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1 Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture
1 Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska

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Mathematical evaluation of deleterious processes of fly ash-based concrete in pipelines

Ondrejka Harbuláková V., Eštoková A., Luptáková A.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

2016

z. 63, nr 2/II

343--350

Concrete performs well when exposed to various atmospheric conditions, water, soil, and many other chemical exposures. However, some chemical environments or even water can deteriorate high-quality concrete. Paper considers the usefulness of current fly ash concrete technology and prevention techniques, and advances a new approach for making concrete resist the deleterious effects of corrosion. This paper is focused on study of the durability of concrete materials based on two types of fly ashes which substitute 5 wt. % of cement in concrete mixture. Mathematical evaluation using correlation analysis was applied for assessment of deterioration of the concrete samples with fly ash of different origins. Experiment was done by measurements of elementary leached-out ions concentration (Ca, Si, Fe, Al, Cu and Mn) and subsequently correlation analysis between the ions each other (in the same type of fly ash or between different types of fly ash respectively) and also correlation between ions concentrations and pH values of leachate. The correlation coefficient showed different mechanism of calcium and silicon ions leaching when comparing the concrete samples with fly ash from brown coal burning and samples with fly ash from black coal burning.

Study of different types of corrosion processes simulated in model conditions

Ondrejka Harbuláková V., Števulova N., Repka M., Luptáková A.

Zeszyty Naukowe Politechniki Rzeszowskiej. Budownictwo i Inżynieria Środowiska

2012

z. 59, nr 1/I

141-148

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.