Anti-stripping agent, hydraulic asphalt concrete based on anti-stripping agent and preparation method of hydraulic asphalt concrete

Abstract

The invention discloses an anti-stripping agent, hydraulic asphalt concrete based on the anti-stripping agent and a preparation method. The anti-stripping agent adopts silicon dioxide gel including rubber powder and mica powder. The hydraulic asphalt concrete based on the anti-stripping agent comprises asphalt, coarse aggregate, fine aggregate, filler, fiber and the anti-stripping agent. The preparation method comprises the following steps: heating and melting asphalt to obtain asphalt liquid; carrying out dry mixing on the coarse aggregate, the fine aggregate, the fiber and the filler to obtain a mixture; and finally, spraying the asphalt liquid into the mixture, mixing, adding the anti-stripping agent, and continuously mixing to obtain the hydraulic asphalt concrete. The anti-stripping agent disclosed by the invention is applied to hydraulic asphalt concrete, the cohesiveness between asphalt and aggregate and filler can be effectively improved, the cracking resistance and stripping resistance of the prepared asphalt concrete are further improved, and meanwhile, based on the addition of the anti-stripping agent, the compactness and seepage resistance of the prepared asphalt concrete can be effectively improved; the cracking resistance and the stripping resistance are further improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydraulic asphalt concrete, and particularly relates to an anti-stripping agent, hydraulic asphalt concrete based on the anti-stripping agent and a preparation method. BACKGROUND

[0002] As a special asphalt material in petroleum asphalt, hydraulic asphalt is widely used in water conservancy engineering construction such as reservoirs, earth-rock dams, canal embankment protection and channel seepage prevention due to its superior flexibility and seepage prevention performance.

[0003] Compared with conventional reinforced concrete, hydraulic asphalt concrete (HAC) is a special asphalt concrete used in water conservancy engineering (such as dams, channels, reservoir seepage prevention, etc.), and has seepage resistance, flexibility, water resistance and durability. Its composition and performance requirements are different from ordinary road asphalt concrete, and need to adapt to long-term water pressure, temperature changes and chemical corrosion environment. Its main characteristics are advantages in deformation adaptability and seepage resistance, and hydraulic asphalt concrete also has the advantages of small engineering quantity and rapid construction. With the rapid development of China's water and electricity industry and the progress of asphalt concrete seepage prevention technology, more and more water conservancy projects will use asphalt concrete seepage prevention technology.

[0004] Since hydraulic asphalt is an important raw material for asphalt concrete seepage prevention, strict quality requirements are put forward for hydraulic asphalt to ensure the safety and durability of water conservancy projects, such as good brittle crack resistance.

[0005] Therefore, the present application provides a hydraulic asphalt concrete and a preparation method thereof, which has excellent seepage prevention performance and can effectively prevent cracking. SUMMARY

[0006] The technical problem to be solved by the present application is to provide an anti-stripping agent capable of effectively improving the anti-stripping performance of hydraulic asphalt concrete, and a hydraulic asphalt concrete prepared based on the anti-stripping agent, which has excellent seepage prevention performance and can effectively prevent cracking.

[0007] The anti-stripping agent is prepared by the following steps:

[0008] (1) uniformly mixing an alcohol solvent and water, adding a silicon source precursor to prepare a sol, adding an acid catalyst to the sol to adjust the pH to 3-4, stirring at 1000-1600 rpm for 2-4 h to perform a hydrolysis reaction, reducing the stirring speed to 300-500 rpm, adding an alkali catalyst to adjust the pH to 9-10, and performing a condensation reaction to prepare a wet gel;

[0009] (2) adding mica powder and rubber powder to the prepared wet gel, stirring uniformly, drying, and then calcining at 500-800 DEG C for 3-6 hours to obtain a composite silica gel; wherein the mass ratio of the mica powder, rubber powder, and silicon source precursor is 1:(2-3):(5-8).

[0010] The silica gel, rubber powder, and mica powder are compounded to prepare the anti-stripping agent, the rubber powder and mica powder are coated by the silica gel, and the coated rubber powder and mica powder are applied to the hydraulic asphalt concrete, so that the interfacial compatibility of the rubber powder and mica powder filled in the gaps between the aggregate and filler and the asphalt is improved by the silica gel, the adhesion of the asphalt and aggregate is improved, the adhesion of the prepared hydraulic asphalt concrete is improved, the anti-stripping property and anti-cracking property are improved, the sheet structure of the mica powder can effectively prevent water from penetrating through the gaps between the aggregate, and the anti-aging property of the overall hydraulic asphalt concrete is improved.

