Rheological properties and microstructure of binary waste red brick powder/metakaolin geopolymer

By P. Rovnaník, P. Rovnaníková, M. Vyšvařil, S. Grzeszczyk, E. Janowska-Renkas. Construction and Building Materials, 2018

156 citations recorded by the source corpus.

Abstract Waste brick powder is a material with sufficient pozzolanic properties to be used as a supplementary cementing material in Portland cement-based concrete or as a precursor for the production of geopolymers. This study aimed to investigate a binary geopolymer system composed of metakaolin (MK), waste red brick (WRB) powder and sodium silicate solution as an alkaline activator. Five different mixtures were prepared where 0, 25, 50, 75, and 100% of the MK was substituted with WRB. The rheological parameters of the fresh pastes were correlated with a structural evaluation of the reaction process. The findings showed that the yield stress of all mixtures was very low, but it increased with time as the geopolymerization reaction proceeded. The more MK was used in the mixture, the faster the yield stress developed. On the other hand, the plastic viscosity strongly depended on the composition of the mixtures and dropped with increasing WRB/MK ratio. The mixtures containing more than 50% MK exhibited a decrease in viscosity with time due to higher reactivity and the faster dissolution of the MK particles.

Subfields: Building and Construction, Civil and Structural Engineering

View Paper: https://www.semanticscholar.org/paper/5b7e032f7201aae0b47fb6222d1afb88b74a9ceb