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Experimental study of alkali-silica reactivity of volcanic rocks
Seidlová, Zuzana ; Přikryl, Richard (advisor) ; Vavro, Martin (referee)
(AJ) Even today, alkali-silica reaction is a significant problem in concrete-making industry. It was first described in 1940 by Stanton and since then the study of alkali-silica reaction of aggregates has proceeded notably. Despite these findings, not everything has been resolved and not all the causes and consequences of this reaction are known. To detect the alkali-silica reaction in the aggregates many methods are used, such as petrographic methods, chemical methods, and expansion tests, which examine the expansion of concrete due to the reactivity of aggregates. Petrographic methods evaluate qualitative and quantitative characteristics of aggregates but can not guarantee whether they still do not cause the reaction. Chemical tests and expansion tests provide so- called potential response (non-reactive, reactive and potentially reactive aggregates), but even they have their errors and can not be taken as a 100% indicator of the presence of alkali-silica reaction of aggregates. The thesis describes the general characteristics of alkali-silica reaction of aggregates, the mechanisms and the factors influencing its formation. It describes the fraction of the concrete in which some volcanic rocks have been used, and which are in some works identified as potentially reactive by the alkali-silica...
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Experimental study of alkali-silica reactivity of volcanic rocks
Seidlová, Zuzana ; Přikryl, Richard (advisor) ; Vavro, Martin (referee)
(AJ) Even today, alkali-silica reaction is a significant problem in concrete-making industry. It was first described in 1940 by Stanton and since then the study of alkali-silica reaction of aggregates has proceeded notably. Despite these findings, not everything has been resolved and not all the causes and consequences of this reaction are known. To detect the alkali-silica reaction in the aggregates many methods are used, such as petrographic methods, chemical methods, and expansion tests, which examine the expansion of concrete due to the reactivity of aggregates. Petrographic methods evaluate qualitative and quantitative characteristics of aggregates but can not guarantee whether they still do not cause the reaction. Chemical tests and expansion tests provide so- called potential response (non-reactive, reactive and potentially reactive aggregates), but even they have their errors and can not be taken as a 100% indicator of the presence of alkali-silica reaction of aggregates. The thesis describes the general characteristics of alkali-silica reaction of aggregates, the mechanisms and the factors influencing its formation. It describes the fraction of the concrete in which some volcanic rocks have been used, and which are in some works identified as potentially reactive by the alkali-silica...
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