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    <title>Transport Research International Documentation (TRID)</title>
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    <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>
    <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>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>COAL-MODIFIED TAR BINDERS FOR BITUMINOUS CONCRETE PAVEMENTS</title>
      <link>https://trid.trb.org/View/100936</link>
      <description><![CDATA[THE POSSIBILITY OF MAKING AN IMPROVED BINDER FOR BITUMINOUS PAVEMENTS OF THE HOT-MIX HOT-LAY TYPE BY DISPERSING COAL IN DISTILLED COAL TARS AND COAL TAR OILS IS STUDIED. SUITABLE LABORATORY AND PILOT PLANT EQUIPMENT WAS ASSEMBLED AND OPTIMUM CONDITIONS FOR THE DISPERSION OF COAL IN TARS AND OILS WERE DETERMINED. VARIOUS COALS, TARS, AND OILS WERE COMPARED AS TO THEIR SUITABILITY FOR THE PURPOSE. EXPERIMENTAL QUANTITIES OF COAL-MODIFIED TAR BINDERS WERE PRODUCED AND ANALYZED AND THEN COMBINED WITH VARIOUS AGGREGATES IN HOT MIXES. THE LATTER WERE THEN COMPARED WITH HOT MIXES CONTAINING TYPICAL ASPHALT CEMENTS AND COAL-TAR BINDERS. THE TESTS APPEARED TO INDICATE THAT IT WOULD BE POSSIBLE TO MAKE HOT MIXES WITH COAL-MODIFIED TAR CEMENTS EQUAL OR SUPERIOR TO THOSE MADE WITH USUAL ASPHALT OR COAL- TAR BINDERS. A PILOT PLANT WAS BUILT TO PRODUCE 150,000 GALLONS OF COAL-MODIFIED TAR BINDER FOR COMPARISON WITH ASPHALT CEMENTS NORMALLY USED IN KENTUCKY IN CLASS I AND CLASS I-MODIFIED BITUMINOUS-PAVEMENTS. DURING A PERIOD OF THREE MONTHS IT PRODUCED 104 BATCHES OF BINDER, OF WHICH 100 BATCHES WERE OF THE THREE-COMPONENT TYPE (COAL, TAR, AND OIL), TWO OF THE TWO-COMPONENT TYPE (COAL AND TAR), AND TWO CONSISTED ONLY OF TAR (RT-12). THE BINDER WAS DELIVERED TO 14 TEST SITES IN VARIOUS PARTS OF THE STATE. AT TWO, THREE- COMPONENT BINDER WAS USED IN HOT MIX LAID 2 3/4 INCHES THICK ON A TAR-PRIMED SOIL BASE (CLASS I-MODIFIED). AT ALL OTHER SITES, THE BINDER WAS USED IN 1 1/2 INCH CLASS I OVERLAYS ON EXISTING BLACK-TOP PAVEMENTS WHICH FOR THE MOST PART HAD REQUIRED EXTENSIVE MAINTENANCE BECAUSE OF BASE FAILURES, EXCESSIVE CRACKING, OR THE DEVELOPMENT OF SLIPPERY SURFACES. COAL-MODIFIED TAR BINDERS APPEARED TO BE SOMEWHAT SUPERIOR TO USUAL ASPHALTIC HOT-MIXES WITH RESPECT TO SET-UP DURING ROLLING AND EARLY TRAFFIC, BUT INFERIOR WITH RESPECT TO FUMING, ESPECIALLY WHEN THE TEMPERATURES OF THE MIXES EXCEEDED 260 F. INSPECTION OF SOME OF THE TEST SECTIONS IN SPRING 1960, FOLLOWING UNUSUALLY SEVERE WINTER WEATHER, EMPHASIZED THE NEED FOR BETTER TEMPERATURE SUSCEPTIBILITIES TO PROVIDE GREATER FLEXIBILITY OF THE OVERLAYS AT LOW ATMOSPHERIC TEMPERATURES. COMPARISONS WERE MADE OF THE SUITABILITY OF APPROXIMATELY 40 DIFFERENT COALS FROM VARIOUS PARTS OF THE UNITED STATES AND FOREIGN COUNTRIES, THE USE OF LOW, MEDIUM, AND HIGH-TEMPERATURE TARS AS DISPERSING MEDIA FOR THE COALS, ATTEMPTS TO USE OILS OF PETROLEUM ORIGIN AS FLUXING AGENTS, AND THE ADDITION OF VARIOUS POLYMERS TO THE COAL-DISPERSIONS. ALSO, VARIOUS TYPES OF BINDERS WERE COMPARED AS TO THEIR VISCOSITIES AT SEVERAL TEMPERATURES AND NUMEROUS METHODS FOR COMPARING THE BRITTLENESS OF DIFFERENT HOT-MIX BINDERS AT LOW TEMPERATURES WERE TRIED. /AUTHOR/]]></description>
