Preparation method of normal-temperature powdered sulfur asphalt

Abstract

The invention discloses a preparation method of normal-temperature powdered sulfur asphalt. The preparation method comprises the following steps: S1, preparing an asphalt component; s2, preparing a starch-based component; s3, mixing the materials; in the step S1, the preparation process of the asphalt component comprises the following steps: heating 100 parts of matrix asphalt to a molten state, stirring, adding 2-5 parts of Baize reagent, and uniformly stirring; the step S2 comprises the following sub-steps: S2-1, preparing acidolysis starch milk; s2-2, preparing a rubber powder starch-based mixture; s2-3, preparing a starch-based component through a free radical reaction; the preparation process is simple, the starch-based modifier containing the rubber powder is prepared through the free radical reaction, the whole preparation process does not need a high-temperature and high-pressure reaction process, does not need a rare metal catalyst, does not need air isolation, and the production time is short.

Description

Technical Field

[0001] The invention belongs to the field of polymer materials and relates to a method for preparing asphalt materials, in particular to a method for preparing room-temperature sulfur powder asphalt. Background Art

[0002] Asphalt is an organic gelling mixed material that is waterproof, moisture-proof and anti-corrosive. It is composed of hydrocarbons of different molecular weights and their non-metallic derivatives. It is an indispensable raw material in civil engineering.

[0003] According to the different temperatures required for asphalt during mixing construction, it can be divided into cold mix asphalt mixture, warm mix asphalt mixture and hot mix asphalt mixture. Among them, cold mix asphalt mixture generally uses emulsified asphalt or liquid asphalt to mix and pave with aggregate at room temperature. This type of asphalt does not require heating of aggregates and binders, which can save a lot of energy. The so-called emulsified asphalt is asphalt that is hot-melted and then mechanically sheared, and dispersed in an aqueous solution containing an emulsifier in the form of fine particles to form an oily asphalt emulsion. Emulsified asphalt is suitable for asphalt surface treatment pavement, asphalt penetration pavement, normal temperature asphalt mixture pavement, as well as penetration layer, adhesive layer and sealing layer. However, the low-temperature crack resistance, high-temperature stability, toughness and adhesion to aggregate of emulsified asphalt need to be improved, so it is necessary to add modifiers to improve the softening point, low-temperature ductility, and toughness of asphalt.

[0004] Sulfur is cheap. Adding sulfur to asphalt can improve the adhesion, plasticity, stability and other properties of asphalt. For example, the Chinese invention patent applications with document numbers 201510732824.2 and 201610433025.X have studied warm-mix sulfur asphalt. By adding warm-mix agents to reduce the mixing temperature of asphalt, the generation of toxic gases during the production process is avoided. However, the preparation process is relatively complicated, requiring rare metals such as nickel and cobalt as catalysts, and the production conditions are relatively harsh, requiring high temperatures and high pressures above 400°C. Therefore, other methods need to be considered to continue research on the preparation method of sulfur powder asphalt.

[0005] The Chinese invention patent application with document number 201510634309.0 discloses a sulfur-modified emulsified asphalt and a preparation method thereof. The process is simple and uses emulsifiers of different properties as a medium to achieve sulfur modification of asphalt. The method improves the performance of asphalt to a certain extent, but the asphalt prepared by the method has a softening point of 54.1℃~60.9℃ and cannot adapt to some extreme climates. For example, in the case of summer exposure, problems such as road softening and asphalt sticking to wheels will occur.

[0006] Therefore, it is necessary to further explore the preparation process of sulfur powder asphalt, simplify the preparation process, reduce the mixing temperature, and at the same time improve the adhesion, plasticity, stability and softening point of sulfur powder emulsified asphalt. Summary of the invention

[0007] The purpose of the present invention is to further explore the preparation process of sulfur powder asphalt, simplify the preparation process, reduce the mixing temperature, improve the adhesion, plasticity, stability and softening point of the emulsified asphalt of asphalt, so as to prepare a new type of sulfur powder asphalt with convenient construction and excellent comprehensive performance.

[0008] The technical solution adopted by the present invention provides a method for preparing normal temperature sulfur powder asphalt, the key being that, by weight, the above-mentioned preparation method comprises the following steps:

[0009] S1. preparing asphalt components;

[0010] S2, preparing a starch-based component;

[0011] S3, material mixing;

[0012] In the above step S1, the preparation process of the asphalt component is to heat 100 parts of the base asphalt to a molten state and stir, add 2 to 5 parts of the Bian Ze reagent and stir evenly;

[0013] The above S2 step is specifically divided into:

[0014] S2-1, preparation of acid-hydrolyzed starch milk;

[0015] S2-2, preparation of a rubber powder starch-based mixture;

[0016] S2-3, preparing a starch-based component through a free radical reaction;

[0017] In the above-mentioned step S3, specifically at room temperature, epoxy resin is added to the above-mentioned asphalt component and mixed evenly, starch-based components, sulfur powder and curing agent are added in sequence and mixed and stirred, and the solid content is adjusted to prepare the above-mentioned room temperature sulfur powder asphalt. The mass ratio of asphalt component, starch-based component, epoxy resin, curing agent and sulfur is 10:1~2:0.5~1:0.02~0.04:0.02~0.04.

