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Inazumi S.,Kyoto University | Wakatsuki T.,Nihon Chemical Paints Co. | Kato K.,Nihon Chemical Paints Co. | Kobayashi M.,Nihon Chemical Paints Co.
Zairyo/Journal of the Society of Materials Science, Japan | Year: 2012

In the civil engineering field, water-swelling materials are often used as joint sealing materials to improve water cut-off performance in the joints of the steel (pipe) sheet pile. In short, water-swelling materials are extremely effective as water sealing materials. However, many characteristics of water-swelling materials have not yet been proved, and one of the unproven characteristics is the swelling pressure. Solving the issue of the swelling pressure will contribute to improving water sealing in the joints of the steel (pipe) sheet pile. At the same time, it is also expected to greatly contribute to the application of water-swelling materials for other purposes, or the new development and improvement of water-swelling materials. The purpose of this paper is to prove the characteristics of swelling pressure of water-swelling materials which are applied to joint sealing materials, e.g., a steel (pipe) sheet pile, etc., and to experimentally evaluate the swelling pressure of water-swelling materials. The results we obtained are : (1) the swelling pressure depends on the membrane thickness of the waterswelling materials. The thicker a membrane becomes, the bigger the pressure tends to be. (2) While the swelling pressure is not much influenced by the temperature of the water to be immersed, it is influenced by the quality of water to be immersed. Similar to the traits of the swelling rate, the swelling pressure when immersed in artificial sea water is lower compared with that when immersed in freshwater. (3) For example, water-swelling materials 1 mm thick achieve a swelling pressure of 6.7MPa when immersed in fresh water, and 4.2MPa when immersed in artificial sea water, respectively. Accordingly, we assume they should fully perform the swelling functions under a restricted environment as well. © 2012 The Society of Materials Science, Japan.


Inazumi S.,Kyoto University | Kimura M.,Kyoto University | Kakuda T.,Kyoto University | Kobayashi M.,Nihon Chemical Paints Co.
Soils and Foundations | Year: 2011

In this research, under various conditions, we evaluate the water cut-off performance of H-jointed steel pipe sheet piles (SPSPs) with the H-H joints attaching water-swelling materials which are components of SPSPs for water cut-off in a coastal waste landfill site. Specifically, we research the water cut-off performance when these H-H joints have foreign particles, when they are in a wet-dry cyclic condition, and when the water-swelling material has deteriorated. As a result of this research, it has been found that in any of the above cases, H-jointed SPSPs with H-H joints attaching water-swelling materials are capable of providing water cut-off performance, and meet seepage control work standards as long as they are under less than certain pressure levels to be considered in coastal waste landfill sites. Also, it has been proved that the above conditions do not affect the water cut-off performance of H-jointed SPSPs with H-H joints attaching water-swelling materials.


Inazumi S.,Kyoto University | Kimura M.,Kyoto University | Wakatsuki T.,Nihon Chemical Paints Co. | Kobayashi M.,Nihon Chemical Paints Co.
Zairyo/Journal of the Society of Materials Science, Japan | Year: 2011

A water swelling material is one of the rubbery impermeable materials which mixed synthetic resin elastomers as a base material, high absorbency polymers, filler and solvents. In this study, swelling characteristics of the water swelling material on the water polluted with COD and BOD, as an impermeable material at coastal waste landfill site, are examined by laboratory swelling ratio test. Furthermore, the factor in which it influences the swelling pressure of water swelling material is clarified by measuring the swelling pressure. As the results, the COD nor the BOD concentrations in the soaked water influence the swelling ratio of the water swelling material. When the thicknesses of water swelling material are 2 and 3mm, the maximum swelling pressure of 0.5 and 0.7MPa that correspond to hydraulic pressure by depth of 50 and 70 m is possessed, respectively. © 2011 The Society of Materials Science, Japan.

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