Setting, Strength, and Autogenous Shrinkage of Alkali-Activated Fly Ash and Slag Pastes

Setting, Strength, and Autogenous Shrinkage of Alkali-Activated Fly Ash and Slag Pastes: Effect of Slag Content

Nedeljković, Marija (TU Delft Materials and Environment)
Li, Z. (TU Delft Materials and Environment)
Ye, G. (TU Delft Materials and Environment)

2018

The engineering properties of alkali activated materials (AAMs) mainly depend on the constituent materials and their mixture proportions. Despite many studies on the characterization of AAMs, guidelines for mixture design of AAMs and their applications in engineering practice are not available. Extensive experimental studies are still necessary for the investigation of the role of different constituents on the properties of AAMs. This paper focuses on the development of alkali-activated fly ash (FA) and ground granulated blast furnace slag (GBFS) paste mixtures in order to determine their suitability for making concretes. In particular, the influence of the GBFS/FA ratio and liquid-to-binder (l/b) ratio on the slump, setting, strength, and autogenous shrinkage of the alkali activated pastes is studied.It is shown that fresh properties largely depend on the type of precursor (GBFS or FA). The slump and setting time of GBFS-rich pastes was significantly reduced. These pastes also have higher compressive strength than FA-rich pastes. The study identifies important practical challenges for application of the studied mixtures, such as the behavior of their flexural strength and high amplitudes of autogenous shrinkage of GBFS-rich mixtures. Finally, the optimum GBFS/FA ratio for their future use in concretes is recommended.

alkali-activated pastes
slag content
workability
setting
compressive and flexural strength
autogenous shrinkage

http://resolver.tudelft.nl/uuid:7c64d8c5-6b37-47ac-8f78-39ff36446d37

https://doi.org/10.3390/ma11112121

1996-1944

Materials, 11 (11)

Institutional Repository

journal article

© 2018 Marija Nedeljković, Z. Li, G. Ye