| 摘要 |
An object of the invention is to provide a low-activation cement concrete structure having the ability to block off radiations. The invention provides a low-activation hydraulic composition, wherein calcium aluminosilicate has a chemical composition comprising, in the total of CaO, Al 2 O 3 , SiO 2 , MgO and ZrO 2 , 25 to 55 parts of CaO, 16 to 45 parts of Al 2 O 3 , 23 to 40 parts of SiO 2 , 0 to 1 part of MgO and 0 to 4 parts of ZrO 2 , with an Eu content being less than 0.3 mg/kg and a Co content being less than 15 mg/kg. Preferably, the calcium aluminosilicate has a percentage of glass content of at least 70%, and a free calcium oxide content of 0 to less than 2 parts in the calcium aluminosilicate. Gypsum or cement may also be contained. |
