The main goal of the master’s thesis was to investigate the influence of alkaline carbonate reaction on the process of self-repairing materials with a cement binder. The used mixture was composed of portland cement and dolomite in the role of aggregate and stone filler. Samples were exposed to accelerated testing conditions simulated by 1M NaOH at 60 °C or deionized water at 60 °C. During the ageing process, microstructure characteristics of the samples after various ageing periodes were investigated by means of electron microscopy. In addition, mechanical examinations of the samples were conducted to verify the effect of self-repairing in samples.
It was shown that the alkaline carbonate reaction effects the mechanical properties of the aged samples. Namely, secondary calcite and phases that include so-called »new phases« enriched with Mg, Al and Si are precipitated within pre-existing cracks. Over a period of one year, we observed that small cracks were completely filled. In the case of larger cracks, the width was effectively reduced.
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