INFLUENCE OF ADMIXTURE ON THE CORROSION OF EMBEDED STEEL BARS IN HARDENED CEMENTIOUS MATRIX MATERIALS
著者(1)
大即 信明/OTSUKI/Nobuaki
(1)の日本語所属
東京工業大学工学部
(1)の英語所属
Department of Civil Engineering, Faculty of Engineering, Tokyo Institute of Technology.
著者(2)
中下 兼次/NAKASHITA/Kenji 東京工業大学工学部 Department of Civil Engineering, Faculty of Engineering, Tokyo Institute of Technology. 長瀧 重義/NAGATAKI/Shigeyoshi 東京工業大学工学部 Department of Civil Engineering, Faculty of Engineering, Tokyo Institute of Technology.
Recently, blast furnace slag, silica fume and fly ash, are increasingly used as admixtures for concrete in marine environment. Hany researches have been done for the chloride penetration properties of the hardened cementious matrix materials with these admixtures, however, researches of these admixtures from the view of corrosion prevention properties, including electrochemical ones, are insufficient. In this study, the influence of these admixtures on the corrosion prevention properties as well as on the chloride penetration properties of mortar are quantitatively investigated. Mortar spesimens (~SxlOcm) with embedded steel bars were manufactured with these admixtures. These specimens were exposured in submerged condition (in tap or salt water), wet (in salt water) and dry condition, or spray (salt water') condition. After the exposure, chloride penetration depth into mortar, and electro- chemical properties and corrosion of embedded steel bars were measured. Based on the expermental results, the following conclusions can be made: (1)These admixtures are effective to improve the electrochemical and corrosion prevention properties as well as permeability of mortar against chloride ion penetration. (2)ln spray condition, chloride ion and oxygen gas can diffuse into mortar faster than in the other conditions.