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: A method for manufacturing a concrete structure comprises an installation step of installing a formwork 30 for concrete placement, a placement step of performing concrete placement in a state where a curing sheet 10 is attached to an inner surface of the formwork 30, and a demolding step of removing the formwork 30 after placement of concrete C. A contact angle of a contact surface of the curing sheet 10 for use in the placement step with water is 50 degrees or more, wherein the contact surface faces the concrete. Thus, generation of bleeding water is suppressed.

Abstract: A method for manufacturing a concrete structure comprises an installation step of installing a formwork 30 for concrete placement, a placement step of performing concrete placement in a state where a curing sheet 10 is attached to an inner surface of the formwork 30, and a demolding step of removing the formwork 30 after placement of concrete C. A contact angle of a contact surface of the curing sheet 10 for use in the placement step with water is 50 degrees or more, wherein the contact surface faces the concrete. Thus, generation of bleeding water is suppressed.

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.