A method for strengthening building structures based on hybrid glass fiber-epoxy mortar

Abstract

This invention relates to the field of building structure reinforcement technology, and in particular to a method for reinforcing building structures based on a mixed glass fiber-epoxy mortar. The method includes the following steps: mixing epoxy resin and an active diluent; adding filler and glass fiber while stirring; and stirring until homogeneous to obtain a first component; adding a curing agent to the first component and stirring until homogeneous to obtain glass fiber-epoxy mortar; cleaning the part of the building structure to be reinforced and sanding the surface; placing the glass fiber-epoxy mortar into a shotcrete machine and spraying the sanded surface of the building structure multiple times; and curing for 7-28 days. This invention employs the above-mentioned method for reinforcing building structures based on a mixed glass fiber-epoxy mortar. The glass fiber-epoxy mortar used has excellent adhesion, and its flexible network structure composed of disulfide bonds facilitates self-healing. Simultaneously, the added filler increases tensile strength and wear resistance, resulting in excellent reinforcement effects.

Description

Technical Field

[0001] This invention relates to the field of building structure reinforcement technology, and in particular to a building structure reinforcement method based on hybrid glass fiber-epoxy mortar. Background Technology

[0002] Currently, the aging of buildings is becoming increasingly serious. This aging problem means that as buildings age, issues such as structural deterioration and material degradation will gradually emerge. Concrete and masonry structures face problems such as degradation, insufficient strength, and low durability and safety. With economic development, the need for assessment and reinforcement of existing industrial and civil buildings, as well as disaster-damaged buildings, in my country is becoming increasingly urgent. For concrete structures, common methods include: increasing the cross-section, replacing concrete for reinforcement, external steel cladding, prestressing, changing the structural force transmission path, steel bonding, and FRP reinforcement.

[0003] Masonry structures are a common type of building structure, primarily constructed from materials such as bricks, stones, and concrete blocks bonded together with mortar. This type of structure is widely used in residential and commercial buildings worldwide, especially in traditional buildings and low-cost housing. Reinforcement methods for masonry structures include: adding structural columns and ring beams, adding external steel mesh, replacing or repairing mortar, chemical grouting, and floor slab reinforcement.

[0004] Epoxy mortar is a commonly used repair material in engineering. It is frequently used for repairing concrete structures, masonry structures, roads, and for processing corrosion-resistant materials in some chemical plants. However, epoxy mortar has low tensile strength, resulting in poor bonding strength between the new and old materials after reinforcement. Under renewed stress, it can cause a "two-layer" phenomenon and has poor self-healing properties. Summary of the Invention

[0005] The purpose of this invention is to provide a method for reinforcing building structures based on hybrid glass fiber-epoxy mortar. The glass fiber-epoxy mortar used has excellent adhesion, and the flexible network structure composed of disulfide bonds facilitates self-healing. At the same time, the added fillers can increase tensile strength and wear resistance, resulting in excellent reinforcement effect.

[0006] To achieve the above objectives, the present invention provides a method for strengthening building structures based on hybrid glass fiber-epoxy mortar, comprising the following steps:

[0007] S1. Mix epoxy resin and reactive diluent, add filler and glass fiber while stirring, and stir evenly to obtain the first component;

[0008] S2. Add curing agent to the first component and stir evenly to obtain glass fiber-epoxy mortar;

[0009] S3. Clean the parts of the building structure that need to be reinforced and sand the surface with sandpaper;

[0010] S4. Place the glass fiber-epoxy mortar from S2 into the shotcrete equipment and spray it onto the polished building structure surface multiple times.

[0011] S5. Use a scraper to smooth out uneven areas on the building structure surface, remove surface air bubbles, and cure for 7-28 days.

[0012] Preferably, in S1, the epoxy resin includes one or more of guaiacol-based epoxy resin, vanillin-based epoxy resin, and bisphenol A type epoxy resin.

[0013] Preferably, in S1, the length of the glass fiber is 1-10 mm, and the amount of glass fiber added is 0.6-1.0% of the volume of the glass fiber-epoxy mortar.

[0014] Preferably, in S1, the filler includes one or more of fine aggregate, fly ash, heavy calcium carbonate powder, and iron powder.

[0015] Preferably, in S2, the mass ratio of epoxy resin, curing agent and filler is 3:1:19-30.

[0016] Preferably, in S2, the curing agent includes one or more of the following: ethylenediamine, phthalic acid, amination cyclodextrin and 1-amino-adamantane.

