EFFECT OF ALKALI INGRESS AND BINDER COMPOSITION ON DAMAGING ASR

The effects of cement replacement by fly ash and the effect of alkali content of Portland cement and fly ash on damaging ASR in concrete due to ingress of deicing salt has been investigated using greywacke as reactive aggregate. Concrete specimens were subjected to cyclic storage scheme using moist and dry conditions as well as temperatures of 20 and 60°C and exposure to 10 wt.% NaCl solution. Exposure to salt resulted in a high degree of expansion and damage. Cement replacement by 30 wt.% fly ash reduced the damage by as much as a factor of 10. Investigations of pore structure, phase and pore solution composition indicate that, besides the densification of the pore structure due to fly ash, ASR due to external alkalis is affected by the alkali content of both cement and fly ash and the aluminium content of fly ash.     «

The effects of cement replacement by fly ash and the effect of alkali content of Portland cement and fly ash on damaging ASR in concrete due to ingress of deicing salt has been investigated using greywacke as reactive aggregate. Concrete specimens were subjected to cyclic storage scheme using moist and dry conditions as well as temperatures of 20 and 60°C and exposure to 10 wt.% NaCl solution. Exposure to salt resulted in a high degree of expansion and damage. Cement replacement by 30 wt.% fly a...     »