Challenges of the African environmental conditions for concrete mixture composition
- Concrete technology was exposed to a rapid development during the last three decades. For the longest time in its history, concrete was considered as a three component System consisting of aggregates, which are bound by the hardened cement paste consisting of hydrated cement. Traditionally, the only way of adjusting the consistency of concrete was using well adjusted aggregates and grading curves and adding excess water to the concrete, accepting that the latter in return reduces strength and durability. During the last three decades, however, concrete has developed further from a three component System towards an (at least) five component system, since the use of mineral additions and Chemical admixtures has become state of the art. Both components are able to enhance the workability, the compactability, and the density of the microstructure with effects on strength, ductility and durability, while cement can be saved in parallel. Due to reasonable use of admixtures and additions,Concrete technology was exposed to a rapid development during the last three decades. For the longest time in its history, concrete was considered as a three component System consisting of aggregates, which are bound by the hardened cement paste consisting of hydrated cement. Traditionally, the only way of adjusting the consistency of concrete was using well adjusted aggregates and grading curves and adding excess water to the concrete, accepting that the latter in return reduces strength and durability. During the last three decades, however, concrete has developed further from a three component System towards an (at least) five component system, since the use of mineral additions and Chemical admixtures has become state of the art. Both components are able to enhance the workability, the compactability, and the density of the microstructure with effects on strength, ductility and durability, while cement can be saved in parallel. Due to reasonable use of admixtures and additions, concrete can be designed to match mechanically high performance specifications. Traditionally, cement paste was considered the weakest component in concrete. Flowever, in modern concrete a good paste composition can yield highest performance, passing the role of the mechanical bottleneck towards the aggregates.…
Autor*innen: | Wolfram SchmidtORCiD |
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Dokumenttyp: | Beitrag zu einem Tagungsband |
Veröffentlichungsform: | Eigenverlag BAM |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Workshop cement and concrete for Africa (Proceedings) |
Jahr der Erstveröffentlichung: | 2011 |
Verlag: | Bundesanstalt für Materialforschung und -prüfung (BAM) |
Verlagsort: | Berlin |
Erste Seite: | 37 |
Letzte Seite: | 49 |
Freie Schlagwörter: | Africa; Cement; Climatic conditions; Concrete; Mixture composition |
Veranstaltung: | Workshop cement and concrete for Africa |
Veranstaltungsort: | Berlin, Germany |
Beginndatum der Veranstaltung: | 17.08.2011 |
Enddatum der Veranstaltung: | 17.08.2011 |
ISBN: | 978-3-9814281-4-8 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 19.02.2016 |
Referierte Publikation: | Nein |