リサイクルプラスチック補強材による地盤補強効果についての検討

抄録

In general, in cases when the shallow ground is soft, a method of surface soil stabilization is adopted. However, problems regarding surface soil stabilization often arise. There are a lack of guaranty regarding construction quality, dispersion of the solidification material, prolonging of the curing time, operating efficiency at the time of disassembly and anxiety concerning the workability of clear and leaching of hexavalent chromium. We've developed an alternative method of surface soil stabilization in which the recycled plastic piles are driven under the foundation in fixed intervals. The piles are manufactured from material recovered by The Containers and Packaging Recycling Law and the remnants from a plastic factory. The main ingredients are polypropylene and polystyrene. The end of the pile is cone-shaped, and the axis is not hollow but filled with plastic. To verify the reinforcement effect on the composite ground by the pile, two loading tests were executed. They consisted of pushing and pulling tests of the pile, and pushing tests of the plate. In order to verify the durability of the recycled plastic piles under the ground, age acceleration tests in the laboratory and aging degradation tests of the exposed specimens were performed. The main findings of the loading tests and the durability tests are as follows : (1) The bearing capacity of the ground driven piles was more than matched that of the separate ground and piles. (2) The bearing capacity of the pile was calculated from The Swedish Weight Sounding Test and the bearing capacity of the ground driven piles were able to be evaluated by a reinforcement coefficient of 1.6. (3) The recycled plastic piles satisfied all criteria on durability tests, and no deterioration on the molecular level was confirmed.