[0011] In addition, the surface active groups of the rubber powder and mica powder can be combined with the groups on the surface of the silica gel in the preparation process, so that the hydroxyl groups on the surface of the silica are reduced, the hydrophilicity is reduced, the penetration of water is effectively reduced, and the anti-stripping property is improved.

[0012] Further, in step (1) of the preparation of the anti-stripping agent, the mass ratio of the silicon source precursor, alcohol solvent, and water is 1:(20-35):(8-16).

[0013] Further, in step (1) of the preparation of the anti-stripping agent, the alcohol solvent is methanol, ethanol, or isopropyl alcohol, and the silicon source precursor is tetraethyl orthosilicate or tetramethyl orthosilicate.

[0014] Further, the acid catalyst in the preparation of the anti-stripping agent is citric acid, tartaric acid, or acetic acid, and the base catalyst is ammonia water or sodium hydroxide.

[0015] The hydraulic asphalt concrete based on the above anti-stripping agent comprises the following raw materials: asphalt, coarse aggregate, fine aggregate, filler, fiber, and the above anti-stripping agent; wherein the asphalt accounts for 10-15% of the total amount of the hydraulic asphalt concrete, the oil stone ratio is 5-8%, the fiber accounts for 0.5-1% of the total amount of the hydraulic asphalt concrete, and the anti-stripping agent accounts for 0.3-0.6% of the total amount of the hydraulic asphalt concrete.

[0016] Further, the mass ratio of the coarse aggregate, fine aggregate, and filler used in the hydraulic asphalt concrete is 35-48% of coarse aggregate, 40-50% of fine aggregate, and 12-16% of filler.

[0017] Further, the water conservancy asphalt concrete uses the coarse aggregate with the particle size of 19-10mm, 10-5mm, 5-2.5mm in continuous gradation.

[0018] Further, the water conservancy asphalt concrete uses the fine aggregate with the particle size of 2.5-1mm, 1-0.5mm, 0.5-0.075mm in continuous gradation.

[0019] Further, the water conservancy asphalt concrete uses the filler with the particle size less than 0.75mm of limestone powder, and the fiber with the particle size of 1-3mm of basalt fiber.

[0020] The preparation method of the water conservancy asphalt concrete is prepared by the present application, comprising the following steps:

[0021] (1) heating and melting the asphalt to obtain an asphalt liquid;

[0022] (2) dry mixing the coarse aggregate, the fine aggregate, the fiber and the filler to obtain a mixture;

[0023] (3) spraying the asphalt liquid obtained in the step (1) into the mixture obtained in the step (2), and after mixing, adding the anti-stripping agent and continuing to mix to obtain the water conservancy asphalt concrete.

[0024] Beneficial effects: compared with the prior art, the significant advantages of the present application are that the anti-stripping agent applied in the water conservancy asphalt concrete can effectively improve the adhesion between the asphalt and other materials, thereby improving the anti-cracking and anti-stripping properties of the prepared asphalt concrete, and at the same time, based on the addition of the anti-stripping agent, the density and impermeability of the prepared asphalt concrete can be effectively improved, further improving its anti-cracking and anti-stripping properties. DETAILED DESCRIPTION

[0025] The technical solutions of the present application will be further described in detail below in combination with the embodiments.

[0026] It should be noted that the raw materials used in the present application can be purchased from the market. Among them, the coarse aggregate used in the present application is a continuous gradation of 19-10mm, 10-5mm, 5-2.5mm. The fine aggregate is a continuous gradation of 2.5-1mm, 1-0.5mm, 0.5-0.075mm. The filler is limestone powder with a particle size less than 0.75mm, and the fiber is basalt fiber with a particle size of 1-3mm.

[0027] The mass ratio of the coarse aggregate, the fine aggregate and the filler used in the following embodiments of the present application is 45% of the coarse aggregate, 40% of the fine aggregate and 15% of the filler.

