KR-102963323-B1 - Method for restoring concrete sections using grout mortar

Abstract

The present invention relates to a method for repairing a concrete section using grout mortar, and more specifically, to a method for repairing a concrete section damaged by cracks, spalling, etc., while simultaneously increasing resistance to salt damage, resistance to freezing and thawing, and resistance to chemical corrosion, thereby suppressing re-striping and re-cracking of the repaired section and ensuring that the repaired section is stably maintained for a long period even after repair.

Inventors

• 신명순

Assignees

• 주식회사 리가채움

Dates

Publication Date

20260511

Application Date

20250402

Claims (4)

1. A method for repairing a concrete section using grout mortar, comprising: a first step of spraying a rust inhibitor onto the surface of exposed rebar in a decomposed concrete section; a second step of applying an alkali agent over the coating surface sprayed in the first step; a third step of repairing the decomposed concrete section by applying a repair mortar after the second step; and a fourth step of finishing the surface by applying a waterproofing agent to the repaired section after the third step; Before performing the first step above, the corrosion status of the exposed rebar is inspected, and if corrosion is present, a pretreatment step is further performed to clean the corroded area and remove the corrosion, wherein the pretreatment step involves mixing and stirring 100g of dish soap, 200g of sodium percarbonate, and 200g of citric acid in 1 liter of hot water at 70-80℃, spraying this mixture onto the exposed rebar while scrubbing with a wire brush to remove the corrosion, and then washing with high-pressure water; The rust inhibitor used in the first step above is in the form of a mixture comprising 0.2 liters of ethanolamine, 450 g of potassium phosphate, 100 g of boric acid, and 150 g of benzoic acid, based on 1 liter of water; The alkali agent used in the second step above is a mixture prepared by mixing 200g of polysiloxane, 200g of water-soluble nitrite, and 200g of lithium silicate salt based on 1 liter of water to achieve a pH of 11 or higher; The repair mortar used in the third step above consists of 20-30% by weight of Portland cement, 20-30% by weight of silica sand, 20-30% by weight of epoxy resin, 5-10% by weight of methylcellulose, 4-6% by weight of alkylphenol, and the remainder being water; To the above repair mortar, 5.5 parts by weight of sulfur trioxide, 4.5 parts by weight of melamine sulfonate, and 5 parts by weight of magnesium oxide are further added to 100 parts by weight of the repair mortar; A method for repairing a concrete section using grout mortar, characterized in that the waterproofing material used in the fourth step above is composed of mixing 5.5 parts by weight of vinylpyrrolidone, 5 parts by weight of 2-phenylimidazole, 5.5 parts by weight of polymethylpentene, 4.5 parts by weight of tridymite, and 10 parts by weight of methylsulfonylmethane with respect to 100 parts by weight of polyurethane resin.
2. delete
3. delete
4. delete

Description

Method for restoring concrete sections using grout mortar The present invention relates to a method for repairing a concrete section using grout mortar, and more specifically, to a method for repairing a concrete section damaged by cracks, spalling, etc., while simultaneously increasing resistance to salt damage, resistance to freezing and thawing, and resistance to chemical corrosion, thereby suppressing re-striping and re-cracking of the repaired section and ensuring that the repaired section is stably maintained for a long period even after repair. Generally, concrete structures deteriorate over time due to carbonation, where carbon dioxide reacts with moisture to cause corrosion of reinforcing steel; chloride intrusion, where bases from sea breezes, seawater, and de-icing calcium chloride penetrate the concrete to cause corrosion of reinforcing steel; and alkali-silica reaction, where high-alkali cement and specific aggregates react and expand in the presence of moisture, causing cracking in the concrete, thereby shortening their lifespan. In particular, as traffic volume has increased rapidly recently, the carbonation of concrete is accelerating rapidly due to the generation of carbon dioxide in exhaust gases emitted from automobiles. When concrete becomes carbonated, the passivation film protecting the reinforcing steel is destroyed, causing the reinforcing steel to corrode. When the reinforcing steel inside the concrete corrodes, cracking and spalling of the concrete occur due to the expansion of the reinforcing steel volume, and in severe cases, it can even lead to the collapse of the structure. Therefore, it is necessary to inhibit the corrosion of reinforcing steel inside the concrete. In addition, in concrete structures, the interior and exterior walls may experience partial damage due to cracks or detachment over time, requiring periodic repairs. Typically, the section is repaired by applying concrete mortar, but because it has poor compatibility with the existing concrete wall and has a short lifespan, it often falls off again after a short time. Therefore, improvements to this are necessary. Hereinafter, preferred embodiments according to the present invention will be described in more detail. This invention is primarily applied to the restoration of cross-sections of apartment exterior walls and concrete structures. A method for repairing a concrete section using grout mortar according to the present invention comprises: a first step of spraying a rust inhibitor onto the surface of exposed reinforcing bars in a decomposed concrete section; a second step of applying an alkali agent onto the coating surface sprayed in the first step; a third step of repairing the section by applying a repair mortar to the decomposed concrete section after the second step; and a fourth step of finishing the surface by applying a waterproofing agent to the repaired section after the third step. At this time, the first step is a step for reinforcing the exposed rebar in the detached section because it is corroded or prone to corrosion. Therefore, before performing the above first step, a pretreatment step may be performed first to inspect the corrosion status of the exposed rebar and, if it is corroded, to clean the corroded area to remove the corrosion. The above pretreatment step is a step of removing corrosion by mixing and stirring 100g of dish soap, 200g of sodium percarbonate, and 200g of citric acid in 1 liter of hot water at 70-80℃, spraying the mixture onto exposed rebar, and scrubbing with a wire brush. In addition, it includes the process of high-pressure washing with water after brushing with a wire brush. In addition, the rust inhibitor used in the first step above is in the form of a mixture of 0.2 liters of ethanolamine, 450 g of potassium phosphate, 100 g of boric acid, and 150 g of benzoic acid, based on 1 liter of water. At this time, ethanolamine performs surfactant and corrosion prevention functions; potassium phosphate contributes to maintaining the balance of acids and bases by adjusting the pH; boric acid contributes to increasing water resistance and corrosion protection effects; and benzoic acid contributes to increasing the anti-corrosion effect. And, the second step above is a step of applying an alkali agent to prevent carbonation of the exposed rebar. In this case, the alkali agent used is a mixture of 200g of polysiloxane, 200g of water-soluble nitrite, and 200g of lithium silicate salt based on 1 liter of water, so that the pH becomes 11 or higher. These enhance the anti-corrosion effect through the reduction of moisture and chloride ions. Meanwhile, the third step above includes the process of manufacturing a repair mortar. The above repair mortar consists of 20-30% by weight of Portland cement, 20-30% by weight of silica sand, 20-30% by weight of epoxy resin, 5-10% by weight of methylcellulose, 4-6% by weight of alkylphenol, and the remainder being water. At this time, Portland cem