<rss version="2.0" xmlns:atom="https://www.w3.org/2005/Atom">
  <channel>
    <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" />
    <description></description>
    <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>PROPERTIES OF BITUMINOUS MIXTURES CONTAINING DIFFERENT FILLERS</title>
      <link>https://trid.trb.org/View/488032</link>
      <description><![CDATA[This paper is aimed at characterizing the role of fillers in bituminous mixtures.  Emphasis is mainly given to the low temperature properties of bituminous mixes.  Four types of filler (limestone, quartz, fly ash, and kaolin) with different physical properties were evaluated.  The characteristics of the fillers were determined using several different physical tests. It was found that the dry compacted filler test method is a good test method for filler characterization.  Some modifications in the test procedure were made in order to produce more repeatable results.  The four fillers were combined with one type of bitumen at different filler levels and routine bitumen tests were carried out.  The temperature susceptibility of the various filler-bitumen mixes were determined using the penetration index values.  The results of the viscosity testing showed how the fillers stiffened the filler-bitumen mixes.  The filler-bitumen ratios used in the study were evaluated in a typical dense-graded asphaltic concrete mix.  Marshall testing was performed at different temperatures ranging from 30 to 70 deg C and two Marshall test parameters, namely, Marshall temperature index of stability and Marshall temperature index of stiffness, were determined.  Flexural testing was also carried out at a range of different low temperatures to determine the flexural properties of mixes containing different types and amounts of fillers.  A toughness parameter (i.e., the area under stress-strain curve in flexural testing) was evaluated at different low temperatures.  It was found that, for each mix, there is an optimum filler content corresponding to maximum toughness.  For the fillers tested in this research, the maximum toughness corresponded to a region of filler/bitumen ratio between 0.25 and 0.75.]]></description>
      <pubDate>Fri, 07 Aug 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/488032</guid>
    </item>
    <item>
      <title>AXISYMMETRIC SQUEEZING TESTS ON SOFT CLAY</title>
      <link>https://trid.trb.org/View/476485</link>
      <description><![CDATA[The apparatus and interpretation procedures for axisymmetric squeezing tests on soft clays are shown.  Testing procedures are much simpler than the previously used plane strain tests.  These tests may become practical when dealing with clays that occur in thin layers.  Test results are consistent with results obtained by conventional triaxial tests.  Both shear strength and plastic viscosity are obtained.]]></description>
      <pubDate>Tue, 03 Mar 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/476485</guid>
    </item>
    <item>
      <title>LABORATORY DEVELOPMENT OF THIRD/FOURTH GENERATION SULPHLEX BINDERS</title>
      <link>https://trid.trb.org/View/472780</link>
