Highway Research Record最新文献

{"title":"LAG AND GAP ACCEPTANCES AT STOP-CONTROLLED INTERSECTIONS","authors":"P. Solberg, J. C. Oppenlander","doi":"10.5703/1288284313651","DOIUrl":"https://doi.org/10.5703/1288284313651","url":null,"abstract":"THE PURPOSE OF THIS RESEARCH STUDY WAS TO INVESTIGATE THE LAG AND GAP ACCEPTANCES FOR DRIVERS ENTERING AND CROSSING A MAJOR ROADWAY FROM A STOPPED POSITION. THIS DRIVER-BEHAVIOR EVALUATION INCLUDED A DETERMINATION OF A LAG-AND-GAP ACCEPTANCE DISTRIBUTION FOR THE SIDESTREET DRIVERS, CONSIDERATION OF COMMUNITY INFLUENCE ON THIS DISTRIBUTION, AND COMPARISONS OF TIME-INTERVAL ACCEPTANCES BY DRIVERS MAKING THROUGH, LEFT-TURN, AND RIGHT-TURN MOVEMENTS. THE STUDY WAS PERFORMED AT RIGHT-ANGLE INTERSECTIONS FORMED BY TWO-WAY, TWO-LANE, URBAN STREETS. FOUR SITES, SELECTED IN LAFAYETTE AND INDIANAPOLIS, IND., WERE AS IDENTICAL AS POSSIBLE REGARDING GEOMETRY AND ADJACENT LAND USE. THE DATA WERE COLLECTED AT THESE SITES BY MEANS OF A MOTION PICTURE CAMERA. THE TECHNIQUE OF PROBIT ANALYSIS WAS EMPLOYED IN THE STATISTICAL TREATMENT OF THE OBSERVATIONS. IN ADDITION, TWO OTHER METHODS, ONE DEVELOPED BY RAFF AND THE OTHER BY BISSELL, WERE CONSIDERED IN THIS EVALUATION OF DRIVER BEHAVIOR AT STOP-CONTROLLED INTERSECTIONS. THE ACCEPTANCE DISTRIBUTIONS WERE WELL DESCRIBED BY A LINEAR RELATIONSHIP BETWEEN THE PROBIT OF ACCEPTANCE AND THE LOGARITHM OF ACCEPTANCE TIME. THERE WAS NO SIGNIFICANT DIFFERENCE BETWEEN THE MEDIAN LAG-ACCEPTANCE AND THE MEDIAN GAP- ACCEPTION TIMES AT THE FOUR INTERSECTIONS. HOWEVER, SIGNIFICANT VARIATIONS WERE FOUND BETWEEN RIGHT-AND LEFT- TURNING DRIVERS AND BETWEEN DRIVERS PROCEEDING THROUGH THE INTERSECTION AND THOSE MAKING LEFT TURNS. RIGHT-TURNING DRIVERS AND THOSE CROSSING THE INTERSECTION HAD STATISTICALLY EQUAL MEDIAN ACCEPTANCE TIMES. COMMUNITY SIZE APPARENTLY HAS SOME INFLUENCE ON DRIVER PERFORMANCE AT INTERSECTION APPROACHES CONTROLLED BY STOP SIGNS. A GENERAL AGREEMENT EXISTED AMONG THE THREE METHODS OF ANALYSIS INVESTIGATED. /AUTHOR/","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131564457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Normal Stresses at the Tire-Soil Interface in Yielding Soils","authors":"D. R. Freitag, A. J. Green, N. R. Murphy","doi":"10.21236/ad0744224","DOIUrl":"https://doi.org/10.21236/ad0744224","url":null,"abstract":"THE U. S. ARMY ENGINEER WATERWAYS EXPERIMENT STATION AT VICKSBURG, MISSISSIPPI, IS CONDUCTING SYSTEMATIC STUDIES THAT WILL PROVIDE INFORMATION ON FACTORS WHICH INFLUENCE VEHICLE MOBILITY IN DEFORMABLE SOILS. THE ULTIMATE PURPOSE OF THESE STUDIES IS TO DEVELOP RATIONAL MEANS OF DESIGNING MILITARY VEHICLES THAT WILL PROVIDE SPECIFIED LEVELS OF PERFORMANCE IN OFF-ROAD CONDITIONS. THIS PAPER PRESENTS THE RESULTS OF A STUDY CONDUCTED TO DETERMINE THE MAGNITUDE AND DISTRIBUTION OF THE NORMAL STRESSES AT THE TIRE-SOIL INTERFACE. /NTIS/","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1964-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127411597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Simulation