Existing evidence has shown that in many concrete structures exposed to aggressive aqueous environments corrosion problems are present. In places like marine environments, sewers, agricultural structures, underground and hydraulic structures, chemical plants, industrial structures, liquid-containing structures these problems are especially very well visible. Degradation mechanisms such as alkali silica reaction, chloride penetration, carbonation, acid corrosion, leaching etc. have necessitated the renewal of complete structures. Leaching and acid corrosion mechanisms were chosen for detailed study and partial results are present in this paper. Concrete samples without coal fly ash addition and as well as sample with addition of 5% resp. 10 % of coal fly ash were used for experiment. Paper is aimed on study and evaluation of chemical corrosion and leaching due to sulphuric acid/distilled water influence on concrete samples. After the experiment of exposure of concrete samples to these different environments the concrete surface changes and the pH values changes of leachate were measured and evaluated.