Effects of Wetting and Drying Cycles on Thaumasite Formation in Cement Mortars

As part of a study into the controls on the deterioration of concrete due to sulfate attack, mortars (50-mm cubes and 40 × 40 × 160  mm prisms) made with portland cement CEMI, and 90% CEMI + 10% limestone blend were exposed to BRE DS4 sulfate solution based on magnesium sulfate (MgSO₄  •  7H₂O) under wetting and drying cycles for 18 months at 5°C. The effect of these cycles on thaumasite formation was studied and compared with samples immersed continuously in the same solutions. Visual observations and mass and length changes were used to assess the mortar deterioration, along with X-ray diffraction and infrared spectroscopy, which were used to determine the mineralogy of deterioration products. It was found that at 5°C, wetting and drying cycles significantly delayed thaumasite formation compared with control specimens.

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  • English

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  • Accession Number: 01531267
  • Record Type: Publication
  • Files: TRIS, ASCE
  • Created Date: Jul 11 2014 3:01PM