<?xml version="1.0" encoding="utf-8"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>TRB Publications Index</title><link>http://pubsindex.trb.org/</link><atom:link href="http://pubsindex.trb.org/common/TRIS Suite/feeds/rss.aspx?tc=NN%3ARbespnm%2A" rel="self" type="application/rss+xml" /><description></description><language>en-us</language><copyright>Copyright © 2015. 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>TRB Publications Index</title><url>http://pubsindex.trb.org/Images/PageHeader-wTitle.png</url><link>http://pubsindex.trb.org/</link></image><item><title>LABORATORY INVESTIGATION ON THE USE OF HIGH MOISTURE CONTENT SOILS IN HIGH FILLS</title><link>http://pubsindex.trb.org/view/122468</link><description><![CDATA[A LABORATORY INVESTIGATION ON THE USE OF HIGH MOISTURE CONTENT SOILS IN HIGH FILLS IS DESCRIBED. THE PURPOSES WERE TO INVESTIGATE (1) THE EFFECT OF THIXOTROPY, INITIAL MOISTURE CONTENT AND DENSITY, AND CONSOLIDATION ON THE SHEAR STRENGTH OF CLAY-LIKE SOILS WITH MOISTURE CONTENTS UP TO 8 PERCENTAGE POINTS ABOVE OPTIMUM, (2) THE EFFECT OF INITIAL MOISTURE CONTENT AND DENSITY ON THE CONSOLIDATION CHARACTERISTICS OF THESE SOILS, AND (3) THE POSSIBILITY OF USING THESE SOILS IN HIGH FILLS AND THE MANNER IN WHICH THEY SHOULD BE USED. TWO SOILS - A DUNMORE SILT LOAM AND A CLARKESVILLE CLAY LOAM - WERE INVESTIGATED. SOIL SPECIMENS WERE FABRICATED BY STATIC COMPACTION AND LATER INVESTIGATED FOR SHEAR STRENGTH BY THE DIRECT SHEAR TEST AND FOR CONSOLIDATION CHARACTERISTICS BY THE CONVENTIONAL CONSOLIDATION TEST. THE RESULTS SHOW THAT, WHEN A SOIL IS CONSOLIDATED UNDER HIGH PRESSURES, THE INITIAL MOISTURE CONTENT AND DENSITY HAVE LITTLE EFFECT ON THE FINAL SHEAR STRENGTH. THIS LEADS TO THE CONCLUSION THAT HIGH MOISTURE CONTENT SOILS CAN BE USED IF THEY ARE PLACED IN THE LOWER PART OF A HIGH FILL AND IF SUFFICIENT TIME IS ALLOWED FOR THEM TO CONSOLIDATE. A PROCEDURE FOR USING THESE SOILS IN HIGH FILLS IS ALSO SUGGESTED. /AUTHOR/]]></description><pubDate>Sun, 15 Aug 2004 02:43:35 GMT</pubDate><guid>http://pubsindex.trb.org/view/122468</guid></item><item><title>THE UNCONFINED COMPRESSIVE STRENGTH OF SOIL-CEMENT MIXTURES</title><link>http://pubsindex.trb.org/view/122054</link><description><![CDATA[TESTS MADE WITH SOIL-CEMENT CYLINDERS FROM SANDY LOAM, SANDY CLAY LOAM OR A CLAY LOAM AND 5, 7, 9, OR 11% OF CEMENT AND CURED FOR 28 DAYS INDICATED THAT (1) THE INITIAL CHARACTERISTICS OF A SOIL HAVE MORE EFFECT UPON THE COMPRESSIVE STRENGTH OF A SOIL-CEMENT MIXTURE THAN ANY OTHER FACTOR, (2) INCREASING THE AMOUNT OF CEMENT IN A GIVEN SOIL FROM 5 TO 11% PRODUCES A GREATER INCREASE IN COMPRESSIVE STRENGTH THAN DO THE FACTORS OF VARYING DENSITY AND VARYING MOISTURE CONTENT.]]