The plaster board is classified into a construction supply has characteristics such as fire endurance, sound insulation, airtightness and thermal insulation properties and is inexpensiveness. It is, therefore, extensively-utilized as a construction supply without limitation to the kind of buildings such as house and towering building. For such reasons, utilization of bassanite obtained from waste plasterboard. This paper describes the results of examination in terms of following 3 points.
(1) Consideration of soildfication characteristics
The strength of cement-stabilised soil material can be increased by mixing bassanite and compacting, and then it can be tenacious. This improvement effect can be brought out shortly after the mixing and it doesn’t change with curing. The strength increase of mixed material can be expected by the additive of ancillary solidification material. It was revealed by the falling head permeability test that the material that the recycled bassanite and ancillary solidification material added to the dehydrated cake met the required performance of low-permeable soil and impermeable sheet and exhibit low permeability.
(2) Evaluation of heavy metal elution characteristics.
Fluorine elute consistency from material increased by addition to recycle bassanite increased. It is possible to elute restrain fluorine by the addition of portland bast-furance cement.
(3) Examination of accrual hydrogen sulfide
It is essential to examine the risk of hydrogen sulfide evolution. And so, hydrogen sulfide test was carried out. As a result, it is clear that the material improved by recycled bassanite does not cause hydrogen sulfide evolution even under the presence of sulfate-reducing bacteria.