Abstract: To estimate a fracture starting point of steel due to hydrogen embrittlement with high accuracy. A steel fracture starting point estimation device includes a hydrogen concentration distribution calculation unit adapted to calculate a hydrogen concentration distribution in steel-to-be-estimated when the steel fractures due to hydrogen embrittlement; a local critical hydrogen content calculation unit adapted to calculate critical hydrogen content at which the steel-to-be-estimated fractures due to hydrogen embrittlement; and a fracture starting point estimation unit adapted to read the hydrogen concentration distribution out of a storage unit. To estimate, calculate, from the hydrogen concentration distribution, a location in the steel in which hydrogen concentration of the critical hydrogen content is distributed, and designate the location in the steel as the fracture starting point of the steel-to-be-estimated.

Abstract: To easily detect a crack having occurred in a steel material. A current measurement device measures a value of a current flowing through a target steel material that is immersed in an electrolyte aqueous solution and applied with tensile stress while subjected to hydrogen charging, and a device for detecting the occurrence of a crack or the like uses the measured current value to determine the occurrence of a crack in the target steel material when the amount of change in the current flowing through the target steel material, the change rate of the amount of change in the current, or the change rate of the change rate of the amount of change in the current exceeds a threshold value.

Abstract: An accelerated corrosion test apparatus includes: a moisture sensor disposed near the reinforcing steel exposed from a cracked portion of concrete; a weight measuring instrument that measures a weight of the reinforced concrete specimen; and a control terminal that is connected both to the moisture sensor and to the weight measuring instrument and controls a temperature and humidity control device, thereby alternately and repeatedly performing a wetting step of supplying moisture to the inside of a crack in the cracked concrete, and a drying step of removing moisture in the inside of the crack and moisture on the exposed surface of the reinforcing steel, wherein the control terminal terminates the wetting step and starts the drying step when moisture is detected in the moisture sensor, or when change in slope of weight change of the reinforced concrete specimen is detected, after the start of the wetting step.

Abstract: A composition ratio calculating unit configured to calculate a first composition ratio that is a ratio of substance quantities of rust collected from a broken surface of internal steel of an updated old concrete structure and a second composition ratio that is a ratio of substance quantities of rust collected from a surface different from the broken surface, a composition ratio calculating unit configured to calculate a first corrosion time corresponding to the first composition ratio and a second corrosion time corresponding to the second composition ratio from characteristics representing a relation between a first corrosion time and the first composition ratio and a relation between a second corrosion time and the second composition ratio, respectively, and a breaking time calculating unit configured to calculate a time for the internal steel to break by subtracting the first corrosion time from the second corrosion time are included.

Abstract: An occluded hydrogen content estimation method implemented by an occluded hydrogen content estimation device performs an occluded hydrogen content estimation step in which, based on an occluded hydrogen unit content which is a content of hydrogen occluded in a metal due to a change in humidity from a wet state to a dry state, a period after the metal is placed, and meteorological data corresponding to the period for an area where the metal is located, a content of occluded hydrogen that is absorbed in the metal for the period after the metal is placed is estimated. In the occluded hydrogen content estimation step, the occluded hydrogen content is estimated by multiplying the number of rainfalls in the meteorological data by the occluded hydrogen unit content.

Abstract: To estimate penetration behavior of hydrogen up until hydrogen content reaches saturation even if load stress on steel is equal to or higher than threshold stress.

Abstract: An estimation device has: determination unit for acquiring a characteristic color of reinforced concrete in a dry state from an initial image obtained by capturing an image of a concrete surface of the concrete, analyzing a first image of the concrete surface that is captured after spraying water onto the reinforced concrete, and determining a portion having a predetermined color difference from the characteristic color as a crack; and an estimation unit for impregnating the crack with water, analyzing a second image of the concrete surface that is captured after the concrete surface is dried, and estimating whether or not the inside of the crack is carbonated, using a color around the crack.

Abstract: A composition ratio calculating unit configured to calculate a first composition ratio that is a ratio of substance quantities of rust collected from a broken surface of internal steel of an updated old concrete structure and a second composition ratio that is a ratio of substance quantities of rust collected from a surface different from the broken surface, a composition ratio calculating unit configured to calculate a first corrosion time corresponding to the first composition ratio and a second corrosion time corresponding to the second composition ratio from characteristics representing a relation between a first corrosion time and the first composition ratio and a relation between a second corrosion time and the second composition ratio, respectively, and a breaking time calculating unit configured to calculate a time for the internal steel to break by subtracting the first corrosion time from the second corrosion time are included.

Abstract: Provided is a method for evaluating a hydrogen embrittlement fracture risk of an iron reinforcing bar that is performed by a hydrogen embrittlement fracture risk evaluation apparatus, the method including: a fracture probability curved surface generation step of obtaining a fracture probability curved surface representing a probability of the iron reinforcing bar fracturing by performing regression analysis on results obtained by repeatedly carrying out a hydrogen embrittlement test while changing an amount of hydrogen absorbed in the iron reinforcing bar provided in a concrete structure and a tensile stress applied to the iron reinforcing bar and using the amount of hydrogen and the tensile stress as variables; a lower limit stress acquisition step of acquiring, from the fracture probability curved surface, a lower limit stress property representing a relationship between a lower limit stress that is a lower limit of the tensile stress at which no fracture occurs in the iron reinforcing bar at a predetermine

Abstract: The accuracy in simulation values of environmental elements is improved. A simulation value calculation device includes: a simulation copula calculation unit that calculates simulation values of a plurality of environmental elements in an actual environment by using a predetermined copula function indicating a correlation between marginal distributions of the plurality of environmental elements; a simulation value calculation unit; and a data recording unit that stores the simulation values.

