Cement hydration with zeolite-based additive

Abstract

This study has examined the effect of a zeolite-based additive on cement hydration processes. This additive and samples of hardened cement pastes have been examined using X-ray diffraction, thermoanalytical methods (TG and DSC) and FTIR spectroscopy analysis. The results show that a modified zeolite additive increases the compressive strength of hardened cement paste specimens. The increase in compressive strength may be related to active SiO2 and Al2O3 present in the modified zeolite. The highest density was recorded in specimens containing 10% of the modified zeolite additive. Instrumental analysis has revealed that with the increase of this zeolite additive content the content of portlandite – Ca(OH)2 – in the mineral composition of hardened cement paste reduces from 11.9 to 5.3% after 3 days of setting and from 15.0 to 7.6% after 28 days of setting. The highest amounts of C-S-H gel are observed when the modified zeolite additive is used.