[0028] Example 1

[0029] The anti-stripping agent of the example 1 is prepared by the following steps:

[0030] (1) weigh tetraethyl orthosilicate, methanol and water according to the mass ratio of 1:30:12, and weigh mica powder and rubber powder according to the mass ratio of 1:2:6 of the three of mica powder, rubber powder and tetraethyl orthosilicate;

[0031] (2) mix methanol and water uniformly, add tetraethyl orthosilicate to obtain a sol; add citric acid to the sol to adjust the pH to 3.5, and stir at 1200 rpm for 3 h to carry out hydrolysis reaction; reduce the stirring speed to 400 rpm, add ammonia water to adjust the pH to 10, and carry out condensation reaction to obtain a wet gel;

[0032] (3) add mica powder and rubber powder to the prepared wet gel, stir uniformly, dry, and then calcine at 600℃ for 5 h to obtain a composite silica gel.

[0033] The water conservancy asphalt concrete prepared based on the anti-stripping agent comprises asphalt, coarse aggregate, fine aggregate, filler, fiber and anti-stripping agent; wherein the asphalt accounts for 6.5% of the total amount of the water conservancy asphalt concrete, the oil stone ratio is 7%, the fiber accounts for 0.6% of the total amount of the water conservancy asphalt concrete, and the anti-stripping agent accounts for 0.4% of the total amount of the water conservancy asphalt concrete.

[0034] The water conservancy asphalt concrete is prepared by the following steps:

[0035] (1) heat the asphalt to melt to obtain an asphalt liquid;

[0036] (2) dry mix the coarse aggregate, fine aggregate, fiber and filler to obtain a mixture;

[0037] (3) spray the asphalt liquid obtained in step (1) on the mixture obtained in step (2), mix, then add the anti-stripping agent, and continue to mix to obtain the water conservancy asphalt concrete.

[0038] Example 2

[0039] The anti-stripping agent of Example 2 is prepared by the following steps:

[0040] (1) weigh tetraethyl orthosilicate, methanol and water according to the mass ratio of 1:25:14, and weigh mica powder and rubber powder according to the mass ratio of 1:2.5:7 of the three of mica powder, rubber powder and tetraethyl orthosilicate;

[0041] (2) mix methanol and water uniformly, add tetraethyl orthosilicate to obtain a sol; add citric acid to the sol to adjust the pH to 3, and stir at 1400 rpm for 2 h to carry out hydrolysis reaction; reduce the stirring speed to 300 rpm, add ammonia water to adjust the pH to 9, and carry out condensation reaction to obtain a wet gel;

[0042] (3) adding mica powder and rubber powder to the prepared wet gel, stirring uniformly, drying, and then calcining at 700 DEG C for 4h to prepare a composite silica gel.

[0043] The water conservancy asphalt concrete prepared based on the anti-stripping agent comprises asphalt, coarse aggregate, fine aggregate, filler, fiber and anti-stripping agent; wherein the asphalt accounts for 5.6% of the total amount of the water conservancy asphalt concrete, the oil stone ratio is 6%, the fiber accounts for 0.8% of the total amount of the water conservancy asphalt concrete, and the anti-stripping agent accounts for 0.5% of the total amount of the water conservancy asphalt concrete.

[0044] The water conservancy asphalt concrete is prepared by the following steps:

[0045] (1) heating the asphalt to be molten to obtain an asphalt liquid;

[0046] (2) dry mixing the coarse aggregate, fine aggregate, fiber and filler to obtain a mixture;

[0047] (3) spraying the asphalt liquid obtained in step (1) into the mixture obtained in step (2), mixing, adding the anti-stripping agent, and continuing to mix to prepare the water conservancy asphalt concrete.

[0048] Example 3

[0049] The anti-stripping agent of Example 3 is prepared by the following steps:

[0050] (1) weighing tetraethyl orthosilicate, methanol and water according to the mass ratio of 1:20:8, and weighing mica powder and rubber powder according to the mass ratio of 1:2:5 of the three;

[0051] (2) mixing the methanol and water uniformly, adding the tetraethyl orthosilicate to prepare a sol, adding citric acid to the sol to adjust the pH to 3, stirring at 1000 rpm for 4h to carry out hydrolysis reaction, reducing the stirring speed to 300 rpm, adding ammonia water to adjust the pH to 9, and carrying out condensation reaction to prepare a wet gel;

[0052] (3) adding mica powder and rubber powder to the prepared wet gel, stirring uniformly, drying, and then calcining at 500 DEG C for 6h to prepare a composite silica gel.