></description><pubDate>Sun, 15 Aug 2004 02:41:54 GMT</pubDate><guid>http://pubsindex.trb.org/view/122054</guid></item><item><title>DRYING PHASE OF SOIL-ASPHALT CONSTRUCTION</title><link>http://pubsindex.trb.org/view/122023</link><description><![CDATA[A LABORATORY STUDY WAS MADE OF THE RATE OF DRYING OF WATER AND HYDROCARBON VOLATILES FROM A SOIL-ASPHALT MIXTURE AND THE EFFECT ON THE STABILITY AND OTHER BASIC PROPERTIES OF THE COMPACTED MIXTURE. THE SOIL WAS A SANDY LOAM WITH A LIQUID LIMIT OF 21, A PI OF 5, AND A FLUFF POINT RANGE FROM 6 TO 12 PERCENT. THE ASPHALT USED AS THE STABILIZING AGENT WAS MC-3 CUTBACK. THE RESULTS OF THIS STUDY INDICATE THAT SOILS STABILIZED WITH CUTBACKS NEED TO BE DRIED OUT BEFORE COMPACTION TO PROVIDE HIGH INITIAL STRENGTH. AFTER COMPACTION, ADDITIONAL CURING RESULTS IN EVEN MORE STRENGTH. THE INDICATIONS ARE THAT SOIL STABILIZED WITH CUTBACK CANNOT BE COMPACTED TO A DENSITY REQUIREMENT. /AUTHOR/]]></description><pubDate>Sun, 15 Aug 2004 02:41:46 GMT</pubDate><guid>http://pubsindex.trb.org/view/122023</guid></item><item><title>PROGRESS REPORT OF SPECIAL PROJECT ON STRUCTURAL DESIGN OF NONRIGID PAVEMENTS: SUBGRADE MOISTURE CONDITIONS BENEATH AIRPORT PAVEMENTS</title><link>http://pubsindex.trb.org/view/104544</link><description><![CDATA[THE REPORT PRESENTS AN ANALYSIS OF SUBGRADE MOISTURE DATA OBTAINED FROM AIRFIELD EVALUATION REPORTS OF THE OFFICE OF CHIEF OF ENGINEERS, WAR DEPARTMENT. THE MOISTURE CONTENTS BENEATH BOTH RIGID AND FLEXIBLE AIRPORT PAVEMENTS IN 8 DISTRICTS, EXTENDING FROM THE SOUTHEASTERN HUMID AREA OF THE COUNTRY TO THE ARID SOUTHWESTERN SECTION WERE STUDIED. IT WAS FOUND CONVENIENT TO DIVIDE THE SOILS INTO TEXTURAL CLASSES AND TO EXPRESS THE MOISTURE CONTENTS IN TERMS OF PERCENTAGE OF SATURATION, PERCENTAGE OF PLASTIC LIMIT, AND PERCENTAGE OF OPTIMUM MOISTURE CONTENT. THE MOISTURE CONDITIONS, EXPRESSED IN ALL THREE WAYS, VARIED WITH THE TEXTURE OF THE SOIL AND THE CLIMATE OF THE REGION. THE AVERAGE CONDITION INCREASED FOR A TEXTURAL PROGRESSION FROM SANDS THROUGH SANDY LOAMS, CLAY LOAMS, AND CLAYS. THE PERCENTAGE OF THE SOILS WHICH WERE 90 PER CENT OR MORE SATURATED OR WERE WETTER THAN THEIR PLASTIC LIMIT OF OPTIMUM MOISTURE CONTENT WAS HIGHER FOR THE HEAVIER TEXTURED SOILS THAN FOR THE LIGHT ONES. IN HUMID OR SEMIHUMID AREAS, THE SANDS AND LOAMY SANDS HAD LOW RELATIVE SATURATION VALUES, THE SANDY LOAMS WERE VARIABLE, AND THE HEAVIER SOILS SHOWED UP TO MORE THAN HALF THEIR VALUES IN EXCESS OF 90 PER CENT SATURATION. A MAJORITY OF THE SOILS OTHER THAN SANDS WERE WETTER THAN THEIR OPTIMUM MOISTURE CONTENT. THE DATA OBTAINED FROM ARID OR SEMI-ARID REGIONS SHOWED THE SUBGRADE CONDITIONS IN SUCH AREAS TO BE DEFINITELY DRIER THAN THOSE IN HUMID REGIONS. EVEN THE HEAVIER TEXTURED SOILS TENDED TO EXIST AT RELATIVELY LOW MOISTURE CONTENTS. COMPARISONS OF THE MOISTURE CONTENTS IN SIMILAR SOILS BENEATH RIGID AND FLEXIBLE PAVEMENTS ON THE SAME AIRFIELD GENERALLY SHOWED THE GREATER VALUES FOR THE RIGID TYPE. IN ARID REGIONS THE VARIATIONS OF MOISTURE CONTENT IN THE UPPER 3 FT. OF SUBGRADE WERE SLIGHT AND SHOWED NO DEFINITE TRENDS. /AUTHOR/]]></description><pubDate>Fri, 05 Aug 1994 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/104544</guid></item><item><title>ADSORPTION OF HEAVY METAL POLLUTANTS BY LANDFILL SOILS</title><link>http://pubsindex.trb.org/view/370722</link><description><![CDATA[The leachate in landfill sites carries out highly concentrated inorganic and organic pollutants.  