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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>A comparative life cycle assessment of asphalt mixtures modified with a novel composite of diatomite powder and lignin fiber</title>
      <link>https://trid.trb.org/View/1910406</link>
      <description><![CDATA[Some additives such as lignin fiber and diatomite powder were developed and used as modifiers in asphalt mixes to enhance the asphalt pavement performance by mitigating pavement distresses such as rutting, thermal cracking, and freeze–thaw cycles. Despite various advantages obtained from utilizing the additives in modified asphalt mixtures, there are many uncertainties regarding their environmental impacts. This study aims to analyze and evaluate the environmental impacts of four types of asphalt mixtures namely, Control Asphalt Mix (CAM), Diatomite Modified Asphalt Mix (DMAM), Lignin Fiber Modified Asphalt Mix (LFMAM), and Diatomite-Lignin Fiber Composite Modified Asphalt Mix (DLFMAM) through applying the life cycle assessment (LCA) methodology. Results demonstrate that DMAM and CAM offers distinct improvements in all impact categories as compared to other types of asphalt mixtures. As well as, the environmental burdens of DMAM is similar to CAM. Nevertheless, LFMAM showed higher negative impacts in all categories, followed by DLFMAM. Excluding the HTP (Human Toxicity) impact, both LFMAM and DLFMAM offer minimal negative effects in all other impact categories compared to the control asphalt mixture. Thus, it can be concluded that the usage of DMAM, LFMAM, and DLFMAM does not result in an excessive risk to the environment, and their applications as alternatives to the base asphalt mixture do not cause significant deteriorations in the environmental profile.]]></description>
      <pubDate>Tue, 01 Mar 2022 09:47:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1910406</guid>
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    <item>
      <title>A bottom-up approach to study the moisture susceptibility of bio-modified asphalt</title>
      <link>https://trid.trb.org/View/1726433</link>
      <description><![CDATA[Causes and remedies for moisture damage at the interface of binder and siliceous stone aggregates is not fully understood and is considered as one of the most elusive and intractable pavement distresses. In recent years, increasing environmental awareness and decreasing availability of virgin materials have promoted the use of bio-materials to decrease adverse environmental impacts from petroleum-based products and support sustainable practices. Considering source dependency and composition variation in bio-materials, it is important to relate composition to fundamental materials properties in order to ensure adequate overall performance particularly in terms of resistance to moisture. Therefore, the current study uses a bottom-up approach to evaluate the performance of an asphalt binder additive from swine manure (Bio-modifier) as a means of not only improving but also understanding moisture resistance in asphalt pavement. Bio-modification was found to show improved moisture resistance at the binder level and the mixture level when compared to two other commercially available additives. Further analysis of the binder doped with representative molecules of the additives showed varying differences in adhesion and moisture susceptibility. To provide in-depth understanding of the underlying interaction mechanisms between water and binder, molecular dynamic simulations were performed on a blend of asphaltene and dopant molecules placed on a silica oxide substrate and exposed to water molecules. Study results revealed the passivation mechanism of bio-modifiers as a dominant factor contributing to enhanced resistance to moisture damage. It was found that bio-modifiers molecules occupy active sites of silica oxide preventing nucleation and growth of acidic compounds at the binder-silica interface. Such acidic compounds are water soluble and their presence at the interface can be detrimental leading to moisture damage. Study results showed anchored bio-modifiers molecules further interact with asphaltene molecules to provide bridging mechanism between binder and silica. This in turn leads to enhanced resistance to moisture damage in bio-modified binders adhered to siliceous surfaces such as quartz and granite stone aggregates.]]></description>
