Abstract
It has been reported that concrete containing alginine, a kind of amino acid, could promote the growth of microalga on concrete surface during the setting in marine environment, which would improve the habitat for fishes in the sea. On the other hand, if the alginine mixed concrete is applied to a reinforced concrete structure in the marine environment, high durability against the chloride induced corrosion should be assured. Such a data relating durability of alginine mixed concrete hasn’t been investigated so far.
Considering this background, in this study, salt water spraying test and marine exposure test using reinforced concrete specimens containing alginine were conducted to investigate the resistance performance of concrete containing alginine against chloride induced corrosion. Moreover, pore solution of mortar specimens was extracted by the high compressive pressure for the chemical analysis to measure the concentration of several ions. As a result, Cl－/OH－ molar ratio in pore solution was decreased and a steel corrosion in concrete monitored by electrochemical indexes was suppressed with the addition of alginine. Furthermore, alginine contained in pore solution changed to other kinds of amino acid, ornithine or citrulline, especially in the case of mortar using normal cement compared with the case using blast furnace slag cement.