      <pubDate>Fri, 03 Jun 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/100936</guid>
    </item>
    <item>
      <title>SOME NOTES ON BASE COURSE STABILITY</title>
      <link>https://trid.trb.org/View/104817</link>
      <description><![CDATA[INVESTIGATIONS INTO THE CAUSES OF EXTENSIVE PAVEMENT DISTRESS ON A SECTION OF THE TRANS CANADA HIGHWAY NEAR GOLDEN HAVE SHOWN THAT, IN SPITE OF AN ADEQUATE THICKNESS OF PAVEMENT STRUCTURE, THE BASE GRAVEL HAD INSUFFICIENT STABILITY DURING THE SPRING THAW PERIOD TO SUPPORT TRAFFIC. EXTENSIVE RUTTING AND ALLIGATORING OF THE PAVEMENT OCCURRED AND SOME SECTIONS COMPLETELY DISINTEGRATED. BENKELMAN BEAM SURVEYS WERE CARRIED OUT WHICH SHOWED THAT VERY HIGH DEFLECTION OCCURRED DURING THE PERIOD OF GREATEST WEAKNESS BUT THE DURATION OF THIS PERIOD WAS SHORT. REBOUND READINGS TAKEN A FEW DAYS AFTER THE WEAKEST PERIOD WERE LESS THAN .020 INCHES. IT WAS NOT POSSIBLE TO PREDICT WHERE HIGH READINGS WOULD OCCUR. DENSITY TESTS ON THE BASE GRAVEL SHOWED THAT IN WEAK AREAS DENSITY WAS HIGHER AND VOIDS LOWER THAN IN STRONG AREAS. SPECIAL FREEZING TESTS IN WHICH PORE PRESSURES WERE MEASURED SHOWED THAT FREEZING GRADUALLY SATURATED THE GRAVEL AND PORE PRESSURES WERE GENERATED UNDER APPLIED LOADS. UNCONSOLIDATED UNDRAINED TRIAXIAL TESTS ALSO SHOWED A HIGH DEGREE OF PORE PRESSURE RESPONSE UNDER LOAD. THE BASE GRAVEL HAD A PERMEABILITY OF ABOUT 1X10 EXPONENT-5 CM/SEC. AND WAS DILATANT WHEN ALMOST SATURATED. THE PASSING ?200 CONTENT VARIED FROM 8% TO 15%. IT WAS DEDUCED THAT FAILURE WAS CAUSED BY THE HIGH DEFORMATION WHICH OCCURRED UNDER WHEEL LOADS WHEN THE EFFECTIVE STRESSES WERE REDUCED BY THE LOAD INDUCED PORE-PRESSURES AND THAT THESE PORE- PRESSURES WERE INDUCED BECAUSE THE PERMEABILITY OF THE GRAVEL WAS TOO LOW TO ALLOW RAPID ENOUGH DRAINAGE. THE AMOUNT OF ADDITIONAL MOISTURE REQUIRED TO PRODUCE THIS CONDITION WAS VERY SMALL (ABOUT 0.5%). THIS AMOUNT OF MOISTURE WAS DRAWN INTO THE GRAVEL BY FREEZING EVEN THROUGH THE GRAVEL WAS NOT CONSIDERED FROST SUSCEPTIBLE BY NORMAL STANDARDS. THE ANGLE OF SHEARING RESISTANCE OF THE GRAVEL WAS OVER 40 DEGREES, NORMALLY SUFFICIENT FOR STABILITY. IT IS CONSIDERED THAT OTHER PAVEMENTS IN THE PROVINCE MAY BE FAILING BY A SIMILAR MECHANISM RATHER THAN BECAUSE OF INSUFFICIENT PAVEMENT THICKNESS. FURTHER TESTING IS UNDER WAY TO INVESTIGATE THIS. TENTATIVE RESULTS SHOW THAT SOME GRAVELS USED FOR BASES EITHER BECAME CONTAMINATED WITH FINES DURING CONSTRUCTION AND SUBSEQUENT TRAFFICKING OR THAT DEGRADATION OF AGGREGATE OCCURS DURING CRUSHING AND LAYING OPERATION. IT IS RECOMMENDED THAT ENGINEERS EXAMINE SPECIFICATIONS TO ENSURE THAT BASE GRAVELS HAVE A LOW FINES CONTENT, A HIGH PERMEABILITY AND DO NOT TEND TO DEGRADE DURING CRUSHING OPERATIONS. DURING CONSTRUCTION GRAVELS SHOULD BE CHECKED TO SEE THAT THE FINES CONTENT IS NOT INCREASING AND THAT PERMEABILITY REMAINS HIGH. /AUTHOR/]]></description>