      <pubDate>Thu, 27 Aug 2020 10:16:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1726433</guid>
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    <item>
      <title>Friction and Texture Retention of Concrete Pavements</title>
      <link>https://trid.trb.org/View/1708860</link>
      <description><![CDATA[In the late 1980s and early 1990s, the Alabama Department of Transportation (ALDOT), U.S., noticed a decline in skid trailer numbers on concrete pavements shortly after grinding operations. The engineers at the time suspected that the coarse aggregate caused the decline in these numbers and the resulting conclusion led to a ban of carbonate aggregates in mainline concrete pavement in Alabama that is still in place. This detailed laboratory study re-examines the fundamental friction issues that led to this policy. A total of 48 aggregate, grinding, and grooving combinations were tested as part of this study. Three aggregate sources were examined: a siliceous source, a “hard” limestone source, and a “soft” limestone source. Two blade spacings were examined for grinding operations: 52 blades/ft and 60 blades/ft. Some ground specimens were also grooved. Finally, a set of specimens had the Next Generation Concrete Surface (NGCS) applied to them. The specimens were polished with the National Center for Asphalt Technology (NCAT) three-wheel polishing device (TWPD). The dynamic friction tester was used to evaluate friction values at various points through the polishing process. After the polishing, the macrotexture was characterized using the circular track meter. Across the board, the highest performing texture was that with no grooves and 52 blades/ft. Very generally, the loss of friction decreased with increasing siliceous content. However, some of the trends were extremely minor and, in a few cases, siliceous aggregates caused higher friction loss. There were numerous instances when blended carbonate/siliceous concrete pavement surfaces performed better than sole siliceous concrete pavement surfaces.]]></description>
      <pubDate>Mon, 01 Jun 2020 18:43:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1708860</guid>
    </item>
    <item>
      <title>TWO-DAY CONFERENCE ON EXPLORATORY BORING AND CORE SAMPLING</title>
      <link>https://trid.trb.org/View/121082</link>
      <description><![CDATA[AFTER EXPLAINING THE REASONS FOR THE ORGANIZATION OF THIS CONFERENCE AND THE OBJECTIVES AIMED AT, THE AUTHOR COMMENTS ON THE DIFFERENT EXPERIMENTS INVOLVED. FIRST, SOME SOIL AUGERS WERE PRESENTED ON A FOREST SITE. THE BORINGS HAD TO BE MADE IN SILICEOUS CLAY. THE RESULTS OF THE DEMONSTRATION ARE GIVEN IN TWO TABLES AND A COMPARISON IS MADE BETWEEN THE DIFFERENT TECHNIQUES, ON THE ONE HAND BETWEEN SLOW SPEEDS AND HIGH SPEEDS, AND ON THE OTHER HAND BETWEEN LARGE- DIAMETER SINGLE-SPIRAL AUGERS AND SMALL-DIAMETER CONTINUOUS AUGERS. THEN CAME A PRESENTATION OF MACHINERY MAINLY DESIGNED FOR RECONNAISSANCE AND EXPLORATION IN SUBMERGED NON-COHESIVE ALLUVIAL FORMATIONS. THE AUTHOR CONSIDERS THAT STUDY OF THE SUBJECT SHOULD MAKE IT POSSIBLE TO REDUCE THE DRAWBACKS NOTED IN RESPECT OF THE BENOTO DRILLING RIG, WHICH IS PERFECTLY SUITED TO SUBMERGED ALLUVIAL SOIL. THE DEMONSTRATION OF THE P.T.C. VIBRATORY DRIVER DID NOT BRING OUT THE POTENTIALITIES OF THIS MACHINE, WHICH OPERATES PERCUSSIVELY WHEN THE RESISTANCE OF THE SOIL IS HIGH, AND BY VIBRATION WHEN THE RESISTANCE DROPS. THE MENARD ROTARY VIBRATORY DRIVER IS A LIGHTWEIGHT MACHINE WHICH, BY VIBRO- PERCUSSION, ENABLES A TUBE COLUMN TO BE LOWERED AND RAISED AND CORE SAMPLES TO BE TAKEN BY ROTATION. SOME MOBILE DRILLING RIGS, SUCH AS THE MOBILE DRILLING MINUTEMAN AND THE S.L.R., WERE ALSO PRESENTED, ALONG WITH TWO CORE BORERS, ONE OF THE SCREW TYPE, THE OTHER OF THE PRESSURE TYPE, WHICH CAN PROVIDE SAMPLES FOR C.B.R. TESTS. TWO STATIC PENETROMETERS, THE FRENCH PAREZ AND THE DUTCH GOUDA, WERE COMPARED. ESPECIALLY NOTEWORTHY WAS THE INKING SYSTEM OF THE LATTER. THE SECOND PART OF THE ARTICLE IS DEVOTED TO ROADBUILDING CORE BORERS. THE RESULTS OF TESTS CARRIED OUT ON BITUMINOUS MIX, CONCRETE AND GRAVEL-CEMENT TRACKS, AND IN A CONCRETE WALL, ARE GIVEN IN A GENERAL TABLE, SOME CRITICISM AND SUGGESTIONS ARE ALSO FORMULATED. IT APPEARS IN PARTICULAR THAT ROAD-MAKING CORE BORINGS MAY NECESSITATE AT LEAST TWO TYPES OF VARIOUS CORE BORERS IN A LIMITED RANGE OF DIAMETERS. /AUTHOR/]]></description>
