PROBLEM TO BE SOLVED: To provide a concrete structure and a concrete slab, which, by using a continuous fiber-reinforced polymer material as a main reinforcing material or a tendon, and by mixing a short fiber reinforcing material in concrete, compensate for the mechanical shortcomings of the continuous fiber-reinforced polymer material, not rusting, and taking advantage of superior characteristics of the continuous fiber-reinforced polymer material, with low manufacturing cost and ultra-high durability.

MEANS TO SOLVE THE PROBLEM: In a concrete structure, in which a continuous fiber-reinforced polymer material is arranged as a main reinforcing material or a tendon, a short fiber reinforcing material consisting of an organic fiber is mixed in 0.5% or more with respect to an entire volume, the continuous fiber-reinforced polymer material is shaped like a rod or a stranded wire, a ratio Lf/Gm between a fiber length Lf of the organic fiber of the short fiber reinforcing material and a maximum aggregate diameter Gm of a concrete composition is 1.2 to 3.7, and an aspect ratio Lf/De when an equivalent diameter De, which is a cross-sectional area of the organic fiber converted into a circle diameter, is 30 to 69.

PROBLEM TO BE SOLVED: To provide a concrete structure and a concrete slab, which, by using a continuous fiber-reinforced polymer material as a main reinforcing material or a tendon, and by mixing a short fiber reinforcing material in concrete, compensate for the mechanical shortcomings of the continuous fiber-reinforced polymer material, not rusting, and taking advantage of superior characteristics of the continuous fiber-reinforced polymer material, with low manufacturing cost and ultra-high durability.

MEANS TO SOLVE THE PROBLEM: In a concrete structure, in which a continuous fiber-reinforced polymer material is arranged as a main reinforcing material or a tendon, a short fiber reinforcing material consisting of an organic fiber is mixed in 0.5% or more with respect to an entire volume, the continuous fiber-reinforced polymer material is shaped like a rod or a stranded wire, a ratio Lf/Gm between a fiber length Lf of the organic fiber of the short fiber reinforcing material and a maximum aggregate diameter Gm of a concrete composition is 1.2 to 3.7, and an aspect ratio Lf/De when an equivalent diameter De, which is a cross-sectional area of the organic fiber converted into a circle diameter, is 30 to 69.

A concrete composition having an optimized formulation and suitable for 3-D printing is provided. The composition may include a hydraulic cement composition, aggregate, cement and/or aggregate by-product dust, one or more rheology modifiers, a plasticizer, fibers, and a sufficient amount of water to effect setting of the composition. Optionally the concrete composition may include a setting agent. A method for 3D printing multiple layers of the concrete composition is also provided.

The present invention provides a crack repair material of a concrete vacuum tube segment using ultra-high performance concrete (UHPC) for a hyper-speed transportation system and a crack repairing method for the same capable of, in a case in which a vacuum tube segment of a hyper-speed transportation system, such as the Hyperloop, is manufactured using UHPC, repairing cracks formed in the UHPC vacuum tube segment easily and conveniently using a crack growth prevention material and a patch repair material and capable of immediately repairing cracks formed in the UHPC vacuum tube segment to secure airtightness so that operation of a vacuum pump is minimized and overload of the vacuum pump is prevented.

The present invention provides a crack repair material of a concrete vacuum tube segment using ultra-high performance concrete (UHPC) for a hyper-speed transportation system and a crack repairing method for the same capable of, in a case in which a vacuum tube segment of a hyper-speed transportation system, such as the Hyperloop, is manufactured using UHPC, repairing cracks formed in the UHPC vacuum tube segment easily and conveniently using a crack growth prevention material and a patch repair material and capable of immediately repairing cracks formed in the UHPC vacuum tube segment to secure airtightness so that operation of a vacuum pump is minimized and overload of the vacuum pump is prevented.

The present invention provides a concrete vacuum tube segment for a hyper-speed transportation system using ultra-high performance concrete (UHPC) and a manufacturing method thereof. A concrete vacuum tube segment for a hyper-speed transportation system can be easily manufactured using UHPC, in which shrinkage and structural cracking do not occur due to mixing a binder and a short fiber to secure airtightness on the basis of a maximum fill theory, and accordingly, shrinkage of the concrete vacuum tube segment can be reduced even in a partial-vacuum state in which the magnitude of drying shrinkage is very small and quick drying occurs; when mixing the UHPC, an antifoaming agent is mixed and a circular vacuum pump is used to remove generated entrapped air to minimize the entrapped air; and a capsule-type crack healing material, which is able to repair fine cracks, is compacted to secure airtightness of the concrete vacuum tube segment.

The present invention relates to a cured composite comprising (A) an aluminosilicate source, (B) an alkali activator and (C) alkali-resistant fibers, in which: the aluminosilicate source (A) contains a blast furnace slag, in which the content of the blast furnace slag is 40% by mass or more relative to a total solid content in the aluminosilicate source (A); the content of the alkali activator (B) is 10% by mass or less relative to a total solid content in the curable composition; and the water content in the cured composite is 10.0% by mass or less relative to a total mass of the cured composite.

The present invention relates to a cured composite comprising (A) an aluminosilicate source, (B) an alkali activator and (C) alkali-resistant fibers, in which: the aluminosilicate source (A) contains a blast furnace slag, in which the content of the blast furnace slag is 40% by mass or more relative to a total solid content in the aluminosilicate source (A); the content of the alkali activator (B) is 10% by mass or less relative to a total solid content in the curable composition; and the water content in the cured composite is 10.0% by mass or less relative to a total mass of the cured composite.

Reinforcing filaments or fibers, such as aromatic polyamide (aramid) fibers, can be reliably measured and consistently mixed into asphalt cement concrete by soaking the fibers in a wetting agent, then severing them to a desired length, and mixing the segments with other ACC ingredients. The wetting agent holds the fibers together loosely, so they can be distributed more uniformly throughout the ACC without clumping. The wetting agent soaks into the ACC mixture and/or evaporates, leaving the reinforcing fibers behind.

Reinforcing filaments or fibers, such as aromatic polyamide (aramid) fibers, can be reliably measured and consistently mixed into asphalt cement concrete by soaking the fibers in a wetting agent, then severing them to a desired length, and mixing the segments with other ACC ingredients. The wetting agent holds the fibers together loosely, so they can be distributed more uniformly throughout the ACC without clumping. The wetting agent soaks into the ACC mixture and/or evaporates, leaving the reinforcing fibers behind.