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    <title>Transport Research International Documentation (TRID)</title>
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    <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>
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      <title>LA MICROSTRUCTURE D'UN GRANITE ALTERE CHIMIQUEMENT</title>
      <link>https://trid.trb.org/View/1046552</link>
      <description><![CDATA[UN MICROSCOPE ELECTRONIQUE A BALAYAGE A ETE UTILISE POUR L'OBSERVATION DES CHANGEMENTS DE MICROSTRUCTURE QUI AFFECTENT UN GRANITE SOUMIS A L'ALTERATION METEORIQUE. LA PREMIERE AVANCEE DE L'ALTERATION SE PRODUIT LE LONG DE  CRAQUELURES ET DE PORES PREEXISTANTS ET DE CLIVAGES OUVERTS ; ELLE ABOUTIT A LA DECOMPOSITION ET A LA DISSOLUTION DES FELDSPATHS LE LONG DE PLANS CORRESPONDANT A LA STRUCTURE, A LA DECOMPOSITION ET A L'EXPANSION DU RESEAU DE LA BIOTITE, A LA DISSOLUTION ET A LA MICROFRACTURATION DU QUARTZ. EN CE QUI CONCERNE LA NATURE FONDAMENTALE DU GRANITE ALTERE, LES PREMIERES PHASES DE L'ALTERATION SONT DOMINEES PAR L'OUVERTURE DES SURFACES DE SEPARATION DES GRAINS, LA MICROFRACTURATION ET LE DEVELOPPEMENT D'UNE POROSITE INTRAGRANULAIRE DANS LES FELDSPATHS. LES PHASES SUIVANTES SONT DOMINEES PAR LA NATURE VARIABLE DE L'ARGILE D'ALTERATION. (A)]]></description>
      <pubDate>Sat, 20 Nov 2010 23:19:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1046552</guid>
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      <title>INTERNAL DETERIORATION OF CONCRETE BY THE OXIDATION OF PYRRHOTITIC AGGREGATES</title>
      <link>https://trid.trb.org/View/755449</link>
      <description><![CDATA[The incorporation of rock as aggregate in concrete may lead to a steep acceleration of the natural rock deterioration.  Concrete is a very aggressive environment, compared with the natural conditions where the rock was located; the concrete pore solution is mainly composed of alkali ions and hydroxide ions, and the pH is generally higher than 13.0.  This article presents research results on the causes of a severe concrete deterioration, which occurred in many building foundations approximately 2 years after construction. Concrete samples were investigated with X-ray diffraction (XRD) analysis, a scanning electron microscope (SEM) and a petrographic examination performed with a stereomicroscope.  The authors found that the early cracking of concrete stemmed from the oxidation of the pyrrhotite found in the anorthosite aggregates used to produce the concrete.  The oxidation of the iron sulphides provides a series of chemical reactions leading to the precipitation of iron hydroxides and ettringite.  These secondary products have a larger volume than the initial products have, which initiates microcracks.  The presence of micas (biotite) close to the pyrrhotite seemed to promote and accelerate the oxidation process.  The authors conclude that precautions should be taken with aggregates containing minerals such as pyrrhotite or pyrite combined with micas before incorporation into concrete.]]></description>
      <pubDate>Mon, 18 Apr 2005 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/755449</guid>
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    <item>
      <title>FACTORS AFFECTING THE FREQUENCY DISTRIBUTION OF CLAY MINERALS IN SOILS</title>
      <link>https://trid.trb.org/View/127983</link>
      <description><![CDATA[AN EXTENSIVE SURVEY OF THE CLAY MINERALS AND THE OTHER MINERAL COLLIODS OF MANY SOILS LED TO THE CONCLUSIONS THAT THE CHEMICAL ENVIRONMENT THAT EXISTS IN A SOIL DURING ITS DEVELOPMENT DETERMINES THE KIND OF CLAY MINERALS THAT ARE BEING FORMED AND THAT THE FREQUENCY DISTRIBUTION OF THE CLAY MINERALS AND THE OTHER MINERAL COLLOIDS, EXCLUSIVE OF THOSE INHERITED FROM THE PARENT MATERIAL, ARE DETERMINED BY THE CHEMICAL ENVIRONMENT OCCURRING DURING SOIL FORMATION. FUTHERMORE, THE CHEMICAL ENVIRONMENT ALSO DETERMINES THE NATURE AND EXTENT OF THE ALTERATION THAT BIOTITE AND MUSCOVITE UNDERGO DURING BREAKDOWN TO COLLOIDAL DIMENSIONS. BECAUSE THE CHEMICAL ENVIRONMENT OF A SOIL IS DETERMINED BY THE FACTORS OF SOIL FORMATION, A GOOD CORRELATION EXISTS BETWEEN THESE FACTORS AND THE FREQUENCY DISTRIBUTION OF THE CLAY MINERALS. ANY OF THE FACTORS OF SOIL FORMATION THAT FUNCTION TO MAINTAIN A NEUTRAL OR AN ALKALINE ENVIRONMENT AND TO ACCUMULATE CACO ALSO INDUCE THE FORMATION AND ACCUMULATION OF MONTMORILLONITE--WHETHER THIS FORMATION IS THROUGH SYNTHESIS OR THROUGH THE ALTERATION OF MICAS AND VERMICULITES. ANY OF THE FACTORS, HOWEVER, THAT FUNCTION TO MAINTAIN A HIGHLY BASE-DEPLETING ENVIRONMENT, SUCH AS HIGH RAINFALL, GOOD DRAINAGE AND A HIGH PERMEABILITY, OR THE POSITION OF A SOIL IN THE PROFILE AS SURFACE HORIZONS, ARE CONDUCIVE TO KAOLINITE AND HALLOYSITE FORMATION. ANY OF THE FACTORS THAT FUNCTION TO MAINTAIN AN INTERMEDIATE ENVIRONMENT, I.E. BETWEEN A HIGHLY ACCUMULATING AND A HIGHLY DEPLETING ONE, INDUCE THE FORMATION OF VERMICULITE EITHER BY SYNTHESIS OR BY THE ALTERATION OF THE MICAS. /AUTHOR/]]></description>
