Marine concrete underwater engineering geopolymer repairing material and preparation method thereof

Abstract

The invention discloses a marine concrete underwater engineering geopolymer repairing material. The repairing material is prepared from the following raw materials in parts by weight: 10-15 parts of a composite alkali activator, 30-40 parts of granulated blast furnace slag powder, 20-25 parts of fly ash, 10-15 parts of cement, 1-2 parts of silica fume, 1-2 parts of wollastonite, 0.1-0.3 part of a flocculating agent, 0.2-0.5 part of a water reducing agent, 2-5 parts of an expanding agent, 0.1-0.3 part of a thickening time control agent, 3-5 parts of latex powder and 5-10 parts of water. The marine concrete underwater engineering geopolymer repairing material has the characteristics of self-leveling, self-compacting, vibration-free, high early strength, good dispersion resistance, strong binding power with an original cement concrete base material, capability of realizing self-falling construction in water and moderate price, and can better meet the performance requirements of underwater repairing of marine concrete structures.

Description

Technical Field

[0001] The invention relates to the technical field of marine concrete underwater engineering repair, and in particular to a geopolymer-based marine concrete underwater engineering repair material and a preparation method thereof. Background Art

[0002] Marine concrete and reinforced concrete structures, during their long-term service, are affected by harsh natural conditions, especially water scouring and marine biological erosion, which often cause local damage to some components, impair the strength of concrete, affect the durability of concrete, and even cause major economic losses and safety hazards in severe cases, so they must be repaired in time. Unlike general repair environments, the specific damage to underwater structural diseases is difficult to detect. At the same time, the repair surface is immersed in water. The wet construction surface will not only reduce the adhesion between the traditional repair slurry based on cement slurry and the old concrete surface, but also in areas with a certain water depth, the active ingredients of the slurry will quickly disintegrate under the action of water pressure and cannot be consolidated. Therefore, there is an urgent need for a new type of underwater repair material for marine concrete engineering that has high strength, strong bonding ability with the old concrete surface, good underwater anti-dispersion and good constructability. Summary of the invention

[0003] The purpose of the present invention is to provide a marine concrete underwater engineering repair material, in particular a geopolymer-based underwater repair material, which has the characteristics of high strength, strong bonding ability with old concrete surface, good underwater anti-dispersion, easy construction, etc.

[0004] In order to achieve the above-mentioned purpose, the first aspect of the present invention provides a marine concrete underwater engineering geopolymer repair material, which comprises: 10 to 15 parts of a composite alkali activator, 30 to 40 parts of granulated blast furnace slag powder, 20 to 25 parts of fly ash, 10 to 15 parts of cement, 1 to 2 parts of silica fume, 1 to 2 parts of wollastonite, 0.1 to 0.3 parts of a flocculant, 0.2 to 0.5 parts of a water reducer, 2 to 5 parts of an expansion agent, 0.1 to 0.3 parts of a setting regulator, 3 to 5 parts of latex powder, and 5 to 10 parts of water.

[0005] As a preferred embodiment of the present invention, the composite alkali activator is obtained by compounding NaOH and Na2SiO3 solution, and the modulus is adjusted to 1.3~1.6M.

[0006] As a preferred embodiment of the present invention, the fly ash is Class I fly ash.

[0007] As a preferred embodiment of the present invention, the wollastonite has a fineness of 600-800 mesh.

[0008] As a preferred embodiment of the present invention, the flocculant is polyacrylamide with a molecular weight of 8 to 12 million.

[0009] As a preferred embodiment of the present invention, the expansion agent is low-activity magnesium oxide with a mesh size of 200-400 meshes.

[0010] As a preferred embodiment of the present invention, the setting agent is anhydrous sodium tetraborate.

[0011] As a preferred embodiment of the present invention, the latex powder is a redispersible latex powder of styrene and butadiene copolymer.

[0012] The second aspect of the present invention provides a method for preparing the marine concrete underwater engineering geopolymer repair material, the preparation method comprising: (1) Mixing NaOH and Na2SiO3 solution in a certain proportion to obtain a composite activator; (2) Mix granulated blast furnace slag powder, fly ash, cement, silica fume, wollastonite, water reducing agent, expansion agent, setting agent and latex powder in a mixer for 5 minutes to obtain a premix for later use; (3) After adding 50% of the water used to the beaker, place it under a stirrer and stir it at a speed of 300-400 r / min. Sprinkle the flocculant evenly around the vortex. When the flocculant is dissolved, a flocculant solution is obtained. (4) Add the premix into the concrete mixer, add the flocculant solution, stir for 60 seconds, add the composite activator and make up the required amount of water, and continue stirring for not less than 2 minutes to obtain the marine concrete underwater engineering geopolymer repair material.