      <description><![CDATA[This report presents the findings of a 2-year, multitask study to provide a new generation of Sulphlex binders with enhanced low-temperature fracture resistance.  The initial phases of the program dealt with the preparation and base-line characterization of Sulphlex 233 and 198, First and Second Generation Sulphlex, respectively, considered the more promising of a broad series of formulations developed under earlier Federal Highway Administration programs.  These binders were prepared individually and blended at ratios of 50/50 and 75/25 (198/233) and designated as Third Generation Sulphlex.  The former was prepared by directly blending the two binders as well as by a one-pot synthesis.  These binders were subjected to a series of screening tests including (a) Penetration @ 25 deg C, (b) Viscosity @ 135 deg C, (c) Specific Gravity, (d) Solubility in CHCl3, (e) Storage Stability, and (f) Glass Transition temperature.  A "new and improved" Sulphlex binder designated as Fourth Generation was formulated utilizing the rationale derived from the earlier systems.  Sulphlex mixtures along with a control using an AC-20 asphalt were prepared using a crushed limestone aggregate and tested in accordance with Asphalt Aggregate Mixture Analysis System (AAMAS), American Association of State Highway and Transportation Officials (AASHTO), Strategic Highway Research Program (SHRP or Superpave), and Viscoelastic Systems (VESYS) procedures including (a) Indirect Tension, (b) Diametral Resilient Modulus, (c) IDT Creep, (d) Compressive Creep, (e) Unconfined Compression, (f) Repeated Load Permanent Deformation, and (g) Aging using Resilient Modulus.  A set of generic manufacturing plans and procedures were generated for the production of Sulphlex in sufficient quantity to satisfy the requirements of an hypothetical test road section.]]></description>
      <pubDate>Fri, 27 Feb 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/472780</guid>
    </item>
    <item>
      <title>PROPERTIES OF MICROWAVE RECYCLED ASPHALT CEMENT BINDERS</title>
      <link>https://trid.trb.org/View/574883</link>
      <description><![CDATA[Recycling asphalt concrete pavements are currently limited to about 40% to 60% of recyclable asphalt pavement (RAP) in the mixture, with the remaining material composed of new asphalt and aggregates.  The use of microwaves for heating allows the possibility of recycling with 100% RAP material.  The effect of microwaves on asphalt cement binders was evaluated using conventional viscosity and penetration tests.  The binders were also evaluated using Gel Permeation Chromatography (GPC), Fourier-Transform Infrared Spectroscopy (FTIR), and Dynamic Shear Rheometer (DSR).  Viscosity and penetration testing provided opposing results with each showing slight increases in value after microwaving of the binder.  A noticeable change in the molecular size distribution was observed with the GPC with the addition of a recycling agent.  An increase in complex shear modulus occurred at high temperatures or low frequencies after microwaving.  This increase was more pronounced on severely oxidized or hardened asphalts.  The increase in complex shear modulus did not correlate well with measured viscosity and penetration values.  The steady-state viscosity values obtained followed the same general trend as the results from conventional viscosity testing.]]></description>
      <pubDate>Sat, 28 Jun 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/574883</guid>
    </item>
    <item>
      <title>VARIABILITY ANALYSIS OF HOT-MIX ASPHALT CONCRETE CONTAINING HIGH PERCENTAGE OF RECLAIMED ASPHALT PAVEMENT</title>
