A Petrological and Mineralogical Consideration on Unusual Cracking
of Concrete Structures
By A. Maru
Concrete Journal, Vol.42, No.12, Dec. 2004
- Synopsis
- The unusual cracking of concrete is mostly attributable to related to the materials such as the aggregate and cement used in concrete, and cracking caused by the alkali-aggregate reaction is one of the typical examples. A petrological and mineralogical survey was conducted on specimens from various concrete structures throughout the country. The results indicated that the unusual cracking of concrete might be influenced to the abnormal cement reaction by insufficient curing and the elution of some constituents of aggregate. The conventional theory, which ascribes unusual cracking to the alkali-aggregate reaction, is inapplicable to the many caces. Gel generation has also been considered to cause cracking by the alkali-aggregate reaction. However, this paper reports that gel generation is not directly involved in concrete swelling and suggests that the need to review the mechanism of unusual concrete cracking, including the alkali-aggregate reaction.
- Keywords:
- unusual cracking, alkali-aggregate reaction, abnormal reaction of cement, elution of some constituents of aggregate, curing