Such pollutants can be intercepted by the adsorption of landfill soil and will proceed with a long-term stabilization-degradation reaction in the soil. Moreover, the possibility of groundwater pollution due to the leachate from landfill can be reduced through the intercepted adsorption by the soil.  Simulated adsorption batch experiments were carried out in this study to investigate the adsorption removal of heavy metals by soils.  The tested soils included red loam from the Taichung sanitary landfill site and six alluvial soils located over the most widespread area in Taiwan.  The results indicated the following trend for the ability of heavy metal adsorption removal by such tested soils:  Hsinying soil &gt; Chunghsin Village soil &gt; Chung Hsing University soil about = to Hsuehchia soil &gt; Taichung sanitary landfill soil &gt; Mashan soil &gt; Tunghsiao soil.  The adsorption removal of heavy metals followed Pb about = to Cu &gt; Ni about = to Cd about = to Zn.  The adsorption removal by red loam increased with Cd concentration; however, part of the Cd removal in the high-pH region for high Cd concentration was due to precipitation.  Thus, consideration of the speciation distribution was necessary to determine the maximum probable precipitated amount and the minimum probable adsorbed amount.  In addition, in the presence of organic ligand [ethylenediamine tetraacetic acid (EDTA)], the adsorption effect of Cd by red loam was suppressed because of the complexation with EDTA, and the adsorption decreased with increasing EDTA concentration.]]></description><pubDate>Fri, 22 Oct 1993 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/370722</guid></item><item><title>CALCIUM MAGNESIUM ACETATE DEGRADATION IN ROADSIDE SOIL: ACETATE MICROCOSMS</title><link>http://pubsindex.trb.org/view/371504</link><description><![CDATA[Aseptic soil samples from the loam cover of a state highway shoulder in southeastern Massachusetts were placed in sterile serum bottles, forming a series of aerobic soil microcosms.  The samples were dosed with reagent grade acetate solutions without acclimation, then sacrificed at various time intervals and analyzed by gas chromatography in a laboratory determination of the aerobic microbial degradation kinetics.  The acetate degraded rapidly in the loam layer, demonstrating that the shoulder has the potential to reduce oxygen demand by acetate on groundwater under the highway.]]></description><pubDate>Wed, 24 Feb 1993 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/371504</guid></item><item><title>GEOTECHNICAL INSTRUMENTATION FOR MONITORING FIELD PERFORMANCE</title><link>http://pubsindex.trb.org/view/181735</link><description><![CDATA[Geotechnical instrumentation for monitoring field performance rather than for investigating and determining in situ properties for design is examined in this synthesis.  