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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <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>
    </image>
    <item>
      <title>THE TESTING OF PULVERIZED FUEL ASH FROM SEVERAL SOURCES SUPPLIED TO ONE SITE</title>
      <link>https://trid.trb.org/View/122216</link>
      <description><![CDATA[THE CONTROL TESTING OF PULVERISED FUEL ASH FROM ONE SOURCE HAS A SET PROCEDURE, BUT IF THE ASH IS FROM SEVERAL SOURCES AND MIXED IN SITU TO FORM A FILL MATERIAL, CONTROLLING IT HAS ITS PROBLEMS. THE FOLLOWING OUTLINES A METHOD TO OVERCOME THIS USING STANDARD COMPACTION AT FIELD MOISTURE CONTENT AS CONTROL, AND ACCEPTING A PERCENTAGE OF THIS IN THE FIELD DRY DENSITY. USING A 4-IN. SAND REPLACEMENT TEST IN THE FIELD THERE IS ENOUGH MATERIAL RECOVERED TO FILL THE STANDARD COMPACTION MOULD. THIS MATERIAL WHEN RECOMPACTED IS USED COMPLETELY AS THE MOISTURE CONTENT SAMPLE. THE RATIO OF THE IN-SITU BULK DENSITY TO THE RECOMPACTED BULK DENSITY GIVES THE ANSWER ON COMPLETION OF THE LABORATORY TESTS WITHOUT HAVING TO WAIT FOR THE DRYING OUT OF THE MOISTURE CONTENT. /RRL/A/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:42:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/122216</guid>
    </item>
    <item>
      <title>A SURVEY OF EXISTING INFORMATION ON DUST LAYING</title>
      <link>https://trid.trb.org/View/122029</link>
      <description><![CDATA[WATER-BOUND MACADAM AND OTHER MECHANICALLY STABLE ROADS GENERALLY REQUIRE ONLY A SURFACE TREATMENT TO PREVENT DUST. ON EARTH ROADS WHERE THE SURFACE IS OFTEN LOOSE AND FRIABLE IT IS GENERALLY NECESSARY TO TREAT THE SOIL TO A DEPTH OF SEVERAL INCHES. THE PRINCIPAL AGENTS FOR BOTH THESE PURPOSES ARE CLASSIFIED AS FOLLOWS: (1) FRESH WATER AND SEA WATER, (2) DELIQUESCENT CHEMICALS SUCH AS CALCIUM CHLORIDE, APPLIED EITHER IN SOLUTION OR IN CRYSTALLINE FORM, (3) BITUMINOUS MATERIAL, AND (4) ORGANIC NON-BITUMINOUS BINDERS. THESE BINDERS MAY BE: (1) SULPHITE LYE, WASTE SULPHITE LIQUOR AND OTHER WOOD-PULP WASTE PRODUCTS, (2) MOLASSES RESIDUES, AND (3) VEGETABLE OILS, ANIMAL OILS AND FATS. METHODS OF TREATMENTS ARE DESCRIBED WITH EACH OF THESE AGENTS. TEMPORARY RELIEF FROM DUST MAY BE OBTAINED BY SPRAYING WITH WATER. TAR AND BITUMEN PRODUCTS ARE PROBABLY THE MOST FAMILIAR OF THE DUST-LAYING AGENTS. THEIR GENERAL USE AS ROAD-BINDING MATERIALS HAS LED TO THE PRODUCTIONS OF SPECIFIC TYPES FOR DIFFERENT ROAD PURPOSES AND IT IS POSSIBLE TO OBTAIN LIGHT TARS, CUT-BACK BITUMENS AND HEAVY OILS WHICH ARE EMINENTLY SUITABLE FOR DUST-LAYING. IT IS EMPHASIZED THAT THE SUCCESS OF BITUMINOUS TREATMENTS DEPENDS LARGELY ON THE SELECTION OF A BINDER OF SUITABLE VISCOSITY. VISCOSITY RANGES FOR BOTH TAR AND BITUMEN FOR THE DIFFERENT TYPES OF TREATMENT ARE GIVEN IN A TABLE. THE HIGHER VISCOSITIES SHOULD BE USED IN HOTTER CLIMATES. WHENEVER POSSIBLE, THE CHOICE OF VISCOSITY SHOULD BE A MATTER FOR TRIAL ON THE ROAD. IN SPECIAL CIRCUMSTANCES, DUST MAY BE REMOVED FROM THE ROAD SURFACE BY MACHINERY. A MACHINE WHICH HAS BEEN USED SUCCESSFULLY IN SWEDEN CONSISTS OF A WHEELED CONTAINER CARRYING A ROTARY BRUSH WHICH THROWS THE DUST ON TO A PROJECTING SHIELD, FROM WHICH IT IS BLOWN BY COMPRESSED AIR THROUGH A SCREEN INTO THE BODY OF THE VEHICLE.]]></description>