      <pubDate>Sun, 15 Aug 2004 02:37:58 GMT</pubDate>
      <guid>https://trid.trb.org/View/121082</guid>
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    <item>
      <title>PRODUCTION AND USE OF LIGHTWEIGHT SILICATE AGGREGATES</title>
      <link>https://trid.trb.org/View/107119</link>
      <description><![CDATA[LIGHTWEIGHT PELLETIZED AGGREGATES WERE PREPARED FROM VARIOUS TYPES OF LOCAL SHALES. ANALYSIS INDICATED THAT THE CLAYS ARE MONTMORILLONITE-BEARING CLAYS, WITH SOME QUARTZ, AND FAIR AMOUNTS OF FLUXES (MAINLY IRON OXIDE, ALKALIES, AND ALKALINE EARTHS). THE CLAYS REACHED MAXIMUM BLOATING AT 1250 DEGREES, AND FUSED AT 1300-1400 DEGREES. THE EASTERN DESERT SHALES SHOWED A MAXIMUM OF 4 TO 5-FOLD EXPANSIVITY AT 1250 DEGREES. THE PELLETIZED AGGREGATES WERE COATED WITH A SILICEOUS CLAY VARIETY BEFORE FIRING TO PREVENT THE PELLETS FROM STICKING TOGETHER. STANDARD CONCRETE MIXES WERE PREPARED FROM THE PELLETIZED AGGREGATES, NORMAL PORTLAND CEMENT, AND WATER. THE LIGHTWEIGHT CONCRETE SAMPLES WERE CHARACTERIZED BY LOW DENSITY, AND RELATIVELY GOOD STRENGTHS (CRUSHING STRENGTH 42, TENSILE STRENGTH 5, AND BENDING STRENGTH) AFTER 7 DAYS CURING UNDER WATER. /AUTHOR/]]></description>
      <pubDate>Tue, 10 Aug 2004 16:50:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/107119</guid>
    </item>
    <item>
      <title>DEVELOPMENT OF A METHOD FOR MEASURING WATER-STRIPPING RESISTANCE OF ASPHALT/SILICEOUS AGGREGATE MIXTURES</title>
      <link>https://trid.trb.org/View/465161</link>
      <description><![CDATA[This Innovations Deserving Exploratory Analysis (IDEA) project developed a nondestructive method for measuring the water stripping resistance at the molecular level of asphalt/siliceous aggregate mixtures using the technique of Fourier Transform Infrared Spectroscopy-Multiple Internal Reflection (FTIR-MIR). This report summarizes the research and presents the results on the use of the spectroscopic technique for evaluating the effectiveness of different antistripping agents for asphalts. Also, based on the interfacial water information, the mechanisms of stripping of an asphalt from a siliceous aggregate and of the transport of water from the environment to the asphalt/aggregate interface are presented.]]></description>
      <pubDate>Thu, 11 Oct 2001 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/465161</guid>
    </item>
    <item>
      <title>EFFECTS OF HIGH TEMPERATURE ON THE RESIDUAL COMPRESSIVE STRENGTH OF HIGH-STRENGTH SILICEOUS CONCRETES</title>
      <link>https://trid.trb.org/View/539838</link>
      <description><![CDATA[The use of high-strength concretes (f sub c > 60 MPa) in special structures designed to work in a high-temperature environment or to withstand severe thermal accidents requires the mechanical properties of the material to be assessed with regard to high-temperature effects.  In this context, the residual mechanical properties of two high-strength concretes (f sub c=72 and 95 MPa), with siliceous aggregates (mostly flint) are studied under uniaxial compression after a single thermal cycle at 105, 250, 400, and 500 deg C.  The results show that while concrete toughness increases after a cycle at high temperature, strength and stiffness decrease dramatically, and the recovery of strength in time is either nil or negligible.  Furthermore, the stress-strain curves exhibit a rather pronounced softening branch, which has never so far been measured in a high-temperature context and is instrumental in assessing concrete toughness in compression.  The knowledge of the residual mechanical properties of a concrete is necessary whenever the thermally damaged structure is required to bear a significant share of the loads even after a severe accident.]]></description>