of Traffic Flow to Obtain Volume Warrants For Intersection Control","authors":"R. Lewis","doi":"10.5703/1288284313617","DOIUrl":"https://doi.org/10.5703/1288284313617","url":null,"abstract":"THE PAPER REPORTS THE RESULTS OF A RESEARCH PROJECT IN WHICH A DIGITAL SIMULATION MODEL WAS DEVELOPED TO DETERMINE VOLUME WARRANTS AT STREET INTERSECTIONS. THE PARTICULAR TYPE OF INTERSECTION STUDIED WAS THE FOUR-LEGGED, RIGHT-ANGLED INTERSECTION OF A HIGH-VOLUME MAJOR ARTERIAL STREET WITH A LOWER-VOLUME MINOR ARTERIAL STREET. THE MAJOR ARTERIAL HAD FOUR TRAVEL LANES WITH PARKING PROHIBITED, WHEREAS THE MINOR ARTERIAL HAD TWO TRAVEL LANES WITH PARKING PERMITTED ON BOTH SIDES. BOTH ARTERIALS WERE OPERATED AS TWO-WAY STREETS. TWO TYPES OF INTERSECTION CONTROL WERE STUDIED, THE SEMI- TRAFFIC-ACTUATED SIGNAL AND THE TWO-WAY STOP SIGN. THE DELAYS ENCOUNTERED AT THE INTERSECTION WERE MEASURED AND USED AS CRITERIA FOR THE ESTABLISHMENT OF WARRANTS. /AUTHOR/","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117198061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SERVICEABILITY RATINGS OF HIGHWAY PAVEMENTS","authors":"Velma Fumiko Nakamura, H. Michael","doi":"10.5703/1288284313603","DOIUrl":"https://doi.org/10.5703/1288284313603","url":null,"abstract":"THERE IS A NEED FOR A SIMPLE, ACCURATE AND ECONOMICAL METHOD OF EVALUATING PAVEMENT SERVICEABILITY. THE USE OF RATING PANELS TO MEASURE THE PRESENT ADEQUACY OF A HIGHWAY PAVEMENT WAS STUDIED EXPERIMENTALLY AND THE RESULTS WERE ANALYZED STATISTICALLY. IT WAS FOUND THAT THE PANEL METHOD OF EVALUATING PAVEMENT SERVICEABILITY IS PRACTICAL, IS APPLICABLE TO RIGID, OVERLAY AND FLEXIBLE PAVEMENTS, AND MINIMIZES THE VARIATION AND PERSONAL BIAS INVOLVED WHEN PAVEMENT MAINTENANCE AND RECONSTRUCTION PRIORITY PROGRAMS ARE DETERMINED ON THE BASIS OF THE KNOWLEDGE AND JUDGEMENTS OF INDIVIDUALS. RATINGS BETWEEN INDIVIDUALS VARIED WIDELY, REGARDLESS OF THE EXTENT OF THEIR HIGHWAY EXPERIENCE. RATINGS BY PANELS, HOWEVER, DO NOT VARY WIDELY AND ARE GOOD ESTIMATES OF THE PRESENT SERVICEABILITY OF HIGHWAY PAVEMENT SECTIONS. KNOWLEDGE AND EXPERIENCE IN THE HIGHWAY ENGINEERING FIELD IS NOT IMPORTANT IN SELECTING PANEL MEMBERS. THE RELATIONSHIP BETWEEN PANEL SIZE AND RATING ACCURACY IS PRESENTED. THE ROUGHOMETER METHOD OF EVALUATING PAVEMENT SERVICEABILITY WAS ALSO STUDIED. WHILE SIMPLE AND OBJECTIVE, IT WAS FOUND TO GIVE EXCELLENT CORRELATIONS TO THE JUDGEMENT OF THE TRAVELING PUBLIC WHEN USED ON RIGID PAVEMENTS, BUT ONLY FAIR CORRELATION ON FLEXIBLE AND OVERLAY PAVEMENTS.","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1962-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129424664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accidents at Median Crossovers","authors":"G. R. Garner","doi":"10.13023/KTC.RR.1969.278","DOIUrl":"https://doi.org/10.13023/KTC.RR.1969.278","url":null,"abstract":"THE PURPOSE WAS TO EXAMINE THE NECESSITY FOR AND THE VALUE OF MEDIAN CROSSOVERS ON LIMITED-ACCESS FACILITIES. AN ACCIDENT ANALYSIS PROVIDED INFORMATION ON