      <pubDate>Sun, 23 Jan 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/104817</guid>
    </item>
    <item>
      <title>COMPUTER GRAPHICS DISPLAY OF SIMULATED TRACTOR MOTION</title>
      <link>https://trid.trb.org/View/59005</link>
      <description><![CDATA[Interactive computer graphics display of simulated tractor motion enable the investigator to predict time and location of impact points during overturn.  General motion studies can be made which give the illusion of real overturns. Response to steering directions and operator timing suggest optimum evasive maneuvers when encountering a ditch bank.]]></description>
      <pubDate>Wed, 23 Nov 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/59005</guid>
    </item>
    <item>
      <title>BASIC TECHNIQUES AND EXAMPLES OF COMPUTER SIMULATION</title>
      <link>https://trid.trb.org/View/58789</link>
      <description><![CDATA[Computer simulation is one of the most useful techniques available to the statistician.  However, current literature indicates that this approach has been widely used by engineers.  This paper provides the basic tools for anyone with an elementary knowledge of statistical theory and computer programming to simulate a random normal process on a digital computer.  The usefulness of this technique is illustrated by two examples that involve concrete strength specifications.  The first deals with the determination of the best sampling plan for a quality-assurance testing program, and the second illustrates the simulation of a statistical acceptance procedure with a reduced pay schedule.  Several FORTRAN subroutines are described for generating both uniform and normal random numbers, sorting a data array, selecting a random sample, calculating statistical parameters, and printing a histogram.  /Author/]]></description>
      <pubDate>Thu, 13 Oct 1977 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/58789</guid>
    </item>
    <item>
      <title>NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM. SUMMARY OF PROGRESS THROUGH 1974</title>
      <link>https://trid.trb.org/View/25235</link>
      <description><![CDATA[This report which illustrates in detail how the National Cooperative Highway Research Program functions, outlines the projects in each of the twenty two areas of research. The Program sponsors applied research, and Program policy ensures maximum exposure of the research results while in progress, so promoting the adoption of the results in the form of policies, procedures, specifications and standards of state highway and transportation departments.  The research content of the program is solely the preorgative of the American Association of State Highway and Transportation Officials.  