Retention of strontium in high- & low-pH cementitious matrices – OPC vs. model systems

Matan E. Shiner, Ofra Klein-BenDavid, Emilie L'Hôpital, Alexandre Dauzères, Mejdi Neji, Nadya Teutsch, Alva Peled, Gabriela Bar-Nes

Research output: Contribution to journalArticlepeer-review


Strontium can be found in low/intermediate level radioactive waste streams, often solidified by Ordinary Portland Cement (OPC) matrices. Amorphous silica is added to improve wasteform performance, leading to low-pH systems. Our aim is to identify the phases controlling strontium immobilization in OPC matrices. The novelty of this work resides in combination between two approaches: 1) Comparing OPC systems to model systems based on alite, yielding matrices containing only major phases, emphasizing the relative role of minor phases; 2) Comparing high- & low-pH pastes. Pastes were characterized using calorimetry, XRD, DTG, SEM/EDS and porosimetry. Leaching experiments were conducted to study Sr retention and diffusivity. Strontium diffusivities in low-pH pastes are lower with respect to high-pH equivalents, despite their higher porosities, due to preferred Sr sorption to low Ca/Si C-S-H. OPC pastes show better Sr retention relative to model systems, suggesting that minor phases (like ettringite and AFm) improve Sr retention.

Original languageEnglish
Article number106659
JournalCement and Concrete Research
StatePublished - Feb 2022
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2021 Elsevier Ltd


  • CS
  • Leaching
  • Low-pH cement
  • Portland cement
  • Radioactive waste
  • Strontium immobilization

ASJC Scopus subject areas

  • Building and Construction
  • General Materials Science


Dive into the research topics of 'Retention of strontium in high- & low-pH cementitious matrices – OPC vs. model systems'. Together they form a unique fingerprint.

Cite this