THE FREQUENCY AND NATURE OF ACCIDENTS AT MEDIAN CROSSOVERS. THE TYPE OF AND NECESSITY FOR CROSSOVER USAGE BY AUTHORIZED PERSONNEL WAS DETERMINED FROM INTERVIEWS WITH HIGHWAY MAINTENANCE ENGINEERS AND QUESTIONNAIRES COMPLETED BY STATE POLICE WHO PATROL LIMITED-ACCESS FACILITIES. IT WAS FOUND THAT CROSSOVERS DO CAUSE FREQUENT ACCIDENTS IN SOME LOCATIONS, THUS NEGATING THE POSITIVE BENEFITS OF HAVING CROSSOVERS. UNDERSIRABLE LOCATIONS FOR CROSSOVERS INCLUDE URBAN AREAS, INTERCHANGE AREAS, AND ANY LOCATION WHERE USE BY THE GENERAL PUBLIC IS LIKELY. APPLYING MORE STRINGENT CONTROLS TO THE LOCATION AND USE OF MEDIAN CROSSOVERS THAN NOW EMPLOYED MAY RESULT IN A 5 PERCENT REDUCTION IN ACCIDENTS ON LIMITED-ACCESS FACILITIES. /AUTHOR/","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128605144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Repeated Loading on Gravel and Crushed Stone Base Course Materials Used in the AASHO Road Test","authors":"J. H. Haynes, E. J. Yoder","doi":"10.5703/1288284313622","DOIUrl":"https://doi.org/10.5703/1288284313622","url":null,"abstract":"THIS PAPER PRESENTS THE RESULTS OF A LABORATORY INVESTIGATION OF THE BEHAVIOR OF THE AASHO ROAD TEST GRAVEL AND CRUSHED STONE MIXTURES SUBJECTED TO REPEATED LOADING. APPROXIMATING THOSE THAT WOULD BE FOUND IN THE BASE COURSE OF A HIGHWAY PAVEMENT. THE REPETITIVE LOADINGS WERE APPLIED WITH EQUIPMENT DEVELOPED IN THE LABORATORIES OF THE SCHOOL OF CIVIL ENGINEERING AT PURDUE UNIVERSITY. THE MATERIALS USED IN THE STUDY WERE OBTAINED FROM THE SITE OF THE AASHO ROAD TEST. THE GRAVEL AND CRUSHED STONE WITH GRAIN-SIZE DISTRIBUTION EQUAL TO THAT USED IN THE ROAD TEST AND COMPACTED TO THE MEAN DENSITY LEVELS FOUND IN THE FIELD WERE THE SUBJECT OF PRIMARY INTEREST. VARIATION IN PERCENT FINES AND DEGREE OF SATURATION WERE CONSIDERED TO HAVE A GREAT EFFECT ON THESE BASIC GRADATIONS. THEREFORE, THE PERCENT PASSING THE NO. 200 SIEVE WAS VARIED SO THAT THREE MIXTURES OF EACH MATERIAL WERE OBTAINED. THESE THREE MIXTURES WERE TESTED AT THREE LEVELS OF SATURATION. THE EFFECTS OF THESE VARIABLES ON THE DEFORMATION-REBOUND CHARACTERISTICS OF THE MATERIALS UNDER REPEATED LOADS WERE STUDUED. FROM THESE STUDIES, THE ADVANTAGES AND BASE COURSE MATERIALS, WERE FOUND AND ARE REPORTED IN DETAIL . ALSO, A COMPARISON BETWEEN THE LABORATORY AND FIELD PERFORMANCE OF THE TWO AASHO MATERIALS IS PRESENTED. /AUTHOR/","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124007484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A SIMPLIFIED PROCEDURE FOR MAJOR THOROUGHFARE PLANNING IN SMALL URBAN AREAS","authors":"A. D. Jones, W. L. Grecco","doi":"10.5703/1288284313838","DOIUrl":"https://doi.org/10.5703/1288284313838","url":null,"abstract":"THE PURPOSE OF THE RESEARCH PROJECT WAS TO DEVELOP A SIMPLIFIED PROCEDURE FOR MAJOR THOROUGHFARE PLANNING IN SMALL URBAN AREAS. PREVIOUSLY DEVELOPED CORRIDOR GROWTH FACTOR MODELS FOR DEVELOPING FUTURE ESTIMATES OF INTERNAL TRAFFIC INSMALL URBAN AREAS WERE TESTED, MODIFIED, AND REFINED. LAFAYETTE, INDIANA, DATA WERE