Expansion of Alite Paste Caused by Gypsum Formation during Sulfate Attack

This paper introduces a study carried out to investigate sulfate attack caused by gypsum formation. The aim, specifically, was to study whether gypsum formation can be a factor leading to expansion in concrete exposed to solutions containing sulfate ions. It was found from the laboratory study that...

Full description

Saved in:
Bibliographic Details
Published in:Journal of materials in civil engineering 2000-02, Vol.12 (1), p.24-25
Main Authors: Tian, Bing, Cohen, Menashi D
Format: Article
Language:English
Subjects:
TECHNICAL PAPERS
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper introduces a study carried out to investigate sulfate attack caused by gypsum formation. The aim, specifically, was to study whether gypsum formation can be a factor leading to expansion in concrete exposed to solutions containing sulfate ions. It was found from the laboratory study that alite paste specimens (0.48 water-to-alite ratio) expanded and cracked significantly in 5% Na2SO4 solution after a "dormant" period of about 1 year. X-ray diffraction confirmed that gypsum was the main product-ettringite does not form in the system, because of the lack of aluminate. The detailed study of the mechanism for expansion and cracking is continuing. These findings confirm the long-term understanding that sulfate attack mechanism is a complicated process. A highlight of the study, therefore, reveals that expansion and cracking of portland cement concrete may not be attributed solely to ettringite formation. Gypsum formation may be a cause leading to expansion and subsequent cracking. More research is needed in this area.
ISSN:0899-1561
1943-5533
DOI:10.1061/(ASCE)0899-1561(2000)12:1(24)