Rate controls on silicate dissolution in cementitious environments

  • Tandre Oey
  • Yi-Hsuan Hsiao
  • Erika Callagon
  • Bu Wang
  • Isabella Pignatelli
  • Mathieu Bauchy
  • Gaurav N. Sant Department of Civil and Environmental Engineering, University of California

Abstract

The dissolution rate of silicate minerals and glasses in alkaline environments is of importance in cementitious systems due to its influences on: (a) early-age reactivity that affects the rate of strength gain and microstructure formation, and/or, (b) chemical durability of aggregates; compromises in which can result deleterious processes such as alkali-silica reaction (ASR). In spite of decades of study, quantitative linkages between the atomic structure of silicates and their dissolution rate in aqueous media (i.e., chemical reactivity) has remained elusive. Recently, via pioneering applications of molecular dynamics simulations and nanoscale-resolved measurements of dissolution rates using vertical scanning interferometry, a quantitative basis has been established to link silicate dissolution rates to the topology (rigidity) of their atomic networks. Specifically, an Arrhenius-like expression is noted to capture the dependence between silicate dissolution rates and the average number of constraints placed on a central atom in a network (nc, i.e., an indicator of the network’s rigidity). This finding is demonstrated by: (i) ordering fly ashes spanning Ca-rich/poor variants in terms of their reactivity, and, (ii) assessing alterations in the reactivity of albite, and quartz following irradiation due to their potential to induce ASR in concrete exposed to radiation, e.g., in nuclear power plants.       

Author Biography

Gaurav N. Sant, Department of Civil and Environmental Engineering, University of California

Associate Professor and Henry Samueli Fellow
Civil and Environmental Engineering

Published
2017-12-30
How to Cite
OEY, Tandre et al. Rate controls on silicate dissolution in cementitious environments. RILEM Technical Letters, [S.l.], v. 2, p. 67-73, dec. 2017. ISSN 2518-0231. Available at: <https://letters.rilem.net/index.php/rilem/article/view/35>. Date accessed: 16 nov. 2018. doi: https://doi.org/10.21809/rilemtechlett.2017.35.
Section
Articles