Issue 50

A.G. Lekatou et alii, Frattura ed Integrità Strutturale, 50 (2019) 423-437; DOI: 10.3221/IGF-ESIS.50.36

Figure 5 : SEM cross-sectional micrographs of 304L rebar after cyclic polarization in acidic electrolyte containing Ca(OH) 2 , acid rain simulating solution and (a)-(d) 20 wt.% fly ash, (e) 25 wt.% fly ash (wt.%: with respect to (Ca(OH) 2 + fly ash) ), showing the deposition of films on the steel surface; (b) representative EDX point analysis from the steel surface film in (a); (d): EDX elemental mapping of (c); (f) & (g): EDX mapping for Ca and Si, respectively. Some comments on the role of fly ash Although the acid rain simulating environment in this effort does not quite correspond to the actual rain kinetics through reinforced concrete, the findings have given a sound evidence of the effect of fly ash on the electrochemical behavior of the reinforcement under the attack of AR to the rebar. Two different cases have been investigated: (a) in the first case, Ca(OH) 2 could not act as an acid buffer due to its low volume in the acid rain mimicking solution. In this case, fly ash acted as the

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