RESPONDING TO THAUMASITE FORM OF SULPHATE ATTACK

This paper reviews some of the ground engineering aspects of the Thaumasite Expert Group's (TEG's) recent report on the thaumasite form of sulphate attack (TSA). In particular, it describes the ground conditions contributing to the occurrence of the thaumasite form of attack on some bridges on the M5 motorway in England, and reviews the procedures recommended by the TEG to cater for such conditions in new construction. Research shows that TSA may occur in buried concrete if five conditions are simultaneously present. The bridge foundations affected by TSA were on the Gloucestershire section of the M5, and were built around 1970. They were either constructed in excavations in the Lower Lias Clay which were than backfilled with the same clay, or they passed through embankments consisting of the clay. Three specific causes contributing to TSA occurrence were identified. Previous guidance documents for concrete design, such as Digest 363 and British Standard BS 5328, have ignored the potential for sulphate concentration to be increased as a result of oxidation due to disturbance. The report of the TEG recommends that, if buried concrete is likely to be exposed to disturbed sulphide-bearing ground, a specific formula be used to calculate the potential sulphate concentration in the disturbed ground.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00174653
• Corporate Authors:

  EMAP CONSTRUCT LIMITED

  151 ROSEBERY AVENUE
  LONDON,   United Kingdom  EC1R 4QX
• Authors:
  • LONGWORTH, I
• Publication Date: 1999-4

Language

• English

Media Info

• Features: References;
• Pagination: p. 24-5
• Serial:
  • GROUND ENGINEERING
  • Publisher: EMAP CONSTRUCT LIMITED
  • ISSN: 0017-4653

Subject/Index Terms

• TRT Terms: Bridges; Chemical analysis; Clay; Concrete; Corrosion; Design; Embankments; Evaluation and assessment; Excavation; Excavations; Foundations; Freeways; Methodology; Prevention; Standards; Sulfates; Teams; Workshops
• Geographic Terms: United Kingdom
• ITRD Terms: 3455: Bridge; 7163: Chemical analysis; 4177: Clay; 4755: Concrete; 5252: Corrosion; 9011: Design (overall design); 2801: Embankment; 9020: Evaluation (assessment); 5155: Excavation (process); 3377: Foundation; 9102: Method; 2752: Motorway; 9149: Prevention; 187: Specification (standard); 7310: Sulphate; 8119: United Kingdom; 9090: Working group
• Subject Areas: Bridges and other structures; Design; Highways; Security and Emergencies;

Filing Info

• Accession Number: 00767114
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Aug 6 1999 12:00AM