Page 9 - April-Month

TECHNICAL PAPER

chloride and carbonated exposure, organic inhibitor 7.
reduces the corrosion rate, while inorganic inhibitor fails to
do so. The authors gratefully acknowledge the financial support
provided by the Atomic Energy Regulatory Board under
3. Chloride and carbonation profile suggest that, AB acts as Committee for Safety Research Programmes (Sanction No.
a pore blocker whereas TEP fails to resist the movement of AERB/CSRP/73/02/19). The authors also acknowledge Dr.
aggressive ions which leading to corrosion of embedded Vijay Luxami (Associate professor, School of Chemistry and
steel rebar.
Biochemistry, TIET) for providing the helpful suggestion for this
research.
6. FUTURE SCOPE
The ability of an RC structure to withstand aggressive REFERENCES
environmental actions, while at same time able to maintain [1] Tumidajski, P. J., & Chan, G. W. (1996). “Effect of sulfate
its performance well above a minimum acceptable level is and carbon dioxide on chloride diffusivity”, Cement and
defined as ‘durability’. Effective service life of an RC structure is Concrete Research, Vol. 26, No. 4, pp. 551-556.
defined as the time period for which the structure, or a structural [2] Lee, M. K., Jung, S. H., & Oh, B. H. (2014). “Effects of
element, can be used for its indented purpose without the need carbonation on chloride penetration in concrete”.
for maintenance. Deterioration of concrete structures concludes ACI Materials Journal, V. 110, No. 5, pp. 559-566.
that 50% of all cases of deterioration considered were caused [3] Ye, H., Jin, X., Fu, C., Jin, N., Xu, Y., & Huang, T. (2016).
by corrosion of reinforcement, from chloride penetration or “Chloride penetration in concrete exposed to cyclic drying-
carbonation , emphasis should be paid on utilizing service-life wetting and carbonation”. Construction and Building
[40]
estimation tools (SLT) on such types of deterioration processes Materials, Vol. 112, pp. 457-463.
as they can be vital aids. After all, the prospect that a structure [4] Al-Otaibi, M. S., Al-Mayouf, A. M., Khan, M., Mousa, A. A.,
is durable can only be accessed through tools simulating the Al-Mazroa, S. A., &Alkhathlan, H. Z. (2014). “Corrosion
deterioration processes to which the structure is likely to be inhibitory action of some plant extracts on the corrosion
subjected. of mild steel in acidic media”. Arabian Journal of
Chemistry, Vol. 7, No. 3, pp. 340-346.
Service Life Modelling (SLM) is intended to allow quantification
of the design service life of structures, for purposes of economic [5] Obot, I. B., Obi-Egbedi, N. O., &Umoren, S. A. (2009).
optimisation, operational efficiency, and sustained structural Antifungal drugs as corrosion inhibitors for aluminium in 0.1
and aesthetic performance. One of the principal challenges in M HCl. Corrosion Science, Vol. 51, No. 8, pp. 1868-1875.
developing a mathematical model for service life prediction is [6] Królikowski, A., &Kuziak, J. (2011). “Impedance study on
that many parameters, including material characteristics, climatic calcium nitrite as a penetrating corrosion inhibitor for steel in
environment, and construction method, will all affect service life. concrete”. Electrochimicaacta, Vol. 56, No. 23, pp. 7845-7853.
The service life of a reinforced concrete structure can be divided [7] Popov, B. N. (2015). “Corrosion engineering: principles and
into two stages, the initiation period and the propagation solved problems”. Elsevier.
period. In service life estimation, it is common to conservatively [8] Raja, P. B., Ismail, M., Ghoreishiamiri, S., Mirza, J., Ismail,
assume the service life end when corrosion initiates. M. C., Kakooei, S., & Rahim, A. A. (2016). “Reviews on
corrosion inhibitors: a short view”. Chemical Engineering
So far, various models have been proposed, such as empirical Communications, Vol. 203, No. 9, pp. 1145-1156.
models, statistical models, numerical models and simulation
models. Most models cover either service life prediction of [9] Ormellese, M., Lazzari, L., Goidanich, S., Fumagalli, G.,
structure subjected to chloride induced corrosion [41-45] or & Brenna, A. (2009). “A study of organic substances
carbonation induced corrosion [46-47] . But these models cannot as inhibitors for chloride-induced corrosion in
concrete”. Corrosion Science, Vol. 51, No. 12, pp. 2959-2968.
be valid for combined (chloride and carbonation ingress)
environment due to various uncertainty in data. [10] Malik, A. U., Andijani, I., Al-Moaili, F., &Ozair, G. (2004).
“Studies on the performance of migratory corrosion
The above study concludes that organic inhibitors able inhibitors in protection of rebar concrete in Gulf seawater
to restrict the chloride and carbon-dioxide penetration in environment”. Cement and concrete composites, Vol. 26,
combined environmental exposure. This can be related with the No. 3, pp. 235-242.
increase in corrosion initiation period and increment in service [11] Fedrizzi, L., Azzolini, F., &Bonora, P. L. (2005). “The use of
life of reinforced structure subjected to real environmental migrating corrosion inhibitors to repair motorways’ concrete
exposure of RC structure. In order to contribute with the service structures contaminated by chlorides”. Cement and
life prediction of the structures when inserted in combined saline Concrete Research, Vol. 35, No. 3, pp. 551-561.
and CO 2 environments with admixed inhibitor, a mathematical [12] Jamil, H. E., Shriri, A., Boulif, R., Bastos, C., Montemor, M.
model need to be developed. F., & Ferreira, M. G. S. (2004). “Electrochemical behaviour of

THE INDIAN CONCRETE JOURNAL | APRIL 2021 35