WO2015085807A1

WO2015085807A1 - Method for reinforcing and protecting concrete using fiber composite material

Info

Publication number: WO2015085807A1
Application number: PCT/CN2014/087180
Authority: WO
Inventors: 丁铸; 李伟文; 隋莉莉; 李大望; 董必钦; 邢锋
Original assignee: 深圳大学
Priority date: 2013-12-13
Filing date: 2014-09-23
Publication date: 2015-06-18
Also published as: CN103738000B; CN103738000A

Abstract

A method for reinforcing and protecting concrete using a fiber composite material. An adhesive-fiber sheet reinforcing material layer is adhered to the surface of a concrete member, comprising the following steps: (1) the surface of a concrete member is roughened; (2) an inorganic adhesive is mixed with an organic resin to form an adhesive; (3) a layer of the adhesive is applied to the surface of the treated concrete member; (4) a fiber sheet is adhered to the adhesive; (5) after the fiber sheet has been paved and compacted, a layer of the adhesive is applied to the outer surface of the fiber sheet. The present method increases the flexural strength and impact toughness of concrete, reinforces and protects internal materials of concrete structures, and can extend the service life of concrete. The reinforcing material layer has good high-temperature resistance and a long lifespan. The reinforcing material layer is also safe and environmentally friendly. The present invention is simple in structure, can be easily applied to construction and reinforcement, and has positive economic benefits.

Description

Method for reinforcing and protecting concrete by fiber composite material

Technical field

The invention relates to concrete reinforcement, in particular to a method for reinforcing and protecting concrete by fiber composite material.

Background technique

The durability of concrete has become an important issue in building structures. A large amount of concrete requires huge funds due to structural deterioration, repair, reinforcement, and reinforcement. During the service process, the concrete structure is affected by the load and various environmental corrosive media, and the structural deterioration is gradually caused, resulting in cracks, cracks and even damage, thereby reducing the safety of the concrete structure and shortening the service life. In order to repair the deteriorated concrete structure in time, to ensure the safety of its use and to prolong its service life, it is necessary to repair and reinforce the deteriorated concrete. At present, the reinforcement of concrete is mostly made of surface-bonded fiber reinforced composite materials, such as fiber reinforced composites (CFRP) composed of carbon fiber cloth and epoxy organic rubber. CFRP has been widely used due to its advantages of high strength, high efficiency, light weight and convenient construction. It has formed a relatively mature technical system. China has also formulated the Code for Concrete Structure Reinforcement Design (GB). 50367-2006) and "Carbon Fiber Sheet for Structural Reinforcement Repair" (GB/T 21490-2008). However, the epoxy-based organic glue used for pasting has the following defects: (1) The softening temperature is low, generally 60-80 ° C, and toxic gas is volatilized under high temperature and fire, and the epoxy group will be various with the human body. The group reacts, so it is usually considered to be toxic or carcinogenic, which poses a great threat to the safety of people's lives and property; (2) it accelerates aging under ultraviolet light and seriously affects the bonding performance; (3) Inorganic concrete materials have large differences in elastic modulus. Under the conditions of multiple thermal expansion and contraction and expansion and contraction, the deformation of the two materials is not coordinated, and cracks are easily generated, so the compatibility is poor. Chinese invention patent application for this kind of problem (CN 102351443 A, CN201210356357) discloses a high temperature resistant alkali slag cementing material and a preparation method thereof, which can solve the problem that the epoxy organic rubber is not resistant to high temperature to a certain extent, but because the construction method is relatively cumbersome, it is not conducive to the popularization and application in engineering practice.

technical problem

The technical problem to be solved by the present invention is to provide a method for reinforcing and protecting concrete by using a fiber composite material which is safe, environmentally friendly, long in life and simple in construction.

Technical solution

In order to solve the above technical problems, the technical solution adopted by the present invention is a method for reinforcing and protecting concrete by a fiber composite material, and an adhesive-fiber sheet reinforcing material layer is pasted on the surface of the concrete member, and the construction includes the following steps:

(1) roughening the surface of the concrete member;

(2) mixing the inorganic cementing material with water and stirring to form an inorganic adhesive; mixing the inorganic adhesive with the organic resin to form an adhesive;

(3) Applying a layer of adhesive to the surface of the treated concrete member;

(4) attaching the fiber sheet to the adhesive;

(5) After the fiber sheet is flattened, compacted, and vented, a layer of adhesive is applied to the outer surface of the fiber sheet.

In the above method, the fiber sheet is a unidirectional fiber layer or a fiber fabric layer; the organic resin is one of unsaturated polyester, epoxy resin, phenolic resin, silicone glue; The inorganic binder is a mixture of a phosphate cementitious material and water.