      <pubDate>Sun, 11 Oct 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/539838</guid>
    </item>
    <item>
      <title>EFFECT OF CONFINEMENT ON SILICEOUS AGGREGATE CONCRETE SUBJECTED TO ELEVATED TEMPERATURES AND CYCLIC HEATING. DISCUSSION</title>
      <link>https://trid.trb.org/View/487002</link>
      <description><![CDATA[A discussion of a paper with the aforementioned title by M.J. Terro and S.A. Hamoush, published in this journal (Volume 94, Number 2, March-April 1997), is presented.  The discussers raise three issues.  First, there is a solid body of experimental and numerical evidence to suggest that an initial stress inhibits thermal damage during heating, giving a substantial relative improvement in compressive strength.  Second, nearly all of the stress-strain plots for temperatures beyond 200 deg C show an initially flat slope to the curve, followed by a steeper response before reaching the plastic limit.  Finally, it would be valuable to explain fully the observation that heating cycles improve compressive strength above 300 deg C.]]></description>
      <pubDate>Wed, 17 Jun 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/487002</guid>
    </item>
    <item>
      <title>EARLY AGE PERFORMANCE OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENT WITH DIFFERENT TYPES OF AGGREGATE</title>
      <link>https://trid.trb.org/View/576097</link>
      <description><![CDATA[The effect of coarse aggregate on pavement performance has been attributed to the volume of aggregate used in pavement construction.  The different patterns of crack development for limestone (LS) and siliceous river gravel (SRG) are a typical example of aggregate-induced variable performance in continuously reinforced concrete pavement (CRCP).  An attempt was made to find a reasonable solution for pavements with SRG. As a way to solve the performance problem observed from the SRG pavement, a blended aggregates mixture was suggested. Laboratory and field tests were performed to check the feasibility of their application in pavements.  From the laboratory test, a 50:50 blending ratio was suggested after considering the effect on tensile strength and thermal coefficient of expansion.  Field test sections were also constructed to verify previous performance observations for the two aggregates and to provide performance data for new variables such as blended aggregates and special curing methods. Unexpectedly, the blended mixture did not improve the performance of SRG pavement; rather it experienced worse cracking than SRG alone.  A controlled experiment with additional field test sections is needed to verify or disprove this finding.  The only definitive finding was that selection of aggregate in the concrete pavement is a vital consideration for the design of the pavement.  The CRCP8 analytical program reasonably predicted crack spacing for both SRG and LS pavements, predicting mean crack spacing of 0.99 m (3.25 ft) for SRG and 1.98 m (6.41 ft) for the limestone.  These values are somewhat below the actual spacing observed at 100 days.  Data collected after the first winter period will be required to calibrate the program.]]></description>
      <pubDate>Mon, 25 Aug 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/576097</guid>
    </item>
    <item>
      <title>EFFECT OF CONFINEMENT ON SILICEOUS AGGREGATE CONCRETE SUBJECTED TO ELEVATED TEMPERATURES AND CYCLIC HEATING</title>
      <link>https://trid.trb.org/View/575228</link>
      <description><![CDATA[This paper describes an experimental study of the behavior of confined siliceous-aggregate concrete exposed to elevated temperature conditions such as those experienced during a fire. Locally produced gravel was used as coarse aggregates in the concrete specimens tests.  Equally-spaced steel rings were employed in the cylinders to simulate the effect of confinement on the material.  Three different types of concrete specimens were tested:  plain concrete cylinder, cylinders with six rings, and cylinders with nine rings.  The spacing between the rings is 28 mm and 17.5 mm for the six- and nine-ring specimens, respectively.  The cylinders were exposed to cycles of heating and cooling up to 700 deg C.  Results have indicated an improvement in the residual compressive strength up to about 30 percent and in the ductility of concrete at elevated temperatures due to the effect of confinement by ties.]]></description>
