A modifier for improving the stability of steel slag aggregate and its preparation method and application

Abstract

The present invention relates to the technical field of road engineering materials, and proposes a modifier for improving the stability of steel slag aggregate, a preparation method and an application thereof, wherein the modifier comprises the following components by weight: 20-30 parts of ternary chloroacetic acid resin, 10-15 parts of phenolic resin, 3-14 parts of acetylacetone, 3.5-6.5 parts of sodium sulfate, 1-2 parts of stabilizer, and 80 parts of cyclohexanone. The above technical scheme solves the problem of high water expansion rate of steel slag aggregate in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering materials, and in particular to a modifier for improving the stability of steel slag aggregates, and a preparation method and application thereof. Background Art

[0002] Steel slag aggregate refers to the granular material used as the aggregate of the mixture after crushing and screening steel slag. Because of its certain thermal stability and good mechanical properties such as hardness, strength, impact resistance and wear resistance, it has great potential and prospects in road engineering applications. At present, steel slag aggregate has been widely used in road asphalt mixture, which not only saves costs and reduces environmental pollution, but also prolongs the service life of the road surface.

[0003] However, due to the presence of free calcium oxide and free magnesium oxide in steel slag, the water expansion rate of steel slag aggregate is relatively high. When steel slag aggregate is used in asphalt mixture, the water expansion of steel slag aggregate will reduce the performance of asphalt mixture, and even cause cracks in asphalt mixture in severe cases, causing road damage and safety hazards. Therefore, in order to reduce the water expansion rate of steel slag aggregate and improve the stability of steel slag aggregate, it is of great significance to develop a modifier that can improve the stability of steel slag aggregate. Summary of the invention

[0004] The invention provides a modifier for improving the stability of steel slag aggregate, a preparation method and application thereof, and solves the problem of high water expansion rate of steel slag aggregate in the related art.

[0005] The technical solution of the present invention is as follows:

[0006] The invention provides a modifier for improving the stability of steel slag aggregate, comprising the following components in parts by mass: 20-30 parts of ternary chloroacetic acid resin, 10-15 parts of phenolic resin, 3-14 parts of acetylacetone, 3.5-6.5 parts of sodium sulfate, 1-2 parts of stabilizer and 80 parts of cyclohexanone.

[0007] The ternary vinyl acetate resin can be selected from one or two of hydroxyl-modified ternary vinyl acetate resin and carboxyl-modified ternary vinyl acetate resin; the hydroxyl-modified ternary vinyl acetate resin can be selected from TP-500A, TP-500S, VINNOL-E22 / 48A, etc.; the carboxyl-modified ternary vinyl acetate resin can be selected from TP-400M, DY-VMCH-1, MC-1A, etc.; the phenolic resin can be selected from 2402 phenolic resin, SP-1068, PR-4582L, etc.

[0008] As a further technical solution, the mass ratio of acetylacetone to sodium sulfate is 1-2:1.

[0009] When the mass ratio of acetylacetone to sodium sulfate is 1-2:1, it helps to further reduce the water expansion rate of the steel slag aggregate and improve the stability of the steel slag aggregate.

[0010] As a further technical solution, the ternary vinyl chloride resin includes a hydroxyl-modified ternary vinyl chloride resin and a carboxyl-modified ternary vinyl chloride resin.

[0011] When the ternary chloroacetic acid resin includes a hydroxyl-modified ternary chloroacetic acid resin and a carboxyl-modified ternary chloroacetic acid resin, on the one hand, it can further prevent the modified layer formed by the modifier on the surface of the steel slag aggregate from rupture, further reducing the risk of water expansion; on the other hand, it can further inhibit the hydration of free calcium oxide and free magnesium oxide in the steel slag aggregate, thereby further reducing the water expansion rate of the steel slag aggregate and improving the stability of the steel slag aggregate.

[0012] As a further technical solution, the mass ratio of the hydroxyl-modified ternary chloroacetic acid resin to the carboxyl-modified ternary chloroacetic acid resin is 1:9~9:1.

[0013] When the mass ratio of hydroxyl-modified ternary vinyl acetate resin to carboxyl-modified ternary vinyl acetate resin is 1:9~9:1, the water expansion rate of steel slag aggregate can be further reduced and the stability of steel slag aggregate can be improved.

[0014] As a further technical solution, the mass of the hydroxyl-modified ternary chloroacetic acid resin is less than the mass of the carboxyl-modified ternary chloroacetic acid resin.

[0015] When the mass of the hydroxyl-modified ternary chloroacetic acid resin is less than the mass of the carboxyl-modified ternary chloroacetic acid resin, it helps to further reduce the water expansion rate of the steel slag aggregate and improve the stability of the steel slag aggregate.

