Concrete alteration due to 55 years of exposure to river water: Chemical and mineralogical characterisation

Research output: Contribution to journalArticle

Abstract

This article presents a study on concrete alteration mechanisms due to 55 years of exposure to river water. Many hydro power structures in cold regions suffer from concrete deterioration at the waterline. Progressive disintegration of the concrete surface leads to exposure of the coarse aggregate and eventually the reinforcing steel. Concrete cylinders drilled out at four vertically different locations on the upstream face of a concrete dam were analysed by electron microprobe analysis, X-ray diffraction, thermogravimetry and scanning electron microscopy. Long-term exposure to the river water, which is regarded as soft water, has led to chemical and mineralogical zonation of the cement paste. Up to five zones with different chemical and mineralogical composition, parallel to the upstream face, were observed in the outermost 8–9 mm of the concrete. Decalcification, precipitation of secondary ettringite and the formation of a magnesium-rich silica gel constitute the major changes that define the zones.

Details

Authors
Organisations
External organisations
  • University of Toulouse
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Materials Engineering

Keywords

  • Characterisation [B], Concrete [E], EPMA, Long-term performance [C], Portland cement [D]
Original languageEnglish
Pages (from-to)110-120
Number of pages11
JournalCement and Concrete Research
Volume92
Publication statusPublished - 2017 Feb 1
Publication categoryResearch
Peer-reviewedYes