[0017] Preferably, in S2, the mass ratio of curing agent to epoxy resin is 1:1-3.

[0018] Preferably, in S3, cleaning involves blowing away impurities from the surface of the part of the building structure to be reinforced and washing away oil stains.

[0019] Preferably, in S4, the injection speed is 5-10 m / s and the injection angle is 60-80°.

[0020] Preferably, in S4, the thickness of a single spray is 80-100mm, and the total spray thickness is 1-30mm.

[0021] Therefore, the present invention employs the above-mentioned method for reinforcing building structures based on mixed glass fiber-epoxy mortar, the beneficial effects of which are as follows:

[0022] 1. Guaiac phenol-based epoxy resin or vanillin-based epoxy resin undergoes a curing reaction with the amine groups in the curing agent. The disulfide bonds in the vanillin-based epoxy resin or the disulfide bonds in the guaiaac phenol-based epoxy resin, as well as the disulfide bonds in the combination of amination cyclodextrin and 1-amino-adamantane, together form a flexible network structure after curing, giving the cured glass fiber-epoxy mortar self-healing properties.

[0023] 2. The glass fiber-epoxy mortar provided by the present invention has excellent adhesion. The addition of filler increases the hardness, corrosion resistance, wear resistance and compressive strength of the glass fiber-epoxy mortar. Glass fiber enhances the tensile strength and durability of the glass fiber-epoxy mortar and has good insulation properties.

[0024] 3. The reinforcement method provided by this invention is widely used in historical buildings in China, such as ancient city walls and ancient towns.

[0025] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0026] The present invention will be further described below with reference to embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.

[0027] Example 1

[0028] This invention provides a method for reinforcing building structures based on hybrid glass fiber-epoxy mortar, comprising the following steps:

[0029] S1. Mix epoxy resin and reactive diluent, add filler and glass fiber while stirring, and stir evenly to obtain the first component;

[0030] In S1, the epoxy resin is guaiacol-based epoxy resin.

[0031] In S1, the length of the glass fiber is 6mm, and the amount of glass fiber added is 1.0% of the volume of the glass fiber-epoxy mortar.

[0032] In S1, the filler is a mixture of fine aggregate (5.0-10.0mm), fly ash, and iron powder in a mass ratio of 1:0.5:0.3.

[0033] S2. Add curing agent to the first component and stir evenly to obtain glass fiber-epoxy mortar;

[0034] In S2, the mass ratio of epoxy resin, curing agent, and filler is 3:1:24.

[0035] In S2, the curing agent is a combination of amination cyclodextrin and 1-amino-adamantane in a molar ratio of 1:1.

[0036] In S2, the mass ratio of curing agent to epoxy resin is 1:2.

[0037] S3. Clean the part of the concrete structure to be reinforced. Cleaning involves blowing away impurities from the surface of the part of the concrete structure to be reinforced and washing away oil stains. Then, sand the surface with sandpaper.

[0038] S4. Place the glass fiber-epoxy mortar from S2 into the shotcrete equipment. The spraying speed is 8 m / s, and the spraying angle is 70°. Spray the ground concrete surface multiple times, with a single spray thickness of 80 mm. The total spray thickness is determined by the degree of reinforcement required for the concrete structure, ranging from 1 to 30 mm.

[0039] S5. Use a scraper to smooth the uneven areas of the concrete structure surface, remove surface air bubbles, and cure for 7-28 days.

[0040] Example 2

[0041] This invention provides a method for reinforcing building structures based on hybrid glass fiber-epoxy mortar, comprising the following steps:

[0042] S1. Mix epoxy resin and reactive diluent, add filler and glass fiber while stirring, and stir evenly to obtain the first component;

[0043] In S1, the epoxy resin is vanillin-based epoxy resin.

[0044] In S1, the length of the glass fiber is 6mm, and the amount of glass fiber added is 0.8% of the volume of the glass fiber-epoxy mortar.

[0045] In S1, the filler is a mixture of fine aggregate (5.0-10.0 mm), heavy calcium carbonate powder, and iron powder in a mass ratio of 1:1:0.3.

[0046] S2. Add curing agent to the first component and stir evenly to obtain glass fiber-epoxy mortar;

[0047] In S2, the mass ratio of epoxy resin, curing agent, and filler is 3:1:24.

