Pozzolanic Activity Of Clinoptilolite: A Comparative Study With Silica Fume, Fly Ash And A Non-Zeolitic Natural Pozzolan

WOS: 000274869600006
Pozzolanic activity of clinoptilolite, the most common natural zeolite mineral, was studied in comparison to silica fume, fly ash and a non-zeolitic natural pozzolan. Chemical, mineralogical and physical characterizations of the materials were considered in comparative evaluations. Pozzolanic activity of the natural zeolite was evaluated with various test methods including electrical conductivity of lime-pozzolan suspensions; and free lime content, compressive strength and pore size distribution of hardened lime-pozzolan pastes. The results showed that the clinoptilolite possessed a high lime-pozzolan reactivity that was comparable to silica fume and was higher than fly ash and a non-zeolitic natural pozzolan. The high reactivity of the clinoptilolite is attributable to its specific surface area and reactive SiO(2) content. Relatively poor strength contribution of clinoptilolite in spite of high pozzolanic activity can be attributable to larger pore size distribution of the hardened zeolite-lime product compared to the lime-fly ash system. (C) 2009 Elsevier Ltd. All rights reserved.
Scientific and Technological Research Council of Turkey [104M393]
This study was funded by The Scientific and Technological Research Council of Turkey under Project Number: 104M393. The instrumental analyses in this study were carried out in Middle East Technical University Central Laboratory. Acknowledgment is given to Emeritus Professor P. Kumar Mehta from the Civil and Environmental Engineering Department at the University of California, Berkeley, for his helpful comments during the investigation.