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Matsuda, Takeshi*; Noda, Masaru*; Iriya, Keishiro*; Konishi, Kazuhiro*; Nakayama, Masashi; Kobayashi, Yasushi
JAEA-Research 2007-089, 139 Pages, 2008/05
JAEA-Research-2007-089.pdf:13.57MB
In Horonobe Underground Research Center construction of underground facility began in 2005 and construction practicality test with HFSC (Highly Fly-ash contained Silica-fume Cement) is planned in a part of the gallery. Before the HFSC will be contracted in the gallery it is necessary to check that the HFSC has performance under the actual construction. The main work of this Japanese fiscal year is making a detailed test plan for the HSFC construction practicality, that is scheduled after 2007 and laboratory tests on lowering behavior of pH in the HFSC concrete were conducted. On the construction practicality test with low alkaline concrete, HFSC in-situ experiment plan was studied in case using HSFC424N as shotcrete. The aims of the in-situ test are the validation in applicability of low alkaline concrete as a support member for underground opening in the realistic geological environment and building the method to evaluate influence to the surrounding geological environment. The location of the in-situ test is in the connection tunnel of a depth of 140m and the geology is the Koetoi formation. The period of the test is approximately 10 years. The test plan was designed to be able to make a comparison with Ordinary Portland Cement. As it is necessary to confirm the strength property of the HFSC concrete with materials procured at construction site, strength of the base concrete using local procured fine aggregate and coarse aggregate based on the result of the selection of mix proportion in 2005 research was checked. On laboratory tests on lowering behavior of pH in HFSC concrete, the pH of immersion fluid was measured and components of the immersion fluid and the solid phase were analyzed using test specimens in a long-term immersion test which had been continued since 2005.
Takeda, Nobufumi*; Iriya, Keishiro*; Hitomi, Takashi*; Konishi, Kazuhiro*; Kurihara, Yuji*
Obayashigumi Gijutsu Kenkyushoho (CD-ROM), (72), 8 Pages, 2008/00
To evaluate applicability as the steel reinforced concrete of the concrete with the low alkalinity cement which contains pozzolan that has been examined to apply for high level radioactive waste disposals, concrete of 30% water-cement ratio was performed 6-year marine exposure examination, aging of their compressive strength, the intrusion width of the chloride ion and the corrosion of reinforcing bar were investigated. And based on these results, progress of corrosion of reinforcing bar and the outbreak time of reinforcing corrosion crack were predicted. As a result, the following result became clear. (1) There is no fall of the compressive strength of test pieces in 6-year marine exposure examination. (2) There is little penetration of the chloride ion in comparison with the concrete consists of ordinary Portland cement. (3) The corrosion of reinforcing bar starts for the early stage with a little quantity of chloride ion intrusion, the progress until six years is extremely small. (4) the corrosion speed of the reinforcing bar of concrete with low alkali cement in underground water including sea water were estimated as 0.30
0.55 mg/(cm
year). In case of using this concrete to structure with 100 mm cover thickness and 22 mm reinforcing bar diameter, the outbreak time of reinforcing corrosion crack were predicted as 50100 years after construction.
Miura, Norihiko*; Konishi, Kazuhiro*; Iriya, Keishiro*; Nakayama, Masashi; Matsui, Hiroya
Semento, Konkurito, (728), p.63 - 67, 2007/10
High level radioactive waste(HLW) repository is to be constructed at depth of over 300m below the surface. Shotcrete and lining will be used for safety under construction and operational period. Concrete is a kind of composite material which is constituted by aggregate, cement and additives. Low alkaline cement has been developed from the viewpoint of long term stability of the barrier systems which would be influenced by high alkaline arising from cement material. Japan Atomic Energy Agency(JAEA) has been developed HFSC(Highly Fly-ash contained Silica-fume Cement) which is one of a low alkaline cement contained silica-fume and fly-ash. JAEA is now implementing the construction of the underground research laboratory(URL) at Horonobe for the purpose of research in deep geological science and repository engineering technology. This report shows the properties of HFSC using as shotcrete.
Kobayashi, Yasushi; Yamada, Tsutomu; Nakayama, Masashi; Matsui, Hiroya; Matsuda, Takeshi*; Konishi, Kazuhiro*; Iriya, Keishiro*; Noda, Masaru*
JAEA-Review 2007-007, 42 Pages, 2007/03
JAEA-Review-2007-007.pdf:3.12MB
Shotcrete and lining will be used for safety under construction and operational period in HLW repository. Concrete is a kind of composite material which is constituted by aggregate, cement and other mixture. Low alkaline cement has been developed from the viewpoint of long term stability of the barrier systems which would be influenced by high alkaline arising from cement material. HFSC is one of a low alkaline cement. It has been developed in Japan Atomic Energy Agency. JAEA are now implementing the construction of the under ground research laboratory (URL) at Horonobe. This report shows the in situ test plan for shotcrete using HFSC at Horonobe URL with identifying requirements for cement materials to be used in HLW repository, and also reviews major literatures of low alkaline cement. This in situ test plan is aiming to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on.
Konishi, Kazuhiro; Nakayama, Masashi; Mihara, Morihiro; Yoshida, Yasushi*; Iriya, Keishiro*; Akiyoshi, Kenji*; Noda, Masaru*
JAEA-Research 2006-040, 53 Pages, 2006/06
JAEA-Research-2006-040.pdf:12.6MB
no abstracts in English
Aoyanagi, Shigeo; Yui, Mikazu; Tanai, Kenji; Kawakami, Susumu; Fujita, Tomoo; Taniguchi, Naoki; Shibata, Masahiro; Konishi, Kazuhiro; Nishimura, Mayuka; Kikuchi, Hirohito*; et al.
JAEA-Review 2006-014, 61 Pages, 2006/03
JAEA-Review-2006-014.pdf:5.03MB
no abstracts in English
Iriya, Keishiro*; Nakayama, Masashi; Konishi, Kazuhiro; Mihara, Morihiro
Konkurito Kogaku Nenji Rombunshu (DVD-ROM), 28(1), p.173 - 178, 2006/00
no abstracts in English
Nakayama, Masashi; Kobayashi, Yasushi; Iriya, Keishiro*; Konishi, Kazuhiro*
no journal, ,
no abstracts in English
