Changes of pore solution composition under accelerated mortar bar and concrete prism test conditions
- Accelerated tests of mortar bars and concrete prism were carried out at temperatures ≥ 40°C in order to reduce the test duration. Because the OH-/SO42- equilibrium is shifted to lower values with increasing temperature and alkali content of the cement, there exists the possibility of side reactions between sulphate ions from the cement and aluminate ions which can come from mineral admixtures and aggregates. Solubility measurements of two types of aggregates in sulphate free KOH solutions indicate that the temperature effect on the silica releasing rate is bigger than the inhibiting effect of the decreasing OH- concentration. To avoid side reactions during aggregate test procedure, expansion measurements should be performed at 40°C in combination with adapted solubility measurements.
Author: | Klaus-Jürgen HüngerGND, Cornelia Hübert, Yvonne Scholz, Jens Kronemann |
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URL: | https://www-docs.b-tu.de/fg-baustoffe/public/050_021811-HUNG.pdf |
Title of the source (English): | ICAAR, 14th International Conference on Alkali Aggregate Reaction, May 20-25, 2012, Austin, TX |
Document Type: | Conference Proceeding |
Language: | English |
Year of publication: | 2012 |
Tag: | mineral admixture; pore solution; solubility of aggregates; temperature |
Number of pages: | 10 |
Faculty/Chair: | Fakultät 6 Architektur, Bauingenieurwesen und Stadtplanung / FG Baustoffe und Bauchemie |