Material properties of water-swelling material used as a water cutoff treatment material at waste landfill sites

Abstract

Water-swelling material (WSM) is a fl uid sealant obtained by blending high-absorbency polymer, a fi ller, and a solvent by using a synthetic resin elastomer as the base material. In this research, we studied experimentally the composition of WSM, the extent of swelling, the strength of the WSM and the long-term performance of the swelling material used as a jointed water cutoff treatment material at waste landfi ll sites. One of the results was that adjusting the degree of etherifi cation of the high-absorbency polymer, which is a component of the WSM, and the resin content of the synthetic elastomer contributed to improvement of the swelling of the sealant and the strength of the swelling material. Further, in long-term tests, the strength of the WSM tended to become stabilized and it was confi rmed that it had suffi cient pressure resistance for use in coastal landfi ll sites, where its application as a water cutoff treatment material is being considered.

Water Cut-Off Performance of H-Jointed Steel Pipe Sheet Piles with H-H Joints Attaching Water-Swelling Materials

“…Also, the strength of the center of the swelling membrane reduces from 1400 to 110 kPa during 44 days of the curing period. The existing study has demonstrated that the strength of the center of the swelling membrane of waterswelling material immersed in water at a water temperature of 209 C reduces from about 930 to about 135 kPa in one year and maintains an almost constant value after that (Inazumi et al, 2010). This means that curing at a water temperature of 409 C for 44 days can simulate the curing at a water temperature of 209 C for a year.…”

“…The water extracted from a dried lm of water-swelling material fulˆlls the Food Sanitation Law Standards and is not harmful to the environment. At present, the composition of frequently used water-swelling materials is such that when it is soaked in plain water or sea water for 24 hours, it swells up to 15-30 times and 5-7 times, respectively, in terms of weight ratio (Inazumi et al, 2010). Also, inside the H-H joints where the water cut-oŠ treatment is implemented by the waterswelling material is forced with approximately 200×200 mm is formed ( see Figs.…”

“…In addition, deterioration behavior (referred to as``deterioration'' below) of the water-swelling material attached to the ‰ange of an H-H joint is also reviewed and researched using the strength of the swelling membrane (Inazumi et al, 2010). Figure 10 shows the result of strength tests of the swelling membrane implemented by Inazumi et al (2010) who reported that the strength of the swelling membrane applied to H-H joint is reduced from about 930 to about 140 kPa over the course of a year and after that it continues to show a certain constant value. The strength of swelling material was deˆned as the strength required (by the penetration elastic tool with a 3 mm diameter) for penetration and breaking of the water-swelling material (Inazumi et al, 2010).…”

“…Figure 10 shows the result of strength tests of the swelling membrane implemented by Inazumi et al (2010) who reported that the strength of the swelling membrane applied to H-H joint is reduced from about 930 to about 140 kPa over the course of a year and after that it continues to show a certain constant value. The strength of swelling material was deˆned as the strength required (by the penetration elastic tool with a 3 mm diameter) for penetration and breaking of the water-swelling material (Inazumi et al, 2010). It is believed that this eŠect is caused because a superabsorbent polymer included in the water-swelling material continues to elute for a year from the beginning of the curing and after that year, the elution is complete.…”

Evaluation of Maintenance Strategies Based on Leakage Risk Assessment on Side Impervious Walls at Coastal Landfill Sites

“…Other factors include reduction in durability due to chemical reactions and wet-dry cycles. Waterswelling materials do not react with chemical substances except trichloroethylene, dichloromethane, and carbon tetrachloride [7]. Nevertheless, the durability of the water-swelling materials is independent of reactions with these three chemicals in the concentration equivalent with the standard of waste acceptability [3].…”