Abstract: Provided is an anticorrosion device that does not require the installation of electrical equipment and has no concern about loss of anticorrosion effect due to deterioration of the anode. An anticorrosion device that prevents corrosion of a metal material in a structure, including a thermoelectric power generation unit 10 configured to generate an electromotive force due to a temperature gradient, an anode unit 20 that is responsible for an anode reaction corresponding to the electromotive force, and a cathode unit 30 that is responsible for a cathode reaction corresponding to the electromotive force, in which the cathode unit 30 is a metal material (target metal) in the structure.

Abstract: To improve the accuracy of estimating when a fracture occurred in the metal material. In the estimation apparatus, the fracture temperature estimation unit performs estimate calculation of the fracture temperature of a fractured metal material from the hydrogen embrittlement rate of the fractured metal material, the fracture occurrence time narrowing unit performs calculation by using the temperature information of the installation environment in which the fractured metal material is installed and narrow down the period during which the fracture temperature is obtained as the fracture occurrence period of the metal material, and the fracture time estimation unit performs estimate calculation of the timing of when stress was applied to the fractured metal material during the fracture occurrence period as the timing of when a fracture occurred in the metal material.

Abstract: To repair reinforced concrete easily and at low cost. An anticorrosion method includes infiltrating an anticorrosion solution held inside concrete of reinforced concrete into a vicinity of a reinforcing bar through the concrete to passivate the reinforcing bar, detecting that the anticorrosion solution is infiltrated to a surface of the concrete, and discharging, after detecting the anticorrosion solution, the anticorrosion solution to outside of the concrete to form an anticorrosive coating on a surface of the reinforcing bar.

Abstract: A cumulative distribution function of fracture time is calculated from large quantities of hydrogen embrittlement fracture test data measured under test conditions that assume reinforcing bars in prestressed concrete, transition probability is calculated from the cumulative distribution function of fracture time with a hydrogen embrittlement fracture being regarded as a stochastic process through which a degraded state progressively reaches a fractured state, and the time integral of the transition probability is found as the degree of progress of hydrogen embrittlement.

Abstract: A hydrogen generation device capable of generating hydrogen using an inexpensive material is provided. The hydrogen generation device includes: a water flow path unit through which a solution flows in from outside and exits; a hydrogen generation unit made of a metal, the hydrogen generation unit generating hydrogen by a reaction with the flowing-in solution; and a hydrogen collection unit for collecting the generated hydrogen, wherein the hydrogen generation unit is disposed so that friction with the flowing-in solution peels off a surface film of the metal to expose an active surface of the metal, the metal being the hydrogen generation unit itself.

Abstract: Reinforced concrete is protected from corrosion without conducting an operation involving exposure of rebar. A reinforced concrete structure is provided with a storage part that is formed inside concrete of the reinforced concrete structure, and that retains an anticorrosion solution. The anticorrosion solution diffuses and permeates through the concrete from the storage part, prevents the concrete in the vicinity of rebar from drying, and passivates the rebar.

Abstract: Reinforced concrete is easily repaired at a low cost. An anti-corrosion method for preventing corrosion of a reinforcing bar inside reinforced concrete includes: an impregnation step of impregnating with water a cracked portion having occurred in the reinforced concrete, and a drying step of removing the water from the cracked portion and forming an anti-corrosive coating on the surface of the reinforcing bar. The anti-corrosive coating is formed by the neutralization of an alkali component by the drying step, the alkali component having been leached from concrete in the cracked portion by the impregnation step.

Abstract: An accelerated corrosion test apparatus that accelerates corrosion of reinforcing steel contained in reinforced concrete specimen having cracking includes: a moisture sensor disposed near the reinforcing steel exposed from a cracked portion of concrete; a weight measuring instrument that measures a weight of the reinforced concrete specimen; and a control terminal that is connected both to the moisture sensor and to the weight measuring instrument and controls a temperature and humidity control device, thereby alternately and repeatedly performing a wetting step of supplying moisture to the inside of a crack in the cracked concrete, and a drying step of removing moisture in the inside of the crack and moisture on the exposed surface of the reinforcing steel, wherein the control terminal terminates the wetting step and starts the drying step when moisture is detected in the moisture sensor, or when change in slope of weight change of the reinforced concrete specimen is detected, after the start of the wetting

Abstract: A repair apparatus for repairing damaged reinforcing bars in a structure includes a strip-shaped conductor including a plurality of conductive wires arranged in a height direction, the plurality of conductive wires being arranged in parallel to each other, a high-frequency current generation unit configured to supply a high-frequency current between the plurality of conductive wires of a first end side of the conductor and the plurality of conductive wires of a second end side of the conductor, and a connection body configured to connect the plurality of conductive wires to each other and connect the first end side and the second end side of the conductor so that the plurality of conductive wires form a coil, and the high-frequency current generation unit supplies a high-frequency current between a conductive wire at an upper end or a lower end of the first end side of the conductor and a conductive wire at a lower end or an upper end of the second end side of the conductor.

Abstract: A test time for measuring hydrogen diffusion in a steel material is improved. The reproducibility of a position where hydrogen exists in the steel material is improved. A control terminal controls a solution supply/discharge control device, a gas supply control device, a first potentiostat/galvanostat, and a second potentiostat/galvanostat on the basis of a predefined procedure, so that a plurality of processing steps, which are performed for analyzing hydrogen diffused from the inside to the surface of a steel material to be measured, are performed continuously. Further, the processing of inactivating the surface of the steel material to be measured is performed before the main processing using a metal ion replacement method, or an inert gas is injected into the solution during the main processing.