      <pubDate>Fri, 11 Aug 2000 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/127983</guid>
    </item>
    <item>
      <title>BIOTITE GNEISSES OF THE CANADIAN SHIELD AS COARSE AGGREGATE FOR CONCRETE</title>
      <link>https://trid.trb.org/View/107027</link>
      <description><![CDATA[THE GENERAL CHARACTERISTICS OF GNEISSES AS CONCRETE AGGREGATES ARE DISCUSSED, WITH PARTICULAR ATTENTION TO THE BIOTITE GNEISSES THAT OCCUR IN THE CANADIAN SHIELD OUTSIDE THE GEOLOGICAL GRENVILLE PROVINCE. TESTS INDICATED THAT ALTHOUGH THEIR USE CAN CAUSE SOME PROBLEMS THEY CAN BE GENERALLY SATISFACTORY. /CGRA/]]></description>
      <pubDate>Wed, 02 Feb 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/107027</guid>
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      <title>DETERIORATION OF BITUMINOUS PAVEMENT SURFACES BY GROWTH OF ALUM CRYSTALS</title>
      <link>https://trid.trb.org/View/269451</link>
      <description><![CDATA[Some 1.5-in. bituminous pavements in Stafford County, Virginia, have developed numerous small domes from 2 to 4 in. in diameter and about 1 in. high. Each dome has a core of white, astringent-tasting crystals that are under the bituminous pavement and at the top of the subbase. The crystals appear to be closest in composition to pickeringite, a magnesium alum, which commonly results from the weathering of pyritic schists. The domes were observed primarily between vehicle wheel tracks and in areas of poorest drainage. The aggregate in the bituminous pavement is quartz sand and gravel and does not appear to be casually involved in the deterioration. The subbase aggregate is largely crushed biotite schist and granite and is from a quarry near Culpeper. Analyses of water in the quarry and of salts leached from stone piles indicate that the quarry is the probable source of the alum, and that the salts are in the subbase stone. It appears that salts concentrate under the bituminous pavement because water without the contained salts moves through the bituminous pavement, which appears to act as a semipermeable membrane. A particle count of subbase aggregate under the bituminous pavement indicates that the darker particles of biotite schist have produced local zones of capillarity in the subbase. This allows for water to be transmitted upward at certain spots, thus causing the salts to concentrate in mushroom-like masses under the bituminous pavement.]]></description>
      <pubDate>Fri, 28 Feb 1986 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/269451</guid>
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      <title>THE INFLUENCE OF THE DEGREE OF WEATHERING OF HORNFELS ROCK ON ITS PHYSICAL PROPERTIES AND DURABILITY</title>
      <link>https://trid.trb.org/View/186355</link>
      <description><![CDATA[This study is concerned with the influence of the degree of weathering of quartz-cordierite-biotite Hornfels rock on its physical properties and durability with particular reference to the boral resources (Victoria) quarry at Wollert.  Some comparison is made with Hornfels outcropping at Lysterfield and that exposed at the CRB quarry at Avenel. Samples were subject to microscope examination, x-ray diffraction studies, chemical and thermal analyses, the Washington degradation test, and rock shrinkage and weight measurements on cycles of wetting and drying.  These results showed that the physical properties and durability of quartz-cordierite-biotite Hornfels rock are very dependent upon its degree of metamorphism and subsequent weathering (a). The number of the covering abstract of the conference is TRIS No. 368448.  (TRRL)]]></description>
      <pubDate>Thu, 30 Dec 1982 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/186355</guid>
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    <item>
      <title>BALLAST QUARRYING IN NEW SOUTH WALES</title>
      <link>https://trid.trb.org/View/25754</link>
      <description><![CDATA[This article describes the operation of the Shepherd's Hill quarry 350 miles west of Sydney. The Shepherd's Hill outcrop consists of a rhyolite-porphyry with phenocrusts of feldspar, quartz, chlorite, biotite and sphene. Details are given of face operations, including drilling and blasting, loading and transportation, the primary and secondary crushing plant, the power supply, and maintenance of plant.]]></description>
      <pubDate>Tue, 22 Apr 1975 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/25754</guid>
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