Alkali-resistant glass fiber composite rib for concrete and preparation method thereof

Abstract

The invention relates to the technical field of fiber reinforced composite materials, in particular to an alkali-resistant glass fiber composite rib for concrete and a preparation method of the alkali-resistant glass fiber composite rib. The alkali-resistant glass fiber composite rib for the concrete is obtained by dipping composite alkali-resistant glass fiber bundles in bonding resin and carrying out pultrusion, the composite alkali-resistant glass fiber bundle is formed by bundling alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with the diameter of 2 + / -0.3 mm, then dipping the alkali-resistant glass fiber bundle into reaction type resin slurry, and carrying out traction, drying, curing and collection to obtain the composite alkali-resistant glass fiber bundle. The alkali-resistant glass fiber composite bar for concrete prepared by the invention has excellent mechanical properties, high temperature resistance and alkali resistance, can partially replace steel bars to prepare concrete, and is widely applied to ocean engineering.

Description

Technical Field

[0001] The invention relates to the technical field of fiber-reinforced composite materials, and in particular to an alkali-resistant glass fiber composite reinforcement for concrete and a preparation method thereof. Background Art

[0002] Fiber-reinforced composite materials are widely used in marine engineering and other fields due to their advantages such as light weight, high strength and corrosion resistance. However, the alkali resistance of glass fiber reinforced composite bars limits their long-term application in concrete structures, especially their durability in alkaline environments.

[0003] The strength and performance of tendons are highly dependent on the bond strength between the fiber and the resin. In an alkaline environment, the penetration of hydroxide ions will cause the bond strength of the fiber-resin interface to decrease, resulting in debonding, which directly affects the mechanical properties of the composite material. In addition, alkali-resistant glass fibers may hydrolyze and dissociate in strong alkaline solutions, resulting in the destruction of their molecular structure and a decrease in strength. Long-term immersion can cause microscopic defects and cracks in the fibers, which further reduces the material's load-bearing capacity. Summary of the invention

[0004] In view of this, the object of the present invention is to provide an alkali-resistant glass fiber composite reinforcement for concrete and a preparation method thereof, so as to improve the alkali resistance and reinforcement effect of the glass fiber composite reinforcement in concrete.

[0005] Based on the above purpose, the present invention provides an alkali-resistant glass fiber composite reinforcement for concrete, which is obtained by impregnating a composite alkali-resistant glass fiber bundle in a bonding resin and then pultruding it.

[0006] Preferably, the diameter of the alkali-resistant glass fiber composite reinforcement for concrete is 6mm-40mm;

[0007] More preferably, the diameter of the alkali-resistant glass fiber composite reinforcement for concrete is 10±0.5 mm.

[0008] Preferably, the weight content of the composite alkali-resistant glass fiber bundle in the alkali-resistant glass fiber composite reinforcement for concrete is 60%-65%.

[0009] Preferably, the bonding resin is a mixture of vinyl resin and curing agent in a weight ratio of 100:1.

[0010] Furthermore, the composite alkali-resistant glass fiber bundle is obtained by grafting alkali-resistant glass fiber with sodium-montmorillonite, bundling it into an alkali-resistant glass fiber bundle with a diameter of 2±0.3 mm, and then impregnating it in a reactive resin slurry, pulling it, drying and curing it, and collecting it to obtain a composite alkali-resistant glass fiber bundle.

[0011] Preferably, the weight content of the alkali-resistant glass fiber bundle in the composite alkali-resistant glass fiber bundle is 98%±0.5%.

[0012] Furthermore, the preparation method of the reactive resin slurry is as follows:

[0013] (1) adding polyethylene glycol with a molecular weight of 2000 and isophorone diisocyanate to butanone, stirring and dissolving, heating to 45-50° C., reacting for 1-2 hours, and further heating to 75-85° C., adding N-hydroxymethyl acrylamide, 2-hydroxypropyltrimethylammonium chloride and epoxy resin E51, reacting for 5-6 hours, and rotary evaporating to obtain a reactive resin;

[0014] (2) Add the reactive resin and sodium montmorillonite into deionized water, raise the temperature to 60-70° C., stir and disperse, and obtain a reactive resin slurry.

[0015] Preferably, the vinyl resin is epoxy vinyl resin.

[0016] Preferably, the traction speed is 0.2-0.3 m / min.

[0017] Preferably, the drying and curing temperature is 150-160° C. and the time is 5-6 hours.

[0018] Preferably, in step (1), the weight ratio of polyethylene glycol, isophorone diisocyanate, butanone, N-(hydroxymethyl)acrylamide, 2-hydroxypropyltrimethylammonium chloride and epoxy resin E51 is 10:2.2:25:0.25:0.38:9.

