CLOSING REMARKS BY CHAIRMAN

RECENT PUBLICATIONS ARE DISCUSSED DEALING WITH MODERN ENGINEERING MATERIAL SCIENCE. SPECIFIC ASPECTS ARE DISCUSSED OF THE SOIL-WATER PROBLEM IN REGARD TO IONS AND MOLECULES. THE DEGREE OF RESTRAINT SUFFERED BY THE MOLECULES IN THE VARIOUS LAYERS MANIFESTS ITSELF IN A LOWER SPECIFIC AND MOLE HEAT AS COMAPRED WITH THAT OF NORMAL WATER, THE DIFFERENCE BEING GIVEN OFF AS HEAT OF WETTING. AS THE WATER CONTENT OF A CLAY WATER SYSTEM IS DECREASED FROM A CONDITION WHERE THERE IS PLENTY OF ROOM FOR THE HYDRATED EXCHANGE IONS TO SWIM FREELY IN THE WATER PHASE TO THE INITIAL CONDITION OF DRYNESS, THEN VARIOUS HYSTERESIS PHENOMENA WILL BE ENCOUNTERED BECAUSE THE HYDRATED CATIONS WILL REQUIRE TIME TO SHED THEIR HYDRATION HULL AND RETURN TO THEIR PROPER PLACES WITHIN THE MINERAL SURFACE. DEPENDING ON THE RATE OF WETTING AND DRYING, RESPECTIVELY, MINERAL-WATER SYSTEMS MAY AT THE SAME WATER CONTENT EXHIBIT MARKEDLY DIFFERENT PROPERTIES IF THIS CONTENT IS REACHED BY WETTING IN ONE CASE AND BY DRYING IN THE OTHER. VERY THIN WATER FILMS BETWEEN MINERAL PARTICLES MAY ACT AS STRONG CEMENTS, BUT APPRECIABLE EFFECTS ON CONSISTENCY PROPERTIES OF SOILS ARE OBSERVED EVEN WITH A WATER CONTENT THAT FALLS WITHIN THE RANGE WHERE OSMOTIC SWELLING PREDOMINATES. THERE EXISTS A BODY OF EVIDENCE THAT THE DIFFERENCE IN CONSISTENCY PROPERTIES OF MONOIONIC VARIATIONS OF THE SAME CLAY MINERAL AT THE SAME MOISTRUE CONTENT IS DUE MORE TO DIFFERENCES IN STATE OF DISPERSION AND STRUCTURE OF THE CLAY MINERALS, AFFECTED BY THE IONS IN INTERPLAY WITH THE WATER PRESENT, THAN TO DIRECT EFFECT OF THE IONS ON VISCOSITY OF THE WATER INVOLVED.

Media Info

  • Monograph Title: Discussions on Water and Its Conduction in Soils
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00237874
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 27 1970 12:00AM