| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide blast furnace slag cement which hardly expands due to a sulfate, in order to solve the following problem: concrete produced from blast furnace slag cement and being a mixture of high alumina blast furnace slag fine powder with portland cement expands due to the generation of ettringite when the concrete is in contact for a long period of time with soil in which sulfate remains, resulting in the destruction of the concrete structure. <P>SOLUTION: Mixed cement mainly contains blast furnace slag fine powder where the ratio of alumina is 12-17.5 mass% and portland cement, wherein the mixing ratio of the blast furnace slag fine powder is controlled to 10-60 mass% and the mixed cement is mixed with gypsum having≥7,000 cm<SP>2</SP>/g specific surface area, wherein the mixing ratio is 2-4 mass% expressed in terms of SO<SB>3</SB>. The mixed cement is used as a raw material of the sulfate-resisting concrete. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