[0019] Preferably, in step (2), the weight ratio of the reactive resin, sodium montmorillonite and deionized water is 1:0.1-0.5:100.

[0020] Furthermore, the present invention also provides a method for preparing an alkali-resistant glass fiber composite reinforcement for concrete, comprising the following steps:

[0021] (1) mixing a vinyl resin and a curing agent to obtain a bonding resin;

[0022] (2) The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin, and then subjected to pultrusion winding, high-temperature curing, and traction cutting to obtain an alkali-resistant glass fiber composite reinforcement for concrete with a diameter of 10±0.5 mm.

[0023] Beneficial effects of the present invention:

[0024] The present invention adopts alkali-resistant glass fiber to prepare composite reinforcement. The alkali-resistant glass fiber contains zirconium dioxide, which can obviously produce zirconium enrichment phenomenon under the corrosion of concrete alkaline environment, form a dense protective film, slow down the corrosion rate of hydroxide ions on silicon dioxide, and significantly improve alkali resistance.

[0025] The alkali-resistant glass fiber composite reinforcement for concrete prepared by the present invention adopts ammonium salt, olefin group and epoxy group to construct a reactive resin, which can be adhered to the surface of the alkali-resistant glass fiber through ionic bonds and coordination bonds. The ammonium salt helps to improve the alkali resistance and conduct ion exchange with the internal nano-montmorillonite, and the olefin group helps to further react with the outer vinyl resin, thereby building a "bridge" between the vinyl resin and the alkali-resistant glass fiber, improving the adhesion and giving full play to the reinforcement effect of the alkali-resistant glass fiber.

[0026] The present invention further adds sodium montmorillonite into the reactive resin slurry, and the sodium montmorillonite is uniformly dispersed in the reactive resin through ion exchange, thereby improving the alkali resistance and tensile strength of the alkali-resistant glass fiber composite reinforcement.

[0027] The alkali-resistant glass fiber composite reinforcement for concrete provided by the present invention has high mechanical properties, high temperature resistance and alkali resistance, can partially replace steel bars for preparing concrete, and is widely used in marine engineering. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0029] In the specific implementation manner of the present invention, the epoxy resin is Aliance 430ACT; the curing agent is Shuojin MEKP-925H, sodium montmorillonite was purchased from NANOCOR Company, model number is PGW.

[0030] The main physical parameters of the alkali-resistant glass fiber in the specific embodiment of the present invention are shown in Table 1.

[0031] Table 1 Main physical parameters of alkali-resistant glass fiber

[0032] Single filament diameter / μm Elastic modulus / GPa Tensile strength / MPa Zirconium content / % Loss on ignition / % 14 75 1650 16.7 2.2

[0033] Embodiment 1:

[0034] (1) 10 g of polyethylene glycol with a molecular weight of 2000 and 2.2 g of isophorone diisocyanate were added to 25 g of butanone, stirred and dissolved, heated to 45° C., reacted for 2 h, and then heated to 75° C., 0.25 g of N-hydroxymethyl acrylamide, 0.38 g of 2-hydroxypropyltrimethylammonium chloride and 9 g of epoxy resin E51 were added, reacted for 6 h, and rotary evaporated to obtain a reactive resin;

[0035] (2) Add 10 g of reactive resin and 1 g of sodium montmorillonite to 500 g of deionized water, heat to 60° C., and stir to disperse to obtain a reactive resin slurry.

[0036] (3) bundling the alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with a diameter of 1.8 mm, and then immersing the bundle in a reactive resin slurry, pulling the bundle at a speed of 0.2 m / min, drying and curing the bundle at 150° C. for 6 h, and collecting the bundle to obtain a composite alkali-resistant glass fiber bundle, wherein the weight content of the alkali-resistant glass fiber bundle in the composite alkali-resistant glass fiber bundle is 97.8%;

[0037] (4) mixing the epoxy resin and the curing agent in a weight ratio of 100:1 to obtain a bonding resin;

[0038] (5) The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin, and pultruded to obtain an alkali-resistant glass fiber composite reinforcement for concrete with a diameter of 10.3 mm, wherein the weight content of the composite alkali-resistant glass fiber bundle in the alkali-resistant glass fiber composite reinforcement for concrete is 64.5%.

