PSI - Issue 11

Gibson R. Meira et al. / Procedia Structural Integrity 11 (2018) 122–129

128

7

Author nam

e / Structural Inte

grity Procedia 0

0 (2018) 000–00 00

A the c time A solut corro corro the g 4. A T initia and was corro F cem corro F the l crite curre throu

s well as the orrosion rate . s the pH bec ion, non-gal sion current sion. On the alvanized bar nalysis of res hrough the el l behaviour. the corrosion generated on sion current or galvanized entitious mat sion potentia igure 9 easily ast five meas ria proposed b nt density is gh electroche

open-circuit for the spec omes more vanized steel density drop other hand, t s. ults ectrochemica This means t current densi these bars density, signi bars, the r rices with hi l (CSE) and a demonstrates urements of y Alonso an widely used i mical metho

corrosion pot imens at earl alkaline with bars exhibi to values b he increase o

ential, corros y ages. In ad the addition t improved c etween 0.1 a f the pH of th

ion current d dition, the cu of potassium orrosion per nd 0.25 μA/c e liquid phas

ensity shows, rrent density hydroxide t formance. Th m², indicatin e causes an in

over time, a readings tend o saturated c is can be s g low or neg crease in the

slight decrea to stabilize alcium hydro een thorough ligible degre corrosion rat

se in over xide the e of e for

l monitoring, hat the corro ty assumed i in alkaline s ficantly reduc esults of ele gh pH. The n increase in this behavio the corrosion d Andrade (19 n the technica ds.

it was possib sion potential nitial values s olution, whic ing the degre ctrochemical increase in p corrosion cur ur. It shows t current dens 90) are also l-scientific en

le to observ s of the bars lightly highe h increased e of corrosion monitoring H had an ef rent density v he average co ity as a func shown. The c vironment to

e that the car assumed init r. However, a their corrosi . show the su fect on more alues, especia rrosion rate c tion of pH o orrosion rate estimate and

bon-steel bar ial values mo s time passed on potentials sceptibility o electronegat lly in medium alculated from f the solution estimated thro evaluate the c

s had very si re electroneg , the passive and reduced f the materi ive values o with pH = 1 Equation 1 s. The evalu ugh the corro orrosion inte

milar ative film the al to f the 3.5. with ation sion nsity

Fig. 9. Relation ), Eq is the density, in μA that the incr they have n media, an his shows th

ship between pH 3,27. gram equiva /cm², and d i ease of alkali egligible corr opposite be at, probably,

of the cement m ���� lent of the m s the metal de nity media is osion rates fo haviour occ passive film

atrix and corrosi

on rate for the typ

es of bars used.

Equation (1 sion current igure 9 shows tures, that is, ly alkalinity roximately). T

(1)

etal species nsity, in g/cm beneficial to r pH above 1 urs, showin is not efficie

involved in c ³. carbon-steel b 3.1 (approxim g active cor ntly formed o

orrosion, in ars used in r ately). For g rosion for n the surface

grams; I corr i einforced con alvanized ba pHs above of the galvan

s the crete rs in 13.2 ized

In corro F struc high (app