ABSTRACT
Cementitious mortar coats have been successfully employed for corrosion protection of steel reinforcements in the course of concrete rehabilitation. The use of such coats for other corrosion protection applications would offer several advantages, such as good protective properties and insensitivity to rusty substrates. Because of the extremely low content of volatile organic compounds (VOC) they would also be environmentally friendly However, there are some reservations concerning carbonation and also the rapid evaporation of the mixing water during the application since the latter will affect the setting process. Finally, the application of the coating is likely to cause difficulties.
An investigation was conducted to examine the behaviour of epoxy modified (ECC) and polymer modified (PCC) type mortars with and without top coats, both on blast cleaned and on manually cleaned steel substrates. As expected, the application of the mortars posed serious problems. Apart from this, the results were very encouraging. It was of interest that the results of accelerated tests as well as of natural weathering ranked mortar coats without an additional top coat as among the best. It is worth noting, that even after 8 years of natural weathering the alkalinity and, as a result of this, the passivity of the steel, had been maintained.