      <link>https://trid.trb.org/View/469970</link>
      <description><![CDATA[A research project was undertaken to evaluate the production and construction variability of hot-mix asphalt concrete (HMAC) containing large quantities of recycled asphalt pavement (RAP) material.  Four construction projects were selected.  Two of the projects used 35% RAP material, while the other two used 40% and 50% RAP, respectively.  The projects differed in size with total hot-mix ranging from 12,000 to 30,000 tons.  In all cases, dedicated RAP stockpiles were used.  A series of tests was performed at both the hot-mix plant laboratory and the University of Texas (UT) asphalt laboratory.  The tests at the plant included extraction, gradation, and asphalt content using nuclear gauge.  A number of specimens were also compacted and shipped to the Texas Department of Transportation Materials and Tests Division for Hveem stability testing.  Asphalt recovery, penetration, and viscosity tests for both HMAC and RAP were conducted at the UT laboratory.  Each day, four sublots were sampled.  The results obtained from the tests were analyzed. The gradation and asphalt content deviations, air voids, penetrations and viscosities, and stabilities were included in the analysis.  Pay adjustment factors were determined for gradation and asphalt content deviation, as well as for air voids.  In general, these high-percentage RAP projects indicated higher variability than a typical HMAC project without RAP.  The gradations of plant-produced mixtures were finer than the job mix formula target gradations, possibly because of aggregate crushing during the milling operation.]]></description>
      <pubDate>Mon, 03 Feb 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/469970</guid>
    </item>
    <item>
      <title>PRODUCTION VARIABILITY ANALYSIS OF HOT-MIXED ASPHALT CONCRETE CONTAINING RECLAIMED ASPHALT PAVEMENT. FINAL REPORT</title>
      <link>https://trid.trb.org/View/447700</link>
      <description><![CDATA[A research project was undertaken to evaluate the production and construction variability of HMAC (hot mix asphalt concrete) containing high quantities of RAP (reclaimed asphalt pavement) material.  Four construction projects were selected for this purpose.  Two of the projects used 35% RAP material (both type-C mixes), while the other two used 40% (a type-B mix) and 50% (a type-D mix) of the RAP material, respectively.  The projects differed in sizes, with total construction tonnage ranging from 10.9 million kg to 27.2 million kg (12,000 to 30,000 tons).  In all cases, dedicated stockpiles of RAP material were used.  A series of tests according to Texas Department of Transportation (TxDOT) Special Specification Item 3007 (Quality Control/Quality Assurance of Hot Mix Asphalt) were performed both in the hot-mix plant laboratory and in The University of Texas (UT) asphalt laboratory.  The tests in the plant included extraction, gradation determination, and determination of asphalt content using a nuclear gauge.  A series of specimens were also compacted and shipped to the TxDOT Materials and Tests Division for Hveem stability testing.  The tests conducted in the UT laboratory were the same as those conducted in the plant; in addition, the researchers undertook asphalt recovery, penetration, and viscosity tests for both the HMAC and RAP. Attempts made to obtain samples four times a day for four sublots (in accordance with TxDOT Special Specification Item 3007) were not successful on all days, owing to low tonnage or other problems.  