Polymer-modified cementitious repair mortars have been used extensively in recent years for concrete repairs in conjunction with electrochemical protection systems. The performance improvements of polymer additions to cementitious mortars generally come at the expense of increased mortar resistivity, an important consideration in the selection of repair mortars particularly when used in conjunction with electrochemical protection systems, such as impressed current cathodic protection and galvanic anode systems. In this paper, four-point Wenner probe resistivity tests of four commercially available mortars marketed as ‘low resistivity’ polymer-modified repair mortars were carried out over a period of 18 months. The experiment results indicated substantial increases in resistivity over time for all mortars in saturated and outdoor exposure conditions, which were beyond the short-term resistivity data of 28 days presented in manufacturers’ technical data sheets and perceived to be the long-term maximum mortar resistivity. The outcome of this paper suggests that polymer-modified mortar resistivity increases substantially over time. The increase of the repair mortar resistivity when used in conjunction with electrochemical protection systems may have a considerable impact on the performance of these systems.

In Australia’s rural regions, road bridges are often subject to aggressive environmental conditions. For reinforced concrete bridges, carbonation is a common mechanism of deterioration. The traditional method of repair involves the removal of all carbonated concrete followed by reinstatement using polymer modified repair mortars.
As part of a strengthening program for three bridges for The Department of State Growth in Tasmania, concrete carbonation was identified as the main cause of existing and potential corrosion problems on the bridge decks. In conjunction with bridge strengthening, and to meet the design requirement of 50 years design life, rectification of all carbonated concrete was required.
For these structures, the removal of sound (but carbonated) concrete would have been overly destructive. Concrete realkalisation treatment was considered as an alternative non-destructive option for the full restoration of the alkalinity of the concrete and for improving the corrosion resistance of embedded rebar by electrochemical means. Following a successful trial application, full realkalisation treatment was successfully completed for the three subject bridges.
This paper will outline the theory of concrete realkalisation, provide details of the realkalisation treatment for the three bridges, and will highlight how innovative technologies can successfully be adopted for extending the service life of infrastructure.

Chloride-induced corrosion can have a severe impact on the integrity of reinforced concrete structures and can dramatically shorten their service life. Cathodic prevention technology has been an effective electrochemical method used to prevent the initiation of corrosion in reinforced concrete structures in marine environments.
In 2005, a cathodic prevention system was installed during construction at the Sea Cliff Bridge along Lawrence Hargrave Drive (LHD) in New South Wales, Australia.
The bridge is located in an unusually severe marine environment as it faces the open ocean and is subject to splashing in high sea swells, putting it at high risk of chloride-induced corrosion.
This paper will present the theory of cathodic prevention and will include a performance summary of the system after nearly 17 years of operation.

This paper presents performance data from a recently completed major rehabilitation project of a multi-story building in Sydney, Australia, where both impressed current and galvanic cathodic protection systems have been utilized.

This paper outlines the reasons behind the selection process of the corrosion protection systems and presents the performance data of some of the protection systems post-construction.

This paper aims to assist owners in the selection process of the optimum corrosion protection solution for their assets.

This paper includes an example of a platform known as CPMS (Cathodic Protection Management System) which has been utilised by several CP system asset owners in Australia in recent years. The system allows for remote functional checks and testing to be performed securely from an off-site computer. The automated system also allows for 24/7 monitoring of CP systems and manages alarms, maintenance planning, historical documentation, original specifications, as-built drawings, maintenance and performance records.

Electrochemical corrosion protection systems have been used in Australia for many years for the corrosion protection of concrete infrastructure assets in marine environments.

Impressed current cathodic protection (ICCP) can be highly effective for the corrosion protection of reinforced concrete structures, however, some of the potential shortcomings of these systems are their performance in high resistivity concrete, anode installation defects in tidal zones, premature failure of some system components and the requirements for ongoing monitoring.

For galvanic-based anode systems, most of the recent innovations have been associated with backfill materials and the development of systems that incorporate a temporary impressed current phase followed by permanent galvanic protection. While the long-term performance of some of the newly developed systems is still subject to ongoing assessment, the overall performance data from galvanic-based systems indicates that one of the potential shortcomings is the inability of these systems to deliver sufficient corrosion protection over time, especially in highly corrosive environments.

This paper presents guidelines related to the selection process of the corrosion protection system for concrete structures. These guidelines have been developed based on the author’s experience with the design, installation, and monitoring of various corrosion protection systems installed in Australia for the protection of marine infrastructure assets.

This paper presents operational data from ICCP systems installed on reinforced and prestressed concrete structures located in atmospheric and tidal zones. The data presented in this paper highlights key issues related to monitoring of such systems.

This paper presents an innovative and practical method utilising existing Wenner Probe equipment, capable of eliminating and/or minimising the influence of these factors in atmospheric conditions. The new method minimises the impact of concrete surface variability by establishing an alternative, reliable electrolytic contact between the Wenner equipment probes and concrete.

