Anticorrosion performance of Anthocleista djalonensis on steel-reinforced concrete in a sulphuric-acid medium

ABSTRACT

This paper employs electrochemical monitoring methods for studying the anticorrosion performance of the leaf-extract admixture of Anthocleista djalonensis (A. djalonensis) on steel-reinforced concrete immersed in the aggressive medium of a sulphuric-acid (H₂SO₄) test solution. The electrochemical monitoring methods employed include corrosion potential, corrosion current and corrosion rate. These were used for testing the corrosion responses of specimens of duplicated steel-reinforced concretes in the industrial/microbial simulating test environment. Analyses of these test measurements, as per American Society for Testing and Materials (ASTM) G16-95 R04, shows that the corrosion rate correlates directly with the leaf-extract admixture concentration and inverse functions of noise resistance; the ratio of the standard deviation of the corrosion potential to that of the corrosion current. It is concluded that 0.4167% A. djalonensis (per weight of cement) is the optimum modelling efficiency, from the ranked predictions of the correlation fitting model, by having an inhibition efficiency of η = 96.11 ± 1.14% (predicted) or 89.84 ± 2.46% (experimental) in the medium. Fittings of the predicted and experimental data show that they both follow the Frumkin adsorption isotherm model with a coefficient of determination r² = 96.17% (predicted) and r² = 89.88% (experimental). The results of the experimental and predicted model agree in support of using A. djalonensis as an eco-friendly inhibitor of corrosion in the reinforcing steel in concrete designed for the industrial/microbial service environment.

KEYWORDS:

• Corrosion of steel reinforcement
• microbial/industrial simulating environment
• eco-friendly inhibitor
• statistical noise resistance
• correlation fitting model
• inhibition efficiency
• adsorption isotherm

ORCiD

Joshua Olusegun Okeniyi http://orcid.org/0000-0002-7444-3977

Cleophas Akintoye Loto http://orcid.org/0000-0003-3735-5983

Abimbola Patricia Idowu Popoola http://orcid.org/0000-0003-4447-8551

Additional information

Notes on contributors

Joshua Olusegun Okeniyi

Notes on contributors

Dr Joshua Olusegun Okeniyi obtained his B.Sc. (Hons) degree in Mechanical Engineering from the Obafemi Awolowo University, Nigeria in 1998, M.Sc. degree in Mechanical Engineering from the University of Ibadan, Nigeria in 2005, and Ph.D. degree in Mechanical Engineering from the Covenant University, Nigeria in 2014. He is a member of NACE International and the Minerals, Metals and Materials Society (TMS), a Registered Engineer with the Council for the Regulation of Engineering in Nigeria (COREN), a member of the Nigerian Society of Engineers (NSE) and a member of the Nigerian Institution of Mechanical Engineers (NIMechE). He is currently a Senior Lecturer and Researcher in the Mechanical Engineering Department at Covenant University. His research focus is on corrosion protection for materials, environmental protection and sustainability, and analyses/modelling of engineering systems.

Cleophas Akintoye Loto

Prof Cleophas Akintoye Loto is a Professor of Mechanical Engineering at the Covenant University, Nigeria. He has worked at universities for over 30 years, serving as a Department Head in various universities and as a Dean of Colleges in his present university, as well as visiting universities in different countries. He is also currently a Professor Extraordinaire in the Tshwane University of Technology, Pretoria, South Africa. He received his B.Sc. (Hons) degree in Chemistry from the University of Lagos, Nigeria in 1977, M.Sc. degree in Metallurgy from Brunel University London, the UK in 1982, and Ph.D. degree in Metallurgical and Materials Engineering – Corrosion from the University of Manchester Institute of Science and Technology, the UK in 1984. He is a NACE International member since 1989, a Chartered Engineer (C.Eng.), the UK and a Registered Engineer (R.Eng.), Nigeria.

Abimbola Patricia Idowu Popoola

Dr Abimbola Patricia Idowu Popoola received her B.Sc. degree in Metallurgical and Materials Engineering from the Obafemi Awolowo University, Nigeria in 1989, both of her M.Tech. degree in Metallurgical Engineering in 2004 and D.Tech. degree in Metallurgical Engineering in 2011 from the Tshwane University of Technology, Pretoria, South Africa. Her research interests lie in laser materials processing and surface/corrosion engineering. She is currently a Professor in the Tshwane University of Technology, and has authored and co-authored over 150 journal and conference papers.