CN-121976684-A - Concrete interface repair material and construction method and application thereof

CN121976684ACN 121976684 ACN121976684 ACN 121976684ACN-121976684-A

Abstract

The invention belongs to the technical field of concrete reinforcement and repair, and particularly relates to a concrete interface repair material, a construction method and application thereof. The concrete interface repair material comprises an interface treatment layer, a first stress buffer layer, a graphene fiber grid layer, a second stress buffer layer and a concrete repair layer, wherein the interface treatment layer comprises graphene, the first stress buffer layer and/or the second stress buffer layer comprises epoxy resin, a curing agent, a toughening agent and graphene nano sheets, and the graphene fiber grid layer comprises fiber grids and a graphene coating deposited on the surface of the fiber grids. The concrete interface repair material disclosed by the invention is beneficial to solving or improving the problems that at least one of poor interface bonding effect, stress concentration and poor long-term durability easily occur in the process of reinforcing concrete in the prior art.

Inventors

PANG BO
ZHANG WEI
YUAN LIANWANG
ZHAO LINGLING
JIN ZUQUAN
WANG HONG
CHEN YIDONG
SONG XIAOYUN
LIU YONG
LIU LIRONG
GAO JIANGUO

Assignees

青岛理工大学
江苏启青新型材料科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251229

Claims (9)

1. The concrete interface repair material is characterized by comprising an interface treatment layer, a first stress buffer layer, a graphene fiber mesh layer, a second stress buffer layer and a concrete repair layer; the components of the interface treatment layer comprise graphene; The components of the first stress buffer layer and/or the second stress buffer layer comprise epoxy resin, a curing agent, a toughening agent and graphene nano sheets; The graphene fiber grid layer comprises a fiber grid and a graphene coating deposited on the surface of the fiber grid.
2. The concrete interface repair material of claim 1, wherein the graphene fiber mesh layer is prepared by a method comprising the steps of: A1, immersing a fiber grid serving as an anode and a stainless steel plate serving as a cathode in electrophoresis liquid, applying voltage to carry out electrophoresis deposition, and depositing a graphene oxide functional layer on the surface of the fiber grid; A2, taking out the fiber grid obtained through the treatment in the step A1 from the electrophoresis liquid, drying, and immersing the fiber grid into an ascorbic acid solution for reduction reaction to obtain a reduced graphene oxide transition layer; And A3, immersing the fiber mesh obtained through the treatment in the step A2 into a silane coupling agent solution for surface modification treatment, and drying and curing after modification, so that the modified graphene layer can be obtained.
3. The concrete interface repair material according to claim 2, wherein in the step A1, the electrophoresis liquid is a mixed solution of graphene oxide, carbon nanotubes, a dispersing agent and a solvent, and the pH of the electrophoresis liquid is adjusted to 7-9 by ammonia water; In the electrophoresis liquid, the concentration of the graphene oxide is 2-4wt% and the concentration of the carbon nano tube is 0.5-1wt%; the dispersing agent is a polycarboxylic dispersing agent, and the solvent is absolute ethyl alcohol and/or N, N-dimethylformamide.
4. The concrete interface repair material of claim 2, wherein in step A1, the voltage of the electrophoretic deposition is 30-50V for 5-15min at 25±2 ℃; In the step A2, the concentration of the ascorbic acid solution is 8-12g/L, the reduction reaction time is 1-3h, and then the heat treatment is carried out for 20-40min at 100-140 ℃; in the step A3, the silane coupling agent solution is ethanol solution with the weight percent of 2-3 percent and the soaking time is 20-40min; the silane coupling agent is at least one of KH-560, KH-550 and KH-570.
5. The concrete interface repair material according to claim 1, wherein the components of the first stress buffer layer and/or the second stress buffer layer comprise, by mass, 100 parts of epoxy resin, 0.5-1.5 parts of graphene nanoplatelets, 30-40 parts of curing agent and 5-10 parts of toughening agent.
6. The concrete interface repair material of claim 5, wherein the epoxy resin is at least one of an E-51 type epoxy resin, an E-44 type epoxy resin, and an E-20 type epoxy resin; the particle size of the graphene nano sheet is 1-10 mu m, the thickness is 5-50nm, and the specific surface area is 50-500m 2 /g; the curing agent is at least one of polyamide curing agent, fatty amine curing agent and aromatic amine curing agent; the toughening agent is at least one of rubber particles, polyurethane and carboxyl-terminated nitrile rubber.
7. The concrete interfacial repair material of claim 1, wherein said first stress buffer layer has a thickness of 1-3mm; the thickness of the second stress buffer layer is 1-2mm; The fiber grid is at least one of a carbon fiber grid, a basalt fiber grid, a glass fiber grid and a hybrid fiber grid.
8. The method of constructing a concrete interfacial repair material as defined in any one of claims 1 to 7, comprising the steps of: (1) Pre-treating old concrete, brushing an interface agent containing graphene after the pre-treatment, and obtaining an interface treatment layer after the surface is finger-dried; (2) Coating the first buffer layer; (3) Paving a graphene fiber grid layer; (4) Coating the second buffer layer; (5) And (5) pouring a concrete repair layer.
9. Use of the concrete interfacial repair material as defined in any one of claims 1 to 7 in bridge reinforcement, building structure reinforcement, tunnel lining repair or hydraulic structure protection.

