model which quantifies vehicle operating costs when driven over various types of road and environment.  This research was undertaken as part of the World Bank Highway Design and Maintenance Study (HDM) and was entitled the Road User Cost Study (RUCS).  Firstly, linear models for 'speeds' which is one of the important variables in determining operating costs, were developed.  Later at the World Bank, models based on mechanistic principles for vehicle speed as well as fuel consumption and other variables like tyre and spare parts consumption, etc, were developed.  It was proposed to study the transferability of these mechanistic models to other countries whose vehicle characteristics, road standards, economic conditions, etc, are different.  For this purpose, the data collected for speed and fuel consumption under RUCS were utilised.  It was observed that the mechanistic principle based on speed and fuel consumption models were generally adaptable. However, further research in certain areas like the driver behaviour under different economic conditions and road width effect on desired speeds is to be done.]]></description>
      <pubDate>Thu, 01 Jul 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/375844</guid>
    </item>
    <item>
      <title>PASSENGER TRIP, DISTRIBUTION BY GRAVITY MODEL FOR REGIONAL TRANSPORT PLANNING</title>
      <link>https://trid.trb.org/View/376890</link>
      <description><![CDATA[The solution to urban transport problems lies in the estimation of travel demand.  Travel demand is customarily estimated in four independent stages under the Urban Transportation Planning Process (UTPP).  The trip distribution phase in the estimation of travel demand has been the focal point to several researchers in the past and several strategies are involved to estimate the zonal trip interchange.  Most widely used technique of trip interchange estimation is the gravity model which in turn has been developed in several forms by considering different types of travel factors. In this paper, the travel time function of the form fij = 1/dl jn has been adopted.  The origin- destination (O-D) studies are used as a data base for the calculation of particular time factors for a defined study area.  Each trip purpose has an individual travel time factor which is calculated by an interactive procedure. The calibration of the model has been carried out till the difference between the average surveyed trip length and the model simulated trip length are within +3 per cent.  The computer programme has been developed and tested at DEC 2050 system of University of Roorkee. It is found that the best model is obtained for the value of power function n = 1.50 as exponent for the deterence used in terms of time taken to travel from zone to zone distance. The coefficient of correlation has been obtained as 0.836 from the model, accurate enough results have been obtained for estimation and forecasting the local passenger trip demand.  (A)]]></description>
      <pubDate>Thu, 01 Jul 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/376890</guid>
    </item>
    <item>
      <title>VALUE OF TRAVEL TIME AND COMFORT BY WILLINGNESS TO PAY APPROACH</title>
      <link>https://trid.trb.org/View/376891</link>
      <description><![CDATA[This paper presents the results of an Indian study of road users' value of travel time.  The objects of the study were to: (1) investigate the value of travel time of suburban commuters by the average wage rate, revealed preference, and willingness-to-pay approaches; (2) investigate the variables affecting the value of travel time; (3) develop models relating value of in-bus travel time by the willingness-to-pay approach with other variables for work and educational trips in peak and off-peak periods; (4) investigate the relative ranking of the variables affecting the travel time of urban commuters; (5) quantify the value of travel time of bus passengers by all three approaches. The findings include the following: (1) females value have lower value of travel time than males; (2) value of travel time decreases as age increases; (3) the effect of income on travel time is quite low; (4) those who travel standing are willing to pay more for reduction in travel time than those who travel seated; (5) with increase in fares, commuters are willing to pay more during peak hours and opt to pay less during off-peak hours; (6) keeping all parameters other than age constant, old people are willing to pay more for provision of seats than young people; (7) the willingness-to- pay approach is better, as it considers the value of travel time evaluated by every individual under different conditions.]]></description>
      <pubDate>Thu, 01 Jul 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/376891</guid>
    </item>
    <item>
      <title>DESIGN OF FLEXIBLE PAVEMENT INCORPORATING LATERAL CONFINEMENT PARAMETER</title>
      <link>https://trid.trb.org/View/376892</link>
