Frost Resistance of Hardened Cement Paste Modified with Synthetic Zeolite / Sintetiniu Ceolitu Modifikuoto Cementinio Akmens Atsparumas Šalciui

The experiment was coducted using synthetic zeolite (modification A) obtained in the laboratory of Kaunas University of Technology by means of low-temperature synthesis (below 105 °C). Aluminium fluoride (AIF3) production waste as well as sodium hydroxide NaOH and aluminium hydroxide Al(OH)3were used to obtain a complex zeolite admixture. SEM analysis revealed that synthetic zeolite admixture was made of modification A zeolite and gypsite. SEM analysis results were confirmed by X-ray analysis. Three batches of specimens were made to determine the effect of synthetic zeolite admixture on the durability of hardened cement paste. The first batch was without synthetic zeolite admixture, the second batch and the third batch contained 5 wt% and 10 wt% of synthetic zeolite admixture, respectively. Synthetic zeolite admixture was found to have a significant effect on the durability of the hardened cement paste. The weight loss in the hardened cement paste containing 5 wt% of the admixture was three times lower, whereas the weight loss in the hardened cement paste containing 10 wt% of the admixture decreased up to 100 times.