抄録
Hitherto, it has been recognized that the deterioration of the concrete structure exposed to chloride ion attack is caused by the expansion force of the rust layer growth in the embedded rebars. In order to prevent such concrete damage, various practical methods have been proposed. However, the use of these methods are limited in practice, because the application is very troublesome. Therefore, we have tried to improve the corrosion resistance of the steel rebar itself and discovered the key to achieve this purpose.
The main concept of the present discovery is to add both Cu and W or 3.3% Ni to high purified rebar. In order to make clear the effect of this steel rebar, electrochemical tests and concrete deterioration accelerated tests using concrete blocks with various rebars were carried out.
The results obtained are summerized as follow.
(1) The corrosion prevension mechanism of the rebar and the role of various elements were clarified.
(2) From the deterioration accelerated tests of concrete blocks, it was found that the resistances against rust formation and crack growth of the rebar were excellent. Cu-W bearing and 3.5% Ni containing high purified steel rebars are suitable for the concrete structure at seaside.
