Abstract
The rapid workability loss of alkali-activated materials (AAM) has been a major obstacle limiting its onsite application. In this study, two conventional SPs (made of polynaphthalene sulfonate (PNS) and lignosulfonate (LS) salts), which have been reported to be effective in some specific AAM mixtures were separately applied in alkali-activated slag (AAS) concretes. A comprehensive testing program was performed to study their effect on reaction kinetics, rheology evolution, and strength development. Results showed sodium silicate-activated AAS mixtures exhibited lower yield stress than those activated by sodium hydroxide. In hydroxide media, PNS and LS remained effective to reduce yield stress and increase slump value, while they both failed to improve the rheological behavior of AAS activated by silicate. Moreover, the inclusion of 2% admixtures did not result in much strength reduction in both activators although LS showed a retardation effect and subsequent increase in the setting time in the fresh state.
| Original language | English |
|---|---|
| Pages (from-to) | 233-245 |
| Number of pages | 13 |
| Journal | ACI Materials Journal |
| Volume | 119 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2022 |
Bibliographical note
Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-careOtherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
Keywords
- Alkali-activated slag concrete
- Reaction kinetics
- Rheology
- Strength development
- Superplasticizer