      <description><![CDATA[This paper reports a study, aiming to identify the structural responses of flexible pavements under wheel loads, to develop a suitable design methodology incorporating lateral confinement mobilised between the pavement edges.  In the experimental part of the study, the variation in elastic modulus of subgrade soil under different lateral confinement conditions was investigated.  In the analytical part, an attempt was made to study the variation in stresses and deflections in two-layered pavement systems, due to wheel loads occupying different positions from unconfined and confined pavement edges.  A proposed methodology for flexible pavement design is presented, using surface deflection as the design parameter and lateral confinement as one of the additional variables. Burmeister's approach was adopted as a guiding tool to develop the methodology, and an economic analysis was also performed.  A finite prism model was used to obtain the analytical solutions of different thicknesses and load positions.  It was found that vertical deflection at the surface under the centre of the wheel load was considerably reduced, due to introduction of a vertical diaphragm at the pavement.  Examples are given of the resulting reductions in pavement thicknesses and construction costs.  The paper's methodology can be extended to multi-layer pavement systems.]]></description>
      <pubDate>Thu, 01 Jul 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/376892</guid>
    </item>
    <item>
      <title>IMPROVEMENT OF WAXY BITUMENS BY THE ADDITION OF SYNTHETIC RUBBERS, POLYMERS AND RESINS</title>
      <link>https://trid.trb.org/View/376893</link>
      <description><![CDATA[The presence of wax in bitumen up to 2 to 4 per cent as permissible is not likely to affect performance of bituminous surfacings. Paving grade bitumens produced at Digboi refinery from indigenous crude contains about 12 per cent wax, which causes bleeding of binder at high road temperature of 80 degrees C and gives poor adhesion resulting in low strength and stability of mixes.  Since, indigenous crude yields waxy bitumen, it is imperative to overcome the situation. This objective can be achieved by neutralising effects of wax in waxy bitumens by adding some polymeric materials to enhance viscosity of bitumen at high road temperature. Polymers, namely styrene-butadiene styrene block copolymer (SBS), ethyl vinylacetate copolymer and aromatic resins have been found effective in improving softening point, viscosity-temperature characteristics, adhesion and stability of bituminous mixes.  About 8 per cent aromatic resins, 4 per cent ethyl vinylacetate copolymer and 6 per cent styrene butadiene-styrene block copolymer have been found to be effective in improving wax bitumens.  The paper contains details of laboratory studies on improvement of waxy bitumens by neutralization of effect of wax.  (A)]]></description>
      <pubDate>Thu, 01 Jul 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/376893</guid>
    </item>
    <item>
      <title>DYNAMIC MODULUS OF ASPHALTIC MIXES</title>
      <link>https://trid.trb.org/View/376894</link>
      <description><![CDATA[Knowledge of elastic modulus of bituminous mixes is essential for scientific design of bituminous pavements. The paper deals with development of instrumentation for determination of elastic modulus of bituminous mixes.  The results of elastic modulus tests on asphalt concrete, dense bituminous macadam and semi- dense bituminous concrete, currently in practice in India, are included in the paper. Three grades of paving bitumens, namely, 30/40, 60/70 and 80/100 were used for fabricating test specimens.  Findings of the research will help the pavement designers to choose the appropriate elastic modulus of the bituminous mixes for design of flexible pavements. (A)]]></description>
      <pubDate>Thu, 01 Jul 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/376894</guid>
    </item>
    <item>
      <title>LABORATORY STUDIES ON THE USE OF ORGANIC POLYMERS IN IMPROVEMENT OF BITUMINOUS ROAD SURFACINGS</title>
      <link>https://trid.trb.org/View/376895</link>
      <description><![CDATA[Polyethylene-bitumen blends, styrene-butadiene-styrene block copolymer- bitumen blends and ethylene vinylacetate copolymer- bitumen blends can be used as high performance road binders.  Durability of bituminous mixes can be considerably improved by the addition of polyethylene, ethyl vinylacetate copolymer and styrene-butadiene- styrene block copolymers to bitumen.  These blends are stable to thermal decomposition well above 200 degree celsius as indicated by thermogravimetric analysis, and are stable to hot storage as they do not undergo demixing.  Polymer modified binders studied in this paper are effective in reducing deformation at high temperatures as viscosity values of binder at 60 degree celsius, tensile strength and Marshall stability of mixes are considerably higher than neat 80/100 bitumen.  Results of adhesion and ageing studies indicate better adhesion and durability of polymer modified binders.  Incorporation of 2 per cent polyethylene, 5 per cent styrene-butadiene styrene and ethyl vinyl-acetate are the optimum concentrations for 80/100 bitumen. Flexural fatigue test results indicate that incorporation of 2 per cent polyethylene, 5 per cent styrene-butadiene- styrene and ethyl vinylacetate increase the fatigue life by 10, 18 and 2 times respectively.  Ethyl vinylacetate and styrene-butadiene- styrene block copolymers are also very efficient in reducing low temperature brittleness of bitumen as indicated by very low value of Fraass breaking point.  (A)]]></description>
      <pubDate>Thu, 01 Jul 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/376895</guid>
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