[0048] In S2, the curing agent is a combination of amination cyclodextrin and 1-amino-adamantane in a molar ratio of 1:1.

[0049] In S2, the mass ratio of curing agent to epoxy resin is 1:2.

[0050] S3. Clean the parts of the old masonry brick structure that need to be reinforced, and sand the surface with sandpaper.

[0051] In S3, cleaning involves blowing away impurities from the surface of the old masonry brick structure that needs to be reinforced, and washing away oil stains.

[0052] S4. Place the glass fiber-epoxy mortar from S2 into the shotcrete equipment. The spraying speed is 6 m / s, and the spraying angle is 60°. Spray the polished old masonry brick structure surface multiple times. The thickness of a single spray is 100 mm, and the total spray thickness is determined by the degree of reinforcement required for the old masonry brick structure, ranging from 1 to 30 mm.

[0053] S5. Use a scraper to smooth the uneven areas on the surface of the old masonry brick structure, remove surface air bubbles, and cure for 7-28 days.

[0054] Test case

[0055] Tests were conducted according to standard GB / T9286-1998. The test results were graded according to integers from 0 to 5, with the adhesion being worse as the value increases. Grade 0 indicates that the coating is intact. Grade 4 indicates that large fragments of the coating peel off along the cut edge, and / or some squares are partially or completely peeled off, with the affected cross-cut area significantly greater than 35% but not significantly greater than 65%. Grade 5 indicates that the degree of peeling exceeds that of Grade 4.

[0056] Adhesion tests were conducted on the building structures repaired in Examples 1-2, and the results are shown in Table 1. It can be seen that the glass fiber-epoxy mortar in Examples 1-2 has excellent adhesion ability and can continuously reinforce the building structure.

[0057] Example 1 Example 2 Adhesion (Grade) 1 1

[0058] Therefore, the present invention adopts the above-mentioned method for reinforcing building structures based on mixed glass fiber-epoxy mortar. The glass fiber-epoxy mortar used has excellent adhesion, and the flexible network structure composed of disulfide bonds facilitates self-repair. At the same time, the added fillers increase tensile strength and wear resistance, resulting in excellent reinforcement effect.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for reinforcing building structures based on hybrid glass fiber-epoxy mortar, characterized in that: Includes the following steps, S1. Mix epoxy resin and reactive diluent, add filler and glass fiber while stirring, and stir evenly to obtain the first component; In S1, the epoxy resin includes one or more of guaiacol-based epoxy resin, vanillin-based epoxy resin, and bisphenol A type epoxy resin; In S1, the length of the glass fiber is 1-10 mm, and the amount of glass fiber added is 0.6-1.0% of the volume of the glass fiber-epoxy mortar. In S1, the filler includes one or more of the following: fine aggregate, fly ash, heavy calcium carbonate powder, and iron powder; S2. Add curing agent to the first component and stir evenly to obtain glass fiber-epoxy mortar; In S2, the mass ratio of epoxy resin, curing agent and filler is 3:1:19-30; S3. Clean the parts of the building structure that need to be reinforced and sand the surface with sandpaper; S4. Place the glass fiber-epoxy mortar from S2 into the shotcrete equipment and spray it onto the polished building structure surface multiple times. S5. Use a scraper to smooth out uneven areas on the building structure surface, remove surface air bubbles, and cure for 7-28 days.

2. The method for reinforcing building structures based on hybrid glass fiber-epoxy mortar according to claim 1, characterized in that: In S2, the curing agent includes one or more of the following: ethylenediamine, phthalic acid, amination of cyclodextrin and 1-amino-adamantane.

3. The method for reinforcing building structures based on hybrid glass fiber-epoxy mortar according to claim 1, characterized in that: In S2, the mass ratio of curing agent to epoxy resin is 1:1-3.

4. The method for reinforcing building structures based on hybrid glass fiber-epoxy mortar according to claim 1, characterized in that: In S3, cleaning involves blowing away impurities from the surface of the parts of the building structure that need to be reinforced and washing away oil stains.

5. The method for reinforcing building structures based on hybrid glass fiber-epoxy mortar according to claim 1, characterized in that: In S4, the injection speed is 5-10 m / s and the injection angle is 60-80°.

6. The method for reinforcing building structures based on hybrid glass fiber-epoxy mortar according to claim 1, characterized in that: In S4, the thickness of a single spray is 80-100 mm, and the total spray thickness is 1-30 mm.