USED. RESGRESSION MODELS TO PROVIDE DATA USUSALLY OBTINED BY USE OF EXTERNAL CORDON SURVEYS WERE DEVELOPED. EXTERNAL SURVEY REPORTS FROM 36 CITIES IN 14 STATES, RANGING IN POPULATION FROM 10,000 TO 90,000, PROVIDED MOST OF THE EATA USED. ALTERNATE PROCEDURES FOR PROVIDING THE EXTERNAL SURVEY INFORMATION, BASED ON USE OF HISTORICAL DATA FROM THE SUBJECT CITY, WERE ALSO DEVELOPED. THE COMPLETED PROCEDURE PROVIDES FORECAST TRAFFIC VOLUMES WITHIN THE ACCURACY NECESSARY FOR MAJOR THOROUHGFARE PLANNING IN SMALL URBAN AREAS AT LOW COST AND WITH A LEVEL OF SOPHISTICATION THAT WILL PERMIT APPLICATION BY PERSONNEL USUALLY AVAILABLE IN SMALL COMMUNITIES. THE FEASIBILITY OF THE COMPLETE PROCEDURE FOR PROVIDING THE REQUIRED TRAFFIC VOLUME FOR MAJOR THOROUGHFARE PLANNING IN SMALL URBAN AREAS WAS DEMONSTRATED IN COLUMBUS, INDIANA.","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132327536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SOME EFFECTS OF FABRICATION PRACTICES ON STRENGTH CHARACTERISTICS OF REINFORCED CONCRETE CULVERT PIPE","authors":"R. Deen, J. H. Havens","doi":"10.13023/KTC.RR.1963.198","DOIUrl":"https://doi.org/10.13023/KTC.RR.1963.198","url":null,"abstract":"WITH THE RECENT INCREASE OF HIGHWAY CONSTRUCTION ACTIVITY, IT SOON BECAME APPARENT THAT THERE WAS A DEFINITE NEED FOR KNOWLEDGE CONCERNING THE MANUFACTURE, INSTALLATION, AND FIELD BEHAVIOR OF PIPE CULVERTS UNDER THE HIGHER FILLS THAT ARE USED. THE STUDY REPORTED IN THIS PAPER CONCERNS THE FABRICATION PRACTICES AND THEIR POSSIBLE RELATIONSHIP TO PIPE STRENGTH, FAILURE OF PIPE UNDER EMBANKMENT LOADS, AND THE FEASIBILITY OF REPAIRING OR RESTORING THE STRUCTURAL INTEGRITY OF IN-PLACE PIPE THAT HAVE BEEN DAMAGED. THIRTY-THREE SECTIONS OF 54-IN. DIAMETER, CLASS III PIPE WERE FABRICATED AND TESTED SO THAT THE FOLLOWING VARIABLES COULD BE STUDIED' /A/ TYPE OF LAP USED TO FABRICATE CAGES OF REINFORCING STEEL /LAPPED AND TIED OR LAPPED AND WELDED/, /B/ RELATIVE POSITION OF JOINTS OF INNER AND OUTER CAGES OF STEEL IN THE PIPE, /C/ POSITION OF JOINTS WITH RESPECT TO POINTS OF APPLICATION OF THE LOAD IN THE THREE-EDGE BEARING TEST, /D/ USE OF REINFORCED GUNITE LINER FOR REPAIR PURPOSES , AND /E/ EFFECT OF LATERAL RESTRAINT ON LOAD-CARRYING CAPACITY OF THE PIPE. RESULTS OF THE INVESTIGATION INDICATE THAT' /A/ THE 0.01- IN. CRACK STRENGTHS AND ULTIMATE STRENGTHS WERE SIGNIFICANTLY AFFECTED BY THE THREE METHODS USED TO PREPARE JOINTS IN REINFORCING CAGES; /B/ THERE APPEARS TO BE NO MEASURABLE DIFFERENCE IN PERFORMANCE OF PIPE IN WHICH JOINTS WERE SPACED 0 DEGREES APART, 90 DEGREES AND 180 DEGREES APART; /C/ LOAD-CARRYING CAPACITIES WERE NOT SIGNIFICANTLY AFFECTED BY ORIENTATION OF JOINTS IN THE THREE-EDGE BEARING TESTS; /D/ REPAIRS MADE ON STRUCTURALLY DAMAGED PIPE SUFFICED TO RESTORE ORIGINAL LOAD-CARRYING CAPACITY TO THE PIPE; AND /E/ RODS USED TO PROVIDE LATERAL RESTRAINT APPEARED TO INCREASE LOAD-CARRYING CAPACITY OF THE PIPE IN THE SAME PROPORTION AS INTERNAL STEEL.","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130444435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AN