Journal of the Clay Science Society of Japan (in Japanese)
Online ISSN : 2186-3563
Print ISSN : 0470-6455
ISSN-L : 0470-6455
Search
Advanced search
OR
Browse
Search
Volume 45, Issue 2
Displaying 1-4 of 4 articles from this issue
Show all abstracts
    • |<
    • <
    • 1
    • >
    • >|
  • A Mineralogical Consideration on Unusual Cracking of Concrete Structures
    Akio MARU
    2006 Volume 45 Issue 2 Pages 75-89
    Published: March 06, 2006
    Released on J-STAGE: September 20, 2011
    DOIhttps://doi.org/10.11362/jcssjnendokagaku1961.45.75
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    Currently, there are many reports on unusual cracking of concrete structures attributable to alkali aggregatereaction. A mineralogical survey was conducted on concrete specimens from various concrete structures throughout thecountry. The resuts indicated the unusual cracking of concrete might be influenced by alkali aggregate reaction or theleaching of some constituents of the aggregate and identified the following characteristics.
    (1) The amount of active minerals to alkali contained in the aggregate is not necessarily related to the cracking.
    (2) The component radio of SiO/(Na2O+K2O) is low in andesite aggregate subject to the cracking.
    (3) In cured cement, ettringite and portlandite are prevalent or 3CaO·Al2O3·8-12H2O and 4CaO·Al2O3·13H2O are found to be generated.
    The so-called alkali aggregate reaction may be an abnormal reaction of cement largely caused by inadequate curing during concrete placement and the leaching of some constituents of the aggregate in concrete.
    View full abstract
    Download PDF (9942K)
  • Adsorption Sequence of Heavy Metal Divalent Ions on Silica
    Kazutoshi SAEKI
    2006 Volume 45 Issue 2 Pages 90-94
    Published: March 06, 2006
    Released on J-STAGE: September 20, 2011
    DOIhttps://doi.org/10.11362/jcssjnendokagaku1961.45.90
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    In order to understand the adsorptive selectivities of heavy metal species on constituents of soil, adsorptions ofheavy metal ions (Cd2+, Co2+, Cu2+, Ni2+, Pb2+ and Zn2+) on a variable charge material, silica which have a surfacefunctional group, Si-OH, were investigated as a function of the solution pH, . The comparative sorption study with Ca2+were also carried out in the similar manners. The adsorptive affinities of the divalent metal ions on silica were numberedwith intrinsic surface complexation constants (K1m (int)) calculated approximately from the adsorptive data using aconstant capacitance model. Experiments of Cd and Pb adsorptions were carried out in a 0.1 mol L-1 (M) NaNO3background solution because a chemical speciation model, SOILCHEM estimated that each proportion of free ions of themetals would be low in a 0.1 M NaCl background solution. The other metal's adsorption experiments used a 0.1 M NaCl background solution. The higher pH the suspension raised, the more heavy metal ions were adsorbed. The adsorptionsof the heavy metals increased rapidly from 0 to 100 % in narrow pH range (about 2 pH units). The heavy metal ionsdiffered from Ca2+ in their great adsorptions at higher pH. Judging from the K1m (int) of each divalent metal ion, theselective order for the metal adsorption by silica was Pb > Cu > Zn > Ni > Cd > Co > Ca. In addition of the data for Fe2+and Mn2+ in my previous study (Saeki, 2004), the order of the nine metals was Pb > Cu > Fe > Zn > Ni > Cd > Mn > Co > Ca.
    View full abstract
    Download PDF (748K)
  • Morphology Control of Clay Mineral Supported Metallocene Catalysts
    Takehiro SAGAE
    2006 Volume 45 Issue 2 Pages 95-101
    Published: March 06, 2006
    Released on J-STAGE: September 20, 2011
    DOIhttps://doi.org/10.11362/jcssjnendokagaku1961.45.95
    JOURNAL FREE ACCESS
    Show abstractHide abstract
    It is effective for saving energy to develop a polypropylene manufacturing technology without a pelletizingstep. Novel clay mineral supported metallocene catalyst technologies to produce PP powders having goodmorphology and large particle size which can be handled like conventional pellets were developed. Producingtechnologies for catalyst supports using montmorillonite with large particle size and narrow particle sizedistribution appropriate for the production of large particle size PP powders were developed. Polymerizationtechnologies for large particle size PP powders utilizing the catalysts mentioned above were developed, andpowders with targeted size and shape could be obtained.
    View full abstract
    Download PDF (7987K)
  • Synthesis and Applications of Hydrotalcites
    Toshiyuki HIBINO
    2006 Volume 45 Issue 2 Pages 102-109
    Published: March 06, 2006
    Released on J-STAGE: September 20, 2011
    DOIhttps://doi.org/10.11362/jcssjnendokagaku1961.45.102
    JOURNAL FREE ACCESS
    Download PDF (15392K)
    • |<
    • <
    • 1
    • >
    • >|
feedback
 Top