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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>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>SOIL COMPACTION STUDY-VOLUMES I, II AND III</title>
      <link>https://trid.trb.org/View/119387</link>
      <description><![CDATA[A STUDY WAS UNDERTAKEN TO DETERMINE' /1/ THE DESIRED CHARACTERISTICS OF COMPACTED SOILS, /2/ THE BEST METHOD FOR MEASUREMENT AND SPECIFICATION OF PROPER COMPACTION AND /3/ THE EFFECTIVENESS OF VARIOUS WAYS OF ACHIEVING COMPACTION. THE FINAL REPORT CONSISTS OF THREE VOLUMES' VOLUME I COVERS THE FIELD PILOT AND LABORATORY STUDIES. THE LABORATORY STUDIES CONSISTED OF THE EVALUATION AND CALIBRATION OF TEST EQUIPMENT AND THE DETERMINATION OF SOIL PROPERTIES. VOLUME II DISCUSSES THE SCOPE OF THE FIELD TESTS AND THE BASIS OF THE RESEARCH PLANS. THE MEASUREMENT APPARATUS AND TECHNIQUES AND COMPACTING EQUIPMENT ARE DESCRIBED IN DETAIL. THE METHODS OF DATA PROCESSING ARE OUTLINED. VOLUME III PRESENTS THE RESULTS OF THE STUDY. PROPERTIES OF THE FIELD COMPACTED SOILS WERE FOUND TO BE SIMILAR TO THESE COMPACTED IN THE LABORATORY. WITHIN THE RANGE OF TEST CONDITIONS MOISTURE CONTENT WAS FOUND TO BE THE MOST SIGNIFICANT FIELD VARIABLE, WITH SOIL TYPE NEXT IN ORDER OF IMPORTANCE. THE COMPACTOR TYPE, LEVEL OF COMPACTIVE EFFORT AND THICKNESS OF LIFT ALSO INFLUENCED THE RESULTS IN MANY CASES. THE MEASURED PROPERTIES ALL INCREASED WITH ROLLER COVERAGE. THE WET DENSITY GROWTH CURVES LEVELED OFF MOST RAPIDLY BUT SIGNIFICANT INCREASES STILL OCCURRED AFTER FOUR COVERAGES. STRENGTH PROPERTIES CONTINUED TO INCREASE AT SIXTEEN COVERAGES FOR MOST TEST CONDITIONS. BOTH DENSITY AND STRENGTH DECREASED WITH AN INCREASE IN LIFT THICKNESS. THE MAGNITUDE OF FIELD VARIABILITY WAS SUCH THAT INDIVIDUAL MEASUREMENTS WOULD APPEAR INADEQUATE FOR COMPACTION CONTROL. /BPR/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:19:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/119387</guid>
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    <item>
      <title>UNEVEN ASPHALT ROLLING FOUND IN MANY STATES</title>
      <link>https://trid.trb.org/View/107443</link>
      <description><![CDATA[RECENT INVESTIGATION IN THE U.S.A. HAS SHOWN ROLLING PRACTICES WHICH RESULT IN LESS DENSITY AT THE EDGES OF ASPHALTIC PAVEMENTS THAN IN THE CENTRE, WHICH OFTEN GETS MORE ROLLING THAN IS NEEDED. A STUDY BY THE BUREAU OF PUBLIC ROADS OF FIELD CONDITIONS AND OPERATOR METHODS, SHOWED THAT JOBS WERE ORGANISED WITHOUT FOREKNOWLEDGE OF TEST- DESIGNATED ROLLER WEIGHTS, TYPES AND NUMBER OF PASSES. IT WAS FOUND THAT STEEL ROLLER OPERATORS FEARED THE BREAK- DOWN OR DISTORTION OF UNCONFINED EDGES, AND SO MADE FEWER PASSES. TESTS WHICH INVOLVED SPEEDS OF 20 TO 51 FT PER MINUTE SHOWED THAT PAVER SPEEDS SEEMED TO HAVE NO EFFECT ON COMPACTION RESULTS. /RRL/]]></description>
      <pubDate>Tue, 10 Aug 2004 16:58:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/107443</guid>
    </item>
    <item>
      <title>ORIENTATION OF PARTICLES WITH SPECIAL REFERENCE TO BITUMINOUS PAVING MATERIALS</title>
      <link>https://trid.trb.org/View/101165</link>
