Acoustic emission study of heat-induced cracking in fly ash-based alkali-activated pastes and lightweight mortars
- Alkali-activated fly ashes have been proposed for various applications where resistance against high temperatures is required, yet several details regarding the response of these materials to heat-exposure need to be clarified. In the present study, heat-induced cracking in fly ash-based alkali-activated pastes and lightweight mortars was analyzed by in-situ acoustic emission (AE) detection during complete heating-cooling cycles (up to ∼1100 °C), augmented by thermogravimetry and ex-situ SEM and XRD analyses. The applicability of the lightweight mortars as passive fire protection coatings was assessed by recording temperature-time curves of mortar-coated steel plates. Cracking during heating was limited and associated exclusively with the dehydration of the materials in the temperature range ∼90–360 °C. However, samples heated to temperatures above ∼600 °C exhibited intense cracking on cooling. This was attributed to differential deformations caused by local sintering and partialAlkali-activated fly ashes have been proposed for various applications where resistance against high temperatures is required, yet several details regarding the response of these materials to heat-exposure need to be clarified. In the present study, heat-induced cracking in fly ash-based alkali-activated pastes and lightweight mortars was analyzed by in-situ acoustic emission (AE) detection during complete heating-cooling cycles (up to ∼1100 °C), augmented by thermogravimetry and ex-situ SEM and XRD analyses. The applicability of the lightweight mortars as passive fire protection coatings was assessed by recording temperature-time curves of mortar-coated steel plates. Cracking during heating was limited and associated exclusively with the dehydration of the materials in the temperature range ∼90–360 °C. However, samples heated to temperatures above ∼600 °C exhibited intense cracking on cooling. This was attributed to differential deformations caused by local sintering and partial melting at the glass transition temperature, and subsequent quenching on cooling.…
Autor*innen: | L. Carabba, Stephan PirskawetzORCiD, Simone KrügerORCiD, Gregor GluthORCiD, M.C. Bignozzi |
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Dokumenttyp: | Zeitschriftenartikel |
Veröffentlichungsform: | Verlagsliteratur |
Sprache: | Englisch |
Titel des übergeordneten Werkes (Englisch): | Cement and Concrete Composites |
Jahr der Erstveröffentlichung: | 2019 |
Organisationseinheit der BAM: | 7 Bauwerkssicherheit |
7 Bauwerkssicherheit / 7.1 Baustoffe | |
7 Bauwerkssicherheit / 7.4 Baustofftechnologie | |
7 Bauwerkssicherheit / 7.5 Technische Eigenschaften von Polymerwerkstoffen | |
Verlag: | Elsevier |
Jahrgang/Band: | 102 |
Erste Seite: | 145 |
Letzte Seite: | 156 |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurbau |
Freie Schlagwörter: | Acoustic emission; Alkali-activated materials; Cracking; Fire proofing; Heat resistance |
Themenfelder/Aktivitätsfelder der BAM: | Infrastruktur |
Infrastruktur / Fire Science | |
DOI: | 10.1016/j.cemconcomp.2019.04.013 |
ISSN: | 0958-9465 |
ISSN: | 1873-393X |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 08.05.2019 |
Referierte Publikation: | Ja |
Datum der Eintragung als referierte Publikation: | 04.07.2019 |