A non-cracking pavement concrete and a method for manufacturing the same

Abstract

The application relates to the technical field of concrete, and discloses anti-cracking pavement concrete and a manufacturing method thereof, which comprises the following components by mass: cement 70-80 parts, fly ash 12-16 parts, slag 8-10 parts, aggregate 240-280 parts, water reducing agent 0.4-0.8 part, polyvinyl alcohol microspheres 1-2 parts, polyacrylamide microspheres 2-4 parts, anti-cracking fiber 1.2-1.6 parts, auxiliary agent 0.5-1 part, dispersant 0.3-0.5 part and water 40-60 parts; the auxiliary agent comprises Span 60 and vinyl-based silane. The technical scheme solves the problem of insufficient anti-cracking performance of pavement concrete in the related art.

Description

Technical Field

[0001] This invention relates to the field of concrete technology, specifically to a crack-resistant pavement concrete and its manufacturing method. Background Technology

[0002] Road surface concrete is mainly used in engineering fields with extremely high requirements for road surface durability, such as highways, urban arterial roads, airport runways, and large logistics parks. These road surface structures are subjected to multiple factors such as heavy traffic loads, changes in environmental temperature and humidity, and foundation settlement over long periods of time. Therefore, their crack resistance directly determines the service life, driving safety, and maintenance costs of the road surface.

[0003] To improve the crack resistance of pavement concrete, existing technologies typically introduce polymer microspheres into the matrix. These microspheres can suppress microcrack formation by filling internal pores and buffering stress concentrations. However, polymer microspheres have a high surface energy, making them prone to agglomeration in cement paste. This significantly reduces their dispersibility in the matrix, hindering their ability to fully exert their crack resistance and potentially damaging the overall performance and durability of the concrete by forming localized defects. Therefore, there is an urgent need to develop a pavement concrete with excellent crack resistance. Summary of the Invention

[0004] This invention proposes a crack-resistant pavement concrete and its manufacturing method, which solves the problem of insufficient crack resistance of pavement concrete in related technologies.

[0005] The technical solution of the present invention is as follows: This invention proposes a crack-resistant pavement concrete, comprising the following raw materials in parts by weight: 70-80 parts cement, 12-16 parts fly ash, 8-10 parts slag, 240-280 parts aggregate, 0.4-0.8 parts water-reducing agent, 1-2 parts polyvinyl alcohol microspheres, 2-4 parts polyacrylamide microspheres, 1.2-1.6 parts crack-resistant fiber, 0.5-1 part additives, 0.3-0.5 parts dispersant, and 40-60 parts water. The additives include Span 60 and vinyl silanes.

[0006] As a further technical solution, the mass ratio of Span 60 to vinyl silane is 3:0.5~1.

[0007] As a further technical solution, the vinyl silanes include methylvinyldiethoxysilane and diethylenetriaminepropylmethyldimethoxysilane.

[0008] As a further technical solution, the mass ratio of the methylvinyldiethoxysilane to diethylenetriaminepropylmethyldimethoxysilane is 2:1~3.

[0009] As a further technical solution, the water-reducing agent includes polycarboxylate water-reducing agent and sodium tripolyphosphate.

[0010] The crack-resistant pavement concrete of this invention uses a combination of polycarboxylate superplasticizer and sodium tripolyphosphate as a superplasticizer, which results in better water reduction, better concrete fluidity, easier air bubble removal, and increased density, thereby making the concrete stronger after curing.

[0011] As a further technical solution, the mass ratio of the polycarboxylate superplasticizer to sodium tripolyphosphate is 8:1~2, for example, it can be 8:1, 8:1.5, or 4:1.

[0012] As a further technical solution, the crack-resistant fiber includes one or more of steel fiber, polypropylene fiber, and lignin fiber.

[0013] As a further technical solution, the dispersant includes one or two of stearic acid and sodium dodecylbenzenesulfonate.

[0014] As a further technical solution, the aggregate is composed of coarse aggregate and fine aggregate in a mass ratio of 2 to 3:1.