[0039] Embodiment 2:

[0040] (1) 10 g of polyethylene glycol with a molecular weight of 2000 and 2.2 g of isophorone diisocyanate were added to 25 g of butanone, stirred and dissolved, heated to 50° C., reacted for 2 h, and then heated to 80° C., 0.25 g of N-hydroxymethyl acrylamide, 0.38 g of 2-hydroxypropyltrimethylammonium chloride and 9 g of epoxy resin E51 were added, reacted for 5 h, and rotary evaporated to obtain a reactive resin;

[0041] (2) Add 10 g of reactive resin and 3 g of sodium montmorillonite to 800 g of deionized water, heat to 65° C., and stir to disperse to obtain reactive resin slurry.

[0042] (3) bundling the alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with a diameter of 2.1 mm, and then immersing the bundle in a reactive resin slurry, pulling the bundle at a speed of 0.2 m / min, drying and curing the bundle at 160° C. for 5 h, and collecting the bundle to obtain a composite alkali-resistant glass fiber bundle, wherein the weight content of the alkali-resistant glass fiber bundle in the composite alkali-resistant glass fiber bundle is 98.2%;

[0043] (4) mixing the vinyl resin and the curing agent in a weight ratio of 100:1 to obtain a bonding resin;

[0044] (5) The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin, and pultruded to obtain an alkali-resistant glass fiber composite reinforcement for concrete with a diameter of 9.9 mm, wherein the weight content of the composite alkali-resistant glass fiber bundle in the alkali-resistant glass fiber composite reinforcement for concrete is 63.2%.

[0045] Embodiment 3:

[0046] (1) 10 g of polyethylene glycol with a molecular weight of 2000 and 2.2 g of isophorone diisocyanate were added to 25 g of butanone, stirred and dissolved, heated to 50° C., reacted for 1 h, and then heated to 85° C., 0.25 g of N-hydroxymethyl acrylamide, 0.38 g of 2-hydroxypropyltrimethylammonium chloride and 9 g of epoxy resin E51 were added, reacted for 5 h, and rotary evaporated to obtain a reactive resin;

[0047] (2) Add 10 g of reactive resin and 5 g of sodium montmorillonite to 1000 g of deionized water, heat to 70° C., and stir to disperse to obtain reactive resin slurry.

[0048] (3) bundling the alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with a diameter of 2.2 mm, and then immersing the bundle in a reactive resin slurry, pulling the bundle at a speed of 0.3 m / min, drying and curing the bundle at 160° C. for 5 h, and collecting the bundle to obtain a composite alkali-resistant glass fiber bundle, wherein the weight content of the alkali-resistant glass fiber bundle in the composite alkali-resistant glass fiber bundle is 98.3%;

[0049] (4) mixing the vinyl resin and the curing agent in a weight ratio of 100:1 to obtain a bonding resin;

[0050] (5) The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin, and pultruded to obtain an alkali-resistant glass fiber composite reinforcement for concrete with a diameter of 9.6 mm, wherein the weight content of the composite alkali-resistant glass fiber bundle in the alkali-resistant glass fiber composite reinforcement for concrete is 60.5%.

[0051] Comparative Example 1:

[0052] The main difference between Comparative Example 1 and Example 2 is that no reactive resin is added;

[0053] (1) Bundling the alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with a diameter of 2 mm;

[0054] (2) mixing the vinyl resin and the curing agent in a weight ratio of 100:1 to obtain a bonding resin;

[0055] (3) The alkali-resistant glass fiber bundle is impregnated in a bonding resin, and pultruded to obtain an alkali-resistant glass fiber composite reinforcement with a diameter of 10 mm, wherein the weight content of the alkali-resistant glass fiber bundle in the glass fiber composite reinforcement is 64.4%.

[0056] Comparative Example 2:

[0057] The main difference between Comparative Example 2 and Example 2 is that: N-hydroxymethyl acrylamide is not added to the reactive resin;

[0058] (1) 10 g of polyethylene glycol with a molecular weight of 2000 and 2.2 g of isophorone diisocyanate were added to 25 g of butanone, stirred and dissolved, heated to 50° C., reacted for 2 h, and then heated to 80° C., 0.38 g of 2-hydroxypropyltrimethylammonium chloride and 9 g of epoxy resin E51 were added, reacted for 5 h, and rotary evaporated to obtain a reactive resin;

[0059] (2) Add 10 g of reactive resin and 3 g of sodium montmorillonite to 800 g of deionized water, heat to 65° C., and stir to disperse to obtain reactive resin slurry.