      <pubDate>Sun, 15 Aug 2004 02:41:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/122029</guid>
    </item>
    <item>
      <title>THE PRACTICE OF TAR STABILISATION IN SWITZERLAND</title>
      <link>https://trid.trb.org/View/121846</link>
      <description><![CDATA[THE ADVANTAGES OF TAR STABILIZATION OVER HOT MIX BASES ARE GIVEN. THE FLEXIBILITY OF THIS TREATMENT ALLOWS CONSIDERABLE DEFORMATION WITHOUT CRACKING. THE TAR STABILIZATION IS MORE ECONOMICAL WHERE THE LOCAL AGGREGATE COULD BE STABILIZED AND TRANSFORMED INTO A FLEXIBLE BASE IN SITU / MIXED IN PLACE/. WHEN THERE IS NO ADEQUATE ACCESS TO A MIXING PLANT, FOR HOT MIXES BASES, THE TAR STABILIZATION METHOD IS SUPERIOR BECAUSE OF THE HAULING PROBLEM. THE TAR STABILIZATION ALSO OFFERS AN ECONOMICAL APPLICATION FOR STRENGTHING EXISTING ROAD PAVEMENTS AND PARTICULARLY THOSE OF UNSURFACED ROADS IN RURAL AREAS.]]></description>
      <pubDate>Sun, 15 Aug 2004 02:41:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/121846</guid>
    </item>
    <item>
      <title>AN INVESTIGATION INTO THE ACCURACY ACHIEVED IN MEASURING THE STATE OF COMPACTION OF CEMENT-BOUND GRANULAR MATERIAL</title>
      <link>https://trid.trb.org/View/121749</link>
      <description><![CDATA[AN INVESTIGATION WAS MADE DURING THE CONSTRUCTION OF A 5 MILE LENGTH OF MOTORWAY INTO THE EFFECT ON THE ACCURACY OF THE RESULTS OF THE SAND-REPLACEMENT METHOD OF VARIATIONS IN THE TIME BETWEEN COMPACTION AND THE MEASUREMENT OF THE DENSITY OF A CEMENT-BOUND GRANULAR BASE. A COMPARISON WAS ALSO MADE OF THE RESULTS OF DRY DENSITY MEASUREMENTS OBTAINED FROM CORES SUBSEQUENTLY CUT FROM THE BASE WITH THE RESULTS OF THE SAND-REPLACEMENT TESTS CARRIED OUT BY A TEAM FROM THE ROAD RESEARCH LABORATORY AND TWO SITE CONTROL TEAMS. THE EXPERIMENTAL PROCEDURE IS DESCRIBED. RESULTS OF THE DRY DENSITY MEASUREMENTS, MADE ON CORES CUT FROM THE BASE ARE COMPARED WITH THOSE OBTAINED BY MEANS OF THE SAND-REPLACEMENT METHOD. THE ARTICLE ALSO REFERS TO LABORATORY INVESTIGATIONS INTO THE EFFECT OF THE PARTICLE SIZE OF THE SAND USED IN THE SAND-REPLACEMENT TEST ON THE ACCURACY IN DETERMINING THE VOLUME OF A FACSIMILE OF A TEST HOLE. /RRL/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:40:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/121749</guid>
    </item>
    <item>
      <title>LABORATORY INVESTIGATION OF THE USE OF MIXTURES OF LIME AND PULVERISED FUEL ASH FOR SOIL STABILIZATION</title>
      <link>https://trid.trb.org/View/121744</link>