[0015] This invention also proposes a method for manufacturing crack-resistant pavement concrete, which includes the following steps: S1 After mixing the water and additives, add polyvinyl alcohol microspheres and polyacrylamide microspheres and mix to obtain a premix; S2. Add the remaining raw materials to the premix and mix to obtain crack-resistant pavement concrete.

[0016] The working principle and beneficial effects of this invention are as follows: This invention prepares a crack-resistant pavement concrete, wherein the polymer microspheres are a mixture of polyvinyl alcohol microspheres and polyacrylamide microspheres, obtained by treatment with Span 60 and vinyl silanes, which can improve the crack resistance of the pavement concrete. Polyvinyl alcohol microspheres have excellent hydrophilicity and toughness, and can form a stable spatial network structure in cement paste, while polyacrylamide microspheres have excellent water absorption and retention and elastic deformation capabilities. However, polymer microspheres have a high surface energy, making them prone to agglomeration in cement paste. Span 60 can effectively reduce the surface energy of polymer microspheres, reducing the mutual adsorption of microspheres in cement paste, thereby preventing agglomeration. Vinyl silanes can further enhance the bonding force between microspheres and the cement matrix. The synergistic effect of both significantly improves the dispersibility and interfacial compatibility of the microspheres, thus fully utilizing the crack resistance of the polymer microspheres. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] In the following embodiments and comparative examples: The cement is silicate cement, type: CA50, manufacturer: Zhengzhou Kanghui Refractory Materials Co., Ltd. The fly ash is power plant fly ash, model: 96-BG, manufacturer: Lingshou County Zhanteng Mineral Products Processing Plant; Slag, model: 0911, manufacturer: Chongqing Jinjuyuan New Material Technology Co., Ltd.; The coarse aggregate is crushed stone with an average particle size of 5-10mm. Manufacturer: Tangshan Jidong Cement Co., Ltd. The fine aggregate is river sand with an average particle size of 20-40 mesh. Model: CWZ-001. Manufacturer: Lingshou Yuexin Mineral Products Co., Ltd. Polycarboxylate superplasticizer, model: HK41274, manufacturer: Guangzhou Huakeli Building Materials Co., Ltd. Aminosulfonate-based water-reducing agent, model: BHY-2, manufacturer: Laiwu Yanhui Building Materials Co., Ltd.; Polyvinyl alcohol microspheres, model: rn0065, manufacturer: Xi'an Ruien Biotechnology Co., Ltd. Steel fiber: average diameter 0.5mm, average length 20mm; Polypropylene fiber: average diameter 2.5μm, average length: 10mm; Lignin fibers: average diameter 15μm, average length 5mm; Polyacrylamide microspheres, model: WD-50, manufacturer: Xi'an Wand Energy Chemical Co., Ltd.

[0019] Example 1 A crack-resistant pavement concrete comprises the following raw materials in parts by weight: 70 parts cement, 12 parts fly ash, 8 parts slag, 240 parts aggregate, 0.4 parts polycarboxylate superplasticizer, 1 part polyvinyl alcohol microspheres, 2 parts polyacrylamide microspheres, 1.2 parts crack-resistant fiber, 40 parts water, 0.5 parts additives, and 0.3 parts stearic acid. The crack-resistant fiber is composed of steel fiber, polypropylene fiber, and lignin fiber in a mass ratio of 5:3:2. The additives are composed of Span 60 and diethylenetriaminepropylmethyldimethoxysilane in a mass ratio of 3:0.5. The aggregate is composed of coarse aggregate and fine aggregate in a mass ratio of 2:1. A crack-resistant pavement concrete, comprising the following steps: S1 mixes water and additives at 300 r / min for 8 min, then adds polyvinyl alcohol microspheres and polyacrylamide microspheres and continues mixing for 10 min to obtain a premix. S2. Add the remaining raw materials to the premix and mix for 20 minutes at 600 r / min to obtain crack-resistant pavement concrete.