In the above method, the fiber is a combination of one or more of glass fiber, carbon fiber, basalt fiber or aramid fiber.

In the above method, the inorganic adhesive is a phosphate adhesive, and the phosphate adhesive consists of the following components by weight:

Dihydrogen phosphate 100;

Magnesia sand 60-80;

Inorganic mineral filler 0-60;

Retarder 4-15;

Water 35-55.

In the above method, the phosphate adhesive consists of the following components in parts by weight:

Dihydrogen phosphate 100;

Magnesia sand 65-75;

Inorganic mineral filler 20-50;

Retarder 5-12;

Water 35-55.

In the above method, the retarder weight is 8%-15% by weight of the magnesia; and the weight of the water is 18-25% by weight of the phosphate cement material.

In the above method, the dihydrogen phosphate salt is at least one of potassium dihydrogen phosphate, sodium dihydrogen phosphate and ammonium dihydrogen phosphate, and the inorganic mineral filler is fly ash, wollastonite powder, blast furnace. At least one of slag powder, steel slag powder, kaolin, metakaolin, zeolite, the retarder is at least one of borax and boric acid; magnesia is calcined magnesia, fused magnesia and seawater magnesia At least one of the calcined magnesia, fused magnesia or seawater magnesia has a magnesia content of not less than 80%.

In the above-described method, steps (4) and (5) are repeated to obtain an adhesive-fiber sheet reinforcing material layer of a multilayer fiber sheet.

In the above method, the organic resin accounts for 10-30% by weight in the adhesive, and the inorganic adhesive accounts for 70-90%.

Beneficial effect

The method for reinforcing and protecting concrete of the fiber composite material of the invention improves the flexural strength and impact toughness of the concrete, and the adhesive-fiber sheet reinforcing material layer blocks the penetration of the external corrosive medium into the concrete, and complements the internal material of the concrete structure. Strong and protective effect can extend the service life of concrete. The adhesive-fiber sheet reinforced material layer has good high temperature resistance, long life, safety and environmental protection, and is close to the elastic modulus of the concrete material, and has good coordination of deformation and good compatibility. The fiber composite reinforced concrete structure of the invention has simple construction, is convenient for popularization and application in engineering construction and reinforcement, and has good economic benefits.

DRAWINGS

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

1 is a schematic cross-sectional view showing a reinforcing structure of a concrete fiber composite material using a 1-layer fiber sheet according to an embodiment of the present invention;

2 is a schematic cross-sectional view showing a reinforcing structure of a concrete fiber composite material using two layers of fiber sheets according to an embodiment of the present invention;

In the figure: 3- concrete member, 2-mixed adhesive, 1-fiber sheet.

Embodiments of the invention

The method for reinforcing and protecting concrete of the fiber composite material of the invention, the adhesive-fiber sheet reinforcing material layer is pasted on the surface of the concrete member, and the construction comprises the following steps:

(1) roughening and chiseling the surface of concrete;

(2) preparing a mixture of an inorganic adhesive and an organic adhesive, wherein the inorganic adhesive is formed by mixing a phosphate cement material with water and stirring uniformly;

(3) uniformly apply a layer of mixed adhesive on the surface of the treated concrete;

(4) affixing the fiber sheet to the mixed adhesive on the flat surface;

(5) After the fiber sheet is flattened, compacted, and vented, a layer of mixed adhesive is applied to the outer surface of the fiber sheet;

(6) If the reinforcing material layer of the multilayer fiber sheet is used, steps (4) and (5) are repeated.

The fiber composite reinforcing layer is an adhesive-fiber sheet reinforcing material layer, and the fiber sheet layer is sandwiched in the adhesive, which may be one or more layers, and the adhesive-fiber sheet reinforcing material layer is pasted on the surface of the concrete; the adhesive is inorganic The adhesive and the organic adhesive are uniformly mixed, wherein the inorganic adhesive is formed by mixing an inorganic cementing material and water, and the organic resin is one of unsaturated polyester, epoxy resin, phenolic resin, silicone rubber; The organic resin accounts for 10-30% in the adhesive, and the inorganic adhesive accounts for 70-90%.

The fibrous sheet may be a unidirectional fibrous layer or a fibrous fabric layer. The fiber is a combination of one or more of glass fiber, carbon fiber, basalt fiber or aramid fiber.

The inorganic adhesive is a phosphate adhesive, wherein the phosphate adhesive consists of the following components by weight:

Dihydrogen phosphate 100;

Magnesia sand 60-80;

Inorganic mineral filler 0-60;

Retarder 3-15;

Water 35-55.