      <description><![CDATA[A STUDY OF HOPPER ASHES COLLECTED FROM 12 POWER STATIONS SHOWED THAT ALTHOUGH THEY ALL POSSESSED POZZOLANIC PROPERTIES, THEIR POZZOLANIC ACTIVITIES VARIED CONSIDERABLY. THE ACTIVITY WAS RELATED TO THE SURFACE AREA AND THE IGNITION LOSS /CARBON CONTENT/ OF THE ASH. IT IS SUGGESTED THAT LIMITING VALUES FOR THESE TWO PROPERTIES SHOULD BE A MINIMUM SURFACE AREA OF 2750 SQ CM/G AND A MAXIMUM IGNITION LOSS OF 7 PER CENT, OF THE 12 ASHES STUDIED, SEVEN WERE SUFFICIENTLY ACTIVE TO MAKE THEM POTENTIALLY USEFUL STABILIZING AGENTS. REMOVAL OF THE SOLUBLE SALTS HAD NO EFFECT ON THE POZZOLANIC ACTIVITY OF ANY OF THE ASHES. THE STRENGTH-AGE RELATIONS OF THE LIME-ASH STABILIZED SANDS DIFFERED MARKEDLY FROM THOSE OF CEMENT-STABILIZED SANDS, AND FOR THE FIRST 14 DAYS LITTLE STRENGTH WAS DEVELOPED, BETWEEN 14 AND 56 DAYS THERE WAS A VERY RAPID INCREASE IN STRENGTH, SO THAT ALTHOUGH AT SEVEN DAYS THE COMPRESSIVE STRENGTH OF LIME-ASH STABILIZED SAND WAS MUCH LOWER THAN THE STRENGTH OF CEMENT-STABILIZED SAND, AT 56 DAYS THE STRENGTHS WERE COMPARABLE. TEMPERATURE EFFECTS ON THE DEVELOPMENT OF STRENGTH OF SANDS STABILIZED WITH LIME- ASH MIXTURES WAS GREATER THAN IT WAS ON EITHER CEMENT OR LIME-STABILIZED SANDS. /RRL/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:40:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/121744</guid>
    </item>
    <item>
      <title>AN INVESTIGATION INTO THE EFFECT OF VARIATIONS IN THE DRYNESS OF THE SAND USED IN THE SAND-REPLACEMENT TEST</title>
      <link>https://trid.trb.org/View/121016</link>
      <description><![CDATA[AN INVESTIGATION IS CONDUCTED INTO THE EFFECT THAT VARIATIONS IN THE DRYNESS OF THE SAND USED IN THE BRITISH STANDARD SAND-REPLACEMENT TEST HAVE ON THE ACCURACY OF THE DETERMINATION IN SITU OF THE DENSITY OF COMPACTED SOILS AND ROAD-BASE MATERIALS. IT HAD BEEN NOTED DURING A NUMBER OF MAJOR ROAD PROJECTS THAT THE DRY DENSITY OF CEMENT-BOUND GRANULAR BASE MATERIALS, DETERMINED BY THE SAND-REPLACEMENT TEST PROCEDURE, DIFFERED SIGNIFICANTLY FROM THAT DETERMINED FROM CORES CUT FROM THE COMPACTED BASES. THE ACCURACY OF THE SAND-REPLACEMENT TEST DEPENDS ON THE EXTENT TO WHICH THE BULK DENSITY OF THE SAND, DETERMINED DURING CALIBRATION, HOLDS WHEN THE SAND IS USED TO FILL THE DENSITY HOLE. THE DRYNESS OF THE SAND IS A FACTOR LIKELY TO AFFECT ITS BULK DENSITY, AND THE INVESTIGATION DESCRIBED IN THIS ARTICLE WAS MADE TO DETERMINE ITS SIGNIFICANCE. /RRL/A/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:37:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/121016</guid>
    </item>
    <item>
      <title>EFFECT OF SOIL LUMPS IN COMPACTED SOIL-CEMENT</title>
      <link>https://trid.trb.org/View/120464</link>
      <description><![CDATA[LABORATORY RESEARCH TO DETERMINE WHAT INFLUENCE SOIL LUMPS HAVE IN COMPACTED SOIL-CEMENT AND WHAT VOLUME OF SOIL LUMPS MAY BE INCLUDED WITHOUT LOWERING QUALITY IS DESCRIBED. TESTS SHOW THAT AT LEAST 80% PULVERIZATION SHOULD BE OBTAINED AND THAT THE SOIL LUMPS SHOULD BE AT OPTIMUM MOISTURE AT TIME OF COMPACTION.]]></description>
      <pubDate>Sun, 15 Aug 2004 02:35:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/120464</guid>
    </item>
    <item>
      <title>SOIL-CEMENT IN COUNTY WORK</title>
