DuoGuard™ Hybrid

Stops corrosion and extends structural life

2nd generation targeted protection
20 – 50 years protection
Benefit of both impressed current and galvanic cathodic protection, no permananet power source required
Manufactured in the UK to ISO9001

Our unique DuoGuard range of discrete anodes features innovative dual technology to arrest steel reinforcement corrosion within 7 days. DuoGuard™ is installed into concrete structures to stop reinforcing steel corrosion caused by chloride salts and carbonation. It can be used to protect contaminated but unspalled concrete saving the time and cost of replacing the concrete material. With a long system lifetime the DuoGuard™ anode provides a cost effective, maintenance free method of corrosion protection.

Problem

DuoGuard™ combats the two main types of corrosion found in reinforced concrete structures.

– Carbonation induced – exposure to atmospheric carbon dioxide combined with prolonged contact to sufficient moisture and oxygen can leave steel vulnerable to corrosion.

– Chloride induced – if chloride in the form of inherently mixed set accelerators or external aggressive salts permeates reinforced concrete in sufficient quantities, an aggressive form of corrosion can be initiated.

When either or both of these take hold in a structure, this can lead to the concrete cracking and being displaced as the steel reinforcement expands and pushes out. The corrosion and its effects often propagate very quickly – so it is crucial to be proactive in assessing and fixing the issue.

DuoGuard™ Anodes

DuoGuard™ anodes feature the new generation electro-chemical technology to stop reinforcing steel corrosion caused by chloride salts and carbonation and can be designed to 50 years.

Anodes are available in the following sizes.

Duoguard Hybrid	Diameter	Length	Zinc Weight
Duoguard Hybrid -175	18mm	42mm	65g
Duoguard Hybrid-350	18mm	77mm	120g
Duoguard Hybrid-400	18mm	95mm	160g
Duoguard Hybrid-500	18mm	115mm	180g
Duoguard Hybrid-750	18mm	170mm	285g
Duoguard Hybrid-1000	18mm	223mm	370g

DuoGuard Ultra™
DuoGuard Ultra™ is a dual technology hybrid anode based on the use of a sacrificial anode, the hybrid Ultra anode is encapsulated in an activating mortar matrix. It is designed for use in areas of congested steel and for new construction applications.

Duoguard Ultra	Diameter	Length	Zinc Weight
Duoguard Ultra -175	32mm	55mm	65g
Duoguard Ultra -350	32mm	95mm	120g
Duoguard Ultra -400	32mm	108mm	160g
Duoguard Ultra -500	32mm	125mm	180g
Duoguard Ultra -750	32mm	180mm	285g
Duoguard Ultra -1000	32mm	235mm	370g

Installation

DuoGuard™ anodes are installed into contaminated areas of reinforced concrete, identified as being at risk of corrosion, by simply drilling 30mm diameter holes and embedding the anodes in DuoCrete SD mortar. These are then temporarily connected in groups to a power supply using titanium wire – just a couple of connections are required for a circuit of up to 200 anodes. The system is discrete with no surface wiring or permanent control systems – totally vandal proof.

How it works

DuoGuard™ is a hybrid treatment. During treatment a sacrificial anode is used as both an impressed current and galvanic anode. Initially, a constant voltage power supply is used to drive a high current from the installed anode to re-passivate the corroding steel, typically for one week. The same anode is then connected directly to the steel to provide maintenance free cathodic protection by means of a galvanic current. The hybrid system means that the requirement for a permanent power supply is eliminated and DuoGuard offers the advantages of a galvanic anode system, requiring little to no maintenance. The system can be designed to meet BS EN ISO 12696:2016 the international standard for cathodic protection.

Duoguard Hybrid Strip Anode System

Duoguard Hybrid Strip system is a dual technology hybrid strip anode utilising a sacrificial metal in both an impressed current and galvanic anode role. Initially an impressed current is driven from the Duoguard Strip anode to the steel using a temporary power supply and corroding sites on the steel are moved to the surface of the installed strip anode. Duoguard Strip system provides increased current distribution and is used to provide corrosion protection to sound but contaminated reinforced concrete elements to minimise maintenance and extend the life of structures.