Wherein the dihydrogen phosphate is at least one of potassium dihydrogen phosphate, sodium dihydrogen phosphate and ammonium dihydrogen phosphate, and the inorganic mineral filler is fly ash, wollastonite powder, blast furnace slag powder, steel slag powder, kaolin, metakaolin And at least one of the zeolite, the retarder is at least one of borax and boric acid; the magnesia is at least one of calcined magnesia, fused magnesia and seawater magnesia, and calcined magnesia and electrofusion The magnesia content in magnesia or seawater magnesia is not less than 80%.

In the phosphate adhesive, the retarder weight is 8%-15% by weight of the magnesia; the weight of the water is 18-25% by weight of the phosphate cement material.

Table 1: Formulation Table of Example 1-9 Phosphate Adhesives

（重量份） (parts by weight)	磷酸二氢钾 Potassium dihydrogen phosphate	镁砂 Magnesia	粉煤灰 Fly ash	硼砂 Borax	水 water
实施例1 Example 1	100 100	65 65	55 55	4 4	55 55
实施例2 Example 2	100 100	70 70	50 50	6 6	40 40
实施例3 Example 3	100 100	75 75	40 40	13 13	45 45
实施例4 Example 4	100 100	80 80	50 50	15 15	55 55
实施例5 Example 5	100 100	80 80	0 0	12 12	35 35
实施例6 Example 6	100 100	75 75	10 10	8 8	40 40
实施例7 Example 7	100 100	68 68	20 20	5 5	45 45
实施例8 Example 8	100 100	70 70	30 30	8 8	50 50
实施例9 Example 9	100 100	60 60	20 20	6 6	40 40

Example 1

In the method of reinforcing and protecting cement concrete of the fiber composite material of the embodiment 1 of the invention, a sample of the C40 cement concrete beam is prepared, and the size is 100 mm×100 mm×550 m. After the concrete sample solidified and hardened and cured under standard conditions for 28 days, the surface was ground and chiseled.

The fiber material adopts the carbon fiber HITEX-C200 of Nanjing Haituo Composite Materials Co., Ltd., and its performance is shown in Table 1.

Table 1: Carbon Fiber Performance Table

单位面积质量（g/m²）Mass per unit area (g/m ² )	抗拉强度标准值（MPa）Tensile strength standard value (MPa)	受拉弹性模量（MPa）Tensile modulus of elasticity (MPa)	伸长率（％）Elongation(%)
≤200 ≤200	≥3400 ≥3400	≥2.4×10⁵ ≥2.4×10 ⁵	≥1.7 ≥1.7

Preparation of the adhesive. In the preparation of the organic adhesive, the two components of the epoxy resin A and B are prepared in a ratio of 1:2 parts by weight, and mixed for use. The inorganic binder is formed by mixing and stirring the powdered phosphate cement material with water.

The parts by weight of the powdery phosphate cementing material in this embodiment are potassium dihydrogen phosphate 100, magnesia 65, Fly ash 55, borax 4. The weight of water is 55. The preparation method of the phosphate adhesive is to weigh and mix the powdery raw materials in proportion, and stir them evenly in a mixer to obtain a desired inorganic adhesive.

The epoxy resin glue and the phosphate adhesive are mixed, and the weight ratio of the mixture is 10 parts by mass of the epoxy resin and 90 parts by weight of the phosphate adhesive to prepare an organic-inorganic hybrid adhesive.

The fiber material is pasted, and the organic-inorganic adhesive is quickly applied to the upper surface of the concrete beam with a clean shovel, and the thickness is about 1 to 1.5 mm. The unidirectional carbon fiber sheet is flatly pasted on the adhesive; compacted and vented. Then, a layer of adhesive is evenly spread on the unidirectional continuous carbon fiber, and the thickness is about 1 to 1.5 mm, compacted and exhausted, and after being hardened, it is trimmed to obtain a concrete beam with a surface-bonded fiber composite material. .

The fiber sheet used in Example 1 was one layer. Repeat the above steps if you need to paste multiple layers.

When the fiber composite material is pasted, a length of 50 mm is left at both ends of the concrete beam to ensure that the fixed constraint at both ends does not have a restraining effect on the fiber cloth during loading.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and each of the three concrete beams was a group, and the average bending strength of the three concrete beams was obtained. For the bending strength of the group. The four-point bending strength of the blank concrete beam is 10.68 MPa. In this embodiment, the concrete beam bonded by the reinforcing layer composed of one layer of unidirectional continuous carbon fiber and organic-inorganic adhesive has an increase in bending strength compared with the blank concrete beam. %.

