قابليت توف هاي زئوليت دار استان مركزي به عنوان پوزولان طبيعي مورد استفاده در صنعت سيمان

Ability of Zeolitic Tuffs from Centeral Province as Natural Pozzolan Using in Cement Industry

The Study area located in southwest Dodehak village in 20km North of Delijan city, Central province, and Eocene volcano- sedimentary rocks in this area which appears to have significant potential in terms of Pozzolanic materials. To evaluate the ability of the Eocene tuffs in this area to supply for industrial cement production, some chemical analysis and physical tests and petrography studies have been carried out on collected samples. The results of petrography and powder x-ray indicated that samples have a minor percentage of glass phase and considerable amount of zeolite-group minerals. The chemical compositions of all samples in terms of pozzolanic composition were consistent with the ISIRI 3433 and ASTM C618 standards, compressive strength were tested for different caring time, 3, 7 and 28 days, and results were higher than required criterion recommended in National Iranian Standard no. 3432 and ASTM-C595-89 as well. Meantime, other physical properties, such as density, autoclave expansion, fineness etc., were measured according to related standards and they also conforms with these standards. In general, this study indicated that zeolitic phases is the main effective factor on pozzolanic properties and Eocene tuffs of this area have a good ability as natural pozzolans because of existence about 20 % zeolitic phases. Keywords: Natural Pozzolans, Cement, Zeolite, Compressive Strength, XRD, XRF