Details are outlined of the formulation of Research programs, the programs received to date, and the financing of the program.  A committee drawn from the officers and ex-officio members of the Transportation Research Board oversees all matters relating to policies and procedures for administration of the program.  The Board has established eight broad research fields under which advisory groups are organized to deal with research in specific problem areas.  The placing of the projects under contract is described and the status of projects for FY '63 through FY '73 are summarized in a table.  Examples are cited of the utilization of the results of NCHRP research projects, and projects which have been recognized as outstanding contributions to the field of highway safety are listed.  The research projects summarized here fall into one of the following fields of study: pavements; economics; traffic operations and control; general materials; illumination and visibility; snow and ice control; traffic planning; urban transportation; bituminous materials; specifications, procedures and practices; law; bridges; equipment; maintenance of way and structures; general design; roadside development; safety; concrete materials; finance; special projects; testing and instrumentation; and vehicle barrier systems.]]></description>
      <pubDate>Thu, 27 Feb 1975 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/25235</guid>
    </item>
    <item>
      <title>SECONDARY MINERALS IN ROCK AS A CAUSE OF PAVEMENT AND BASE FAILURE</title>
      <link>https://trid.trb.org/View/110536</link>
      <description><![CDATA[SECONDARY OR ALTERATION MINERALS WERE FOUND IN LARGE PERCENTAGES IN THE ROCK USED IN BASE AND PAVEMENT OF SEVERAL HIGHWAY SECTIONS WHICH FAILED UNDER USE. THE MOST COMMON OF THESE ARE KAOLIN CLAYS, CHLORITE, SERPENTINE, CALCITE, AND LIMONITE. THEIR PRESENCE CAUSES ROCK IN THE 3/4- TO 0-INCH SIZE TO DISINTEGRATE OR DISSOLVE WHEN SUBJECTED TO WATER AND TRAFFIC LOADS. ROCK IN LARGER SIZES DOES NOT SEEM TO BE AFFECTED, PROBABLY BECAUSE OF THE SHARP DECREASE IN SURFACE AREA. MICROSCOPIC STUDY AND FIELD DATA INDICATE 0 TO 20 PERCENT OF SECONDARY MINERALS IN A FINE AGGREGATE WILL HAVE LITTLE EFFECT; 20 TO 35 PERCENT WILL PRODUCE SOME FAILURES AND BORDERLINE RESULTS; AND 35 PERCENT AND ABOVE WILL ALMOST CERTAINLY CAUSE FAILURES. /AUTHOR/]]></description>
      <pubDate>Mon, 05 Jun 1972 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/110536</guid>
    </item>
    <item>
      <title>EXPERIMENTAL RING NO. 4: A STUDY OF UNTREATED, SAND ASPHALT, AND ASPHALT CONCRETE BASES</title>
      <link>https://trid.trb.org/View/99601</link>