Analysis was performed on the results obtained from the tests.  The gradation and asphalt content deviations, air voids, penetration and viscosities, and stabilities were included in the analysis.  Pay adjustment factors were determined for gradation and asphalt content deviation, as well as for air voids (based on TxDOT Specification 3007).  In general, these high-percent RAP projects indicated a variability higher than that of a typical HMAC without RAP.  The pay adjustment factors for gradation and asphalt content deviation were lower than typical values.  The construction gradations were finer than the job-mix formula target gradations, possibly a result of aggregate crushing during the milling operation.]]></description>
      <pubDate>Fri, 01 Sep 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/447700</guid>
    </item>
    <item>
      <title>DURABILITY OF PAVING ASPHALT - PART II, A STUDY OF THE ROSTLER AND HEITHAUS TEST METHODS FOR PAVING GRADE ASPHALTS</title>
      <link>https://trid.trb.org/View/97671</link>
      <description><![CDATA[THE ROSTLER ANALYSIS WAS PERFORMED ON RECOVERED ASPHALTS FROM THE ZACA-WIGMORE TEST ROAD AND ON A SERIES OF 85-100 PENETRATION GRADE ASPHALTS THAT WERE WEATHERED IN A LABORATORY INFRARED OVEN. ASPHALTENE, NITROGEN BASE, FIRST AND SECOND ACIDIFFINS AND PARAFFIN FRACTIONS WERE OBTAINED BEFORE AND AFTER AGING. THE HEITHAUS TEST WHICH PROVIDES A METHOD FOR MEASURING THE PEPTIZING POWER OF THE MALTENES AND THE PEPTIZABILITY OF THE ASPHALTENES IN ASPHALT TOGETHER WITH A MATHEMATICAL TREATMENT OF THESE FACTORS TO OBTAIN A STATE OF PEPTIZATION OF THE SYSTEM WAS APPLIED TO A SERIES OF 85-100 PENETRATION GRADE PAVING ASPHALTS. SOME OF THE FINDINGS OF THE STUDY ARE' /1/ THE ROSTLER COMPOSITIONAL PARAMETER, A RATIO OF NITROGEN BASES PLUS FIRST ACIDIFFINS TO PARAFFINS PLUS SECOND ACIDIFFINS ON THE ORIGINAL ASPHALT, APPEARS TO RELATE TO ABRASION LOSS AFTER WEATHERING OF THE ASPHALT IN AN INFRARED OVEN. THERE IS NO DEFINITE RELATION WHEN THIS PARAMETER IS COMPARED WITH THE SHEAR SUSCEPTIBILITY OF WEATHERED ASPHALTS AND ONLY A TREND OF A RELATION IS NOTED WHEN THE PARAMETER IS COMPARED WITH THE VISCOSITY OF THE RESIDUE AFTER A SPECIAL DURABILITY TEST, /2/ A FAIR TREND WAS FOUND WHEN SHEAR SUSCEPTIBILITY OF WEATHERED ASPHALTS WAS COMPARED TO A RATIO OF THE ASPHALTENE TO THE NITROGEN BASE CONTENT, /3/ A FAIRLY GOOD RELATION WAS FOUND BETWEEN THE PEPTIZABILITY OF THE ASPHALTENES AND THE VISCOSITY OF A SPECIAL DURABILITY TEST RESIDUE, /4/ NEITHER PEPTIZABILITY OF THE ASPHALTENES OR PEPTIZING POWER OF THE MALTENES CORRELATED WITH THE SHEAR SUSCEPTIBILITY OF THE RESIDUE BUT THE STATE OF PEPTIZATION OF THE SYSTEM PROVIDE A FAIRLY GOOD RELATION, AND /5/ THE RATIO OF NITROGEN BASIS TO PARAFFINS PROVIDED A DEFINITE TREND WHEN COMPARED TO THE PEPTIZING POWER OF THE MALTENES. /BPR/]]></description>
      <pubDate>Thu, 29 Dec 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/97671</guid>
    </item>
    <item>
      <title>STUDY IN THE GENERAL FIELD OF QUALITY CONTROL ENGINEERING</title>
      <link>https://trid.trb.org/View/107982</link>
