Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Alkalis Released from Aggregates – Significance for Concrete Performance Testing
The key question for “ASR performance testing” when subjecting aggregates containing alkalis - and during service life possibly releasing alkalis (“ARA aggregates”) - is whether such properties will be accounted for during the performance testing. Further, how should test results from a testing method assessing the potential alkali contribution from an aggregate (e.g. RILEM AAR-8) be interpreted in context of performance testing and in lab/field relation of such tests?
To investigate this, an attempt is made to detect the alkali release as well as the change of expansion when subjecting ARA aggregates to RILEM AAR-10 testing (and AAR-8). The “ARA-proof-of-concept” in concrete expansion testing is demonstrated (preliminary results) in the present study by including “non-ASR-reactive” alkali releasing fine aggregate to a medium reactive concrete mix design. Further, because the alkali release expectedly is more pronounced in the fine fraction including filler, the attempt is made to explicitly address the effect of filler content and properties on the release.
The testing methods used in the study include RILEM AAR-10, RILEM AAR-8 (on “bulk” 0/4 mm and – modified – on individual fractions with and without filler) and high-pressure pore water extraction. The background context, program outline and preliminary results are presented.
The preliminary results support the hypothesis that a significant part of “ARA” is accounted for during the concrete prism testing, but this should be validated also for other aggregates. The work is still ongoing, and studies on granulometric effects are also in progress.
Alkalis Released from Aggregates – Significance for Concrete Performance Testing
The key question for “ASR performance testing” when subjecting aggregates containing alkalis - and during service life possibly releasing alkalis (“ARA aggregates”) - is whether such properties will be accounted for during the performance testing. Further, how should test results from a testing method assessing the potential alkali contribution from an aggregate (e.g. RILEM AAR-8) be interpreted in context of performance testing and in lab/field relation of such tests?
To investigate this, an attempt is made to detect the alkali release as well as the change of expansion when subjecting ARA aggregates to RILEM AAR-10 testing (and AAR-8). The “ARA-proof-of-concept” in concrete expansion testing is demonstrated (preliminary results) in the present study by including “non-ASR-reactive” alkali releasing fine aggregate to a medium reactive concrete mix design. Further, because the alkali release expectedly is more pronounced in the fine fraction including filler, the attempt is made to explicitly address the effect of filler content and properties on the release.
The testing methods used in the study include RILEM AAR-10, RILEM AAR-8 (on “bulk” 0/4 mm and – modified – on individual fractions with and without filler) and high-pressure pore water extraction. The background context, program outline and preliminary results are presented.
The preliminary results support the hypothesis that a significant part of “ARA” is accounted for during the concrete prism testing, but this should be validated also for other aggregates. The work is still ongoing, and studies on granulometric effects are also in progress.
Alkalis Released from Aggregates – Significance for Concrete Performance Testing
RILEM Bookseries
Sanchez, Leandro F.M. (Herausgeber:in) / Trottier, Cassandra (Herausgeber:in) / Rønning, T. F. (Autor:in) / Lindgård, J. (Autor:in) / Bagheri, M. (Autor:in) / Wigum, B. J. (Autor:in) / Danner, T. (Autor:in) / de Weerdt, K. (Autor:in) / Haugen, M. (Autor:in) / Pedersen, B. M. (Autor:in)
International Conference on Alkali-Aggregate Reaction in Concrete ; 2024 ; Ottawa, ON, Canada
Proceedings of the 17th International Conference on Alkali-Aggregate Reaction in Concrete ; Kapitel: 42 ; 361-369
RILEM Bookseries ; 49
04.05.2024
9 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
Methods for Extracting Alkalis from Spanish Aggregates
| Springer Verlag | 2024
Potential reactivity to alkalis of Portuguese volcanic aggregates for concrete
| BASE | 2014
| Springer Verlag | 2025
SIGNIFICANCE OF AGGREGATES IN CONCRETE, ADVANTAGES OF ARTIFICIAL AGGREGATES FOR CONCRETE
| BASE | 2023
Analysis of interaction of silica and alkalis in concrete
| TIBKAT | 1992