      <pubDate>Tue, 08 Jul 1997 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/575228</guid>
    </item>
    <item>
      <title>EFFECT OF AGGREGATES ON PAVEMENT PERFORMANCE. FINAL REPORT</title>
      <link>https://trid.trb.org/View/454659</link>
      <description><![CDATA[In Texas, rigid (or portland cement concrete) pavements and flexible (or asphaltic concrete) pavements are most often constructed using crushed limestone and/or siliceous river gravel as the coarse aggregate.  Project 1244, sponsored by the Texas Department of Transportation (TxDOT), evaluated the performance of rigid pavements and flexible pavements made with siliceous river gravel and with crushed limestone as coarse aggregates, in order to develop specifications that obtain equal and adequate performance from the different aggregates.]]></description>
      <pubDate>Wed, 24 Apr 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/454659</guid>
    </item>
    <item>
      <title>DEVELOPMENT OF A TECHNIQUE FOR IN SITU MEASUREMENT OF WATER AT THE ASPHALT/MODEL SILICEOUS AGGREGATE INTERFACE</title>
      <link>https://trid.trb.org/View/448355</link>
      <description><![CDATA[The debonding of asphalt from mineral aggregates in the presence of water (stripping) has been a problem ever since asphalt paving came into existence.  Many studies have sought a solution to the problem, but stripping continues to occur.  A SHRP project was charged with developing a nondestructive technique for measuring the stripping of asphalt from siliceous aggregate in the presence of water.  The main objective of the first phase of this study was to develop a spectroscopic technique for measuring in situ water at the interface between an asphalt and a model siliceous aggregate.  This report describes the successful development of the water in situ measurement technique.]]></description>
      <pubDate>Wed, 29 Nov 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/448355</guid>
    </item>
    <item>
      <title>EFFECTS OF AGGREGATE BLENDS ON THE PROPERTIES OF PORTLAND CEMENT CONCRETE PAVEMENTS. INTERIM REPORT</title>
      <link>https://trid.trb.org/View/421340</link>
      <description><![CDATA[Although recent studies have shown that pavement performance does vary by aggregate type, current portland cement concrete pavement design tools do not fully incorporate aggregate properties into the design process.  Aggregate characteristics shown to affect pavement performance include strength, thermal properties, and shrinkage properties.  The objective of this study was to investigate the material properties of crushed limestone and siliceous river gravel, two aggregates predominantly used in current pavement construction, and to determine a relationship between the properties of single-aggregate concrete and concrete made with predetermined blends of limestone and gravel.  This report continues the work of Project 422/1244, which way limited to single-aggregate concretes.  Additional models were developed to predict concrete properties of blended aggregate concrete for use in the design tools, CRCP and JRCP, described in previous 422/1244 reports.  A computer program, CHEM2, was developed, which allows the pavement designer to estimate the material properties of concrete from an inexpensive chemical test.  CHEM2 also predicts the properties of blended aggregates so that the user can determine the necessary blending ratio to control such troublesome properties as thermal coefficient of expansion and drying shrinkage.]]></description>
      <pubDate>Mon, 17 Apr 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/421340</guid>
    </item>
    <item>
      <title>SILICEOUS CONTENT DETERMINATION OF SANDS USING AUTOMATIC IMAGE ANALYSIS</title>
      <link>https://trid.trb.org/View/412852</link>