Example 2

According to the materials and methods described in Example 1, a fiber composite reinforcement layer was prepared on a concrete beam having a surface treated with a chisel. The material weight component of the powdered phosphate cement material is potassium dihydrogen phosphate 100, magnesia 70, Fly ash 50, borax 6. The weight fraction of water is 40. The weight ratio of the epoxy resin to the phosphate adhesive is 20 parts by mass of the epoxy resin and 80 parts by weight of the phosphate adhesive. The unidirectional continuous carbon fiber sheet is one layer.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and the present embodiment was composed of one layer of unidirectional continuous carbon fiber and an organic-inorganic adhesive. The reinforced layer of the reinforced concrete beam has an 87% increase in flexural strength compared to the blank concrete beam.

Example 3

According to the materials and methods described in Example 1, a fiber composite reinforcement layer was prepared on a concrete beam having a surface treated with a chisel. The material weight component of the powdered phosphate cement material is potassium dihydrogen phosphate 100, magnesia 75, Fly ash 40, borax 13. The weight of water is 45. The organic-inorganic adhesive contains 30 parts of epoxy resin and 70 parts of phosphate adhesive. The weight ratio of the epoxy resin to the phosphate adhesive is 30 parts by mass of the epoxy resin and 70 parts by weight of the phosphate adhesive. The unidirectional continuous carbon fiber sheet is one layer.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and the present embodiment was composed of one layer of unidirectional continuous carbon fiber and an organic-inorganic adhesive. The concrete beam of the reinforced layer is increased by 105% compared with the blank concrete beam.

Example 4

According to the material and method of Example 1, a fiber composite reinforcing layer was prepared on a concrete beam whose surface was subjected to chiseling. The material weight component of the powdered phosphate cement material is potassium dihydrogen phosphate 100, magnesia 80, Fly ash 50, borax 15. The weight of water is 55. The organic-inorganic adhesive contains 15 parts of epoxy resin and 85 parts of phosphate adhesive. The weight ratio of the epoxy resin to the phosphate adhesive is 25 parts by mass of the epoxy resin, and the phosphate adhesive is 75 parts of the unidirectional continuous carbon fiber sheet.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and the present embodiment was composed of one layer of unidirectional continuous carbon fiber and an organic-inorganic adhesive. The reinforced layer of the concrete beam has a flexural strength that is increased by 102% compared to the blank concrete beam.

Example 5

According to the material and method of Example 1, a fiber composite reinforcing layer was prepared on a concrete beam whose surface was subjected to chiseling. The material weight component of the powdered phosphate cement material is potassium dihydrogen phosphate 100, magnesia 80, and borax 12. The weight fraction of water is 35. Among the organic-inorganic adhesives, 18 were epoxy resins and 82 were phosphate binders. The weight ratio of the epoxy resin to the phosphate adhesive is 15 parts by mass of the epoxy resin, 85 parts by weight of the phosphate adhesive, and 1 layer of the unidirectional continuous carbon fiber sheet.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and the present embodiment was composed of one layer of unidirectional continuous carbon fiber and an organic-inorganic adhesive. The reinforced layer of the concrete beam has a flexural strength that is increased by 96% compared to the blank concrete beam.

Example 6

According to the material and method of Example 1, a fiber composite reinforcing layer was prepared on a concrete beam whose surface was subjected to chiseling. The material weight component of the powdered phosphate cement material is potassium dihydrogen phosphate 100, magnesia 75, Fly ash 10, borax 8. The weight fraction of water is 40. The organic-inorganic adhesive contained 22 parts of epoxy resin and 78 parts of phosphate adhesive. The weight ratio of the epoxy resin to the phosphate adhesive is 20 parts by mass of the epoxy resin, and the phosphate adhesive is 80 parts of the unidirectional continuous carbon fiber sheet.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and the present embodiment was composed of one layer of unidirectional continuous carbon fiber and an organic-inorganic adhesive. The reinforced layer of the concrete beam has a flexural strength that is increased by 95% compared to the blank concrete beam.

Example 7

According to the material and method of Example 1, a fiber composite reinforcing layer was prepared on a concrete beam whose surface was subjected to chiseling. The material weight component of the powdered phosphate cement material is potassium dihydrogen phosphate 100, magnesia 68, Fly ash 20, borax 5. The weight of water is 45. The organic-inorganic adhesive contains 25 parts of epoxy resin and 75 parts of phosphate adhesive. The weight ratio of the epoxy resin to the phosphate adhesive is 20 parts by mass of the epoxy resin and 80 parts by weight of the phosphate adhesive. The unidirectional continuous carbon fiber sheet is one layer.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and the present embodiment was composed of one layer of unidirectional continuous carbon fiber and an organic-inorganic adhesive. The concrete beam of the reinforced layer is increased by 98% compared with the blank concrete beam.

