Assessment of surface treatment systems for protecting concrete structure

Abstract

The BS EN 1504-2:2004 groups surface treatments into three types: impregnations, hydrophobic impregnations, and surface applied corrosion inhibitors. Impregnations reduce surface porosity by filling concrete pores, while hydrophobic impregnations create a water-repellent surface without filling pores. Surface applied corrosion inhibitors form a protective film on the rebar surface. Impregnation strengthens the surface by blocking pores with reaction products that reduce ingress of aggressive agents. Hydrophobic impregnation produces a hydrophobic and water-repellent surface that inhibits water penetration while allowing concrete to breathe. Corrosion inhibitors migrate to the steel surface and form a mono-molecular film, preventing further corrosion. In this study accelerated corrosion test was used for determination of the effectiveness of each category in offering corrosion protection by subjecting concrete specimens coated with these surface treatments to accelerated corrosion conditions that is intended to induce corrosion in the embedded rebars. This paper presents test results for the performance of these three surface treatments on grade G30 and G40 concretes. Results show that hydrophobic agents are more effective than traditional impregnates in reducing water absorption and chloride penetration.

Keywords

Surface treatment / Impregnation / Hydrophobic surface coating / Surface applied corrosion inhibitors / Concrete protection

References

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