      <description><![CDATA[THREE DIFFERENT KINDS OF BASE MATERIAL OF VARYING BASE THICKNESSES WERE TESTED DURING THE FALL OF 1968 AND THE SPRING OF 1969. TWELVE 18-FOOT TEST SECTIONS CONSISTING OF 4.5, 7.0, 9.5 AND 12 INCHES OF UNTREATED CRUSHED ROCK SURFACING TOP COURSE BASE; 2.0, 4.0, 6.0 AND 8.0 INCHES OF SAND-ASPHALT BASE; AND 0.0, 2.0, 3.5 AND 5.0 INCHES OF CLASS "F" ASPHALT CONCRETE BASE, COVERED BY A UNIFORM 3.0-INCH THICK CLASS "B" ASPHALT CONCRETE WEARING COURSE WERE TESTED DURING THIS PERIOD. THE PAVEMENT STRUCTURE WAS BUILT ON A CLAY-SILT SUBGRADE SOIL. INSTRUMENTATION CONSISTED OF MOISTURE TENSIOMETERS, STRAIN GAGES, PRESSURE CELLS, LVDT GAGES AND THERMOCOUPLES FOR MEASURING MOISTURE, STRAIN, STRESS, DYNAMIC DEFLECTIONS AND TEMPERATURES. BENKELMAN BEAM READINGS WERE TAKEN. THE TESTING REVEALED THAT THE FALL FAILURE MODES WERE DIFFERENT FROM THE SPRING FAILURES. THE FALL FAILURE PATTERN STARTED FROM TRANSVERSE CRACKS IN THE THIN SECTIONS WHICH DEVELOPED INTO ALLIGATOR CRACKING PATTERNS. THESE CRACKS APPEARED AFTER A PERIOD OF COLD WEATHER AND HEAVY RAINS FOLLOWED BY A WARMING TREND. THERMAL AND MECHANICAL LOADS IN CONJUNCTION WITH ADVERSE ENVIRONMENTAL CONDITIONS DURING CONSTRUCTION AND PRIOR TO AND DURING THE FALL TESTING PERIOD WERE BELIEVED TO BE RESPONSIBLE FOR THE EARLY FALL FAILURES ON THE THIN SECTIONS. THE SPRING FAILURES WERE VERY RAPID AND SUDDEN AND WERE DUE TO ENVIRONMENTAL FACTORS WHICH LED TO HIGHLY SATURATED SUBGRADE, THUS RESULTING IN POOR BEARING CAPACITY. PUNCHING SHEAR WAS THE FAILURE MODE. THE THICKEST SECTIONS SURVIVED WITHOUT CRACKS BUT DEVELOPED SEVERE RUTTING. COMPARISON OF THE RESULTS WITH THOSE OBTAINED FROM RINGS #3 AND #4, SHOW THAT THEY WERE SIMILAR IN MANY RESPECTS. THIS INDICATES THAT THE TEST TRACK IS CAPABLE OF REPLICATING RESULTS AND IS A RELIABLE RESEARCH INSTRUMENT. EQUIVALENCIES WERE DEVELOPED FOR THE DIFFERENT MATERIALS. ON THIS BASIS THE CLASS "F" ASPHALT CONCRETE BASE WAS SUPERIOR TO THE SAND-ASPHALT AND UNTREATED CRUSHED ROCK BASES IN THAT ORDER. MAXIMUM VALUES FOR STATIC AND DYNAMIC DEFLECTIONS, STRAINS AND STRESSES FOR DIFFERENT TIMES AND TEMPERATURES WERE DEVELOPED. THE LATERAL POSITION OF THE DUAL TIRES WITH RESPECT TO THE GAGE SEVERELY AFFECTED THE STRAIN, STRESS AND DEFLECTION VALUES. TEMPERATURE ALSO CAUSED VARIATIONS IN THE MEASUREMENTS. SPRING INSTRUMENT READINGS FOR STATIC AND DYNAMIC DEFLECTIONS, STRAIN AND STRESS SHOW VALUES AS MUCH AS 2 TO 4 TIMES OF THOSE OBTAINED IN THE FALL. SPRING SUBGRADE CONDITIONS PROBABLY WERE RESPONSIBLE FOR THESE DIFFERENCES. RING #4 SERIES OPERATIONAL TIME WAS HALF THAT OF RING #3 AND ABOUT THE SAME AS RING #2. RING #4 SUSTAINED ABOUT A QUARTER OF THE WHEEL LOAD APPLICATIONS OF RING #3. CONSTRUCTION AND TESTING ENVIRONMENTAL CONDITIONS WERE INFERIOR TO THOSE FOR RING #3, ALTHOUGH THEY WERE SIMILAR FOR RING THIS POINTS OUT THAT ENVIRONMENTAL FACTORS ARE VERY #2, AND HENCE CONTRIBUTED TO THE LOWER TEST PERIOD. IMPORTANT TO PAVEMENT LIFE. /AUTHOR/]]></description>
      <pubDate>Sun, 10 Oct 1971 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/99601</guid>
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