Title: Thaumasite Related Deterioration of Concrete Structures

Author(s): J. A. Bickley, R. T. Hemmings, R. D. Hooton, and J. Balinski

Publication: Symposium Paper

Volume: 144

Issue:

Appears on pages(s): 159-176

Keywords: arctic concrete; carbonation; construction; deterioration; durability; ettringite; expansion; gypsum; low temperature; specifications; sulfate attack; thaumasite; Materials Research

DOI: 10.14359/4396

Date: 3/1/1994

Abstract:
Discusses the severe deterioration of concrete that can result from an unusual form of sulfate attack, in which C-S-H and calcium hydroxide in the cement paste are converted to gypsum and thaumasite. This deleterious reaction only occurs at low temperatures in the presence of continuous moisture and where sources of sulfate and carbonate ions are available. Severe deterioration of this type occurred in concrete columns and slab-on-grade at facilities in the Canadian Arctic within 2 years of casting, to the point where some replacement was necessary. Evidence of continuing deterioration led to an extensive investigation of the structures when the concrete was 4 years old. Although it has been relatively well documented in Europe, a few cases of concrete deterioration due to thaumasite formation have been reported in North America. Currently, North American codes and standards do not include any guidance for the avoidance of this type of sulfate attack. Paper contains data that should be of interest to agencies responsible for the development of codes and standard specifications for concrete construction practices in cold areas.