[0013] Compared with traditional underwater repair materials, the present invention has the following main advantages: (1) The underwater geopolymer repair material of the present invention has high early strength, strong adhesion to the old concrete surface, good anti-dispersion, good fluidity, and can realize self-falling construction in water; (2) The present invention uses solid waste as raw material, thus realizing the resource utilization of solid waste, which can reduce costs while improving material performance, and has significant environmental and social benefits; (3) The compressive strength of some of the prepared underwater repair polymer materials is greater than 40 MPa at 1d and greater than 60 MPa at 28d; the 28d water-to-land strength ratio is greater than 90%; and the underwater interface bonding strength is greater than 1.5 MPa at 1d and greater than 3.5 MPa at 28d.

[0014] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0015] The present invention will be further described below in conjunction with specific embodiments so that those skilled in the art can more fully understand the present invention, but the present invention is not limited in any way.

[0016] Example 1: A marine concrete underwater engineering geopolymer repair material (1) Mix NaOH and Na2SiO3 in a certain proportion to obtain a composite alkali activator with a modulus of 1.3M, and weigh 10 portions for later use; (2) 30 parts of granulated blast furnace slag powder, 20 parts of fly ash, 15 parts of cement, 1 part of silica fume, 1 part of wollastonite, 0.2 parts of water reducing agent, 2 parts of expansion agent, 0.1 parts of setting regulator, and 3 parts of latex powder were stirred in a mixer for 5 minutes to obtain a premix, which was set aside; (3) Add 0.1 parts of flocculant to 4 parts of water and stir until completely dissolved to obtain a flocculant solution; (4) Add the premix into a concrete mixer, add the flocculant solution, stir for 60 seconds, add the composite activator and 4 parts of water, and continue stirring for not less than 2 minutes to obtain the marine concrete underwater engineering geopolymer repair material.

[0017] Example 2: A marine concrete underwater engineering geopolymer repair material (1) Mix NaOH and Na2SiO3 in a certain proportion to obtain a composite alkali activator with a modulus of 1.6M, and weigh 15 portions for later use; (2) Grind 35 parts of granulated blast furnace slag powder, 25 parts of fly ash, 10 parts of cement, 2 parts of silica fume, 1 part of wollastonite, 0.3 parts of water reducer, 3 parts of expansion agent, 0.2 parts of setting regulator, and 3 parts of latex powder in a planetary ball mill for 15 minutes to obtain a premix for later use; (3) Add 0.2 parts of flocculant to 4 parts of water and stir until completely dissolved to obtain a flocculant solution; (4) Add the premix into a concrete mixer, add the flocculant solution, stir for 60 seconds, add the composite activator and 4 parts of water, and continue stirring for not less than 2 minutes to obtain the marine concrete underwater engineering geopolymer repair material.

[0018] Example 3: A marine concrete underwater engineering geopolymer repair material (1) Mix NaOH and Na2SiO3 in a certain proportion to obtain a composite alkali activator with a modulus of 1.6M, and weigh 13 portions for later use; (2) Grind 35 parts of granulated blast furnace slag powder, 25 parts of fly ash, 12 parts of cement, 1.5 parts of silica fume, 2 parts of wollastonite, 0.5 parts of water reducer, 3 parts of expansion agent, 0.2 parts of setting regulator, and 5 parts of latex powder in a planetary ball mill for 15 minutes to obtain a premix for later use; (3) Add 0.3 parts of flocculant to 3 parts of water and stir until completely dissolved to obtain a flocculant solution; (4) Add the premix into a concrete mixer, add the flocculant solution, stir for 60 seconds, add the composite activator and 3 parts of water, and continue stirring for not less than 2 minutes to obtain the marine concrete underwater engineering geopolymer repair material.

[0019] Example 4: A marine concrete underwater engineering geopolymer repair material (1) Mix NaOH and Na2SiO3 in a certain proportion to obtain a composite alkali activator with a modulus of 1.5M, and weigh 13 portions for later use; (2) Grind 40 parts of granulated blast furnace slag powder, 20 parts of fly ash, 10 parts of cement, 1.5 parts of silica fume, 2 parts of wollastonite, 0.3 parts of water reducer, 3 parts of expansion agent, 0.2 parts of setting regulator, and 5 parts of latex powder in a planetary ball mill for 15 minutes to obtain a premix for later use; (3) Add 0.2 parts of flocculant to 4 parts of water and stir until completely dissolved to obtain a flocculant solution; (4) Add the premix into a concrete mixer, add the flocculant solution, stir for 60 seconds, add the composite activator and 4 parts of water, and continue stirring for not less than 2 minutes to obtain the marine concrete underwater engineering geopolymer repair material.

