Microscopic analysis for the oxidation of sulphide-bearing aggregate

J Microsc. 2022 May;286(2):74-78. doi: 10.1111/jmi.13065. Epub 2021 Nov 21.

Abstract

Mortar samples were prepared with sulphide-bearing aggregates and tested for the potential of aggregate oxidation followed by sulphate attack. Scanning Electron Microscopy and its associated Energy Dispersive X-Ray analysis were used to analyze the developed phases in the tested samples to confirm that the obtained expansion is attributable to sulphate attack. The Energy Dispersive X-Ray analysis helped identify sulphide phases in aggregates and evidence of sulphate attack in mortars. Ettringite was detected and confirmed in the mortars with sulphide-bearing aggregates suggesting that the test conditions are suitable for reproducing the damaging mechanism of sulphide oxidation.

Keywords: durability; oxidation mortar bar; scanning electron microscopy; sulphide-bearing aggregate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Microscopy, Electron, Scanning
  • Sulfates*
  • Sulfides* / analysis

Substances

  • Sulfates
  • Sulfides