Taiheiyo Cement Corporation

Komatsu Corporation

Eichi Manabe

Yasuhide Higo

Minoru Yoshimoto

Takeshi Hamada

Kazuya Kuriyama

Hiroyuki Takano

Takeshi Yamazaki

Toshihisa Maruta

Wataru Kataoka

Masatoshi Morita

Takashi Kamiya

Osamu Fuse

Disclosed is a counterweight which is filled with a heavy-weight concrete containing, instead of currently used iron ores, a heavy-weight aggregate that scarcely causes the material segregation from cement paste and which can be produced at a low cost and is effectively enhanced in the filling factor of heavy-weight concrete into a case. A counterweightcomprises a caseand heavy-weight concrete filled therein, wherein the heavy-weight concrete contains a heavy-weight fine aggregate containing 20 mass % or more of aggregate particles having particle diameters of less than 0.15 mm and 20 mass % or more of aggregate particles having particle diameters of 2.5 mm to less than 5 mm.

Counterweight

It is aimed at providing a heavy concrete, which does not require addition of a thickener such as methyl cellulose, which is less in segregation between a heavy aggregate and a cement paste, and which is high in flowability and excellent in construction ability. The present invention provides a heavy concrete comprising, at least, a cement, a heavy aggregate, and water, mixed with one another, characterized in that the heavy fine aggregate includes hot scarves brought about in a scarfing process of a steel slab surface. The present invention further provides the above-described heavy concrete characterized in that the heavy fine aggregate includes fine aggregate particles passing through a sieve having a nominal size of 0.15 mm, in an amount of 10% to 20% in mass percentage, and the heavy fine aggregate includes spherical particles each having a distortion irregularity of 3.3 or less as defined below, in an amount of 20% or more in the whole of particles having diameters between 50 &#x3bc;m inclusive and 5 mm inclusive in the heavy fine aggregate:[Distortion irregularity]=[Length of circumferential outline of particle]/[Diameter of true circle having the same area as the area of the particle providing the outline].

Heavy concrete

A method of decontaminating a medium containing polychlorinated biphenyls (PCBs) or dioxins is disclosed. The contaminated medium is brought into contact with hairy roots derived through introduction of an Ri plasmid from,into a plant capable of absorbing, or absorbing and decomposing PCBs or dioxins, or is brought into contact with regenerated plantlets derived from the hairy roots, to thereby cause the hairy roots or regenerated plantlets to absorb, or absorb and decompose PCBs or dioxins.

Method of decontaminating medium containing polychlorinated biphenyls or dioxins

Growing community of inventors

Sakura, Japan

Eichi Manabe