      <description><![CDATA[A METHOD IS DESCRIBED FOR MEASURING PARTICLE ORIENTATION IN BITUMINOUS MIXTURES AND FOR ANALYZING THE DATA BY STATISTICAL TECHNIQUES TO DETERMINE THE EXISTENCE AND DEGREE OF PREFERRED ORIENTATION. SAMPLES PREPARED BY ALTERNATIVE LABORATORY COMPACTIVE PROCEDURES ARE COMPARED WITH EACH OTHER AND WITH THE COMPACTIVE EFFORT OF A FIELD ROLLER IN RESPECT TO THE DEGREE OF PREFERRED ORIENTATION. THE CONCLUSION IS DRAWN THAT FOR THE PARTICULAR MIX EXAMINED, GIVEN NUMBER OF PASSES OF A FIELD ROLLER CAN BE EQUATED WITH A CERTAIN NUMBER OF PASSES OF A LABORATORY ROLLER THAT ACHIEVES THE SAME DEGREE OF ORIENTATION. THIS STRUCTURAL ELEMENT OF THE FIELD SPECIMEN IS CONFIRMED TO BE MORE CLOSELY SIMULATED BY USING THE LABORATORY ROLLER FOR SPECIMEN COMPACTION THAN BY USING STATIC COMPACTION. THE RELATIONSHIP BETWEEN PREFERRED ORIENTATION AND SAMPLE ANISOTROPY AS REVEALED BY STRENGTH TESTS IN MUTUALLY PERPENDICULAR DIRECTIONS IS DISCUSSED. /AUTHOR/]]></description>
      <pubDate>Thu, 29 Sep 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/101165</guid>
    </item>
    <item>
      <title>THE DEVELOPMENT AND EVALUATION OF COMPACTION MACHINERY</title>
      <link>https://trid.trb.org/View/107456</link>
      <description><![CDATA[THE ROAD ROLLER FOR SOIL COMPACTING IS DISCUSSED FROM THE FOLLOWING ASPECTS:  (1) BASIC ROLLER DESIGNS, (2) EVALUATION OF ROLLERS, (3) EXPERIMENTAL TECHNIQUES, (4) EXPERIMENTAL RESULTS, AND (5) RESULTS.]]></description>
      <pubDate>Sun, 18 Sep 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/107456</guid>
    </item>
    <item>
      <title>PAVEMENT DENSITY-WHAT INFLUENCES IT</title>
      <link>https://trid.trb.org/View/100929</link>
      <description><![CDATA[A RESEARCH PROJECT IS REPORTED WHICH WAS CONDUCTED TO STUDY THE PHYSICAL CHARACTERISTICS OF NEWLY CONSTRUCTED ASPHALT CONCRETE PAVEMENTS. A PORTION OF THE STUDY WAS UNDERTAKEN TO ESTABLISH INHERENT VARIABILITY AND TO DETERMINE THE INFLUENCE OF SUCH VARIABLES AS MIX COMPOSITION, PAVEMENT THICKNESS, MIX TEMPERATURE, AND NUMBER OF ROLLER PASSES ON PAVEMENT DENSITY. FORTY-SEVEN TEST SECTIONS, ONE LANE WIDE AND THE LENGTH OF LAYDOWN OF A TRUCK LOAD WERE STUDIED FROM 12 CONSTRUCTION PROJECTS THROUGHOUT THE STATE. TEMPERATURE MEASUREMENTS WERE MADE OF THE MIXTURE DURING COMPACTION, AND ALL ROLLER PASSES WERE RECORDED. BULK DENSITY, ASPHALT EXTRACTION, AGGREGATE GRADATION AND SPECIFIC GRAVITY TESTS WERE CONDUCTED ON PAVEMENT CORES AND MARSHALL SPECIMENS AS WERE PLASTIC FLOW DETERMINATIONS MADE ON THE MARSHALL SPECIMENS. IT WAS CONCLUDED FROM AN ANALYSIS OF THE DATA AS TO PAVEMENT DENSITY VARIABILITY THAT: (1) DENSITY DOES NOT VARY SIGNIFICANTLY IN THE LONGITUDINAL DIRECTION, (2) INITIAL PAVEMENT DENSITY VARIES SIGNIFICANTLY ACROSS THE LANE, BEING GREATEST IN THE CENTER AND LEAST NEAR THE EDGE, (3) TRAFFIC INCREASES PAVEMENT DENSITY AND DECREASES VARIATION, (4) INITIALLY, 29 PERCENT OF THE PAVEMENT AREAS HAD A DENSITY LESS THAN 95 PERCENT MARSHALL, WHICH AFTER ONE YEAR OF TRAFFIC WAS REDUCED TO 8 PERCENT AND AFTER 2 YEARS TO 4 PERCENT, AND (5) AFTER TWO YEARS' SERVICE, THE PAVEMENTS ARE SMOOTH-RIDING WITH NO OBSERVABLE SURFACE DEFECTS. A SERIES OF REGRESSION ANALYSES PERFORMED BY ELECTRONIC COMPUTER SHOWED THE FOLLOWING FACTORS WHICH AFFECTED VOIDS IN THE FOLLOWING ORDER: (1) ASPHALT CEMENT CONTENT, (2) PAVEMENT REBOUND DEFLECTION, (3) AGGREGATE GRADATION, (4) ASPHALT CEMENT VISCOSITY, (5) INTERMEDIATE ROLLER PASSES, (6) BREAKDOWN ROLLER PASSES, AND (7) FINAL ROLLER PASSES. THE NEW YORK STATE SPECIFICATION CONTROL ON TEMPERATURE AND ROLLING OF HOT-MIX ASPHALT CONCRETE WAS DETERMINED TO BE ADEQUATE TO PRODUCE PAVEMENTS OF PROPER DENSITY FOR GOOD PERFORMANCE.]]></description>
