| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a spontaneously decaying hardened body which is formed from materials to be secured easily and is made to spontaneously decay surely in the time required and to provide a method for supplying earth and sand by using the spontaneously decaying hardened body. <P>SOLUTION: The spontaneously decaying hardened body contains a binding material composed of three principal components of portland cement and/or ecocement, gypsum and blast furnace slag, and is hardened by mixing the binding material with water. When the gypsum is expressed in terms of anhydrous gypsum, the binding material of total 100 parts mass contains the portland cement and/or ecocement of≥30 parts mass and <70 parts mass,≥25 parts mass anhydrous gypsum and the blast furnace slag of≥10 parts mass and <49 parts mass. When the spontaneously decaying hardened body is arranged on the shore of a river or sea, or below the water surface, the spontaneously decaying hardened body decays spontaneously after the lapse of eight months or more. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
