CAUSE OF SULPHATE ATTACK ON CONCRETE, RENDER AND STONE INDICATED BY SULPHUR ISOTOPE RATIOS

This article describes work that investigates a method to determine whether sulphate impurities in rock salt used for winter maintenance of the roads could be responsible for higher than expected sulphate levels that have been observed in parts of some road bridges in cambridgeshire. Delta 34 sulphur isotope values were determined for 44 samples of concrete, de-icing salt and other sulphate bearing materials found in association with degraded concrete from a number of known environments. All of the samples were oven dried at 80 degrees c for 24 hours, ground to pass a 0.1 mm sieve and boiled in 10% (v/v) hydrochloric acid for 20 minutes to extract the sulphate. After filtering, the acid-soluble sulphate was precipitated by the addition of 5% (w/v) barium chloride solution. The resulting barium sulphate precipitates were then washed with de-ionized water and dried at 80 degrees c. The 34s/32s ratios were then determined by mass spectrometry performed on the sulphur dioxide obtained by heating the barium sulphate to about 1400 degrees c. These results indicate that deicing salt could not have contributed significantly to the elevated sulphate levels in the cambridgeshire bridges.

• Corporate Authors:

  MacMillan Magazines Limited

  4 Little Essex Street
  London,   England 
• Authors:
  • Pye, K
  • Schiavon, N
• Publication Date: 1989-12-7

Language

• English

Media Info

• Pagination: p. 663-664
• Serial:
  • Nature
  • Volume: 343
  • Issue Number: 6250
  • Publisher: MacMillan Journals Limited

Subject/Index Terms

• TRT Terms: Bridges; Chemical analysis; Concrete; Deicing chemicals; Deterioration; Mass spectrometry; Measurement; Spectrometers; Sulfates
• Geographic Terms: United Kingdom
• Subject Areas: Bridges and other structures;

Filing Info

• Accession Number: 00498853
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Sep 30 1990 12:00AM