Report on the Investigation of ASR Damaged Concrete Structures Influenced by Deicing Salt
By M.Noda,T.Ogawa,W.Koyanagi and M.Kawamura
Concrete Journal,Vol.36,No.9,Sept.1998
- Synopsis
- The investigations were carried out for the 40 bridges in which cracks were found on concrete members influenced by deicing salt. The items in the survey and examinations were compression test,static modulus of elasticity,test,accelerated expansion test,analysis of substances exuded from expanded cores,rock classification of concrete aggregate,classification of minerals of the rocks by the use of the polarized microscope and powder diffraction analysis by x-ray,on cores extracted fromthe concrete structures. The content of chloride ion and alkalis was measured to detect influenses of NaCl as a deicing salt on the ASR damages. The results of investigations have made clear that most cracks were due to ASR caused by some aggragates. However,the reactivity of the aggregates in the concretes were found to be low from the results of accelerated expansion test and the quality of alkali in the concretes. It may be possible that the ASR damades in concrete were accelerated by the deicing salt and other causes.
- Keywords:
- deicing salt,NaCl,bridge,chloride ion,ASR,potential of reaction