[0016] As a further technical solution, the stabilizer includes one or more of zinc stearate, barium stearate, and lead stearate.

[0017] The addition of stabilizer can improve the stability of the modified layer formed by the modifier on the surface of steel slag aggregate, reduce the risk of water swelling of steel slag aggregate, and improve the stability of steel slag aggregate.

[0018] The present invention also provides a method for preparing the modifier for improving the stability of steel slag aggregate, comprising the following steps: uniformly mixing acetylacetone, sodium sulfate and cyclohexanone, adding the remaining components, and shearing to obtain the modifier.

[0019] As a further technical solution, during the shearing, the speed is 4000-6000 r / min and the time is 10-20 min.

[0020] The present invention also proposes the use of the modifier for improving the stability of steel slag aggregate or the modifier prepared by the preparation method in surface modification of steel slag aggregate.

[0021] As a further technical solution, the following steps are included: mixing steel slag aggregate and a modifier, and drying to obtain modified steel slag aggregate.

[0022] As a further technical solution, the mass ratio of the steel slag aggregate to the modifier is 10000:2~4.

[0023] As a further technical solution, the temperature during the drying is 65-75°C.

[0024] The working principle and beneficial effects of the present invention are:

[0025] In the present invention, the modifier can form a modified layer on the surface of the steel slag aggregate, achieving the dual functions of filling the micropores on the surface of the steel slag aggregate and inhibiting the hydration of free calcium oxide and free magnesium oxide, wherein:

[0026] (1) The ternary chloroacetic acid resin in the modifier can prevent the modified layer from cracking during use, reduce the risk of slag swelling due to water immersion, and improve the stability of slag aggregate;

[0027] (2) The organic-inorganic synergistic effect of acetylacetone and sodium sulfate in the modifier can inhibit the hydration of free calcium oxide and free magnesium oxide in the steel slag aggregate, thereby reducing the water expansion rate of the steel slag aggregate and improving the stability of the steel slag aggregate. DETAILED DESCRIPTION

[0028] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the following examples and comparative examples, unless otherwise specified, the model of the hydroxyl-modified ternary chloroacetic acid resin is TP-500A, the model of the carboxyl-modified ternary chloroacetic acid resin is TP-400M, and the model of the phenolic resin is SP-1068.

[0030] Example 1

[0031] A method for preparing a modifier for improving the stability of steel slag aggregate comprises the following steps: by weight, 3 parts of acetylacetone, 3.5 parts of sodium sulfate, 1 part of zinc stearate and 80 parts of cyclohexanone are uniformly mixed, 20 parts of hydroxyl-modified ternary chloroacetic acid resin and 10 parts of phenolic resin are added, and shearing is performed at a speed of 4000 r / min for 20 minutes to obtain the modifier.

[0032] Example 2

[0033] A method for preparing a modifier for improving the stability of steel slag aggregate comprises the following steps: by weight, 14 parts of acetylacetone, 6.5 parts of sodium sulfate, 2 parts of zinc stearate and 80 parts of cyclohexanone are uniformly mixed, 30 parts of hydroxyl-modified ternary chloroacetic acid resin and 15 parts of phenolic resin are added, and shearing is performed at a speed of 6000 r / min for 10 minutes to obtain the modifier.

[0034] Example 3

[0035] A method for preparing a modifier for improving the stability of steel slag aggregate comprises the following steps: by weight, 5.5 parts of acetylacetone, 6.5 parts of sodium sulfate, 2 parts of zinc stearate and 80 parts of cyclohexanone are uniformly mixed, 30 parts of hydroxyl-modified ternary chloroacetic acid resin and 15 parts of phenolic resin are added, and shearing is performed at a speed of 6000 r / min for 10 minutes to obtain the modifier.

[0036] Example 4

[0037] The only difference between this embodiment and embodiment 3 is that, in this embodiment, the mass parts of acetylacetone are 8.5 parts, and the mass parts of sodium sulfate are 3.5 parts.

[0038] Example 5

[0039] The only difference between this embodiment and embodiment 3 is that, in this embodiment, the mass parts of acetylacetone are 6 parts and the mass parts of sodium sulfate are 6 parts.

[0040] Example 6

[0041] The only difference between this embodiment and embodiment 3 is that, in this embodiment, the mass parts of acetylacetone are 8 parts, and the mass parts of sodium sulfate are 4 parts.

[0042] Example 7

[0043] The difference between this embodiment and embodiment 6 is that, in this embodiment, 30 parts of hydroxyl-modified ternary chloroacetic acid resin are replaced by an equal amount of carboxyl-modified ternary chloroacetic acid resin.

