Using MgO activated slag and calcium bentonite slurry to produce a novel vertical barrier material: Performances and mechanisms

Xiao Huang, Jiang shan Li, Ming zhi Guo, Qiang Xue, Yan jun Du, Yong Wan, Lei Liu, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

1 Citation (Scopus)

Abstract

Slag-cement–bentonite (SCB) slurry has been widely used for the construction of vertical cutoff walls to restrain the movement of groundwater at contaminated sites. However, the conventional cement-based slurry needs a long time to evolve satisfactory performance along with a relatively high environmental load. This paper proposes an innovative material for the self-hardening slurry system, consisting of reactive MgO, slag, bentonite and lots of water. The properties of fresh slurry, unconfined compressive strength (UCS) and permeability of the MgO activated slag and bentonite (MASB) slurry are investigated in comparison with SCB slurry. The results indicate that compared with SCB slurry, MASB slurry with appropriate proportions has comparative fresh properties, but possesses higher UCS and much lower hydraulic conductivity (close to 1.0 × 10−10 m/s) at a later age. A massive formation of expansive hydration products (hydrotalcite phases) could satisfactorily fill in the voids of matrix, leading to a dense microstructure which is responsible for the excellent mechanical and penetrative performance of MASB slurry. The overall findings from this study well demonstrate that the developed MASB slurry holds great potential as a novel, eco-friendly and cost-effective material in the construction of vertical cutoff walls.

Original languageEnglish
Article number123365
JournalConstruction and Building Materials
Volume291
DOIs
Publication statusPublished - 12 Jul 2021

Keywords

  • Cutoff wall
  • Ground granulated blast furnace slag
  • MgO
  • Permeability
  • Unconfined compressive strength

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Materials Science(all)

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