[0020] Example 2 A crack-resistant pavement concrete comprises the following raw materials in parts by weight: 75 parts cement, 14 parts fly ash, 9 parts slag, 260 parts aggregate, 0.6 parts polycarboxylate superplasticizer, 1.5 parts polyvinyl alcohol microspheres, 3 parts polyacrylamide microspheres, 1.4 parts crack-resistant fiber, 50 parts water, 0.7 parts additives, and 0.4 parts stearic acid. The crack-resistant fiber is composed of steel fiber, polypropylene fiber, and lignin fiber in a mass ratio of 5:3:2. The additives are composed of Span 60 and diethylenetriaminepropylmethyldimethoxysilane in a mass ratio of 3:0.5. The aggregate is composed of coarse aggregate and fine aggregate in a mass ratio of 2.5:1. A crack-resistant pavement concrete, comprising the following steps: S1 mixes water and additives at 400 r / min for 7 min, then adds polyvinyl alcohol microspheres and polyacrylamide microspheres and continues mixing for 12 min to obtain a premix. S2. Add the remaining raw materials to the premix and mix at 700 r / min for 17 min to obtain crack-resistant pavement concrete.

[0021] Example 3 A crack-resistant pavement concrete comprises the following raw materials in parts by weight: 80 parts cement, 16 parts fly ash, 10 parts slag, 280 parts aggregate, 0.8 parts polycarboxylate superplasticizer, 2 parts polyvinyl alcohol microspheres, 4 parts polyacrylamide microspheres, 1.6 parts crack-resistant fiber, 60 parts water, 1 part additive, and 0.4 parts stearic acid. The crack-resistant fiber is composed of steel fiber, polypropylene fiber, and lignin fiber in a mass ratio of 5:3:2. The additive is composed of Span 60 and diethylenetriaminepropylmethyldimethoxysilane in a mass ratio of 3:0.5. The aggregate is composed of coarse aggregate and fine aggregate in a mass ratio of 3:1. A crack-resistant pavement concrete, comprising the following steps: S1 mixes water and additives at 500 r / min for 5 min, then adds polyvinyl alcohol microspheres and polyacrylamide microspheres and continues mixing for 15 min to obtain a premix. S2. Add the remaining raw materials to the premix and mix at 800 r / min for 15 min to obtain crack-resistant pavement concrete.

[0022] Example 4 The only difference between this embodiment and Embodiment 1 is that the mass ratio of Span 60 and diethylenetriaminepropylmethyldimethoxysilane in this embodiment is 3:0.8.

[0023] Example 5 The only difference between this embodiment and Embodiment 1 is that the mass ratio of Span 60 and diethylenetriaminepropylmethyldimethoxysilane in this embodiment is 3:1.

[0024] Example 6 The only difference between this embodiment and Embodiment 4 is that in this embodiment, diethylenetriaminepropylmethyldimethoxysilane is replaced with equal amounts of methylvinyldiethoxysilane and diethylenetriaminepropylmethyldimethoxysilane in a mass ratio of 2:1.

[0025] Example 7 The only difference between this embodiment and Embodiment 4 is that in this embodiment, diethylenetriaminepropylmethyldimethoxysilane is replaced with equal amounts of methylvinyldiethoxysilane and diethylenetriaminepropylmethyldimethoxysilane in a mass ratio of 1:1.

[0026] Example 8 The only difference between this embodiment and Embodiment 4 is that in this embodiment, diethylenetriaminepropylmethyldimethoxysilane is replaced with equal amounts of methylvinyldiethoxysilane and diethylenetriaminepropylmethyldimethoxysilane in a mass ratio of 2:3.

[0027] Example 9 The only difference between this embodiment and Embodiment 4 is that in this embodiment, diethylenetriaminepropylmethyldimethoxysilane is replaced with an equal amount of methylvinyldiethoxysilane.

[0028] Example 10 The only difference between this embodiment and Embodiment 8 is that in this embodiment, the polycarboxylate superplasticizer is replaced with equal amounts of polycarboxylate superplasticizer and sodium tripolyphosphate in a mass ratio of 8:1.

[0029] Example 11 The only difference between this embodiment and Embodiment 10 is that sodium tripolyphosphate is replaced with an equal mass of aminosulfonate-based water-reducing agent in this embodiment.