[0044] Example 8

[0045] The only difference between this embodiment and embodiment 6 is that, in this embodiment, 30 parts of hydroxyl-modified ternary vinyl acetate resin are replaced by 29 parts of hydroxyl-modified ternary vinyl acetate resin and 1 part of carboxyl-modified ternary vinyl acetate resin.

[0046] Example 9

[0047] The difference between this embodiment and embodiment 8 is that, in this embodiment, the mass part of hydroxyl-modified ternary chloroacetic acid resin is 1 part, and the mass part of carboxyl-modified ternary chloroacetic acid resin is 29 parts.

[0048] Example 10

[0049] The difference between this embodiment and embodiment 8 is that, in this embodiment, the mass parts of hydroxyl-modified ternary chloroacetic acid resin are 27 parts, and the mass parts of carboxyl-modified ternary chloroacetic acid resin are 3 parts.

[0050] Embodiment 11

[0051] The difference between this embodiment and embodiment 8 is that, in this embodiment, the mass parts of hydroxyl-modified ternary chloroacetic acid resin are 3 parts, and the mass parts of carboxyl-modified ternary chloroacetic acid resin are 27 parts.

[0052] Example 12

[0053] The difference between this embodiment and embodiment 8 is that, in this embodiment, the mass parts of hydroxyl-modified ternary vinyl acetate resin are 20 parts, and the mass parts of carboxyl-modified ternary vinyl acetate resin are 10 parts.

[0054] Example 13

[0055] The difference between this embodiment and embodiment 8 is that, in this embodiment, the mass parts of hydroxyl-modified ternary chloroacetic acid resin are 15 parts, and the mass parts of carboxyl-modified ternary chloroacetic acid resin are 15 parts.

[0056] Embodiment 14

[0057] The difference between this embodiment and embodiment 8 is that, in this embodiment, the mass parts of hydroxyl-modified ternary vinyl acetate resin are 10 parts, and the mass parts of carboxyl-modified ternary vinyl acetate resin are 20 parts.

[0058] Comparative Example 1

[0059] The difference between this comparative example and Example 1 is that in this comparative example, acetylacetone is not added and the mass parts of sodium sulfate added are 6.5 parts.

[0060] Comparative Example 2

[0061] The difference between this comparative example and Example 1 is that in this comparative example, no sodium sulfate is added and the mass fraction of acetylacetone added is 6.5 parts.

[0062] Comparative Example 3

[0063] The difference between this comparative example and Example 1 is that in this comparative example, sodium sulfate and acetylacetone are not added.

[0064] Comparative Example 4

[0065] The difference between this comparative example and Example 1 is that in this comparative example, no hydroxyl-modified ternary chloroacetic acid resin is added, and the mass parts of the added phenolic resin are 30 parts.

[0066] The modifiers prepared in Examples 1 to 14 and Comparative Examples 1 to 4 were mixed with steel slag aggregate (with an apparent relative density of 3.41 g / cm 3 , calcium oxide content of 40.48wt%, magnesium oxide content of 5.93wt%) were mixed at a mass ratio of 3:10000, and dried at 70°C to obtain the modified steel slag aggregate. The water expansion rate of the modified steel slag aggregate was tested according to GB / T 24175-2009 "Steel Slag Stability Test Method", in which, on the first day, the test mold containing the modified steel slag aggregate was placed in a constant temperature water bath, and the test mold was completely immersed in water. The initial reading of the dial indicator was immediately read d0, and the water bath was used for heating. After the temperature in the water bath reached 90°C, it was maintained for 6 hours, and the heating was stopped and cooled naturally. The steps of the first day were followed every day for 10 days. After 10 days, the final reading of the dial indicator was read d 10 The water expansion rate of the modified steel slag aggregate is calculated according to the following formula: Water expansion rate (%) = (d 10 -d0) / 120×100. The result is accurate to 0.01%. The test results are shown in Table 1 below.

[0067] Table 1 Water expansion test results

[0068]

[0069] Comparison between Example 1 and Comparative Examples 1 to 3 shows that the organic-inorganic synergistic enhancement of acetylacetone and sodium sulfate in the modifier can significantly reduce the water expansion rate of the steel slag aggregate and improve the stability of the steel slag aggregate. Comparison between Example 1 and Comparative Example 4 shows that the addition of ternary chloroacetic acid resin in the modifier can significantly reduce the water expansion rate of the steel slag aggregate and improve the stability of the steel slag aggregate.