This paper provides guidelines on the selection process for determining the optimum corrosion protection solution for reinforced concrete structures. This paper also highlights the advantages and disadvantages of the available cathodic protection technologies, and presents the latest technological developments in galvanic anode, hybrid, and impressed current cathodic protection systems.

The corrosion protection, repair and maintenance of reinforced concrete structures located along the coast of Australia has been a challenging task for engineers and asset owners over
the past thirty years. Most of these structures are bridges and wharves which are situated in marine environments and are subject to tidal exposure. These environmental conditions create challenges in planning repair work, especially if electrochemical systems such as cathodic protection are installed for corrosion protection of these assets.

The development of new and innovative methods of reliable current delivery for ICCP systems in conjunction with simplifications in the design, installation and monitoring of these systems can substantially reduce the complexity and the cost of ongoing maintenance and ensure that less effective galvanic based systems are not selected for the long term maintenance of infrastructure assets.

This paper verifies a methodology for the prevention of grout acidification in ICCP systems. The results presented in this paper confirm that insufficient anode embedment, often combined with poor quality control and workmanship during ICCP system construction, allow water to ingress to the ribbon anode and these are the primary causes of localised grout acidification.

Impressed current cathodic protection (CP) for reinforced concrete structures is a proven technology which can provide long-term corrosion protection solutions for marine structures.

In 1999, an impressed current cathodic protection(ICCP) system was installed and commissioned on several steel-reinforced concrete structures that support the Port of Brisbane’s Wharves 4 and 5. Atef Cheaitani, managing director of Remedial TechnologyPty., Ltd. (Gladesville, New South Wales, Australia ...

Impressed current cathodic protection (ICCP) for reinforced concrete structures is a proven technology which has provided long term corrosion prevention for a number of marine structures owned by the NSW Department of Industry (DoI) Lands.

Impressed current cathodic protection (CP) for reinforced concrete structures is a proven technology which can provide long term corrosion prevention for marine structures if properly designed and installed. This technology has been applied to a large number of concrete structures in Australia over ....

Impressed current cathodic protection (ICCP) for reinforced concrete structures is a proven technology which can provide long term corrosion prevention solutions for marine structures. The three main issues associated with the long term performance and low cost maintenance of a CP system are the...

Corrosion is a major factor that can affect the service of life and safety of a structure. Steel components, a mainstay in structures constructed of reinforced and prestressed concrete are subject to corrosion stemming from several factors, which include water, chlorides from deicing salts and coa ...

In recent years, increased service life and structural monitoring requirements are often specified for major bridges which will be built in a marine environment. Previously, different measures were considered to improve the durability of these new structures. These measures included the modification ...

In recent years, durability requirements are often specified for new reinforced concrete structures especially for structures to be built in marine environments. It is evident today that the use of high performance concrete, good concrete cover, corrosion inhibitors and protective coating is ...

This paper will review the history of Cathodic Protection (CP) of steel in concrete in Australia, the design of CP systems, the various anode and control systems used, the maintenance
and monitoring of existing CP systems and the method of project delivery of CP contracts in
Australia.

The Trident Building is a 15 storey apartment complex situated on a beach frontage in the Sydney suburb of Manly. As a part of a major building refurbishment during 1996-1997, cathodic protection repair was carried out to selected elements of the building. The refurbishment work included major ...

Chloride-induced corrosion can have severe impacts on the integrity of reinforced concrete structures and can dramatically shorten their service. Cathodic Prevention (CPrev) is an effective electrochemical method used to prevent the initiation of corrosion in reinforced concrete structures in marine ...

Cathodic prevention (CPrev) of reinforced concrete structures is used to improve the corrosion resistance of reinforcement for marine structures that are expected to suffer from chloride-induced corrosion during their service life. As a part of a major rehabilitation programme to the Sydney Opera ...

A range of Queensland Main Roads concrete structures have been instrumented with linear polarisation resistance (LPR) probes to determine the long-term durability performance of repair solutions in two cases and in another case put into a new ...

Corrosion evaluation of reinforcement embedded in concrete is often carried out by employing various techniques and tests. Half-cell potential mapping is a well-known technique used mainly to provide information regarding the probability of corrosion in reinforced concrete structures. In combination ...

Cathodic protection of steel in concrete has emerged in the last 10-15 years from being an experimental method to a well-established technique to combat reinforcement corrosion, particularly chloride-induced corrosion. Various organisations have produced sets of criteria against which the performa ...

Electrochemical treatment of reinfmced concrete structures has been used extensively in Australia This paper will describe one of the largest cathodic protection systems for reinforced concrete structures in Australia. The area of the cathodic protection (CP) system for the Port of Brisbane is ...

A significant number of Australia’s road bridges are located in coastal regions and hence subject to aggressive environmental conditions through direct contact with salt water and indirectly through wind borne salts. This paper describes the electrochemical ...

As a part of a major rehabilitation programme of the Sydney Opera House, cathodic prevention and cathodic protection systems were installed to protect new precast elements, the soffit and piers under the western broadwalk. The CP installation was carried out using a grid anode installed in the new ...