[0030] Comparative Example 1 The only difference between this comparative example and Example 1 is that diethylenetriaminepropylmethyldimethoxysilane is replaced with an equal mass of Span 60.

[0031] Comparative Example 2 The only difference between this comparative example and Example 1 is that Span 60 is replaced with an equal mass of ethylenetriaminepropylmethyldimethoxysilane.

[0032] Test case The crack-resistant pavement concrete prepared in Examples 1-11 and Comparative Examples 1-2 were used as test samples. After curing for 28 days, the samples were prepared according to GB / T50081. The 2019 standard, "Test Methods for Mechanical Properties of Ordinary Concrete," was used to test the compressive strength, splitting tensile strength, and to observe whether cracks appeared on the surface of each sample, recording the length of the cracks. The test sample was a standard cubic specimen measuring 150mm × 150mm × 150mm.

[0033] Table 1 Performance test results of Examples 1-9 and Comparative Examples 1-2

[0034] The splitting compressive strength of Examples 1-9 was higher than that of Comparative Examples 1-2, and no cracks were generated in Examples 1-9 after 28 days of curing. This indicates that the addition of polyvinyl alcohol microspheres and polyacrylamide microspheres obtained by compounding Span 60, methyl vinyl diethoxysilane and diethylenetriaminepropylmethyl dimethoxysilane in this invention improved the crack resistance of pavement concrete.

[0035] Table 2 Performance test results of Examples 8 and 10-11

[0036] The compressive strength of Example 10 is higher than that of Examples 8 and 11, indicating that the addition of polycarboxylate superplasticizer and sodium tripolyphosphate as superplasticizers in this invention improves the compressive strength.

[0037] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An anti-cracking pavement concrete, characterized in that, The raw materials include the following components by weight: 70-80 parts cement, 12-16 parts fly ash, 8-10 parts slag, 240-280 parts aggregate, 0.4-0.8 parts water-reducing agent, 1-2 parts polyvinyl alcohol microspheres, 2-4 parts polyacrylamide microspheres, 1.2-1.6 parts crack-resistant fiber, 0.5-1 part additives, 0.3-0.5 parts dispersant, and 40-60 parts water. The additives include Span 60 and vinyl silanes.

2. The anti-cracking pavement concrete according to claim 1, characterized in that, The mass ratio of Span 60 to vinyl silane is 3:0.5~1.

3. The crack-resistant pavement concrete according to claim 1, characterized in that, The vinyl silanes include methylvinyldiethoxysilane and diethylenetriaminepropylmethyldimethoxysilane.

4. The crack-resistant pavement concrete according to claim 3, characterized in that, The mass ratio of methylvinyldiethoxysilane to diethylenetriaminepropylmethyldimethoxysilane is 2:1~3.

5. The crack-resistant pavement concrete according to claim 1, characterized in that, The water-reducing agent includes polycarboxylate water-reducing agent and sodium tripolyphosphate.

6. The crack-resistant pavement concrete according to claim 5, characterized in that, The mass ratio of the polycarboxylate superplasticizer to sodium tripolyphosphate is 8:1~2.

7. The crack-resistant pavement concrete according to claim 1, characterized in that, The crack-resistant fiber includes one or more of steel fiber, polypropylene fiber, and lignin fiber.

8. The crack-resistant pavement concrete according to claim 7, characterized in that, The dispersant includes one or both of stearic acid and sodium dodecylbenzenesulfonate.

9. The crack-resistant pavement concrete according to claim 1, characterized in that, The aggregate consists of coarse aggregate and fine aggregate in a mass ratio of 2 to 3:

1.

10. A method for manufacturing crack-resistant pavement concrete, used to manufacture the crack-resistant pavement concrete according to any one of claims 1 to 9, characterized in that, Includes the following steps: S1. After mixing the water and the additives, add polyvinyl alcohol microspheres and polyacrylamide microspheres and mix to obtain a premix; S2. Add the remaining raw materials to the premix and mix to obtain crack-resistant pavement concrete.

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