[0070] Comparison between Examples 3-4 and 5-6 shows that when the mass ratio of acetylacetone to sodium sulfate is 1-2:1, it helps to further reduce the water expansion rate of steel slag aggregate and improve the stability of steel slag aggregate. Comparison between Examples 6-7 and 8-14 shows that when the ternary chloroacetic acid resin includes hydroxyl-modified ternary chloroacetic acid resin and carboxyl-modified ternary chloroacetic acid resin, it helps to further reduce the water expansion rate of steel slag aggregate and improve the stability of steel slag aggregate. Comparison between Examples 8-9 and 10-14 shows that when the mass ratio of hydroxyl-modified ternary chloroacetic acid resin and carboxyl-modified ternary chloroacetic acid resin is 1:9-9:1, it can further reduce the water expansion rate of steel slag aggregate and improve the stability of steel slag aggregate. Comparison between Example 14 and Example 12-13 shows that when the mass of hydroxyl-modified ternary chloroacetic acid resin is less than the mass of carboxyl-modified ternary chloroacetic acid resin, it helps to further reduce the water expansion rate of steel slag aggregate and improve the stability of steel slag aggregate.

[0071] Application Example 1

[0072] The modifiers prepared in Example 1 and Example 14 were mixed with steel slag aggregate (with an apparent relative density of 3.41 g / cm 3 , calcium oxide content of 40.48wt%, magnesium oxide content of 5.93wt%) were mixed in a mass ratio of 3:10000, and dried at 70°C to obtain modified steel slag aggregate. By mass, 70 parts of modified steel slag aggregate with a particle size of 4.75~16mm, 50 parts of basalt aggregate with a particle size of 0.075~4.75mm, 7 parts of limestone powder with a particle size of 0.025~0.075mm and 5 parts of 70# road asphalt were mixed and stirred at 150°C for 3h to obtain a modified steel slag asphalt mixture. According to the above method, only the modified steel slag aggregate was replaced with an equal amount of unmodified steel slag aggregate to obtain an unmodified steel slag asphalt mixture. According to the Marshall stability test method of T 0709-2011 asphalt mixture in JTG E20-2011 "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering", the stability MS and water immersion residual stability of the modified steel slag asphalt mixture of Example 1, the modified steel slag asphalt mixture of Example 14 and the unmodified steel slag asphalt mixture were tested. The test results are shown in Table 2 below.

[0073] Table 2 Test results of immersion Marshall test

[0074]

[0075] It can be seen from Table 2 that the performance of the steel slag asphalt mixture can be significantly improved by modifying the steel slag aggregate using the modifier of the present invention.

[0076] The above are only 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 in the protection scope of the present invention.

Claims

1. A modifier for improving the stability of steel slag aggregate, characterized in that: The invention comprises the following components in parts by weight: 20-30 parts of ternary chloroacetic acid resin, 10-15 parts of phenolic resin, 3-14 parts of acetylacetone, 3.5-6.5 parts of sodium sulfate, 1-2 parts of stabilizer, and 80 parts of cyclohexanone; The ternary vinyl chloride resin includes a hydroxyl-modified ternary vinyl chloride resin and a carboxyl-modified ternary vinyl chloride resin.

2. A modifier for improving the stability of steel slag aggregate according to claim 1, characterized in that: The mass ratio of the acetylacetone to sodium sulfate is 1-2:

1.

3. A modifier for improving the stability of steel slag aggregate according to claim 1, characterized in that: The mass ratio of the hydroxyl-modified ternary vinyl acetate resin to the carboxyl-modified ternary vinyl acetate resin is 1:9-9:

1.

4. A modifier for improving the stability of steel slag aggregate according to claim 1, characterized in that: The stabilizer includes one or more of zinc stearate, barium stearate, and lead stearate.

5. A method for preparing a modifier for improving the stability of steel slag aggregate according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: uniformly mixing acetylacetone, sodium sulfate and cyclohexanone, adding the remaining components, and shearing to obtain a modifier.

6. The method for preparing a modifier for improving the stability of steel slag aggregate according to claim 5, characterized in that: During the shearing, the speed is 4000-6000 r / min and the time is 10-20 min.

7. Use of a modifier for improving the stability of steel slag aggregate according to any one of claims 1 to 4 or a modifier prepared by the preparation method according to any one of claims 5 to 6 in surface modification of steel slag aggregate.

8. The use according to claim 7, characterized in that: The following steps are involved: The steel slag aggregate and the modifier are mixed and dried to obtain the modified steel slag aggregate.

9. The use according to claim 8, characterized in that: The mass ratio of the steel slag aggregate to the modifier is 10000:2-4.

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