Pozzolanic reactions of common natural zeolites with lime and parameters affecting their reactivity

• Published in: Cement and concrete research Vol. 39; no. 3; pp. 233 - 240
• Main Authors: Mertens, G., Snellings, R., Van Balen, K., Bicer-Simsir, B., Verlooy, P., Elsen, J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-03-2009; Elsevier
• Subjects: Applied sciences; Buildings. Public works; Ca(OH) 2; Characterization; Corrosion; Durability. Pathology. Repairing. Maintenance; Exact sciences and technology; Kinetics; Lime. Gypsum plaster. Plaster elements; Materials; Pozzolan; Zeolites; Characterization; Kinetics; Pozzolan; Zeolites; Ca(OH) 2; Calcium oxide; Pozzolana; Mineralogy; Zeolite; Ca(OH)2; Physical properties; Lime; Reactivity; Pozzolanic reaction; Chemical properties
• ISSN: 0008-8846; 1873-3948
• DOI: 10.1016/j.cemconres.2008.11.008

The pozzolanic reaction between portlandite and different types of nearly pure natural zeolites was studied. Analcime, phillipsite, chabazite, erionite, mordenite and clinoptilolite-rich tuffs were mixed with portlandite and water (1:1:2 by weight), and the progress of the pozzolanic reaction was quantitatively determined by thermogravimetrical analyses from 3 to 180 days.
A thorough characterization of the raw materials was performed by quantitative XRD, XRF, SEM-EDX, BET specific surface area measurements, grain-size analyses, FTIR and Cation Exchange Capacity measurements. The difference in reactivity of the samples containing zeolites with varying Si/Al ratios, as well as between clinoptilolite-rich samples exchanged with different cations or ground to different grain sizes was assessed.
The results indicate that the external surface area only influences the short-term reactivity, whereas the cation content has an effect on both the long- and short-term reactivity. The early reactivity of the unexchanged samples can be explained by these two parameters, but their long-term reactivity is mainly related to the Si/Al ratio of the zeolites. Samples with zeolites rich in Si react faster then their Al-rich counterparts.