      <pubDate>Tue, 24 May 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/100929</guid>
    </item>
    <item>
      <title>HOW TO RUN A TEST STRIP FOR ASPHALT ROLLING</title>
      <link>https://trid.trb.org/View/173276</link>
      <description><![CDATA[All paving jobs are measured by the amount of asphalt laid down on an hourly basis. To estimate roller requirements, one must estimate the net average speed of the paver covering the particular road cross-section, the hourly laydown tonnage, and paver efficiency. Prior to running a test strip, the paving foreman must estimate the capacity of the roller train necessary to keep up with the paver for the hourly tonnage to be achieved on the project. This requires knowing the density of the mix. The density will be a laboratory density according to Marshall density or to theoretical maximum density. A certain percentage factor must be applied to determine the passing density and this will determine the nuclear count required to meet the specified density for the project. The test strip should be a straight run of at least 100 yards where there are no interruptions. The proper roller must be selected and tested for operation. The use of the nuclear gause is described. Effort must be made to obtain a roller pattern giving the least number of passes to get the optimum density and smooth surface. The vibration frequency of the roller, roller speed, the number of laps necessary to cover a roadway section, and the cooling rate of the asphalt are all discussed.]]></description>
      <pubDate>Fri, 29 Jan 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/173276</guid>
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    <item>
      <title>SOCIAL ASPECTS OF EXPOSURE TO HIGHWAY CRASH</title>
      <link>https://trid.trb.org/View/46953</link>
      <description><![CDATA[Both the sources of finding for crash reseach and the characteristics of the investigators attracted to it tend to produce parochialism, segmentation, and specialization in the field as a whole.  These potentially divisive forces are counteracted only by a shared and largely uncritical loyalty to the status quo--that is, a belief that the privately owned and operated conventional vehicle should continue as the major means of transportation.  As a consequence, despite the increasingly favorable climate for crash research, recent findings have contributed little to the reduction of mortality and morbidity.  The limitations of what is variously called human engineering, engineering psychology, or human factors are delineated, and a broader analytic framework is suggested.]]></description>
      <pubDate>Wed, 06 Oct 1976 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/46953</guid>
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