Contribution to Sustainable Environment through Examination of Durability of Materials in an Aggressive Environment

The paper presents the results of leaching tests of concrete samples with 5 wt. % cement's replacement by fly ash and applies the statistical approach to an interpretation the results. Concrete samples with of two types of fly ashes, originating from anthracite and lignite burning, respectively were exposed to solution of Al2(SO4)3 to sulphate corrosion testing. Deterioration process was manifested by leaching the elementary components of concrete (Ca, Si, Fe, Al) and particular pH changes of leachates in 5 cycles. The leached-out concentrations of elements from concrete matrix measured by X-ray fluorescence method (XRF) and measured pH values were used for the subsequent statistical analysis. A dependency between pH of leachates and leaching trends of Ca and Al, respectively, was confirmed. The correlation coefficients ranged from 0.79 to 0.85. No significant differences between durability of concrete materials based on black or brown-coal fly ashes regarding to leachability were noticed.