A hydraulic composition includes in relative parts by mass with respect to first Portland cement: 100 parts of a first Portland cement the particles of which have a D50 between 10 and 25 μm; from 25 to 76 parts of a second Portland cement the particles of which have a D50 between 0.5 and 6 μm; from 85 to 200 parts of sand; water; the water content being such that the hydraulic composition includes from 170 to 250 kg of water per cubic metre of hydraulic composition; the volume distribution of particle size of the first Portland cement and of the second Portland cement being further such that the ratio D50 of the first Portland cement/D50 of the second Portland cement is greater than 2.

A repaired reinforced concrete structure is provided which includes one or more reinforcing steel bars of cross-sectional area A.sub.x, the one or more reinforcing steel bars having one or more corroded sections of cross-sectional area A.sub.y, wherein A.sub.y is greater than or equal to approximately 0.6 A.sub.x. A reinforced ordinary Portland cement-based repair mortar is positioned directly on the one or more corroded sections of the one or more reinforcing steel bars without the addition of a lapped reinforcing steel bar. The reinforced repair mortar includes at least approximately 1 percent by volume of reinforcing steel fibers such that the reinforced repair mortar restores a strength of a repaired region to greater than approximately 100% of an original strength of the concrete structure in an uncorroded state. The repaired reinforced concrete structure is highly durable, as the repair mortar exhibits an air permeability resistance of greater than 1000 seconds.

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.

A system and a method are provided for inhibiting pyrrhotite-caused damage to concrete structures. The system includes at least one concrete structure, a quantity of migratory corrosion-inhibiting solution, a quantity of concrete reinforcing solution, and a water sealing substance. The concrete structure can be any structure where the concrete aggregate contains pyrrhotite. The quantity of migratory corrosion-inhibiting solution is applied to the concrete structure to prevent further oxidation of pyrrhotite within the concrete structure. The quantity of concrete reinforcing solution is applied to the concrete structure to lower the porosity of the concrete structure and strengthen the overall integrity of the concrete structure. The water sealing substance is applied to the concrete structure to repel water from the concrete structure preventing any further chemical reactions with the pyrrhotite.

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.

An aqueous composition for repairing and/or sealing of hardened cementitious materials, especially of concrete structures, the aqueous composition including colloidal silica and a polycarboxylic acid. An aqueous composition shows a very high penetration depth as well as sealing capacity of cracked cementitious materials.

Repair mortar and methods of preparing repair mortar are provided. The repair mortar comprise a cement binder, fine aggregate and cellulose fibrils. In some embodiments, the cellulose fibrils are dispersed uniformly throughout the repair mortar. In some embodiments, the cellulose fibrils comprise nanofibrillated cellulose and/or microfibrillated cellulose. In some embodiments, the cellulose fibrils comprise an aspect ratio of between about 20 to about 500. The methods comprise mixing a cement binder, fine aggregate with water/chemical admixture to provide a cementitious material of good consistency, mixing cellulose fibrils with water to provide a cellulose fibril slurry, and mixing the cellulose fibril slurry with the workable cementitious material. In some embodiments, the cellulose fibrils are dispersed uniformly throughout the workable cementitious material.

Provided are a concrete structure repaired and reinforced using a textile grid reinforcement and a highly durable inorganic binder and a method of repairing and reinforcing the same, capable of easily repairing and reinforcing an old concrete structure by adhering a textile grid reinforcement, which is coated with a coating material to improve adhesiveness, to the old concrete structure and by adhering a textile grid reinforcement selectively using a highly durable inorganic binder having chloride penetration resistance performance or chemical resistance performance according to a use environment and a reinforcement purpose, that is, by adhering a textile grid reinforcement using an inorganic binder such as cement in place of an organic adhesive. Further, the concrete structure has excellent refractory performance because both the textile grid reinforcement such as a carbon fiber and the highly durable inorganic binder are incombustible materials, and can be effectively applied to reinforcing facilities exposed to the danger of fire.

A system and a method are provided for inhibiting pyrrhotite-caused damage to concrete structures. The system includes at least one concrete structure, a quantity of migratory corrosion-inhibiting solution, a quantity of concrete reinforcing solution, and a water sealing substance. The concrete structure can be any structure where the concrete aggregate contains pyrrhotite. The quantity of migratory corrosion-inhibiting solution is applied to the concrete structure to prevent further oxidation of pyrrhotite within the concrete structure. The quantity of concrete reinforcing solution is applied to the concrete structure to lower the porosity of the concrete structure and strengthen the overall integrity of the concrete structure. The water sealing substance is applied to the concrete structure to repel water from the concrete structure preventing any further chemical reactions with the pyrrhotite.

A structure repairing method applied to concrete structures ensures a short construction period and high reliability in a wide temperature range. The method includes a first repairing layer forming step of applying a radical-polymerizable resin composition (A) to a structure to form a first repairing layer, a second repairing layer forming step of applying a repairing material (X) containing a radical-polymerizable resin composition (Ax) and a filler (B) to the first repairing layer before the first repairing layer is cured, thereby forming a second repairing layer, and a repairing layer curing step of curing the radical-polymerizable resin composition (A) and the radical-polymerizable resin composition (Ax), wherein (A) and (Ax) each contain a radical-polymerizable resin (a1), a radical-polymerizable unsaturated monomer (a2), a hydroxy group-containing aromatic tertiary amine (a3), and an organic peroxide (a4), and (a1) and (a2) in each of (A) and (Ax) total 75% by mass or more.