      <description><![CDATA[THIS REPORT DESCRIBES CURRENT METHODS OF CONTROL FOR VARIOUS CONSTRUCTION MATERIALS AND APPLICATIONS OF RANDOM SAMPLING TECHNIQUES FOR THE USE OF THESE MATERIALS. RESEARCH AREAS FOR ADDITIONAL DEVELOPMENT WERE DEFINED FROM LIMITED STUDIES IN MANY AREAS RATHER THAN EXPLORING A FEW AREAS TO THEIR FULLEST EXTENT AND THOSE STUDIES INCLUDED WERE' A/ INSTRUCTION OF STATE ROAD DEPARTMENT PERSONNEL IN METHODS AND APPLICATIONS OF STATISTICAL ANALYSIS; B/ ASPHALT PENETRATION AND VISCOSITY CONTROL TESTS; C/ BITUMINOUS MIX MATERIALS CONTROL TESTS; D/ EVALUATION OF RECORD TEST DATA; E/ RANDOM SAMPLING TECHNIQUES; F/ RESEARCH PROBLEM TESTING AREAS RECOMMENDED FOR ADDITIONAL STUDY WERE' /1/ ASPHALT EXTRACTION TESTING, /2/ MARSHALL STABILITY MIXING TEMPERATURES, /3/ COMPARATIVE MOISTURE DETERMINATION METHODS, /4/ MOISTURE-DENSITY TEST REPEATABILITY, /5/ FLORIDA BEARING VALUE TEST, /6/ NUCLEAR DENSITY CALIBRATION CURVE DEVELOPMENT. /BPR/]]></description>
      <pubDate>Thu, 01 Dec 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/107982</guid>
    </item>
    <item>
      <title>HARDENING OF ASPHALT IN HOT BITUMINOUS MIXES DURING THE HAULING PROCESS</title>
      <link>https://trid.trb.org/View/100786</link>
      <description><![CDATA[THE EFFECT OF ASPHALT HARDENING /IN HOT BITUMINOUS MIXES/ DURING HAULING ON THE BRITTLENESS AND LIFE OF AN ASPHALT CEMENT PAVEMENT IS BEING DETERMINED. MIX SAMPLES WERE TAKEN FROM HOT BITUMINOUS MIXES AT DIFFERENT TIMES AFTER PREPARATION AND FROM DIFFERENT SOURCES OF CRUDE. VISCOSITY MEASUREMENTS WERE MADE AT DIFFERENT TEMPERATURES TO DETERMINE ASPHALT HARDNESS. PENETRATION AND DUCTILITY TESTS WERE ALSO CONDUCTED. TO PROVIDE SOME INDICATION OF MOLECULAR CHANGES, THIN ASPHALT FILMS WERE PLACED BETWEEN SODIUM CHLORIDE PLATES AND TESTED ON AN INFRARED SPECTOPHOTOMETER. SIGNIGICANT HARDENING OCCURRED IN ALL OF THE ASPHALTS STUDIED. THE EXTENT OF HARDENING VARIED WITH THE ASPHALT SOURCE. ALSO ASPHALT VISCOSITIES VARIED SIGNIFICANTLY WITH THE POSITION AND DEPTH FROM WHICH THE MIX SAMPLE WAS TAKEN FROM THE TRUCK BED. ASPHALT SAMPLES TAKEN FROM THE UPPERMOST 1 IN. WERE GENERALLY SOFTER THAN THOSE IN THE REMAINDER OF THE MIX. ASPHALT DUCTILLITY DECREASED WITH INCREASE IN HAUL TIME.]]></description>
      <pubDate>Fri, 18 Nov 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/100786</guid>
    </item>
    <item>
      <title>DEVELOPMENT OF A LABORATORY DURABILITY TEST FOR ASPHALTS</title>
      <link>https://trid.trb.org/View/101125</link>
      <description><![CDATA[A LABORATORY TEST PROCEDURE FOR EVALUATING THE DURABILITY OF PAVING ASPHALTS IS PROPOSED WHICH RECOGNIZES AND IS INTENDED TO SIMULATE THE TWO-STAGE HARDENING OF ASPHALT DURING MIXING PROCESSES AND SUBSEQUENT PAVEMENTS SERVICE LIFE. THE TEST CONSISTS OF FIRST SUBJECTING THE ASPHALT TO THE THIN FILM OVEN TEST (TFOT) AND THEN TREATING THE RESIDUE IN OXYGEN AT HIGH PRESSURES. THE TFOT AT 325 F IS TO SIMULATE THE CHANGES THAT MAY OCCUR IN ASPHALT DURING HOT- MIXING AND THE PRESSURE-OXIDATION PROCESS AT 150 F IS TO SIMULATE THE CHANGES THAT MAY OCCUR IN ASPHALT DURING PAVEMENT SERVICE LIFE. A 1/8-IN. FILM THICKNESS IS USED IN BOTH TREATMENTS. THE EFFECTIVENESS OF THE PROPOSED TEST IN ACCELERATING THE HARDENING AND OTHER CHANGES OF ASPHALT, THE ABILITY OF THE TEST IN DIFFERENTIATING ASPHALTS WITH RESPECT TO CHANGES (BOTH PHYSICAL AND CHEMICAL), AND THE EFFECTS OF TIME AND OXIDATION PRESSURE ARE DEMONSTRATED BY RESULTS OF THE PROPOSED DURABILITY TEST ON FIVE 85-100 PENETRATION GRADE ASPHALT CEMENTS AND ONE OF 120-150 PENETRATION GRADE. THE PROPERTIES