Graphene enhanced conductive cementitious coating (GREC)

Research Project, 2021 – 2023

Graphene enhanced conductive cementitious coating (GREC)

Chloride induced corrosion is one of the most occurring degradation scenarios in reinforced concrete structures. The repair work usually involves removing large pieces of damaged concrete which is very costly and therefore not favorable. An alternative well-known reparation method is using cathodic protection (CP) with imposed current. This method although cheaper than the first alternative also has some down sides such as long required time, labor cost and down time for installation of the anode required in the CP method. The conventional anode systems used in CP with imposed current are usually coated titanium anode, band anode and titanium mesh. However, to overcome the noted down sides with these materials development of conductive coatings as an anode in the CP system has been a subject of interest for the past 20 years. The coatings are usually a conductive organic paint containing carbon particles. The challenge in this development is to assure an adequate conductivity in the coating (5–20 mA/m2), while its durability with respect to adhesion and hardness is also demonstrated.

This project, therefore, aims to overcome the noted challenges proposing a durable graphene enhanced cement based conductive coating to be utilized as an anode in a CP system.

The function of 2D materials is to provide the conductivity in the coating matrix, while the coating provides a medium for imbedding these products. The project is divided in four technical phases:

I. Coating development: where the right type of Graphene or any other 2D material to be used as the conductive medium as well as the coating medium itself is taken into consideration

II. Conductivity: where Galvanostatic polarization are to be carried out on the anode material immersed in saturated calcium hydroxide solutions in order to evaluate the maximum anode current output.

III. Application: where anodic current densities in the range 5–50 mA/m2 with respect to the anode surface are imposed on concrete specimens with multiple layers of rebars that simulate reinforced concrete specimens.

IV. Durability: where the properties of the coating with respect to adhesion and hardness considering different applied magnitudes of current is investigated.