Field performance monitoring commonly includes measurement of pore pressure, earth pressure, deformation, load, and strain.  This report addresses key issues that need to be considered when planning and implementing an instrumentation program.  The purpose is to provide guidance that will lead to improved cost effectiveness of instrumentation programs.  (Author)]]></description><pubDate>Thu, 30 Dec 1982 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/181735</guid></item><item><title>SAWDUST AS A SOIL AMENDMENT FOR TURF GROWTH</title><link>http://pubsindex.trb.org/view/104355</link><description><![CDATA[TWO HIGHWAY LOCATIONS IN LOUISIANA WERE CHOSEN TO TEST THE EFFECT OF SAWDUST ON TURF GROWTH. THE FIRST, ALONG U.S. 90 IN THE SOUTHWEST PART OF THE STATE, WAS A HYDRAULIC SAND FILL BLANKETED WITH A LAYER OF CLAY AND COMPACTED TO A DEPTH OF 4 INCHES. THE CLAY WAS FROM SUBSOIL. THE AREA WAS FERTILIZED WITH 8-8-8, THEN DISKED AND ROLLED. BERMUDA AND ALTA FESCUE WERE PLANTED AND THE AREA WAS AGAIN ROLLED. A YEAR AND A HALF LATER, IN THE SPRING OF 1955, SAWDUST WAS APPLIED AS AN AMENDMENT AND AS A TOP MULCH, AND BERMUDA AND KOBE LESPEDEZA WERE SEEDED. SUBSEQUENT OBSERVATIONS SHOWED THAT THE SAWDUST DISKED INTO THE SOIL PRODUCED A GOOD STAND THAT WITHSTOOD HARD RAINS, WHEREAS PREVIOUSLY GULLIES WERE BEING CUT INTO THE UNDERLYING CLAY. THE MULCHED AREAS PERFORMED LESS WELL BUT IN A MUCH SUPERIOR WAY TO AREAS THAT RECEIVED NO TREATMENT AT ALL. THE SECOND LOCATION, ALSO ON U.S. 90, WAS IN SOUTH CENTRAL LOUISIANA. THE HIGHWAY CUTS THROUGH A RIDGE WHOSE SURFACE SOIL, BENEATH THE TOPS OF THE SLOPES, IS OF FINE LOAMY GRADE BECOMING HEAVIER IN CLAY NEAR THE BOTTOM. IN THIS CASE ALL SAWDUST WAS DISKED IN. THE AGE OF THE SAWDUST WAS IN EXCESS OF 30 YEARS. THE IMMEDIATE RESULTS WERE NOT AS GOOD AS THOSE ON THE FIRST PROJECT, BUT DURING THE SECOND YEAR EXCELLENT STANDS WERE PRODUCED.]]></description><pubDate>Mon, 22 Nov 1971 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/104355</guid></item><item><title>POLYACIDS AND LIGNIN USED WITH LARGE ORGANIC CATIONS FOR SOIL STABILIZATION</title><link>http://pubsindex.trb.org/view/126599</link><description><![CDATA[THE IMMERSED STRENGTH AND AIR-DRY STRENGTH OF AN IOWA SILTY LOAM TREATED WITH LARGE ORGANIC CATIONIC MATERIALS CAN BE INCREASED BY THE ADDITION OF VARIOUS POLYACIDS. THIS INCREASE IS APPARENTLY DUE PRIMARILY TO AN IONIC ABSORPTION COMPLEX IN WHICH THE POLYACIDS BOND BETWEEN LARGE ORGANIC CATIONS COATING THE MINERAL SURFACES. THE STRENGTH OF THE TREATED SOIL CAN BE FURTHER INCREASED BY THE ADDITION OF SMALL AMOUNTS OF FERROUS CARBONATE. ALSO INVESTIGATED WAS THE USE OF SPENT SULFITE LIQUOR WITH LARGE ORGANIC CATIONS WHICH APPEARS MOST PROMISING ON AN ECONOMIC BASIS. /AUTHOR/]]></description><pubDate>Mon, 