MEASURED TO INDICATE CHANGES INCLUDE PENETRATION, SOFTENING POINT, ABSOLUTE VISCOSITY, ASPHALTENE CONTENT, AND PERCENT OXYGEN. THE MAJOR CONCLUSIONS FROM THIS STUDY ARE THAT (1) THE APPROACH OF THE PROPOSED DURABILITY TEST IS SOUND AND THE PROCEDURE REPRODUCIBLE, (2) THE PROCEDURE IS CAPABLE OF ACCELERATING THE HARDENING OF ASPHALT IN A RELATIVELY SHORT PERIOD OF TIME, (3) DIFFERENCES EXIST AMONG ASPHALTS IN HARDENING DURING THE PRESSURE-OXIDATION PROCEDURE, AND THEREFORE THE PROCEDURE CAN DISTINGUISH BETWEEN ASPHALTS THAT ARE SUSCEPTIBLE TO HARDENING AND THOSE THAT ARE NOT, (4) THE HARDENING IN THE PRESSURE-OXIDATION PROCESS IS A HYPERBOLIC FUNCTION OF TIME, WHICH SUGGESTS THAT A DEFINITE CORRELATION CAN BE ESTABLISHED BETWEEN FIELD HARDENING AND THE PROPOSED LABORATORY DURABILITY TEST, AND (5) CONTINUED STUDY INTO THE NEXT PHASE OF THE DURABILITY TEST INVESTIGATION IS NECESSARY AND WARRANTED SO THAT INFORMATION OBTAINED CAN BE PUT INTO USEFUL AND APPLIED FORM IN ASPHALT PAVING DESIGN AND QUALITY CONTROL. /AUTHOR/]]></description>
      <pubDate>Fri, 14 Oct 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/101125</guid>
    </item>
    <item>
      <title>RELATIONSHIPS OF FLOW PROPERTIES TO CHEMICAL COMPOSITION FOR PAVING ASPHALTS</title>
      <link>https://trid.trb.org/View/101123</link>
      <description><![CDATA[IN RECENT YEARS CONSIDERABLE RESEARCH HAS BEEN DEVOTED TO THE PHYSICAL AND CHEMICAL PROPERTIES OF ASPHALT. BECAUSE OF THE DEPENDENCY OF THE PHYSICAL PROPERTIES ON CHEMICAL COMPOSITION, THERE IS A NEED FOR MORE FUNDAMENTAL KNOWLEDGE OF THEIR INTERRELATIONSHIPS. THIS STUDY WAS CONDUCTED TO DETERMINE RELATIONSHIPS BETWEEN CHEMICAL COMPOSITION AND RHEOLOGICAL PROPERTIES OF PAVING-GRADE ASPHALTS. RHEOLOGICAL PROPERTIES AND CHEMICAL COMPOSITIONS WERE DETERMINED FOR NINE PAVING-GRADE ASPHALTS. FLOW PROPERTIES AT 45, 77, AND 120 F WERE OBTAINED BY MEANS OF A SLIDING-PLATE MICROVISCOMETER. A MODIFIED CORBETT-SWARBRICK CHROMATOGRAPHIC METHOD FOR CHEMICAL COMPOSITION DATA WAS EMPLOYED. MULTIPLE-LINEAR-REGRESSION ANALYSIS YIELDED EQUATIONS THAT RELATED FLOW PROPERTIES AT 120 F TO CHEMICAL COMPOSITION. THE COEFFICIENT OF THERMAL EXPANSION WAS FOUND TO BE A SIGNIFICANT QUANTITY FOR THE DESCRIPTION OF THE FLOW PROPERTIES AT THE LOWER TEMPERATURES. REGRESSION EQUATIONS WERE OBTAINED FOR THE FLOW PROPERTIES AT 45 AND 77 F, AND FOR THE WALTHER VISCOSITY-TEMPERATURE SLOPE WHEN THE EXPANSION COEFFICIENTS WERE INCLUDED IN THE REGRESSION ANALYSIS. IT WAS CONCLUDED THAT THE FLOW BEHAVIOR OF ASPHALTS IN THE LOWER RANGE OF SERVICE TEMPERATURE WAS MORE DEPENDENT ON FACTORS SUCH AS ASSOCIATION AND COLLOIDAL STATE THAN ON THE RELATIVE CONTENT OF THE GENERIC CHEMICAL GROUPS USED IN THIS STUDY. /AUTHOR/]]></description>
      <pubDate>Fri, 14 Oct 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/101123</guid>
    </item>
    <item>
      <title>FUNDAMENTAL VISCOSITY TESTING OF ASPHALT CEMENTS</title>
      <link>https://trid.trb.org/View/94999</link>
      <description><![CDATA[THERE ARE CRITICAL POINTS ON THE TEMPERATURE CONSISTENCY CURVE OF ASPHALT CEMENT. SOME OF THESE POINTS, FOR ASPHALT MIX PAVING, ARE: MIXING AND COMPACTING TEMPERATURES, MAXIMUM PAVEMENT TEMPERATURE (140 DEGREES F.) AND TESTING TEMPERATURE FOR VOIDS (77 DEGREES F.). GRADING AND TESTING PROCEDURES FOR ASPHALT CEMENTS ADOPTED BY THE BRITISH COLUMBIA DEPARTMENT OF HIGHWAYS ARE DISCUSSED AND THE MORE RIGID SPECIFICATIONS IN THEIR ROAD BUILDING PROCEDURES ARE OUTLINED. /CGRA/]]></description>
