Title:
Effect of Fly Ash in Concrete on the Corrosion of Steel Reinforcement
Author(s):
C. Andrade
Publication:
Symposium Paper
Volume:
91
Issue:
Appears on pages(s):
609-620
Keywords:
calcium; concretes; corrosion; corrosion tests; fly ash;
mortars (material); reinforcing steels; sulfates.
DOI:
10.14359/10090
Date:
2/1/1986
Abstract:
The substitution in the concrete fabricated with ordinary portland cement by blended materials may affect the excellent protective properties of the concrete vis-a-vis the steel reinforcements. Although the blended materials produce the favourable effect of increasing the concrete impermeability and density, they decrease the alkalinity. In the present paper, the results of the addition in the mix of two ashes (with low and high calcium and sulfate content) to mortars and concrete, are presented. In order to evaluate the possible corrosion, the Polarization Resistance and the Impedance as techniques of measurement, have been used. The specimens were held about two months in a chamber with 90-100 % of relative humidity. The results show that the protective properties of the concrete vis-a-vis the steel bars are not altered by the blended materials, while may induce localized corrosion. in mortars some proportion of them