      <link>https://trid.trb.org/View/120438</link>
      <description><![CDATA[EFFECTIVE STABILIZATION OF SUBSOIL CAN BE ACHIEVED MECHANICALLY, CHEMICALLY AND BY MEANS OF ADDITIVES SUCH AS CEMENT. HOWEVER, THE PRESENCE OF MORE THAN 2% OF ORGANIC MATTER REQUIRES INCORPORATING 2% OF CALCUM CHLORIDE WITH CEMENT AND IN CASE OF ACID SOIL, AN ADDITION OF 2% LIME IS ADVISABLE. DETAILS ARE GIVEN OF TYPICAL SOIL-CEMENT WORK CARRIED OUT ON COUNTY ROADS.]]></description>
      <pubDate>Sun, 15 Aug 2004 02:35:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/120438</guid>
    </item>
    <item>
      <title>THE STABILITY OF AGGREGATES USED IN ROAD SUB-BASES</title>
      <link>https://trid.trb.org/View/110447</link>
      <description><![CDATA[THE PROPERTIES OF ELEVEN TYPICAL AGGREGATES ECONOMICALLY AVAILABLE IN THE MIDLANDS FOR SUB-BASE CONSTRUCTION, ARE COMPARED WITH THE MINISTRY OF TRANSPORTS SPECIFICATION /1963/ FOR TYPE I GRANULAR SUB-BASE. IT IS SHOWN THAT CRUSHER RUN ROCK AGGREGATES GENERALLY DO NOT COMPLY WITH THE SPECIFICATION, BECAUSE THEIR FINES /NO. 200 B.S. SIEVE/ ARE PLASTIC. EXPERIMENTS INVESTIGATING THE INFLUENCE OF THE FINES CONTENT AND PLASTICITY ON THE STABILITY OF SOME CRUSHED STONE AGGREGATES ARE DESCRIBED. THE RESULTS INDICATE THAT A FINES CONTENT OF BETWEEN 4% AND 8% GIVES MAXIMUM STABILITY TO AGGREGATES COMPACTED TO DENSITIES ACHIEVED WITH MODIFIED A.A.S.H.O. COMPACTION. THIS, AND PRACTICAL CONSIDERATIONS SUGGEST THAT SUCH AGGREGATES ARE LIKELY TO PERFORM MOST SATISFACTORILY UNDER ADVERSE CONDITIONS, ALTHOUGH IT IS SHOWN THAT AGGREGATES HAVING NO FINES PASSING THE NO. 200 B.S. SIEVE MAY HAVE VERY HIGH STABILITY IF COMPACTED TO A HIGH DENSITY. TESTS ALSO INDICATE THAT THE HIGHEST STABILITY IS OBTAINED IF THE MATERIAL PASSING A NO. 36 SIEVE HAVE LOW PLASTICITY. IT IS SUGGESTED THAT THE MINISTRY OF TRANSPORT SPECIFICATION FOR TYPE I SUB-BASE MAY BE IMPROVED BY' SPECIFYING A FINENESS INDEX /%PASSING NO. 200 PLASTICITY INDEX/ AS A MEANS OF CONTROLLING THE PROPERTIES OF THE FINES CONTENT. A VALUE OF 40 WOULD BE SUITABLE, AND CARRYING OUT PLASTICITY TESTS ON MATERIAL PASSING THE NO. 36 SIEVE INSTEAD OF ON FINES PASSING THE NO. 200 SIEVE. /RRL/]]></description>
      <pubDate>Tue, 10 Aug 2004 17:50:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/110447</guid>
    </item>
    <item>
      <title>ROAD MARKING WITH CHLORINATED RUBBER PAINT</title>
      <link>https://trid.trb.org/View/110073</link>
      <description><![CDATA[TWO TYPES OF ROAD MARKING PAINTS ARE DESCRIBED. THE PAINTS WITH THE ADDITION OF BALLOTINI GLASS SPHERES HAVE BEEN USED FOR PROVIDING REFLECTORIZED EDGE MARKING ON A 17-MILE STRETCH OF THE M1 AND THE M45 MOTORWAYS. DETAILS OF STRIPING EQUIPMENT AND THE SPRAYING OPERATIONS ARE GIVEN. /RRL/]]></description>
      <pubDate>Tue, 10 Aug 2004 17:49:28 GMT</pubDate>
      <guid>https://trid.trb.org/View/110073</guid>
    </item>
    <item>
      <title>PVC TAR IN BRITAIN</title>
      <link>https://trid.trb.org/View/95202</link>