[0018] Specifically, in parts by mass, the preparation of the above-mentioned S2-1, acid-decomposed starch milk is specifically as follows: 5 to 10 parts of dry starch are added to prepare starch milk, stirred at a temperature of 38° C. to 42° C., a mixed solution of acetic acid and hydrochloric acid with a mass percentage of 8% to 10% of the mass of the dry starch is added dropwise, stirring is continued, and then 0.5 to 1 part of ferrous chloride is added to prepare the above-mentioned acid-decomposed starch milk;

[0019] Specifically, in parts by mass, the preparation of the above-mentioned S2-2, rubber powder starch-based mixture is as follows: 5 to 10 parts of rubber powder are dissolved in 20 parts of toluene, mixed with the above-mentioned acid-hydrolyzed starch emulsion, and stirred at room temperature to obtain the above-mentioned rubber powder starch-based mixture.

[0020] More specifically, in terms of mass fraction, the starch-based modifier component prepared by free radical reaction in S2-3 is as follows:

[0021] S2-3-1, take 50 parts by weight of the rubber powder starch-based mixture, mix it evenly with 2.0-2.5 parts by weight of maleic anhydride and 0.1-0.2 parts of hydroquinone, and heat it to react to obtain a maleic anhydride-modified rubber powder starch-based mixture;

[0022] S2-3-2. Add 0.5-1 parts by mass of ferrous sulfate and 4-5 parts by mass of acrylic acid to 30-50 parts by mass of polyether monomer, add 2-3 parts of hydrogen peroxide at room temperature, stir evenly, and then add the maleic anhydride-modified rubber powder starch-based mixture prepared in step S2-3-1 by continuous dropwise addition, and at the same time, add 0.3-0.8 parts by mass of vitamin C and 1.5-2.0 parts of mercaptopropionic acid mixed solution, react after completion of the addition, and adjust the pH to neutral with liquid alkali after the reaction to obtain a starch-based component.

[0023] Furthermore, in the above-mentioned step S2-3-1, the reaction temperature of the above-mentioned heating reaction is 95°C to 105°C, and the reaction time is 2h to 4h.

[0024] Furthermore, in the above step S2-3-2, the dropping time of the continuous dropping method is 60 min to 90 min, and the reaction time after the dropping is completed is 40 min to 60 min.

[0025] Furthermore, in the above step S2-3-2, the polyether monomer is ethylene glycol vinyl polyoxyethylene ether or 4-hydroxybutyl vinyl polyoxyethylene ether with a weight average molecular weight of 2500 to 3500.

[0026] Preferably, the epoxy resin is a glycidylamine epoxy resin; the curing agent is an aliphatic polyamine curing agent, specifically any one of dimethylaminopropylamine or diethylpropylamine; the Bian Ze reagent is an aqueous solution containing any one of Brij78, Brij35, and Brij56.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The preparation process of the invention is simple, and the starch-based modifier containing rubber powder is prepared by free radical reaction. The whole preparation process does not require a high-temperature and high-pressure reaction process, does not require a rare metal catalyst, does not require air isolation, and has a short production time.

[0029] The product prepared by the present invention is a new type of emulsified epoxy asphalt containing sulfur powder, which can be mixed at room temperature to avoid problems such as asphalt denaturation caused by high temperature. The cement mixing performance using this product is good, and the strength, toughness and adhesion are all improved, showing excellent mechanical properties. The softening point of the sample prepared by the present invention is also further improved, and can be stabilized at above 70°C, which can better adapt to high temperature environments such as summer exposure, and avoid problems such as asphalt sticking to wheels caused by high temperature. In addition, the sample prepared by the present invention also has a certain water reduction effect, and the sample prepared by the present invention does not have water bleeding. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0031] If no specific conditions are specified in the examples, the experiments can be carried out under conventional conditions; if no manufacturer is specified for the reagents or instruments used, they are conventional products that can be purchased commercially; the normal temperature in the examples is 18°C ​​to 35°C.

[0032] For the convenience of description, the weight fractions are given. The specific process parameters and material types in each embodiment are shown in Table 1.