Description

Concrete interface repair material and construction method and application thereof Technical Field The invention belongs to the technical field of concrete reinforcement and repair, and particularly relates to a concrete interface repair material, a construction method and application thereof. Background As the construction of the infrastructure in China enters the stock age, a large number of concrete structures have the defects of insufficient bearing capacity, crack expansion, peeling of protective layers and the like due to factors such as prolonged service time, increased load, environmental corrosion and the like. According to statistics, the existing bridges in China are over 100 ten thousand, about 40% of the bridges enter a maintenance period, the existing building area is over 600 hundred million square meters, and a large number of buildings need to be subjected to earthquake-resistant reinforcement and performance improvement. Aiming at reinforcing and repairing of bearing structures such as bridges, buildings, tunnels, hydraulic structures and the like, novel reinforcing materials and technologies which are high in performance, easy to construct and capable of being monitored are urgently needed. At present, the concrete structure reinforcement technology mainly comprises bonding steel reinforcement, bonding fiber reinforced composite (FRP) reinforcement, steel cladding reinforcement, a section increasing method and the like. The adhesive fiber cloth reinforcement is widely applied due to the advantages of high strength, corrosion resistance, convenience in construction and the like. In recent years, fiber mesh reinforced cement-based composite materials (TRCs/TRMs) are increasingly emerging as a novel reinforcement technology, which has better air permeability, high temperature resistance and compatibility with substrates than conventional FRP reinforcements. However, the following key problems still exist in the existing fiber reinforcement technology: 1. the interface bonding performance is not enough: The new and old concrete interfaces and the interface between the fiber and the matrix are weak links of the reinforcing structure. Because of the factors of the difference of the properties of new and old concrete materials, improper interface treatment, the existence of microcracks and the like, the interface bonding strength is usually only 50-70% of the strength of the concrete body. Under the action of load, the interface is extremely easy to peel and destroy, so that reinforcement failure is caused. In particular, the interface bonding degradation is more obvious under the long-term actions of fatigue load, temperature cycle and the like. The traditional reinforcement technology mainly relies on structural adhesive or cement mortar to realize bonding, but the interface combination of the materials and fibers and concrete mainly comprises physical adsorption and mechanical interlocking, so that the effective chemical bonding is lacked, the interface microstructure is discontinuous, and a large number of defects exist. 2. The abrupt change in stiffness causes stress concentration: the elastic modulus of fiber reinforced materials (such as carbon fiber cloth) is generally up to 200-300GPa, while the elastic modulus of concrete is only 30-40GPa, which are approximately 10 times different. Such abrupt changes in stiffness can create severe stress concentrations at the interface, accelerating the initiation and propagation of interfacial cracks. The prior art lacks an effective stress transition and buffer mechanism, and is difficult to realize the cooperative stress of new and old materials. 3. Long-term durability issues are prominent: Fiber materials, particularly glass fibers and basalt fibers, are susceptible to performance degradation under the action of alkaline environments, chloride ion attack, freeze-thaw cycles, and the like. The traditional epoxy resin matrix has good bonding performance, but has limited ageing resistance, and can be degraded under ultraviolet irradiation and damp-heat environment. Due to the lack of effective protective measures, the long-term durability of the reinforcing structure is difficult to ensure, and re-reinforcement is often required after 5-10 years. In recent years, graphene has been receiving attention as a novel two-dimensional nanomaterial due to its excellent mechanical properties (tensile strength of about 130GPa, young' S modulus of about 1 TPa), electrical conductivity (electrical conductivity of up to 10 6 S/m), specific surface area (theoretical value of 2630m 2/g) and chemical stability. Application research of graphene in cement-based composite materials shows that the compressive strength, flexural strength and durability of concrete can be remarkably improved by adding a small amount of graphene. The lamellar structure of the graphene can fill microscopic holes of a cement matrix to block penetration of an erosion medium, the functional g