[0053] The water conservancy asphalt concrete prepared based on the anti-stripping agent comprises asphalt, coarse aggregate, fine aggregate, filler, fiber and anti-stripping agent; wherein the asphalt accounts for 5.6% of the total amount of the water conservancy asphalt concrete, the oil stone ratio is 6%, the fiber accounts for 0.8% of the total amount of the water conservancy asphalt concrete, and the anti-stripping agent accounts for 0.5% of the total amount of the water conservancy asphalt concrete.

[0054] The water conservancy asphalt concrete is prepared by the following steps:

[0055] (1) heating bitumen to melt to obtain bitumen liquid;

[0056] (2) dry mixing coarse aggregate, fine aggregate, fiber and filler to obtain mixture;

[0057] (3) spraying the bitumen liquid obtained in step (1) into the mixture obtained in step (2), after mixing, adding anti-stripping agent, continuing to mix to obtain hydraulic asphalt concrete.

[0058] Example 4

[0059] The anti-stripping agent of this example 4 is prepared by the following steps:

[0060] (1) weighing tetraethyl orthosilicate, methanol and water according to the mass ratio of 1:35:16, and weighing mica powder and rubber powder according to the mass ratio of 1:3:8 of mica powder, rubber powder and tetraethyl orthosilicate;

[0061] (2) mixing methanol and water uniformly, adding tetraethyl orthosilicate to obtain sol; adding citric acid to the sol to adjust the pH to 4, stirring at 1600 rpm for 2 h to carry out hydrolysis reaction; reducing the stirring speed to 500 rpm, adding ammonia water to adjust the pH to 10, carrying out condensation reaction to obtain wet gel;

[0062] (3) adding mica powder and rubber powder to the prepared wet gel, stirring uniformly, drying, and calcining at 800℃ for 3h to obtain composite silica gel.

[0063] The hydraulic asphalt concrete prepared based on the anti-stripping agent comprises bitumen, coarse aggregate, fine aggregate, filler, fiber and anti-stripping agent; wherein the bitumen accounts for 7.3% of the total amount of the hydraulic asphalt concrete, the oil stone ratio is 8%; the fiber accounts for 1% of the total amount of the hydraulic asphalt concrete; and the anti-stripping agent accounts for 0.6% of the total amount of the hydraulic asphalt concrete.

[0064] The hydraulic asphalt concrete is prepared by the following steps:

[0065] (1) heating bitumen to melt to obtain bitumen liquid;

[0066] (2) dry mixing coarse aggregate, fine aggregate, fiber and filler to obtain mixture;

[0067] (3) spraying the bitumen liquid obtained in step (1) into the mixture obtained in step (2), after mixing, adding anti-stripping agent, continuing to mix to obtain hydraulic asphalt concrete.

[0068] Comparative Example 1

[0069] The hydraulic asphalt concrete of the comparative example 1 comprises asphalt, coarse aggregate, fine aggregate, filler, fiber, silica gel, mica powder and rubber powder. The asphalt accounts for 7.3% of the total amount of the hydraulic asphalt concrete, and the oil-stone ratio is 8%; the fiber accounts for 1% of the total amount of the hydraulic asphalt concrete; the silica gel accounts for 0.6% of the total amount of the hydraulic asphalt concrete; the mica powder accounts for 0.6% of the total amount of the hydraulic asphalt concrete; and the rubber powder accounts for 0.6% of the total amount of the hydraulic asphalt concrete.

[0070] The hydraulic asphalt concrete prepared in examples 1-4 and the comparative example 1 is subjected to performance detection, and the obtained results are shown in Table 1. In the water stability test, the water stability coefficient R is calculated by the ratio of the compressive strength (average value) of R2 to R1, and the specific test conditions are that R1 is cured in air at 14-16℃ for 48h, R2 is cured in water at 60℃ for 48h, and then cured in water at 14-16℃ for 3h.