      <description><![CDATA[The characteristics of fine aggregate have a significant influence on the field performance of hot asphalt concrete mixtures.  Siliceous and rounded particles, which make up a significant percentage of natural sand, are generally related to rutting and possibly stripping of asphalt mixtures.  This study was conducted to develop and verify manual counting and automatic image analysis techniques to evaluate aggregate blends for amount of siliceous sand-size particles.  Verification involved preparation of samples with known proportions of siliceous (translucent) and calcareous (opaque) particles.  The samples prepared were analyzed manually with the aid of a microscope and automatically with an image analyzer.  It was found that automatic image analysis can be used with a higher degree of confidence and accuracy than manual counting techniques in determining percent translucent particles.  After the image analysis techniques were developed, extracted fine aggregates from field cores of various highway pavements in Indiana were examined with the image analyzer to determine amounts of translucent particles.  The percentages of translucent sand particles, assumed to be natural sand, were evaluated for the effect on the gradation, and it was found that as the siliceous sand content on the field cores increased, humps on the 0.45 power gradation curve were likely to increase. Image analysis was found to be up to four times faster than manual counting techniques.]]></description>
      <pubDate>Tue, 11 Oct 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/412852</guid>
    </item>
    <item>
      <title>RELATIONSHIPS BETWEEN THE DAILY TEMPERATURE WAVE AND THE DEVELOPMENT OF THE NATURAL SOIL PROFILE</title>
      <link>https://trid.trb.org/View/128154</link>
      <description><![CDATA[MORAINES ARE INVESTIGATED WHICH ARE MIXTURES OF CALCAREOUS AND SILICEOUS MATERIALS. THE FIRST PHASE OF SOLUTION WEATHERING IS A DECALCIFICATION. THE REMNANT IS A COLLOIDAL CLAYEY SUBSTANCE THAT IN TEMPERATE CLIMATES IS AT FIRST QUITE MOBILE. THIS SUBSTANCE CHARACTERIZES THE FUNDAMENTAL PROCESS OF SOIL FORMATION THAT IS OF SPECIAL INTEREST IN THIS CONNECTION: THE LESSIVAGE OR CLAY PERMEATION. THE REGULARITY IN THE VARIATION OF SOIL DEVELOPMENT WITH VARIATION IN EXPOSURE CONDITION, AND THE CONSTANCY OF THE BOUNDARY BETWEEN THE UPPER AND LOWER SOIL HORIZONS AT ABOUT 40 CM, RENDER PAIRS OF OPPOSITE DRUMLIN FLANKS FAVORABLE OBJECTS FOR THE STUDY OF THE INFLUENCE OF THE COURSE OF SOIL TEMPERATURE ON SOIL FORMATION. FOR THIS PURPOSE A FOREST-FREE DRUMLIN, NAMED THE WALZENBERG, LOCATED AT THE VILLAGE BOUNDARY OF ALLENSBACH, WAS CHOSEN. THE MICROCLIMATIC INVESTIGATIONS ARE BASED ON THE FOLLOWING CONDITIONS: (1) THE TWO TEST AREAS ARE SITUATED AT AN ELEVATION OF 450 AND 500 M ABOVE SEA LEVEL, IN THE UPPER THIRD OF THE UNFORESTED DRUMLIN, SLOPES OF AN AVERAGE SLOPE ANGLE OF 20 DEGREES TOWARD SOUTHWEST-SOUTH AND NORTHEAST-NORTH, RESPECTIVELY, (2) THE ARTIFICIAL FILLING OF RAW LIME-RICH MORAINE MATERIAL HAS A SINGLE-GRAIN STRUCTURE OF GOOD PERMEABILITY, AND IS NONPLASTIC AND HARDLY SUSCEPTIBLE TO EROSION, AND (3) THE SURFACES OF THE ARTIFICIAL SOIL FILLS WERE FITTED TO THE NATURAL SLOPE AND WERE KEPT CONTINUOUSLY FREE OF VEGETATION. THE FOLLOWING MICROCLIMATIC FACTORS WERE DETERMINED: (1) SOIL TEMPERATURES AT DEPTHS OF 2, 5, 10, 20, 35, 50, 75 AND 100 CM BY CONTINUOUS MECHANICAL RECORDING, (2) PRECIPITATION AND SEEPAGE WATER, AND (3) DRAINAGE. THESE INVESTIGATIONS OF SOIL TEMPERATURES ON BOTH SLOPES OF THE WALZENBERG PRODUCED THE FOLLOWING PRELIMINARY RESULTS:(1) ANALYSIS OF THE 4 GEOTHERM FIELDS RENDERED A GIVEN THERMAL PROFILE, (2) WITH THE AID OF TAUTOCHRONES, A DIVISION INTO 3 PARTS WAS VISUALIZED: THE FANNING OUT OF THE TAUTOCHRONES IN THE ACTIVE UPPER ZONE, THE BOUNDARY LAYER WITH THE LOCALIZED TEMPERATURE INVERSION DURING THE NIGHT HOURS, AND THE ALIGNMENT OF THE TAUTOCHRONES IN THE SAME DIRECTION IN THE PASSIVE LOWER ZONE, AND (3) THE OVERVIEW OBTAINED WITH REGARD TO THE COURSE OF SOIL TEMPERATURES DURING THE GROWING SEASON BY MEANS OF SELECTED TAUTOCHRONE PAIRS LEADS TO THE RECOGNITION OF SUBDIVISIONS THAT ARE FUNCTIONS OF TIME.]]></description>
      <pubDate>Thu, 25 Aug 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/128154</guid>
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