著者

HASEGAWA Mitsuhiro IMANO Makoto YAMAMOTO Takanori KIDA Tetsukazu KONDO Tsutomu SUDO Makoto KATO Kiyoshi KATO Naoki TAKANO Makiko

出版者

日本学術会議 「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」

雑誌

Theoretical and Applied Mechanics Japan (ISSN:13480693)

巻号頁・発行日

vol.55, pp.41-50, 2006

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The fundamental reason of deterioration is the repetitional scaling of the surface layer; further, it has been basically analyzed that the freezing and thawing actions make concrete neutralize from the outside by virtue of the environmental contact water. The wet-dry action is one of the principal deterioration causes. It has been already understood that both actions contribute to the neutralizing acceleration of concrete. The present paper particularly deals with the quantification of the concentration dilution of pore solution and the neutralization of the matrix of concrete, from the viewpoint of the potential Hydrogen (pH) range of general environmental water; in addition, it has been clarified that the equilibration-concentration and the neutralized depth can be obtained, assuming to be the semipermeable membrane on the shell interface. The critical thickness as to the hypothetical thick shell with the through microcrack has been derived for the first time; thus, finally the mechanical cover can be perfectly neutralized due to the approximately fifty cycles of water-microcirculation.

著者

HASEGAWA Mitsuhiro IZAWA Shizuka HSU Ming-Chien SUDO Makoto KIDA Tetsukazu KATO Kiyoshi IMANO Makoto KATO Naoki

出版者

日本学術会議 「機械工学委員会・土木工学・建築学委員会合同IUTAM分科会」

雑誌

Theoretical and Applied Mechanics Japan (ISSN:13480693)

巻号頁・発行日

vol.54, pp.83-91, 2005

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There is a difficult problem that the present freezing and thawing test method indicates the structure-insensitive properties from the point of view of materials science concerning the specimen size, shape and exposure condition, in addition, the mass variation. The &ldquo;surface defect ratio&rdquo; as a new index in place of the above-mentioned factors has been proposed. The fundamental deterioration is dependent on the repetitional scaling of surface layer; further, it has been basically analyzed that the freezing and thawing action makes concrete neutralize from the outside by virtue of the environmental contact water. The wet and dry action as well as the freeze-thaw action is one of the principal deterioration causes and these are the extreme phenomena at both ends on the temperature axis. It has been already understood that the either action contributes to the neutralizing acceleration of concrete.<br>The present paper particularly deals with the quantification of the concentration dilution of pore solution and the neutralization of matrix of concrete, from the viewpoint of the potential Hydrogen (pH) range of general environmental water.