EFFETS DE L’INCORPORATION D’ADJUVANTS MINÉRAUX SUR LES PROPRIÉTÉS DE CIMENTS GÉOPOLYMÈRES A BASE DE SCORIES VOLCANIQUES

DJOBO YANKWA, JEAN NOEL (2013) EFFETS DE L’INCORPORATION D’ADJUVANTS MINÉRAUX SUR LES PROPRIÉTÉS DE CIMENTS GÉOPOLYMÈRES A BASE DE SCORIES VOLCANIQUES. Masters thesis, Université de Yaoundé I.

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    Abstract

    Volcanic ashes are raw materials from geological deposits with a range of chemical compositions. When combined with suitable alkali activators they can be converted to geopolymers cement at ambient temperature. In this work we have investigated the possibility of use bauxite and oyster shells as mineral admixture in volcanic ashes, to enhance the properties of geopolymers synthesized. Different methods of analyses such as Fourier Transform Infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and Scanning Electron Microscopy (SEM) were used to assess the variation of setting time, linear shrinkage and 28 days compressive strength of geopolymers paste. The bauxite and the oyster shells were characterized using inductively coupled plasma (ICP-AES), thermal analyses (DSC/ATG), FTIR and X-ray diffractometry. The results of these analyses has showed that bauxite and oyster shells are respectively source of Al2O3 and of CaO, and can compensate the deficiencies of these oxides in volcanic ashes. Adding mineral admixture dissolve slowly in high alkaline medium. Addition of about 20% of bauxite or 10% of oyster shells is seen to decrease the setting time respectively from 415 to 275 min and 195 min. Linear shrinkage decrease with percentage of bauxite or of oyster shells added. Efflorescence is reduced by adding 10% of bauxite. 28 days compressive strength of geopolymeric materials increase respectively for 4.77 and 7.52% for 10% of bauxite or 20% of oyster shells added. More than these percentage additive has a deleterious effect on compressive strength due to crystalized mineralogical phases of the admixture.

    Item Type: Thesis (Masters)
    Uncontrolled Keywords: Scories volcaniques ; Coquille d’huitre ; Bauxite ; Géopolymère
    Subjects: 500 Natural sciences and mathematics > 540 Chemistry and allied sciences
    Divisions: Africa > Cameroon > Université de Yaoundé 1 (UY1) > Faculté des Sciences
    Depositing User: Jean Noël DJOBO YANKWA
    Date Deposited: 20 Jun 2013 22:22
    Last Modified: 20 Jun 2013 22:22
    URI: http://eprints.campuce.org/id/eprint/76

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