Fly Ash Incorporation into the Concrete Composites in Order to Improve their Environmental Performance

摘要

Fly ash, representing the fine particulate matter, can be widely used in concrete production in order to improve the concrete properties and its environmental performance. The paper is aimed at applying a statistical approach to evaluate the results of the chemical sulphate corrosion of cement composites with and without fly ash addition. Two aggressive media simulating a sulphate corrosion: 0.5 wt.% solution of H_2SO_4 and 0.5 wt.% solution of Al_2(SO_4)_3 were used. The deterioration process was evaluated by dissolution of the basic components of cement composites due to the aggressive media exposure. The concentrations of dissolved Ca, Si, Al, Fe, Mn and Cu ions in leachates were measured and used as input data in a correlation analysis. Significant and up to very high correlation coefficients have been calculated for all analysed ions leachability excepting cuprum. The findings revealed the similar leaching mechanisms of analysed ions from the concrete samples with 5 and 10 wt.% of fly ash addition. The addition of coal fly ash was not definitely confirmed to increase the environmental resistance of concrete samples in terms of calcium and silicon leaching.