ABSTRACT
EFFECTS OF POZZOLAN INCORPORATION AND CURING
CONDITIONS ON STRENGTH AND WATER RESISTANCE OF
NATURAL GYPSUM PASTES
Cengiz, Okan
Ph.D., Department of Civil Engineering
Supervisor : Prof. Dr. Turhan Y. Erdogan
September 2009, 189 pages
There are large reserves of gypsum rock (CaSO4· / 2H2O) in Turkey and in
various regions of the world. Heating gypsum rock to 140 - 190 0C causes it to
lose three-fourths of its water molecules and turn into gypsum, called plaster of
Paris / heat application over 190 0C results in loss of all the water molecules and
this form of the material is called gypsum anhydrite.
When gypsum is mixed with water, it gains cementitious property and hardens
in a short time. Therefore, natural gypsum anhydrite and especially plaster of
Paris are widely used in the construction industry. On the other hand, its not
being water resistant and having low strength restrict the use of gypsum
products for outdoor applications.
In this study, the effects of pozzolan incorporation to natural gypsum pastes
and application of various curing regimes for improving their water resistance
and strength were investigated. Compressive strength and absorption tests on
one thousand one hundred twenty two 5-cm cube specimens produced from
v
13 different mixture types were conducted. Also the microstructures of these
products were investigated using the analytical technique X-Ray Diffraction.
The test results showed that water resistance and strength properties of
pozzolan-incorporated gypsum products were improved. Curing of the product
at elevated temperature regimes was an additional factor that contributed to this
improvement. It was concluded that the natural gypsum mixtures prepared and
cured at the above-mentioned conditions could also be used for outdoor
applications.
Keywords: Pozzolan, Natural Gypsum, Elevated Temperature Curing
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12610922/index.pdf |
| Date | 01 September 2009 |
| Creators | Cengiz, Okan |
| Contributors | Erdogan, Turhan Yasar |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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