      <description><![CDATA[THE ADVANTAGES OF USING POLYVINYL CHLORIDE TAR ARE DISCUSSED. THE DEVELOPMENT OF THIS TECHNIQUE IS DESCRIBED. DESCRIPTIONS ARE GIVEN OF TRIALS CARRIED OUT IN GREAT BRITAIN AND OVERSEAS TO ESTABLISH THE SUITABILITY OF THESE MATERIALS FOR ROAD CONSTRUCTION. THE PARTICULAR PROPERTIES OF THIS TYPE OF TAR ARE DESCRIBED. PLACES WHERE IT HAS BEEN USED IN THIS COUNTRY ARE LISTED, AND COMMENTS GIVEN ON ITS PERFORMANCE. /RRL/]]></description>
      <pubDate>Sat, 18 Nov 2000 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/95202</guid>
    </item>
    <item>
      <title>DESIGN OF THE SUBSURFACE DRAINAGE SYSTEM FOR THE INNER RING ROAD OF THE CITY OF ANTWERP</title>
      <link>https://trid.trb.org/View/123972</link>
      <description><![CDATA[DESCIRBED HERE IS THE PROCEDURE ADOPTED FOR THE DESIGN OF A PERMANENT DEWATERING SYSTEM FOR THE DEPRESSED INNER RING ROAD OF THE CITY OF ANTWERP IN BELGIUM. THIS COSTLY UNDERTAKING NECESSITATED EXTENSIVE INVESTIGATION AND ANALYSIS TO ENABLE THE ARRIVAL AT A SATISFACTORY ENGINEERING SOLUTION. DETAILS ARE GIVEN OF ALL THE STAGES IN THE HYDROLOGICAL DESIGN OF THE SOPHISTICATED SUB-SURFACE DRAINAGE SYSTEM, INCLUDING THE EXECUTION AND ANALYSIS OF EXTENSIVE FIELD PUMPING TESTS, THE CALCULATION OF SEEPAGE QUANTITIES AND THE STUDY OF THE HYDRAULICS OF THE HORIZONTAL INTAKE PIPES ADOPTED TO EFFECT THE GROUND-WATER LOWERING. MUCH SPACE IS DEVOTED TO A DESCRIPTION OF THE ELECTRICAL MODEL TESTS CARRIED OUT TO MAP FLOW NETS FOR A LARGE NUMBER OF VALUES OF THE PARAMETERS WHICH DETERMINED THE CRITICAL PIPE ELEVATIONS. /AUTHOR/]]></description>
      <pubDate>Thu, 04 Aug 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/123972</guid>
    </item>
    <item>
      <title>SOIL PROBLEMS ON THE SEVENOAKS BY-PASS</title>
      <link>https://trid.trb.org/View/123658</link>
      <description><![CDATA[DIFFICULTIES WHICH HAD BEEN ENCOUNTERED WITH GROUND WATER AND EARTH MOVEMENTS IN THE CONSTRUCTION OF A SECTION OF THE SEVENOAKS BY-PASS ARE DISCUSSED. SOIL SURVEYS INDICATED THAT THE GROUND WAS EXTREMELY WATERLOGGED AND TREACHEROUS. IT WAS THEORIZED THAT ANCIENT LANDSLIDS HAD LEFT A NUMBER OF SLIP PLANES IN THE SOIL, COMPRISING THIN LAYERS VERY MUCH WEAKER THAN THE BULK OF THE SURROUNDING SOIL. A LARGE SOIL MOVEMENT OCCURRING IN CONNECTION WITH THE BY-PASS WORKS HAD BEEN CAUSED BY MOVEMENT ALONG THESE LAYERS OF WEAKNESS WHICH WERE ONLY APPROXIMATELY ONE HALF INCH THICK AND UNDETECTED BY NORMAL SOIL INVESTIGATION. THE RECOMMENDED COURSE OF ACTION INCLUDES STABILIZING AND SOME RE-ROUTING.]]></description>
      <pubDate>Tue, 05 Jul 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/123658</guid>
    </item>
    <item>
      <title>NEW OUTLOOKS FOR ROAD TAR</title>
      <link>https://trid.trb.org/View/97117</link>
