By definition, corrosion is the reaction of a material with its ambient environment, causing a measurable change in the material which can lead to function impairment of a component or system. From a practical standpoint, a complete corrosion protection cannot be achieved.
Therefore, applied protective methods are directed towards a reduction of the corrosion attack and the respective damages to the reinforcement or ground control elements during their intended lifetime.
Corrosion Protection Methods
The selection of the optimal corrosion protection method(s) depends on the corrosion potential of the environment, and the type as well as the intended service life of the structure.
The load-bearing element, transition zone between borehole and surface, and the head construction must be assessed separately.
Corrosion protection methods are divided into two main groups.
The first one is called active, and comprises all influencing methods which eliminate or reduce the corrosion reaction. A common example for active corrosion protection is encapsulation with concrete.
The second one is called passive corrosion protection, including methods to produce a protective layer on corrosion endangered parts, for example duplex coating systems.
Self-drilling hollow steel bolt tendons for permanent application are reliably protected by surrounding body of cement grout. The following additional measures can be employed to improve the corrosion protection for special applications.
Hot-dip galvanized self-drilling anchor bolt
Galvanized self-drilling anchor system / full threaded steel self-drilling rock bolt / hollow anchor bar / anchor rods.
In order to reduce the corrosion rate and thus increasing the service life, SINODRILLS offer hot-dip galvanized systems. A complete hot-dip galvanized system is usually including hollow bar, coupler, nut and plate. All hot-dip galvanized items confirm to following standards:
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Hot-dip galvanized zinc coating thickness ( μm ) |
Hot-dip galvanizing standard |
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≥70 |
ISO 1461 |
Duplex Coating Introduction
According to EN ISO 12944-5, duplex systems are understood to be a corrosion protection system which consists of galvanizing in combination with one or more subsequent coatings.
The corrosion protection working mechanism of duplex systems is based on mutual protection of the partners. Protected by the powder coating, the zinc layer remains intact for an extended time period.