International Journal of Civil and Structural Engineering Research ISSN 2348-7607 (Online) Vol. 7, Issue 2, pp: (1-12), Month: October 2019 - March 2020, Available at: www.researchpublish.com
Half-cell potential Measurement of Concrete Resistivity of Exudates Layered Reinforcement in Chloride threshold Corrosive Environment Terence Temilade Tam Wokoma1, Daso Dokibo2, Charles Kennedy3 1
School of Engineering, Department of Civil Engineering, Kenule Beeson Saro-Wiwa Polytechnic, Bori, Rivers State, Nigeria
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School of Engineering, Department of Mechanical Engineering, Kenule Beeson Saro-Wiwa Polytechnic, Bori, Rivers State, Nigeria 1
Faculty of Engineering, Department of Civil Engineering, Rivers State University, Nkpolu, Port Harcourt, Nigeria. Authors E-mail:, terencett.wokoma@gmail.com 2mori7real@yahoo.com, 3ken_charl@yahoo.co.uk
Abstract: The fundamental concept of corrosion inhibition is the development of a stable compound with the metal surface and the formation of an adsorption complex with the metal oxide. This study evaluated the effect of salt water on reinforced concrete structures located in the costal marine environment. Corrosion accelerated simulated process was performed on non-coated and khaya senegalensis exudates / resins coated specimens for 150 days period and evaluate the actions of half cell potential, concrete resistivity and tensile strength of reinforcing steel embedded in concrete and exposed to corrosion. Results of concrete resistivity ρ, kΩcm against potential Ecorr,mV relationship showed averaged potential Ecorr control percentile average value of 30.33509% and percentile difference -69.6649% over 235.1921% corroded specimen. Results of concrete resistivity ρ, kΩcm percentile average value of 183.4935% and percentile difference 83.49351% over -30.1921% corroded specimen. Mechanical properties “ultimate strength” of control specimen value of 93.71429% and percentile difference -6.28571% over 7.138101% corroded specimen. Mechanical properties “weight loss of steel” of control percentile average value of 53.50441% and percentile difference -46.4956% over 91.49347% corroded. Mechanical properties “cross- section area reduction” of control specimen with percentile average value of 118.5055% and percentile difference 18.50551% over -15.6157% corroded specimen. Control specimens result showed no corrosion potential due to the presence of inhibitory exudates / resins that acted as an insulator to reinforcing steel embedded in corrosive environment Keywords: Corrosion, Corrosion inhibitors, corrosion potential, concrete resistivity and Steel Reinforcement.
1. INTRODUCTION When steel corrodes the initial corrosion product formed can slightly improve the bond, but increasing the level of corrosion will often result in cracking and decrease in bond at the steel/concrete interface (Cabrera [1], Chung et al. [2]). The formation of rust involves a substantial volume increase (a factor of about 4) which causes cracking, spalling and staining of concrete, and reduces the effective cross-sectional area of reinforcing bars and weakens the bond between reinforcement and concrete, seriously affecting thedurability, and the service-life of structures (Almusallam et atl [3], Rashid et al.[4]). The fundamental concept of corrosion inhibition is the development of a stable compound with the metal surface and the formation of an adsorption complex with the metal oxide. Inhibitors are of three basic types: anodic, cathodic, and mixed. Anodic inhibitors function by arresting the reaction at the anode. In ideal situations, they react with existing corrosion products to form a highly insoluble film that adheres tightly to the metal surface. This film can act as a barrier to metal dissolution by preventing the metal surface from contacting the corrosive electrolyte.
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