Corrosion inhibitors for chlorides induced corrosion in reinforced concrete structures

Ormellese, Marco; Berra, M.; Bolzoni, F.; Pastore, Tommaso

doi:10.1016/j.cemconres.2005.11.007

Cited by 238 publications

(138 citation statements)

References 21 publications

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“…• from 1997 to 2001 commercial corrosion inhibitors (mixed-in) available on market in 1997 were tested in concrete with W/C ratio equal to 0.5 and curing time 7 days (Series A) [40]; • from 2000 to 2006 commercial corrosion inhibitors (mixed-in and migrating) available on market in 2000 were tested in concrete with an higher W/C ratio, equal to 0.6 and curing time 28 days (Series B) [41][42][43].…”

Section: Methodsmentioning

confidence: 99%

“…In presence of higher chloride content added to the mix (1.5-2.5% by cement weight) in series A concrete the performance of organic inhibitors resulted poor [40]. Calcium nitrite-based inhibitor (NIT) must be analysed separately; more literature data are available on its inhibiting action, suggesting that the corrosion inhibitor is effective if the molar ratio 2 [NO ]/ [Cl ]  is higher than 0.5-0.6 [11].…”

Section: Commercial Corrosion Inhibitors -Admixed -Chloride Induced Cmentioning

confidence: 99%

“…For comparison purposes, specimens without inhibitors were cast [41]. The same four commercial corrosion inhibitors (but available on market in 2000) were added to the concrete mixture in the recommended dosages for series B, as reported in Table 2 [40,43]. Corrosion inhibitors of these two series although nominally identical may have different chemical composition since they were bought in 1997 and 2000, respectively.…”

Section: Commercial Corrosion Inhibitorsmentioning

confidence: 99%

“…The performance of corrosion inhibitors for reinforced concrete structures has been studied at PoliLaPP, Laboratory of Corrosion of materials "P. Pedeferri" of the Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, in the last 15 years on commercial corrosion inhibitors, both mixed in (nitrite based and organic) and migrating [40][41][42][43][44] and on organic compounds, mainly amines, carboxylates and amino acids [45][46][47][48].…”

Section: Introductionmentioning

confidence: 99%

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Experiences on corrosion inhibitors for reinforced concrete

Bolzoni¹,

Brenna²,

Fumagalli³

et al. 2014

Int. J. Corros. Scale Inhib.

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Corrosion of carbon steel reinforcement is the most important cause of premature failure on reinforced concrete structures. Prevention of corrosion is primarily achieved in the design phase by using high quality concrete and adequate cover. Additional prevention methods are adopted when severe environmental conditions occur or on structures requiring very long service life. Among these methods, corrosion inhibitors seem to offer a simple and cost effective prevention technique. They may be used both as a preventative techniques, if added to fresh concrete, and as a repair system, if applied on hardened concrete.The performance of corrosion inhibitors for reinforced concrete structures affected by chloride induced and carbonation corrosion has been studied at PoliLaPP, Laboratory of Corrosion of materials "P. Pedeferri" of the Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, in the last 15 years.Organic commercial admixed corrosion inhibitors delayed the occurrence of chloride induced corrosion. This result is related to two effects: reduction of the rate of chloride transport into concrete and increase of the critical chloride threshold.Commercial migrating corrosion inhibitors (MCI) are able to delay time-to-corrosion of passive rebars in concrete subjected to chlorides ponding; this effect is mainly related to the reduction of chlorides diffusion coefficient. MCI can reduce the corrosion rate after corrosion initiation only in carbonated concrete, nevertheless efficiency is low and residual corrosion rate is not negligible.Commercial MCI can penetrate into concrete mainly through capillary sorption but penetration depth is limited to 20 mm.The results obtained with nitrite-based inhibitor confirm literature data: the inhibitor is effective if the molar ratio is higher than 0.5-0.6; in carbonated concrete, due to insufficient amount of inhibitor, no significant effect has been observed on corrosion rate.Among the tested organic substances, compounds containing carboxylic group showed the best results solution tests: pitting potential, time-to-corrosion and critical chloride content are similar to those obtained with sodium nitrite. In concrete tests, only one amine and one amino acid showed good performance increasing the critical chlorides Int. J. Corros. Scale Inhib., 2014, 3, no. 4, 254-278 255 threshold with respect to the reference condition. For carboxylate substances, a strong link was found between inhibiting properties and molecular structure.

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Section: Methodsmentioning

confidence: 99%

Section: Commercial Corrosion Inhibitors -Admixed -Chloride Induced Cmentioning

confidence: 99%

Section: Commercial Corrosion Inhibitorsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Experiences on corrosion inhibitors for reinforced concrete

Bolzoni¹,

Brenna²,

Fumagalli³

et al. 2014

Int. J. Corros. Scale Inhib.

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, Ormellese et al (2006) found that nitrate and organic admixed inhibitors reduced diffusion coefficient by a factor of 2-4, with only a marginal (if any) increase in critical chloride level.…”

Section: Chloride-induced Corrosionmentioning

confidence: 99%