[0060] (3) bundling the alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with a diameter of 2.1 mm, and then immersing the bundle in a reactive resin slurry, pulling the bundle at a speed of 0.2 m / min, drying and curing the bundle at 160° C. for 5 h, and collecting the bundle to obtain a composite alkali-resistant glass fiber bundle, wherein the weight content of the alkali-resistant glass fiber bundle in the composite alkali-resistant glass fiber bundle is 98.2%;

[0061] (4) mixing the vinyl resin and the curing agent in a weight ratio of 100:1 to obtain a bonding resin;

[0062] (5) The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin, and pultruded to obtain an alkali-resistant glass fiber composite reinforcement for concrete with a diameter of 9.9 mm, wherein the weight content of the composite alkali-resistant glass fiber bundle in the alkali-resistant glass fiber composite reinforcement for concrete is 63.1%.

[0063] Comparative Example 3:

[0064] The main difference between Comparative Example 3 and Example 2 is that: 2-hydroxypropyltrimethylammonium chloride is not added to the reactive resin;

[0065] (1) 10 g of polyethylene glycol with a molecular weight of 2000 and 2.2 g of isophorone diisocyanate were added to 25 g of butanone, stirred and dissolved, heated to 50° C., reacted for 2 h, and then heated to 80° C., 0.25 g of N-hydroxymethyl acrylamide and 9 g of epoxy resin E51 were added, reacted for 5 h, and rotary evaporated to obtain a reactive resin;

[0066] (2) Add 10 g of reactive resin and 3 g of sodium montmorillonite to 800 g of deionized water, heat to 65° C., and stir to disperse to obtain reactive resin slurry.

[0067] (3) bundling the alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with a diameter of 2.1 mm, and then immersing the bundle in a reactive resin slurry, pulling the bundle at a speed of 0.2 m / min, drying and curing the bundle at 160° C. for 5 h, and collecting the bundle to obtain a composite alkali-resistant glass fiber bundle, wherein the weight content of the alkali-resistant glass fiber bundle in the composite alkali-resistant glass fiber bundle is 98.2%;

[0068] (4) mixing the vinyl resin and the curing agent in a weight ratio of 100:1 to obtain a bonding resin;

[0069] (5) The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin, and pultruded to obtain an alkali-resistant glass fiber composite reinforcement for concrete with a diameter of 9.9 mm, wherein the weight content of the composite alkali-resistant glass fiber bundle in the alkali-resistant glass fiber composite reinforcement for concrete is 63.3%.

[0070] Comparative Example 4:

[0071] The main difference between Comparative Example 4 and Example 2 is that no sodium montmorillonite is added to the reactive resin slurry;

[0072] (1) 10 g of polyethylene glycol with a molecular weight of 2000 and 2.2 g of isophorone diisocyanate were added to 25 g of butanone, stirred and dissolved, heated to 50° C., reacted for 2 h, and then heated to 80° C., 0.25 g of N-hydroxymethyl acrylamide, 0.38 g of 2-hydroxypropyltrimethylammonium chloride and 9 g of epoxy resin E51 were added, reacted for 5 h, and rotary evaporated to obtain a reactive resin;

[0073] (2) adding 13 g of reactive resin to 800 g of deionized water, heating to 65° C., stirring and dispersing to obtain reactive resin slurry;

[0074] (3) bundling the alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with a diameter of 2.1 mm, and then immersing the bundle in a reactive resin slurry, pulling the bundle at a speed of 0.2 m / min, drying and curing the bundle at 160° C. for 5 h, and collecting the bundle to obtain a composite alkali-resistant glass fiber bundle, wherein the weight content of the alkali-resistant glass fiber bundle in the composite alkali-resistant glass fiber bundle is 98.1%;

[0075] (4) mixing a vinyl resin and a curing agent in a weight ratio of 100:1 to obtain a bonding resin;

[0076] (5) The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin, and pultruded to obtain an alkali-resistant glass fiber composite reinforcement for concrete with a diameter of 9.9 mm, wherein the weight content of the composite alkali-resistant glass fiber bundle in the alkali-resistant glass fiber composite reinforcement for concrete is 63.4%.

[0077] Performance Test:

[0078] Tensile strength: According to GB / T 30022-2013 "Test methods for basic mechanical properties of fiber reinforced composite material bars", the tensile mechanical properties test was carried out on a universal material testing machine. The sample was then placed at 100°C for 24 hours and then the tensile mechanical properties test was carried out again. The results are shown in Table 2.

[0079] Alkali resistance test: 15 g of sodium hydroxide was dissolved in 1000 ml of deionized water to obtain an alkaline solution, which was then placed in a constant temperature water tank and maintained at 60°C. The alkali-resistant glass fiber composite reinforcement prepared in the embodiment and comparative example with protection at both ends was then immersed in the alkaline solution for 15 d, 30 d, 60 d and 90 d, respectively. The samples were taken out after the immersion time expired, and the tensile strength test was performed. The tensile strength retention rate relative to the blank sample was calculated, and the results are shown in Table 2.

