Search
(Help)
Go!
Contact OCMS
Abstract Help
NEW Personal
Scheduler
Instructions:
Enter any of the following in the search box and then click "Go!": Any part of Conference, symposium, session, or abstract name/title; author first name or last name or both; any part of organization name; abstract presentation date.
Abstract Summary
Conference:
105th Annual Meeting & Exposition
Instructions
and
Links
Symposium:
20. Ceramic Matrix Composites
Session:
Geopolymer Composites -
1:00:00 PM - 5:00:00 PM 4/28/2003
Abs. Title:
Processing, Microstructure and Properties of Fly Ash Based Geopolymers
Abstract #:
7456
Type:
Invited
Submitted:
12/1/2002 10:59:30 PM
Status:
Accepted
Scheduled?
Yes
Abstract:
The geopolymerisation of natural aluminosilicate minerals, which cover a wide range of structures, minerals groups, hardness, densities and Al
2
O
3
and SiO
2
contents, has been investigated. The study of fifteen selected Al-Si minerals shows that the framework structured Al-Si minerals with a high CaO content and a lower K
2
O content, have a higher potential to undergo geopolymerisation in KOH solution with resulting geopolymers possessing a higher compressive strength. It is found in this work that the added silicate solution actually catalyses the geopolymerisation and initiates the polymerisation between the large silicate oligomers and the aluminate monomers. The alkalinity M
2
O/H
2
O, the ratio of added silicate, the SiO
2
/M
2
O ratio, the alkali metal cation K+ and the setting pressure positively affect the geopolymerisation of the stilbite/kaolinite matrix. A method of combining XRD, MAS NMR, SEM/EDX, TEM/EDX and HREM techniques has been established to characterise the structural composition of geopolymers. The results on the geopolymers synthesised from stilbite/kaolinite matrices reveal that the mechanical strength of geopolymers is determined by the gel phase as the binder, the undissolved solid reactants as the filler and the ratio of average surface area and undissolved particles. The mechanisms involved in leaching and geopolymerisation can be explained by the cation anion ion pair theory. The Na+ cation, with a smaller size, better stabilises the smaller silicate oligomers, such as monomer and dimer. K+, possessing a larger size, preferentially coordinates with the larger silicate oligomers, which eventually leads to a higher extent of geopolymerisation.
Abstract Author(s)
1
Primary and Presenting
Jannie van Deventer -
1011768
Organization
University of Melbourne
Phone #
+61383446620
Fax #
+61383444153
Professional Title
Foundation Professor of Mineral and Process Engineering
Street Address
Parkville
City
Victoria
State
Country
Australia
Postal Code
2
Co-Author
Linda Xu -
1011808
Organization
University of Melbourne
Phone #
Fax #
Professional Title
Post doctoral Research Associate
Street Address
City
Parkville
State
Province
Victoria
Country
Australia
Postal Code
3010
3
Co-Author
Grant Luckey -
1011809
Organization
University of Melbourne
Phone #
Tel. : +61-3-8344-7922
Fax #
Professional Title
Post doctoral Research Associate
Street Address
City
Parkville, Melbourne
State
Province
Victoria
Country
Australia
Postal Code
3010
Main Menu
Symposia List
Session List
Abstract List
Instructions:
To modify the text of this abstract or add or delete authors, click the '
Modify Abstract
' button. To list the abstracts in the current session, the sessions in the current symposium, or the symposia in the current conference, click the appropriate link above these instructions.