Example 8

According to the material and method of Example 1, a fiber composite reinforcing layer was prepared on a concrete beam whose surface was subjected to chiseling. The material weight component of the powdered phosphate cement material is potassium dihydrogen phosphate 100, magnesia 70, Fly ash 30, borax 8. The weight fraction of water is 50. Among the organic-inorganic adhesives, 28 were epoxy resins and 72 were phosphate binders. The unidirectional continuous carbon fiber sheet is one layer.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and the present embodiment was composed of one layer of unidirectional continuous carbon fiber and an organic-inorganic adhesive. The concrete beam of the reinforced layer is increased by 100% compared with the blank concrete beam.

Example 9

According to the material and method of Example 1, a fiber composite reinforcing layer was prepared on a concrete beam whose surface was subjected to chiseling. The material weight component of the powdered phosphate cement material is potassium dihydrogen phosphate 100, magnesia 60, Fly ash 20, borax 6. The weight fraction of water is 40. The organic-inorganic adhesive contains 30 parts of epoxy resin and 70 parts of phosphate adhesive. The unidirectional continuous carbon fiber sheet is one layer.

After the concrete specimen of the present embodiment was cured at room temperature for 7 days, the four-point bending strength was tested on a material testing machine (NYL-300 type), and the present embodiment was composed of one layer of unidirectional continuous carbon fiber and an organic-inorganic adhesive. The concrete beam of the reinforced layer is increased by 110% compared with the blank concrete beam.

Embodiments of the invention are not limited to the embodiments described above. For example, the adhesive may be hand lay-up or mechanically sprayed depending on the needs of the field, the fibrous sheet may be a plurality of layers, the surface of the fibrous material may be modified, etc., and are considered to be within the concept of the present invention.

Claims

A method for reinforcing and protecting concrete by a fiber composite material, characterized in that an adhesive-fiber sheet reinforcing material layer is adhered to a surface of a concrete member, and the construction comprises the following steps:

(1) roughening the surface of the concrete member;

(2) mixing the inorganic cementing material with water and stirring to form an inorganic adhesive; mixing the inorganic adhesive with the organic resin to form an adhesive;

(3) Applying a layer of adhesive to the surface of the treated concrete member;

(4) attaching the fiber sheet to the adhesive;

(5) After the fiber sheet is flattened, compacted, and vented, a layer of adhesive is applied to the outer surface of the fiber sheet.
The method according to claim 1, wherein said fiber sheet is a unidirectional fiber layer or a fiber fabric layer; said organic resin is unsaturated polyester, epoxy resin, phenolic resin, silicone glue One of the inorganic binders is a mixture of a phosphate cementitious material and water.
The method of claim 1 wherein said fibers are a combination of one or more of glass fibers, carbon fibers, basalt fibers or aramid fibers.
The method according to claim 2, wherein the inorganic binder is a phosphate binder, and the phosphate binder comprises, by weight, the following components:

Dihydrogen phosphate 100;

Magnesia sand 60-80;

Inorganic mineral filler 0-60;

Retarder 4-15;

Water 35-55.
The method according to claim 4, wherein the phosphate binder consists of the following components in parts by weight:

Dihydrogen phosphate 100;

Magnesia sand 65-75;

Inorganic mineral filler 20-50;

Retarder 5-12;

Water 35-55.
The method of claim 4 wherein said retarder weight is from 8% to 15% by weight of the magnesia; and the weight of water is from 18% to 25% by weight of the phosphate cementitious material.
The method according to claim 4, wherein the dihydrogen phosphate salt is at least one of potassium dihydrogen phosphate, sodium dihydrogen phosphate and ammonium dihydrogen phosphate, and the inorganic mineral filler is pulverized coal. At least one of ash, wollastonite powder, blast furnace slag powder, steel slag powder, kaolin, metakaolin, zeolite, the retarder is at least one of borax and boric acid; magnesia is calcined magnesia, electricity At least one of molten magnesia and seawater magnesia, the magnesia content in the calcined magnesia, fused magnesia or seawater magnesia is not less than 80%.
The method of claim 1 wherein steps (4) and (5) are repeated to obtain an adhesive-fiber sheet reinforcement layer of the multilayer fiber sheet.
The method according to claim 1, wherein the organic resin accounts for 10-30% by weight and the inorganic binder accounts for 70-90% by weight.