[0080] Table 2 Performance test results

[0081]

[0082] Data Analysis:

[0083] From the data of Examples 1-3 in Table 2, it can be seen that the alkali-resistant glass fiber composite reinforcement for concrete prepared by the present invention has a high tensile strength, indicating that it has strong mechanical properties, especially at high temperatures, it can still maintain high mechanical properties. Most importantly, after undergoing an alkali resistance test at 60°C for 90 days, it can still maintain more than 85% of the tensile strength, indicating that it has strong alkali resistance.

[0084] It can be seen from the data of Example 2 and Comparative Examples 1-3 in Table 2 that the reactive resin helps to improve the tensile strength. This is mainly because the reactive resin, on the one hand, adheres to the surface of the alkali-resistant glass fiber through ionic bonds and coordination bonds, and on the other hand, can react with the vinyl resin in the outer layer to build a bridge between the vinyl resin and the alkali-resistant glass fiber, thereby improving compatibility.

[0085] From the data of Example 2 and Comparative Example 4 in Table 2, it can be seen that the montmorillonite in the reactive resin slurry can improve the tensile strength, and most importantly, has a significant effect on the alkali resistance. This is mainly because the montmorillonite has excellent dispersibility in the reactive resin, and the montmorillonite and the ammonium salt in the reactive resin can undergo ion exchange, so that the alkali-resistant glass fiber composite reinforcement for concrete still has a high tensile strength at high temperature. Moreover, the flaky montmorillonite can further block the erosion of the alkali solution on the alkali-resistant glass fiber, thereby improving the alkali resistance.

[0086] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. An alkali-resistant glass fiber composite reinforcement for concrete, characterized in that: The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin and then pultruded to obtain the composite alkali-resistant glass fiber bundle; the weight content of the composite alkali-resistant glass fiber bundle in the alkali-resistant glass fiber composite reinforcement for concrete is 60%-65%; the bonding resin is a mixture of vinyl resin and curing agent in a weight ratio of 100:1; The composite alkali-resistant glass fiber bundle is obtained by bundling alkali-resistant glass fibers into an alkali-resistant glass fiber bundle with a diameter of 2±0.3 mm, then impregnating the bundle in a reactive resin slurry, pulling, drying, curing, and collecting the bundle; the weight content of the alkali-resistant glass fiber bundle in the composite alkali-resistant glass fiber bundle is 98%±0.5%; The preparation method of the reactive resin slurry is as follows: (1) adding polyethylene glycol with a molecular weight of 2000 and isophorone diisocyanate to butanone, stirring and dissolving, heating to 45-50° C., reacting for 1-2 hours, and further heating to 75-85° C., adding N-hydroxymethyl acrylamide, 2-hydroxypropyltrimethylammonium chloride and epoxy resin E51, reacting for 5-6 hours, and rotary evaporating to obtain a reactive resin; (2) Add the reactive resin and sodium montmorillonite into deionized water, raise the temperature to 60-70° C., stir and disperse, and obtain a reactive resin slurry.

2. The alkali-resistant glass fiber composite reinforcement for concrete according to claim 1, characterized in that: The vinyl resin is epoxy vinyl resin.

3. The alkali-resistant glass fiber composite reinforcement for concrete according to claim 1, characterized in that: The pulling speed is 0.2-0.3 m / min.

4. The alkali-resistant glass fiber composite reinforcement for concrete according to claim 1, characterized in that: The drying and curing process is performed at a temperature of 150-160° C. and a time of 5-6 hours.

5. The alkali-resistant glass fiber composite reinforcement for concrete according to claim 1, characterized in that: In the step (1), the weight ratio of polyethylene glycol, isophorone diisocyanate, butanone, N-(hydroxymethyl)acrylamide, 2-hydroxypropyltrimethylammonium chloride and epoxy resin E51 is 10:2.2:25:0.25:0.38:

9.

6. The alkali-resistant glass fiber composite reinforcement for concrete according to claim 1, characterized in that: In the step (2), the weight ratio of the reactive resin, sodium montmorillonite and deionized water is 1:0.1-0.5:

100.

7. A method for preparing the alkali-resistant glass fiber composite reinforcement for concrete according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) mixing a vinyl resin and a curing agent to obtain a bonding resin; (2) The composite alkali-resistant glass fiber bundle is impregnated in a bonding resin, and then subjected to pultrusion winding, high-temperature curing, and traction cutting to obtain an alkali-resistant glass fiber composite reinforcement for concrete with a diameter of 10±0.5 mm.

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