ISSN 0862-5468 (Print), ISSN 1804-5847 (online) 

Ceramics-Silikáty


INFLUENCE OF NATURAL ZEOLITE ON PORTLAND CEMENT HYDRATION PROCESSES AND PROPERTIES OF HARDENED CEMENT PASTE
 
Kriptavičius Dalius, Girskas Giedrius, Skripkiū nas
 
Institute of Building Materials, Vilnius Gediminas Technical University, Saulė

Keywords: Clinoptilolite, Aluminosilicate, Pozzolanic activity, Setting time, Mortar flow, Strength
 

The application of natural zeolite clinoptilolite (Si/Al = 5.8) for substituting up to 20 vol% of the cement (in mortars) was studied. The effect of the natural zeolite on the consistency and compressive strength at 7, 28 and 90 days was tested at different dosages of clinoptilolite in the mixture. The optimal content (15 % by volume) of the active mineral addition was selected according to the achieved strength results of the mixture and the effect of natural zeolite on the early and late cement hydration was studied. The results of Chapelle test for pozzolanic activity, the initial and final setting times of the paste, thermogravimetric analysis and X-ray diffraction analysis of hardened cement paste showed that natural zeolite clinoptilolite accelerates early and late hydration of cement. No significant differences in calcium hydroxide (CH) content between the specimens modified with clinoptilolite and the specimens containing only ordinary Portland cement (OPC) were observed, despite the high pozzolanic activity of the zeolite.


doi: 10.13168/cs.2021.0025
 
 
Licence Creative Commons © 2015 - 2021
Institute of Rock Structure and Mechanics of the CAS & University of Chemistry and Technology, Prague
Webmaster | Journal Contact