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Fong Weng Khiong is a civil engineer with over three decades of work experience.  His knowledge includes assessment of reinforcement corrosion, supported by field tests and laboratory investigations, chloride penetration to predict time to corrosion and service life, estimation of life-cycle-cost assessment and rehabilitation strategies. He has investigated  buildings, bridges, and marine structures. He received formal training in Fundamentals of Corrosion for Engineers and is a Professional Member of the Institute of Corrosion, UK. He serves in the Singapore Concrete Institute as a Board Director since 2005, and lectures at the IES Academy since 2014 on concrete deterioration, inspection and repair.

SUSTAINABLE CORROSION MANAGEMENT OF REINFORCED CONCRETE USING CATHODIC PROTECTION: FROM ELECTROCHEMICAL PRINCIPLES TO INFRASTRUCTURE REHABILITATION (A CASE STUDY)

Fong Weng Khiong

Consultant, Ascent Materials Consultants Pte Ltd 

Director, Singapore Concrete Institute

Email – fongwk@ascentfe.com

Abstract

Reinforced concrete is the world’s most widely used construction material, yet corrosion of embedded steel reinforcement remains one of the principal causes of deterioration and premature infrastructure replacement. In aggressive environments, particularly marine and chloride-contaminated conditions, the breakdown of the steel’s passive layer initiates corrosion, leading to cracking, delamination, loss of structural capacity, and increasing maintenance costs. Conventional repair methods, although effective in restoring damaged concrete, often fail to address the underlying electrochemical processes responsible for continued corrosion, resulting in recurring repairs and significant environmental impacts over the service life of the structure.

This presentation presents cathodic protection (CP) as a sustainable corrosion mitigation technology that extends the service life of reinforced concrete by directly controlling the electrochemical corrosion process. The fundamental principles of reinforcement corrosion are presented, the influence of chlorides, carbonation, oxygen availability, concrete resistivity.  The operating principles of both galvanic (sacrificial anode) and impressed current cathodic protection (ICCP) systems are discussed, together with their advantages, limitations, design considerations, and compliance with BS EN 1504 and BS EN 12696.

A local case study involving ageing marine bridge structures demonstrates the practical application of cathodic protection as part of a durability-based rehabilitation strategy. Through detailed condition assessment, electrochemical testing, durability modelling, and life-cycle evaluation, a sacrificial anode cathodic protection system was integrated with targeted concrete repairs to achieve a design service life extension of 20 years. Rather than relying on repeated concrete replacement, the approach significantly reduces ongoing corrosion activity while preserving the existing structural assets.

The presentation highlights that cathodic protection represents a sustainable engineering solution by extending infrastructure service life, reducing material consumption, minimizing carbon emissions associated with repeated repairs and reconstruction, and supporting asset management based on whole-life performance rather than reactive maintenance. As infrastructure worldwide continues to age, cathodic protection offers a proven technology that aligns corrosion engineering with the principles of sustainability, resilience, and life-cycle cost optimisation.

Keywords

Corrosion, sacrificial anode, impressed current cathodic protection, durability, life-cycle