      <pubDate>Fri, 30 Sep 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/94999</guid>
    </item>
    <item>
      <title>TEMPERATURE-VISCOSITY RELATION OF ASPHALTS USED IN THE UNITED STATES</title>
      <link>https://trid.trb.org/View/101151</link>
      <description><![CDATA[VISCOSITY DATA ARE PRESENTED ON ASPHALT CEMENTS PRODUCED IN THE UNITED STATES FOR USE IN HIGHWAY CONSTRUCTION. ALL PROPERTIES WERE STUDIED BY THE BUREAU OF PUBLIC ROADS TO PROVIDE INFORMATION ON THE PROPERTIES OF ASPHALT PRODUCED FROM VARIOUS CRUDE SOURCES AND BY METHODS OF REFINING IN CURRENT USE. STATES HAVE DIFFERENT SPECIFICATION REQUIREMENTS FOR FUROL VISCOSITY AT CERTAIN TEMPERATURES. FUROL VISCOSITY TESTS WERE MADE ON THE ASPHALTS OF THIS STUDY. THE FUROL VISCOSITY OF 119 ASPHALTS RANGES FROM 85 TO 318 SECONDS. FOUR ASPHALTS HAVE VISCOSITY VALUES LESS THAN 100 SECONDS, WHILE TWO ASPHALTS MORE THAN 300 SECONDS. VISCOSITY OF 80 ASPHALTS IS WITHIN THE RANGE OF 150 TO 250 SECONDS. IT WAS CONCLUDED THAT THE VISCOSITY VARIES GREATLY AND THIS PROPERTY SHOULD BE RECOGNIZED IN PLANT MIXING OF ASPHALTIC MIXTURES, SPREADING AND COMPACTING OF THE MIXTURES ON THE ROAD, AND APPLICATION OF ASPHALTS BY SPRAYING.]]></description>
      <pubDate>Wed, 17 Aug 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/101151</guid>
    </item>
    <item>
      <title>CORRELATION OF THE MICROFILM DURABILITY TEST WITH FIELD HARDENING OBSERVED IN THE ZACA-WIGMORE EXPERIMENTAL PROJECT</title>
      <link>https://trid.trb.org/View/100984</link>
      <description><![CDATA[EXAMINATION OF THE ASPHALTS USED IN THE ZACA-WIGMORE PROJECT BY MEANS OF THE MICROFILM DURABILITY TEST GAVE RATINGS OF THE RELATIVE DURABILITY TO BE EXPECTED OF THE ASPHALTS WHEN ALL ARE USED UNDER THE SAME CONDITIONS. THE ACTUAL ORDER OF OCCURRENCE OF FAILURES IN THE TEST ROAD TO DATE IS IN AGREEMENT WITH THE PREDICTIONS OF THIS RELATIVELY SIMPLE AND RAPID LABORATORY TEST. VISCOSITY MEASUREMENTS SHOW THAT HARDENING DURING THE ASPHALT-AGGREGATE MIXING OPERATION WAS ABOUT TWICE AS GREAT DURING PERIOD 1 OF THIS CONSTRUCTION AS DURING PERIOD 2 AND THIS DIFFERENCE IN HARDENING IN THE MIX PLANT IS STILL EVIDENT AFTER SEVERAL YEARS IN THE ROAD. PROGRESSIVE HARDENING OF THE ASPHALTS IN THE ROAD OVER A PERIOD OF SEVERAL YEARS WAS FOUND TO PARALLEL THAT IN THE MICROFILM DURABILITY TEST IN A FEW HOURS. IN THE FIRST TEST ROAD (PERIOD 1) CONSTRUCTION, WHERE PAVEMENT DEFLECTIONS ARE ABOUT 0.015 TO 0.025 IN. UNDER A 15,000-LB AXLE LOAD, FAILURES DEVELOPED WHEN THE ASPHALT VISCOSITY AT 77 F ENTERED THE RANGE 10,000,000 TO 100,000,000 POISES. IN THE OTHER TEST ROAD (PERIOD 2) CONSTRUCTION WERE DEFLECTIONS ARE ABOUT 0.010 IN. UNDER THE SAME LOAD, THE FIRST DISTRESS WAS NOTED IN AN ASPHALT WHICH REACHED A VISCOSITY AT 77 F OF ABOUT 100,000,000 POISES. RECOVERY OF ASPHALT FROM SLICES OF PAVEMENT CORES SHOWED THAT HARDENING OF THE ASPHALT IS GREATEST AT THE TOP AND DECREASES WITH INCREASING DEPTH IN THE PAVEMENT. PAVEMENTS WITH HIGH AIR VOID CONTENT WERE FOUND TO HARDEN MORE RAPIDLY THAN THOSE WITH LOW AIR VOIDS. HARDENING BY LOSS OF VOLATILE MATTER IS AN IMPORTANT FRACTION OF THE TOTAL HARDENING OBSERVED IN THESE ASPHALTS. IT IS SHOWN THAT THIS CAN BE CONTROLLED BY PROPER SELECTION OF CRUDE OIL OR BY APPLICATION OF DISTILLATION AND BLENDING TECHNIQUES SO AS TO KEEP THE 10 PERCENT DISTILLED POINT OF THE ASPHALT AT OR ABOVE 400 C (CONVERTED TO ATMOSPHERIC PRESSURE).]]></description>
