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KR-102963535-B1 - Moisture-Responsive Mortar Composition and Repair Reinforcement Method for Concrete Structures Using the Same

KR102963535B1KR 102963535 B1KR102963535 B1KR 102963535B1KR-102963535-B1

Abstract

The present invention relates to a wet-responsive mortar composition and a method for repairing and reinforcing concrete structures using the same. More specifically, the invention relates to a mortar composition for repairing concrete structures and a method for repairing and reinforcing concrete structures using the same, which can satisfy required physical properties such as strength, setting time, flow, and non-segregation in water by applying a repair material containing silica fume surface-modified with nanosilica and a wet-responsive admixture in the mortar to repair damaged parts of deteriorated concrete structures, mainly civil engineering structures, hydraulic structures, and underground structures.

Inventors

  • 이선목

Assignees

  • (주)리브릿지씨엠씨

Dates

Publication Date
20260513
Application Date
20251205

Claims (11)

  1. Characterized by comprising a binder comprising 10 to 40 parts by weight of cement, 1 to 10 parts by weight of an expansive agent, and 5 to 30 parts by weight of a filler, 40 to 60 parts by weight of aggregate, and 10 to 15 parts by weight of an admixture. The above filler is characterized by being a mixture of silica fume surface-modified with nanosilica and blast furnace slag fine powder in a weight ratio of 1:0.5 to 3.0, wherein A wet-response mortar composition characterized by surface-modified silica fume with nanosilica, wherein nanosilica containing hydroxyl and carboxyl groups obtained by causing a sol-gel reaction between an amphiphilic nonionic silane and an amphiphilic anionic silane is mixed in a ratio of 1 to 10 parts by weight per 100 parts by weight of silica fume, and the nanosilica is fixed to the surface of silica fume particles using a drying air in a sealed space.
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  4. A wet-response mortar composition according to claim 1, wherein the admixture is mixed with 0.1 to 0.5 parts by weight of a wet-response admixture, 5 to 15 parts by weight of a polymer powder resin, 0.05 to 3.0 parts by weight of a fiber, 0.01 to 1.0 parts by weight of a fluidizing agent, 0.1 to 3.0 parts by weight of an accelerator, and 0.01 to 1.0 parts by weight of an antifoaming agent.
  5. A wet-responding mortar composition according to claim 4, wherein the wet-responding admixture is characterized by an acrylic polymer and a cellulose polymer mixed in a weight ratio of 1:3 to 5.
  6. A wet-response mortar composition according to claim 5, characterized in that the acrylic polymer is one or more selected from polyacrylamide, sodium polyacrylate, and polyethylene oxide.
  7. A wet-response type mortar composition according to claim 5, wherein the cellulose-based polymer is one or more selected from methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, hydroxyethylethylcellulose, carboxymethylcellulose, and carboxyethylcellulose.
  8. A wet-response type mortar composition according to claim 4, characterized in that the polymer powder resin is a VAE (vinyl acetate ethylene) polymer powder resin.
  9. A wet-response mortar composition according to claim 4, characterized in that the fiber is one or more selected from nylon fiber, polyvinyl alcohol (PVA) fiber, polyvinyl chloride (PVC) fiber, glass fiber, polypropylene (PP) fiber, cellulose fiber, and polyethylene fiber.
  10. Step 1: Preparing the substrate surface through chipping and high-pressure water washing; Step 2, removing rust from rebar and applying rebar rust inhibitor after the substrate surface has been prepared; Step 3, applying a primer to the surface coated with a rebar rust inhibitor; and A method for repairing and reinforcing a concrete structure, characterized by comprising: a fourth step of applying a wet-response mortar composition according to claim 1 to a surface coated with a primer.
  11. In claim 10, after the fourth step, A method for repairing and reinforcing a concrete structure, further comprising: a fifth step of applying a surface protection coating agent to the outer surface where the above-mentioned wet-response mortar composition has been filled.

Description

Moisture-Responsive Mortar Composition and Repair Reinforcement Method for Concrete Structures Using the Same The present invention relates to a wet-responsive mortar composition and a method for repairing and reinforcing concrete structures using the same. More specifically, the invention relates to a mortar composition for repairing concrete structures and a method for repairing and reinforcing concrete structures using the same, which can satisfy required physical properties such as strength, setting time, flow, and non-segregation in water by applying a repair material containing silica fume surface-modified with nanosilica and a wet-responsive admixture in the mortar to repair damaged parts of deteriorated concrete structures, mainly civil engineering structures, hydraulic structures, and underground structures. As the aging of large-scale domestic SOC facilities accelerates, as of 2020, there are 27,997 facilities that are 30 years or older, accounting for 157% of all facilities. Of these, excluding buildings such as multi-unit housing, there are 10,278 facilities that are 30 years or older, representing 181% of all facilities, and it is projected that within the next 10 years, more facilities will be over 30 years old than the current ones. Accordingly, approximately 593 trillion won was invested in infrastructure management from 2014 to 2019, and the average annual management cost has been on a continuous upward trend. In particular, in the case of Korea, budget costs for maintenance and performance improvement are expected to increase dramatically as the improvement cycle for infrastructure, which was built in earnest starting in the 1970s, comes to an end. Looking at the road budget over the past five years presented by the Ministry of Land, Infrastructure and Transport, the budget for road management has been continuously increasing, and the proportion of the budget spent on road maintenance has reached 297% (2020). Furthermore, the primary cause of urban sinkholes, which have recently emerged as a social issue, is reported to be the deterioration of sewer pipes. This leads to the leakage of internal sewage, which expands cavities around the pipes and causes them to be unable to withstand the load from above, resulting in subsidence and collapse. To address this problem, maintenance is being carried out through the inspection and repair of sewer pipes. As for major repair methods, trenchless full and partial repair techniques are applied to prevent issues such as urban traffic disruption, environmental pollution, and damage to existing structures. Although repairs are performed after removing most of the moisture from inside the sewer pipes, the current situation presents a problem where, while sufficient repair effects are achieved on the upper and side sections, the repair materials fail to perform fully due to moisture remaining in the lower sections. According to the 2022 National Sewerage Statistics, as of 2022, the coverage rate of public sewers installed nationwide is 95.1%, and the facility capacity is over 25,000 thousand tons/day. The total length of the sewer system is 16,785 km, and concrete pipes, including centrifugal pipes and reinforced concrete pipes, account for more than 40% of the total. In particular, concrete pipes installed before 1997, which have exceeded the 20-year service life limit, account for 42.5% (66,334 km), leading to growing interest in performance improvement and life extension. Since these structures are buried underground, problems such as sinkholes caused by damage and aging occur frequently, highlighting the importance of maintenance. Over time, these underground sewer structures are eroded by various chemical components contained in wastewater, and their service life is significantly reduced due to deterioration, such as cracking caused by a lack of long-term durability resulting from wear and tear from flowing water. The deterioration of concrete used as a material for sewer pipes is characterized by chemical and physical damage depending on factors caused by changes in the internal environment of the pipe; in particular, it is reported that sulfuric acid erosion caused by factors generated in sewage, such as organic matter and sulfate ions contained in the sewage, is causing serious damage. Currently, many new technologies have been developed and extensive research is being conducted on repair and reinforcement methods for exposed onshore facilities. However, there is not much research track record regarding repair and reinforcement technologies for concrete and steel structures that remain underwater—specifically, bridge piers, dock jetties, and steel pipe piles—which are submerged in seawater and subjected to continuous loads. For structures in an underwater state, assessing the extent of damage and performing repairs and reinforcements on damaged areas is difficult. Furthermore, since repairs and reinforcements involve underwater construction, problem