| 摘要 |
PURPOSE:To simplify manufacture and to make light in weight of an expansion member by forming it with an expansion material, thermosoftening material, sodium silicate and a heat resisting material in specific quantities and thereby completing the expansion in a short period. CONSTITUTION:The expansion member 12 is formed by using a compounded soil in which 30-70 pts.wt. of the expansion material, 30-60 of the thermosoftening material, 10-30 of the sodium silicate and 5-30 of the heat resisting material. Around a light-weight core member 11, the expansion member 12 is arranged supported with mails 13, covered with a cardboard tube 15 and made an expansion plug. If the added quantity of the expansion material is less than 30 weight portion, the expansion quantity necessary for filling the tapping hole is not obtained; if more than 70 weight portion, a sufficient strength as a block body is not obtained. Since the expansion material and the thermosoftening material are unified as the expansion member 12, the expansion is completed in a short period and the manufacturing process is also simplified. |
