Damaging ASR in Fly Ash Concrete Exposed to NaCl - Concrete with Borosilicate Glass and Greywacke

The application of de-icing salts is an essential factor for the increase in damage due to the alkali silica reaction (ASR) observed in German concrete pavement in the last two decades. Earlier tests on pure Portland cement concretes performed at high temperatures have indicated that NaCl can accelerate ASR in concrete. In contrast, this work focusses on the effect of NaCl on fly ash concrete at a temperature near service conditions with regard to ASR. Concrete prisms with different binder compositions and alkali reactive aggregates were stored for one year in a synthetic pore solution with and without NaCl. After this period, only concretes with synthetic borosilicate glass showed indications of an ASR. The results indicate that the external application of NaCl increases the damage in concrete caused by ASR and, as opposed to this, the replacement of cement by fly ash leads to a higher resistance to this damaging mechanism. However, the reliable transfer of the present results with borosilicate glass to concrete with greywacke requires results after a longer storage period.     «

The application of de-icing salts is an essential factor for the increase in damage due to the alkali silica reaction (ASR) observed in German concrete pavement in the last two decades. Earlier tests on pure Portland cement concretes performed at high temperatures have indicated that NaCl can accelerate ASR in concrete. In contrast, this work focusses on the effect of NaCl on fly ash concrete at a temperature near service conditions with regard to ASR. Concrete prisms with different binder compo...     »