[0071] Table 1 Performance of the hydraulic asphalt concrete prepared in examples 1-4 and the comparative example 1

[0072]

[0073] As can be seen from Table 1, the hydraulic asphalt concrete prepared by the present application not only has high strength, but also has good impermeability, thereby effectively preventing cracking and peeling. Although the impermeability coefficient of D1 also meets the technical index, it is obviously higher than the impermeability coefficients of examples 1-4 of the present application, and the adhesive strength and the compressive strength are also lower. The reason for this is that the silica gel, the rubber powder and the mica powder are directly and independently added, which causes the silica gel to have poor local strength due to the presence of pores, and the local rubber powder and mica powder to have poor local adhesion due to the difference in surface energy between the two and the segregation.

[0074] In addition to the above examples, the parameters or raw materials defined in the present application can be used to obtain the technical effects claimed above, and therefore experimental evidence is not repeated. For example, the silicon source precursor can also be methyl orthosilicate. The alcohol solvent can also be ethanol or isopropanol. The acid catalyst can also be tartaric acid or acetic acid. The base catalyst can also be sodium hydroxide.

[0075] In addition, when preparing the wet gel of the anti-peeling agent, it can be determined whether the gelation is completed by a simple bottle inversion experiment.

Claims

1. An anti-stripping agent, characterized in that Prepared by the following steps: (1) mixing an alcohol solvent and water uniformly, adding a silicon source precursor to prepare a sol; adding an acid catalyst to the sol to adjust the pH to 3-4, stirring at 1000-1600 rpm for 2-4 hours to carry out a hydrolysis reaction; reducing the stirring speed to 300-500 rpm, adding an alkaline catalyst to adjust the pH to 9-10, and carrying out a condensation reaction to prepare a wet gel; (2) Adding mica powder and rubber powder to the prepared wet gel, stirring evenly and drying, and then calcining at 500-800°C for 3-6 hours to obtain a composite silica gel; wherein the mass ratio of the mica powder, rubber powder and silicon source precursor is 1:(2-3):(5-8).

2. The anti-stripping agent according to claim 1, characterized in that In step (1), the mass ratio of the silicon source precursor, the alcohol solvent and water is 1:(20-35):(8-16).

3. The anti-stripping agent according to claim 1 or 2, characterized in that In step (1), the alcohol solvent is methanol, ethanol or isopropanol, and the silicon source precursor is ethyl orthosilicate or methyl orthosilicate.

4. The anti-stripping agent according to claim 1, characterized in that In step (1), the acid catalyst is citric acid, tartaric acid or acetic acid; the base catalyst is ammonia water or sodium hydroxide.

5. A hydraulic asphalt concrete based on the anti-stripping agent according to claim 1, characterized in that: The hydraulic asphalt concrete comprises the following raw materials: asphalt, coarse aggregate, fine aggregate, filler, fiber and the anti-stripping agent according to claim 1; wherein the asphalt accounts for 3.5-7.5% of the total amount of the hydraulic asphalt concrete, and the oil-stone ratio is 4-8%; the fiber accounts for 0.5-1% of the total amount of the hydraulic asphalt concrete; and the anti-stripping agent accounts for 0.3-0.6% of the total amount of the hydraulic asphalt concrete.

6. The hydraulic asphalt concrete according to claim 5, characterized in that: The mass ratio of the coarse aggregate, the fine aggregate and the filler is 35-48% of the coarse aggregate, 40-50% of the fine aggregate and 12-16% of the filler.

7. The hydraulic asphalt concrete according to claim 5 or 6, characterized in that: The particle size of the coarse aggregate is continuously graded in the order of 19-10 mm, 10-5 mm, and 5-2.5 mm.

8. The hydraulic asphalt concrete according to claim 5 or 6, characterized in that: The fine aggregate is continuously graded in the range of 2.5-1 mm, 1-0.5 mm, and 0.5-0.075 mm.

9. The hydraulic asphalt concrete according to claim 5 or 6, characterized in that: The filler is limestone powder with a particle size of less than 0.75 mm, and the fiber is basalt fiber with a particle size of 1-3 mm.

10. A method for preparing the hydraulic asphalt concrete according to claim 5, characterized in that: The steps include: (1) heating and melting the asphalt to obtain asphalt liquid; (2) dry-mixing coarse aggregate, fine aggregate, fiber, and filler to obtain a mixture; (3) Spraying the asphalt liquid obtained in step (1) into the mixture obtained in step (2), mixing, adding an anti-stripping agent, and continuing to mix to obtain hydraulic asphalt concrete.

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