      <pubDate>Fri, 03 Jun 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/100984</guid>
    </item>
    <item>
      <title>HARDENING OF ASPHALT CEMENTS DURING SERVICE IN PAVEMENTS 1963-66 PROGRAM</title>
      <link>https://trid.trb.org/View/97944</link>
      <description><![CDATA[AN INVESTIGATION IS DESCRIBED WHICH DETERMINES THE CHANGES IN HARDENING AND COMPOSITION THAT OCCUR IN AN ASPHALT CEMENT WHILE THE HOT MIXTURE IS BEING PREPARED AND LAID AND DURING SERVICE IN THE PAVEMENT. SEVENTEEN TESTS SITES WERE SELECTED WHEREBY HOT SURFACINGS COULD BE LAID. IMMEDIATELY PRIOR TO ARRIVAL OF THE PAVING MACHINE, 20 FEET OF HEAVY ALUMINUM FOIL WAS FASTENED TO THE ROAD SURFACE BY ROOFING NAILS. THIS WAS DONE TO PREVENT CONTAMINATION OF THE APPLIED HOT MIXTURE BY THE TACK COAT AND TO FACILIATE REMOVAL OF THE PAVEMENT SAMPLES FOR EXTRACTION, RECOVERY AND TESTING OF THE ASPHALTIC BINDER. ONE DAY AFTER LAYING AND COMPACTING THE SURFACE, A 2- BY 2-FOOT SAMPLE OF THE PAVEMENT WAS REMOVED AND SHIPPED TO THE INSTITUTE IN A WODDEN BOX DESIGNED TO PREVENT BREAKAGE DURING SHIPMENT. SIMILAR SAMPLES WERE OBTAINED AFTER THE PAVEMENT HAD BEEN IN SERVICE FOR PERIODS OF 2 WEEKS, FOUR MONTHS, 1 YEAR, AND FOR 9 OF THE SITES AFTER 3 YEARS IN SERVICE. THE SAMPLES OF PAVING MIXTURES AND THE SLABS OF PAVEMENT SAMPLES WERE SUBJECTED TO LABORATORY EVALUATION AND THE ASPHALT EXTRACTED USING 6 PARTS OF BENZENE AND 1 PART OF PURE ETHYL ALCOHOL. EXTRACTED ASPHALT WAS CAREFULLY RECOVERED FROM SOLUTION AND SUBJECTED TO NUMEROUS TESTS. RELATIVE VISCOSITY, WHICH IS OBTAINED BY DIVIDING THE VISCOSITY OF AN ASPHALT HARDENED BY ENVIRONMENTAL AND SERVICE CONDITIONS BY ITS ORIGINAL VISCOSITY, IS USEFUL FOR COMPARING THE HARDENING OF AN ASPHALT OR DIFFERENT ASPHALTS UNDER DIFFERENT ENVIRONMENTAL CONDITIONS. CAREFUL PREPARATION, HANDLING AND LAYING OF THE HOT MIXTURES RESULTED IN 1.55 TO 2.80 FOLD INCREASE IN VISCOSITY AT 77F OF THE RECOVERED ASPHALT WITH RESPECT TO ORIGINAL BINDER. AFTER THREE YEARS OF SERVICE IN PAVEMENTS, THE INCREASE IN VISCOSITY OF THE RECOVERED ASPHALT RANGED FROM 13.5 TO 41.5 FOLD. HARDENING OF THE ORIGINAL ASPHALT BY THE LABORATORY TEST GAVE ABOUT THE SAME HARDENING AS RESULTED FROM TWO WEEKS IN SERVICE. SEASON OF THE YEAR IN WHICH THE PAVEMENT WAS LAID, THE HVEEM STABILITY TESTS AND THE COHESIVE TESTS APPEAR TO HAVE ONLY SMALL EFFECTS ON THE CONDITIONS OF THE HIGHWAY SURFACE AFTER TWO OR THREE YEARS OF SERVICE. HIGH AVERAGE DAILY TRAFFIC COUNT APPEARS TO BE ASSOCIATED WITH A PAVEMENT SURFACING SHOWING EXCELLENT TO GOOD CONDITION AFTER TWO TO THREE YEARS IN SERVICE. DATA OBTAINED INDICATE THAT THE AGGREGATE USED IN CONSTRUCTION OF A PAVEMENT SURFACE MAY INFLUENCE HARDENING OF THE ASPHALT DURING SERVICE. ASPHALTENE CONTENTS OF THE BINDERS EXTRACTED FROM THE PAVEMENTS AFTER TWO YEARS OF SERVICE WERE GREATER THAN FOR THE ORIGINAL ASPHALTS. OXYGEN CONTENTS OF ORIGINAL AND EXTRACTED ASPHALTS WERE DETERMINED BY NEUTRON ACTIVATION ANALYSIS, AND WERE FOUND TO BE HIGHER THAN THE ASPHALTS AFTER FOUR MONTHS IN SERVICE THAN IN THE ORIGINAL ASPHALTS. HOWEVER, THE OXYGEN DROPPED SLIGHTLY AFTER THE PAVEMENT HAD BEEN IN SERVICE ONE YEAR.]]></description>
      <pubDate>Fri, 03 Jun 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/97944</guid>
    </item>
  </channel>
</rss>