 
          3230
        
        
          Proceedings of the 18
        
        
          th
        
        
          International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
        
        
          2b
        
        
          2a
        
        
          1b
        
        
          1a
        
        
          Photo 1. SEM observation of the Tokyo Bay A and B. Curing period of the Tokyo Bay A are 3 (1a) and 182 (1b) days, and curing period of the
        
        
          Tokyo Bay B are 28 (2a) and 182 (2b) days.
        
        
          5 ACKNOWLEDGEMENTS
        
        
          4 CONCLUSIONS
        
        
          In this study the unconfined compression test, the BE test, and
        
        
          observations of the internal structure using an SEM were
        
        
          conducted on SGM specimens prepared with six different types
        
        
          of source soil to examine how different source soils would
        
        
          impact the strength development of SGM. The findings are
        
        
          summarized as follows:
        
        
          The authors thank Prof. Satoru Shibuya, Kobe University, Japan
        
        
          and Prof. Satoshi Yamashita, Kitami Institute of Technology,
        
        
          Japan for help to prepare the soil samples.
        
        
          6 REFERENCES
        
        
          
        
        
          It was inferred that while the strength and stiffness of the
        
        
          SGM specimens increased with the elapse of curing days,
        
        
          there is a very large variation in their actual levels due to the
        
        
          mineral components and the constituents of pore water
        
        
          contained in the source soil used. In addition, it became
        
        
          clear that the SGM strength cannot be estimated from the
        
        
          flow values of the specimens.
        
        
          Kataoka, S., Kawaguchi, T., Horita, T., Tanaka, M., Sakaiya, T. and
        
        
          Shibuya, S. 2011. Unconfined compression strength and elastic
        
        
          shear modulus of air-form treated lightweight soil.
        
        
          
            Proc. of the 5
          
        
        
          
            th
          
        
        
          
            International Symposium on Deformation Characteristics of
          
        
        
          
            Geomaterials,
          
        
        
          2, 682-686.
        
        
          
        
        
          In SGMs with an approximately equal amount of cement
        
        
          additive and comparable target wet density, the strength and
        
        
          stiffness have a linear relationship as is the case in other
        
        
          cement-treated soil, and their slopes are approximately the
        
        
          same regardless of the soil type.
        
        
          Kawaguchi, T., Yamashita, S., Kataoka, S., Shibuya, S. and Kawajiri, S.
        
        
          2008. Inherent and induced anisotropy of three natural sedimentary
        
        
          clays reflecting on the elastic shear modulus.
        
        
          
            Proc. of the 4
          
        
        
          
            th
          
        
        
          
            International Symposium on Deformation Characteristics of
          
        
        
          
            Geomaterials,
          
        
        
          1, 575-579.
        
        
          
        
        
          The slope obtained from
        
        
          
            G
          
        
        
          hh
        
        
          and
        
        
          
            G
          
        
        
          vh
        
        
          is characterized by an
        
        
          approximately 1:1 relationship, showing that the air foam in
        
        
          the specimens makes SGM a very isotropic material in
        
        
          terms of stiffness.
        
        
          Nagatome, T., Mitarai, Y., Yamatoya, R., Kotou, T. and Noguchi, T.
        
        
          2010. Unprecedented large scale of rapidly construction work of
        
        
          light weight soil with air form for Haneda D-runway Construction
        
        
          Project (Part 1: Validation of field mixing condition).
        
        
          
            The 45
          
        
        
          
            th
          
        
        
          
            Annual Conference of JGS,
          
        
        
          2093-2094. (in Japanese)
        
        
          Seng, S. and Tanaka, H. 2008. Properties of cement-treated soils during
        
        
          initial curing stages.
        
        
          
            Soils and Foundations,
          
        
        
          51 (5), 575-579.
        
        
          
        
        
          The observations of the internal structure of SGM using the
        
        
          SEM on the predetermined curing days suggested the
        
        
          possibility that the increase, growth, and bonding of needle-
        
        
          like ettringite crystals, formed by the hydration process of
        
        
          the cement, were a major factor contributing to the
        
        
          development of the strength and stiffness of the SGM
        
        
          specimens.
        
        
          Sibuya, S. Mitachi, T. and Ozawa, H. 2001. Time/stress-history
        
        
          dependency of deformation-strength characteristics of cement-
        
        
          mixed sand.
        
        
          
            Journal of JSCE,
          
        
        
          687 (III-56), 249-257. (in Japanese)
        
        
          Tuchida, T., Okumura, T., Takeuchi, D. and Kishida, T. 1996.
        
        
          Development of light-weight fill from dredging.
        
        
          
            Proc. of the 2
          
        
        
          
            nd
          
        
        
          
            International Congress on Environmental Geotechnics,
          
        
        
          1, 415-420.
        
        
          Watabe, Y., Itou, Y., Kang, M.S. and Tuchida, T. 2004. One-
        
        
          dimensional compression of air-form treated lightweight geo-
        
        
          material in microscopic point of view.
        
        
          
            Soils and Foundations,
          
        
        
          44
        
        
          (6), 53-67.