[0020] Example 5: A marine concrete underwater engineering geopolymer repair material (1) Mix NaOH and Na2SiO3 in a certain proportion to obtain a composite alkali activator with a modulus of 1.5M, and weigh 15 portions for later use; (2) Grind 35 parts of granulated blast furnace slag powder, 20 parts of fly ash, 10 parts of cement, 2 parts of silica fume, 1 part of wollastonite, 0.5 parts of water reducer, 5 parts of expansion agent, 0.3 parts of setting regulator, and 3 parts of latex powder in a planetary ball mill for 15 minutes to obtain a premix for later use; (3) Add 0.2 parts of flocculant to 3 parts of water and stir until completely dissolved to obtain a flocculant solution; (4) Add the premix into a concrete mixer, add the flocculant solution, stir for 60 seconds, add the composite activator and 3 parts of water, and continue stirring for not less than 2 minutes to obtain the marine concrete underwater engineering geopolymer repair material.

[0021] Example 6: A marine concrete underwater engineering geopolymer repair material (1) Mix NaOH and Na2SiO3 in a certain proportion to obtain a composite alkali activator with a modulus of 1.3M, and weigh 13 portions for later use; (2) Grind 40 parts of granulated blast furnace slag powder, 25 parts of fly ash, 10 parts of cement, 1.5 parts of silica fume, 2 parts of wollastonite, 0.3 parts of water reducer, 5 parts of expansion agent, 0.2 parts of setting regulator, and 3 parts of latex powder in a planetary ball mill for 15 minutes to obtain a premix for later use; (3) Add 0.1 parts of flocculant to 4 parts of water and stir until completely dissolved to obtain a flocculant solution; (4) Add the premix into a concrete mixer, add the flocculant solution, stir for 60 seconds, add the composite activator and 4 parts of water, and continue stirring for not less than 2 minutes to obtain the marine concrete underwater engineering geopolymer repair material.

[0022] The test results of the materials described in the above examples are shown in Table 1.

[0023] Table 1 Performance test results of geopolymer repair materials for marine concrete underwater engineering

[0024] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A geopolymer repair material for underwater marine concrete engineering, characterized in that: The repair material is composed of the following raw materials in parts by weight: 10-15 parts of composite alkali activator, 30-40 parts of granulated blast furnace slag powder, 20-25 parts of fly ash, 10-15 parts of cement, 1-2 parts of silica fume, 1-2 parts of wollastonite, 0.1-0.3 parts of flocculant, 0.2-0.5 parts of water reducer, 2-5 parts of expansion agent, 0.1-0.3 parts of setting regulator, 3-5 parts of latex powder and 5-10 parts of water.

2. The marine concrete underwater engineering geopolymer repair material according to claim 1 is characterized in that : The alkaline activator is a composite of NaOH and Na2SiO3 solution, and the modulus is adjusted to 1.3~1.6 M.

3. The marine concrete underwater engineering geopolymer repair material according to claim 1 is characterized in that : The fly ash is Class I fly ash.

4. The marine concrete underwater engineering geopolymer repair material according to claim 1 is characterized in that : The fineness of wollastonite is 600~800 mesh.

5. The marine concrete underwater engineering geopolymer repair material according to claim 1 is characterized by: The flocculant is polyacrylamide with a molecular weight of 8 to 12 million.

6. The marine concrete underwater engineering geopolymer repair material according to claim 1 is characterized in that : The expansion agent is low-activity magnesium oxide with a mesh size of 200~400 mesh.

7. The marine concrete underwater engineering geopolymer repair material according to claim 1 is characterized in that : The coagulant is sodium tetraborate.

8. The marine concrete underwater engineering geopolymer repair material according to claim 1 is characterized in that : The latex powder is a redispersible latex powder copolymerized with styrene and butadiene.

9. A marine concrete underwater engineering geopolymer repair material, the preparation process of which is as follows: The NaOH and Na2SiO3 solutions are mixed in a certain proportion to obtain a composite activator; The granulated blast furnace slag powder, fly ash, cement, silica fume, wollastonite, water reducing agent, expansion agent, setting agent and latex powder are stirred in a mixer for 5 minutes to obtain a premix, which is then used for later use; After adding 50% of the water used in the beaker, place it under a stirrer and stir it at a speed of 300-400r / min, and sprinkle the flocculant evenly around the vortex. When the flocculant is dissolved, the flocculant solution is obtained; Add premix into a concrete mixer, add flocculant solution, stir for 60 seconds, add composite activator and make up the required amount of water, continue stirring for not less than 2 minutes, and obtain the marine concrete underwater engineering geopolymer repair material.

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