Abstract: In an LNG tank, a dike is formed by arranging precast blocks in the circumferential direction and layering the precast blocks in the vertical direction. Each of the precast blocks has loop joints on the top, bottom, left, and right side faces, and concrete is deposited between each two precast blocks adjacent in the circumferential direction and the vertical direction, whereby masonry joints are formed in the vertical direction and the circumferential direction. Prestress is imparted to the dike by PC steel members. The PC steel members are provided in the circumferential direction and the vertical direction of the dike, and are arranged so as to avoid the masonry joints in the circumferential direction and the vertical direction. Therefore, it is possible to construct the dike in a short time, and it is possible to provide a tank or the like that can reduce the construction period.

Abstract: In an LNG tank, a dike is formed by arranging precast blocks in the circumferential direction and layering the precast blocks in the vertical direction. Each of the precast blocks has loop joints on the top, bottom, left, and right side faces, and concrete is deposited between each two precast blocks adjacent in the circumferential direction and the vertical direction, whereby masonry joints are formed in the vertical direction and the circumferential direction. Prestress is imparted to the dike by PC steel members. The PC steel members are provided in the circumferential direction and the vertical direction of the dike, and are arranged so as to avoid the masonry joints in the circumferential direction and the vertical direction. Therefore, it is possible to construct the dike in a short time, and it is possible to provide a tank or the like that can reduce the construction period.

Abstract: An ultra high strength fiber-reinforced cement composition includes cement, silica fume, coal gasification fly ash, insoluble anhydrous gypsum, and metal fiber having a length between 5 and 30 mm and a diameter of between 0.1 and 1 mm. The coal gasification fly ash is spherical fine particles having a maximum particle size between 5 and 10 ?m. Mass ratio of the silica fume: the coal gasification fly ash is 95 through 50 portions: 5 through 50 portions.

Abstract: Therefore, the problem to be solved by the present invention is to provide highly general purpose ultra high strength fiber-reinforced mortar or concrete that shows a higher fluidity (workability) at the fresh state, a higher bending strength with a less content of metal fiber by enhancing both the absolute value of the compressive strength of mortar -matrix excluding metal fiber and the ratio of the bending strength relative to the compressive strength simultaneously at the hardened state, and acceptability of fine aggregate being used in ordinary ready-mixed concrete. An ultra high strength fiber-reinforced cement composition is characterized in that it contains cement, silica fume, coal gasification fly ash, gypsum and metal fiber and that the mass ratio of silica fume : coal gasification fly ash is 95 through 50 portions: 5 through 50 portions. Ultra high strength fiber-reinforced mortar or concrete contains such a cement composition and fine aggregate.

Abstract: A method is provided for reducing autogenous shrinkage in ultra high-strength concrete in the blending of ultra high-strength concrete with a compression strength in excess of 100 N/mm2, comprising the steps of: replacing 30 vol. % or less of coarse aggregate with artificial lightweight aggregate, and blending in a expansive additive in the amount of 30 kg/m3 of concrete and/or a shrinkage reducing agent in the amount of 4 wt. % or less per unit weight of binder, and thereby bringing the amount of autogenous shrinkage at a curing age of 91 days to 0-600 ?m/m. The artificial lightweight aggregate used has water absorption of 5% or greater and 20% or less, a collapse load of 1000-2000 N and a bone-dry density of 1.4-2.0 g/cm3.