Using Cappadocia tuff as a natural pozzolan in the cement production

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2015

Öğrenci: MUSTAFA CAN ATAN

Danışman: LUTFULLAH TURANLI

Özet:

For the concrete world, it is increasing day by day in importance to use the pozzolans as a cement replacement material or concrete admixture. To be able to use them in this aim, many scientific researchers have been carried out to observe the material's mechanical, physical, and durability characteristics. Moreover, using pozzolan in cement production up to 50%, actually tells that the CO2 emission is decreased nearly by 50%. Furthermore, whether the pozzolan is natural or a vi byproduct, the material offers a huge amount of financial benefit by decreasing production cost with having only grinding procedure. In this study, the natural tuff from Cappadocia Region, Middle Anatolia, was tested as a cement replacement material chemically, mechanically, physically, and for durability. For the tests, one control cement and two blended cements were produced in the laboratory. The materials were intergrinded in this study. At the end of these tests, the observations include 0%, 25% and 50% natural pozzolan replacement with clinker which gives a general idea about the material's efficiency to be used in the cement production with high volume up to 50%. By means of performance, the cements were tested for fineness, particle size distribution, normal consistency, setting times, autoclave expansions, compressive strength, heat of hydration, and alkali-aggregate reaction in the lights of the related standards in ASTM. For a given fineness, the material affected autoclave expansion and alkaliaggregate reaction positively. Also the heat of hydration tend to decrease with the increasing pozzolan amount. It is observed that initial and final setting times get longer and water requirement increased. Furthermore, Cappadocia tuff decreased the early strength, however after 90 and 180 days, the strength gaining was quite appearably going on in the Cappadocia tuff blended cements.