27 Sep 1971 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/126599</guid></item><item><title>CHANGES IN THE CHARACTERISTICS OF CEMENT-STABILIZED SOILS BY ADDITION OF EXCESS COMPACTION MOISTURE</title><link>http://pubsindex.trb.org/view/122797</link><description><![CDATA[THE COMPACTION MOISTURE OF CEMENT-STABILIZED SOILS IS USUALLY SPECIFIED AS THE OPTIMUM MOISTURE CONTENT TO OBTAIN MAXIMUM DENSITY AS DETERMINED BY THE STANDARD PROCTOR TEST. PREVIOUS INVESTIGATIONS HAVE SHOWN THAT IN SOME INSTANCES MAXIMUM DENSITY MAY NOT CORRESPOND TO MAXIMUM STRENGTH. IF COMPACTION OF THE SOIL-CEMENT MIX IS DELAYED, THE RELATIONSHIP BETWEEN COMPACTION MOISTURE AND THE STRENGTH AND DENSITY OF THE SOIL-CEMENT ALSO CHANGES. THIS STUDY INVESTIGATES THE RELATIONSHIP BETWEEN COMPACTION MOISTURE CONTENT AND THE STRENGTH, DENSITY, AND DURABILITY OF CEMENT-STABILIZED SOILS IN WHICH COMPACTION IS DELAYED AFTER MIXING TO CORRESPOND TO TYPICAL HIGHWAY CONSTRUCTION PRACTICES. FOUR TYPES OF SOIL SUITABLE FOR CEMENT STABILIZATION WERE INVESTIGATED. THE COMPACTION MOISTURE CONTENT WAS VARIED FROM 4 PERCENT BELOW TO 4 PERCENT ABOVE THE OPTIMUM MOISTURE CONTENT OBTAINED BY STANDARD PROCTOR TESTS WITH NO DELAY BETWEEN MIXING AND COMPACTION. AT EACH OF THE MOISTURE CONTENTS, AND AT THE OPTIMUM CEMENT CONTENT, SPECIMENS WERE COMPACTED 0, 2, 4, AND 6 HOURS AFTER MIXING WITH NO INTERMITTENT MIXING. SPECIMENS WERE PREPARED FOR UNCONFINED COMPRESSIVE STRENGTH AND DURABILITY TESTS. THE RESULTS SHOW THAT THE LOSS IN STRENGTH AND DURABILITY OF SOIL-CEMENT RESULTING FROM A DELAY IN COMPACTION CAN BE SIGNIFICANTLY REDUCED IN MANY INSTANCES BY THE ADDITION OF EXCESS COMPACTION MOISTURE. THE SOILS MOST BENEFITED AFTER A DELAY IN COMPACTION BY EXCESS MOISTURE WERE THE SILTY LOAMS AND SANDY LOAMS. STRENGTH INCREASES OF 40 TO 50 PERCENT WERE ACHIEVED WITH THESE SOILS BY THE ADDITION OF 2 TO 4 PERCENT EXCESS MOISTURE WHEN COMPACTION WAS DELAYED. CEMENT-STABILIZED SILTY CLAY LOAMS AND SILTS COMPACTED AFTER DELAYS SHOWED LITTLE IMPROVEMENT IN STRENGTH AND DURABILITY WITH EXCESS COMPACTION MOISTURE. WITHOUT DELAY IN COMPACTION, ONLY THE SILTY CLAY LOAMS WERE SIGNIFICANTLY IMPROVED IN STRENGTH AND DURABILITY BY THE ADDITION OF EXCESS COMPACTION MOISTURE. A STUDY OF THE DATA HAS INDICATED THAT THE AMOUNT OF EXCESS MOISTURE REQUIRED FOR MAXIMUM STRENGTH AND DURABILITY DEPENDED ON THE SOIL TYPE AND THE DETENTION TIME BETWEEN MIXING AND COMPACTION. IN GRANULAR SOILS THE ADDITION OF EXCESS MOISTURE IMPROVED THE STRENGTH AND DURABILITY AFTER DELAYS IN COMPACTION. THIS IMPROVEMENT RESULTED FROM THE IMPROVED LUBRICATION OF THE SOIL AGGREGATES AND SUBSEQUENT INCREASE IN DRY DENSITY. WITH FINE-GRAINED SOILS EXCESS MOISTURE IMPROVED THE PROPERTIES OF SOIL-CEMENT MIXES COMPACTED WITHOUT DELAY BY INCREASING THE AMOUNT OF CEMENT HYDRATION. /AUTHOR/]]></description><pubDate>Mon, 09 Nov 1970 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/122797</guid></item></channel></rss>