      <description><![CDATA[VARIOUS EXAMPLES SHOW THAT COAL TAR IS A BINDER WHICH RETAINS ITS VALUE DESPITE THE NEW REQUIREMENTS OF ROAD BUILDING TECHNIQUES. LINKED WITH MANY MATERIALS IT MAY ATTAIN A PERFORMANCE SUPERIOR TO THOSE OF TRADITIONAL BINDERS AND COPE WITH THE STRESSES IMPOSED BY INCREASING TRAFFIC IN REGARDS TO NUMBERS, SPEED, AND WEIGHT OF VEHICLES. RESEARCH IS BEING CARRIED OUT IN MANY DIFFERENT DIRECTIONS: THE OBJECT IS FITTING TAR TO THE DEMANDS MADE ON MODERN ROADS. MANY COUNTRIES CONSIDER THAT TAR-BITUMEN MIXTURES ARE THE SOLUTION FOR THE FUTURE. MUCH PROGRESS IS POSSIBLE IN THIS FIELD. ON THE OTHER HAND THE ASSOCIATION OF CONVENTIONAL BINDERS WITH CERTAIN NATURAL OR SYNTHETIC PRODUCTS OPENS NEW PROSPECTS. TAR HAS A SPECIFIC AFFINITY FOR THESE MATERIALS, AND THIS ADVANTAGE, OF WHICH USE HAS ALREADY BEEN TAKEN, MUST BE USED EVEN MORE IN THE FUTURE TO PERFECT ROAD BUILDING TECHNIQUES. /AUTHOR/]]></description>
      <pubDate>Thu, 26 May 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/97117</guid>
    </item>
    <item>
      <title>THE SURFACE TENSION OF ASPHALTIC BITUMENS AND ALLIED SUBSTANCES AT VARIOUS TEMPERATURES</title>
      <link>https://trid.trb.org/View/95097</link>
      <description><![CDATA[METHODS ARE DISCUSSED FOR THE DETERMINATION OF THE SURFACE TENSION OF ASPHALTIC BITUMENS. THE METHOD OF THE ADHESION RINGS (DU NOUY APPARATUS) SEEMS TO GIVE FAIRLY GOOD RESULTS BUT CANNOT BE CONSIDERED RELIABLE AND ACCURATE. IT IS CONTENDED THAT THE BEST METHOD SEEMS TO BE THAT OF THE AIR- BUBBLE PRESSURE. A STREAM OF PURE NITROGEN IS PRESSED THROUGH A CAPILLARY TUBE, THEN DIPPED INTO THE MOLTEN BITUMEN. FOR ASPHALTIC BITUMENS THE SURFACE TENSION COULD BE DETERMINED WITHIN A RATHER WIDE TEMPERATURE RANGE. DETERMINATION OF THE OILY CONSTITUENTS IN WHICH THE ASPHALTIC BITUMEN MICELLES ARE DISSOLVED IS DISCUSSED. EXTRACTION OF THE OILY CONSTITUENTS IS OUTLINED. THE FOLLOWING SUBSTANCES WERE ANALYZED: OXIDIZED VENEZUELAN ASPHALTIC BITUMEN, SPRAMEX (ROYAL DUTCH-SHELL), SHELFALT (ROYAL DUTCH-SHELL), 50-60, SHELFALT (ID.), 40-50, ASPHALTIC BITUMEN FROM TRINIDAD EPURE, AND COAL TAR PITCH. RESULTS SHOW THAT ALL CURVES HAVE A DEFLECTION POINT. BELOW A CERTAIN TEMPERATURE THE VALUES OBTAINED FOR THE SURFACE TENSION INCREASE RAPIDLY WITH DECREASING TEMPERATURE. IT IS CONCLUDED THAT, WHEN HEATING AN ASPHALTIC BITUMEN OR A PITCH, A SUDDEN DECREASE IN THE COHESION OF THE COLLOIDAL LIQUID OFTEN OCCURS. ABOVE THIS TEMPERATURE, THE ASPHALTIC BITUMEN AND THE PITCH BEHAVE LIKE AN ORDINARY HEAVY MINERAL OIL. DEFLECTION POINTS ARE GIVEN FOR THE DIFFERENT SUBSTANCES. THESE FIGURES SHOW THAT A LOWER PENETRATION OF THE ASPHALTIC BITUMEN DOES NOT ALWAYS CORRESPOND WITH A HIGHER DEFLECTION POINT. CURVES FOR THE OILY CONSTITUENTS SHOW A DEFLECTION POINT BUT AT A MUCH LOWER TEMPERATURE. THE TEMPERATURE DIFFERENCE BETWEEN THE DEFLECTION POINT OF THE ASPHALTIC BITUMENS AND THAT OF THE OILY CONSTITUENTS SHOWS WIDE VARIATIONS. REFERENCES; F. J. NELLERSTEYN, N. M. ROODENBURG, KOLLOID-CHEMISCHE BEIHEFTE, VOL. 31, P. 434, 1930.]]></description>
      <pubDate>Sat, 21 May 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/95097</guid>
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