@article{(Open Science Index):https://publications.waset.org/pdf/3294,
	  title     = {Effect of Na2O Content on Performance of Fly ash Geopolymers at Elevated Temperature},
	  author    = {Kalyan Kr. Mandal and  Suresh Thokchom and  Mithun Roy},
	  country	= {},
	  institution	= {},
	  abstract     = {The present paper reports results of an experimental
program conducted to study performance of fly ash based
geopolymer pastes at elevated temperature. Three series of
geopolymer pastes differing in Na2O content (8.5%, 10% and 11.5%)
were manufactured by activating low calcium fly ash with a mixture
of sodium hydroxide and sodium silicate solution. The paste
specimens were subjected to temperatures as high as 900oC and the
behaviour at elevated temperatures were investigated on the basis of
physical appearance, weight losses, residual strength, shrinkage
measurements and sorptivity tests at different temperatures. Scanning
electron microscopy along with EDX and XRD tests were also
conducted to examine microstructure and mineralogical changes
during the thermal exposure. Specimens which were initially grey
turned reddish accompanied by appearance of small cracks as the
temperature increased to 900oC. Loss of weight was more in
specimens manufactured with highest Na2O content. Geopolymer
paste specimen containing minimum Na2O performed better than
those with higher Na2O content in terms of residual compressive
	    journal   = {International Journal of Geological and Environmental Engineering},
	  volume    = {5},
	  number    = {1},
	  year      = {2011},
	  pages     = {7 - 13},
	  ee        = {https://publications.waset.org/pdf/3294},
	  url   	= {https://publications.waset.org/vol/49},
	  bibsource = {https://publications.waset.org/},
	  issn  	= {eISSN: 1307-6892},
	  publisher = {World Academy of Science, Engineering and Technology},
	  index 	= {Open Science Index 49, 2011},