EXPLORATORY STUDY TO IDENTIFY AND MEASURE THE BENEFITS DERIVED FROM THE SCENIC ENHANCEMENT OF FEDERAL-AID HIGHWAYS","authors":"P. Davidson","doi":"10.1007/978-1-349-11516-7_34","DOIUrl":"https://doi.org/10.1007/978-1-349-11516-7_34","url":null,"abstract":"","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"337 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123549584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-RAY DIFFRACTION AND ADSORPTION ISOTHERM STUDIES OF THE CALCIUM MONTMORILLONITE-WATER SYSTEM","authors":"D. Senich, T. Demirel, R. Handy","doi":"10.31274/RTD-180813-2894","DOIUrl":"https://doi.org/10.31274/RTD-180813-2894","url":null,"abstract":"ADSORPTION ISOTHERM AND X-RAY DIFFRACTION TECHNIQUES WERE USED TO STUDY THE ADSORPTION OF WATER ON A HOMOIONIC CALCIUM MONTMORILLONITE AT 25 C. THE BASAL D SPACINGS OF THE PRIMARY AND SECONDARY REFLECTIONS, THEIR INTENSITIES AND LINE BREADTH VARIATIONS WERE DETERMINED IN A SPECIALLY CONSTRUCTED X-RAY ADSORPTION CHAMBER. THE FIRST-ORDER BASAL SPACING WAS FOUND TO CHANGE IN A CONTINUOUS BUT NONUNIFORM MANNER. THE INTENSITY OF SECONDARY REFLECTIONS WAS EXPLAINED ON THE BASIS OF LAYER ELECTRON DENSITY DISTRIBUTION. A COMPARISON OF THE LINE BREADTH, INTENSITY AND ADSORPTION DATA INDICATES AN ICE-LIKE CONFIGURATION OF INTERLAYER ABSORBED WATER IN THE P/P SUB O RANGE ABOVE 0.95. PROLONGED X-RADIATION CAUSED A DISCOLORATION OF SAMPLES ATTRIBUTED TO RADIATION-INDUCED COLOR CENTERS. TWO SUCCESSIVE ADSORPTION AND DESORPTION ISOTHERMS OF WATER VAPOR ON A MONTMORILLONITE POWDER COMPRESSED AT 25 KG/CM SQ. WERE DETERMINED USING AN ELECTROBALANCE AND AN AUTOMATIC RECORDING DEVICE. THE ISOTHERMS EXHIBITED A HYSTERESIS BUT WERE COMPLETELY REVERSIBLE IN THE RELATIVE VAPOR PRESSURE RANGE FROM ZERO TO 0.20. THE RATE OF ADSORPTION WAS GREATER THAN RATE OF DESORPTION. THE LANGMUIR MONOMOLECULAR MODEL FOR THE ADSORPTION PROCESS AND THE BET /BRUNAUER, EMMETT, TELLER/ MULTI-MOLECULAR MODEL WERE COMPARED, AND THE LATTER WAS FOUND TO FIT THE ADSORPTION DATA MORE CLOSELY. THE BET EQUATION WAS FOUND TO BE APPLICABLE IN THE RELATIVE PRESSURE RANGE FROM P/P SUB O EQUAL TO 0.11 TO P/P SUB O EQUAL TO 0.27. THE SPECIFIC SURFACE AND HEAT OF ADSORPTION OF THE FIRST MONOLAYER WERE CALCULATED FROM THE BET PARAMETERS. THE ADSORPTION ISOTHERMS WERE USED TO CALCULATE THE FREE ENERGY CHANGES ON ADSORPTION. THE FREE ENERGY CHANGES ON SUCCESSIVE ADSORPTION CYCLES COMPARED FAVORABLY WITH LOOSE POWDER DATA, INDICATING THAT COMPRESSION HAD LITTLE EFFECT ON THE MAGNITUDE OF THE FREE ENERGY CHANGE. THE FREE ENERGY CHANGES WERE DIVIDED INTO TWO COMPONTNES: ONE FOR ADSORPTION ON INTERNAL SURFACES AND ONE FOR ADSORPTION ON EXTERNAL SURFACES. USING THE DATA, EXPANSION ENERGIES AND SWELLING PRESSURES EXERTED BY CALCIUM MONTMORILLONITE WERE CALCULATED . /AUTHOR/","PeriodicalId":202069,"journal":{"name":"Highway Research Record","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129231425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}