[0033] Embodiment 1 to Embodiment 4

[0034] S1. Preparation of asphalt components

[0035] Heat the base asphalt to a molten state and stir, add the benzyl reagent, continue to stir evenly and set aside. The benzyl reagent is an aqueous solution containing any one of Brij78, Brij35, and Brij56.

[0036] S2. Preparation of starch-based components

[0037] S2-1. Preparation of acid-hydrolyzed starch milk

[0038] Add dry starch into the mixture to prepare starch milk with a mass concentration of 50%, stir at a temperature of 38° C. to 42° C., dropwise add a mixed solution of acetic acid and hydrochloric acid, continue stirring, and then add ferrous chloride to prepare acid-hydrolyzed starch milk.

[0039] S2-2. Preparation of glue powder starch-based mixture

[0040] The rubber powder is dissolved in 20 parts of toluene, mixed with the prepared acid-hydrolyzed starch emulsion, and stirred at room temperature to react to obtain a rubber powder starch-based mixture.

[0041] S2-3. Preparation of starch-based components by free radical reaction

[0042] S2-3-1. Take a rubber powder starch-based mixture, mix it evenly with maleic anhydride and hydroquinone, heat and react to obtain a maleic anhydride-modified rubber powder starch-based mixture.

[0043] S2-3-2. Add ferrous sulfate and acrylic acid to the polyether monomer, add hydrogen peroxide with a mass concentration of 27.5% at room temperature, stir evenly, and then add the prepared maleic anhydride-modified rubber powder starch-based mixture by continuous addition, and at the same time, add a mixed solution of vitamin C and mercaptopropionic acid, and control the dropping time; after the addition is completed, continue to stir and react, and adjust to neutral after the reaction to obtain a starch-based component; in this embodiment, the polyether monomer is ethylene glycol vinyl polyoxyethylene ether or 4-hydroxybutyl vinyl polyoxyethylene ether with a weight average molecular weight of 2500-3500.

[0044] S3. Material mixing

[0045] At room temperature, glycidylamine type epoxy resin is added to the asphalt component and mixed evenly, starch-based component, sulfur powder and curing agent are added in sequence and mixed and stirred, the rotation speed is controlled at 2000r / min~4000r / min during the mixing process, and the solid content is adjusted to 55%, to prepare room temperature sulfur powder asphalt samples 1~4.

[0046] Table 1: Comparison table of specific parameters and material types and amounts of each step in the examples

[0047]

[0048]

[0049] Table 1: Comparison table of specific parameters and material types and amounts of each step in the embodiment

[0050]

[0051] Table 1: Comparison table of specific parameters and material types and amounts of each step in the embodiment

[0052]

[0053] Comparative Example 1

[0054] The implementation method is the same as Example 1, except that the epoxy resin used is not a glycidylamine epoxy resin, but an equal mass fraction of a glycidyl ether epoxy resin is selected to prepare a reference substance 1.

[0055] Comparative Example 2

[0056] The implementation method is the same as Example 1, except that the curing agent used is not dimethylaminopropylamine or diethylpropylamine, but an equal mass fraction of m-phenylenediamine to prepare a reference substance 2.

[0057] Comparative Example 3

[0058] The implementation method is the same as Example 1, except that during the process of "S3, material mixing", no sulfur is added to prepare reference substance 3.

[0059] Analysis and testing

[0060] With reference to "Water-based Epoxy Resin Emulsified Asphalt Mixture for Road Use" (GB / T 38990-2020), the elongation at break, breaking strength, elastic recovery, demulsification rate, viscosity and storage stability of the evaporation residue of the sample were tested; with reference to "Determination of Mixability of Emulsified Asphalt with Cement" (SH / T 0099.6-1991), the cement mixing property of the sample was tested; with reference to "Testing Procedure for Asphalt and Asphalt Mixture for Highway Engineering" (JTG E20-2011), the adhesion pull strength was tested. The results are shown in Table 2.

[0061] Table 2: Summary of performance test results of samples and reference products

[0062]

[0063] Table 2: Summary of performance test results of samples and reference materials

[0064]

[0065] As can be seen from the results in Table 2, the samples prepared by the present invention can be mixed at room temperature, avoiding problems such as asphalt denaturation caused by high temperature. The cement mixing performance of the product is good, the strength and toughness are improved, and excellent mechanical properties are shown. At the same time, the adhesion of the samples prepared by the present invention is also improved, and is less affected by temperature. The softening point of the samples prepared by the present invention is also further improved, and can be stabilized at above 70°C, which can better adapt to high temperature environments such as summer exposure, and avoid problems such as asphalt sticking to wheels caused by high temperature.

[0066] In addition, it was found during the test that the samples prepared by the present invention also have a certain water-reducing effect, which can reduce the amount of water used in the mixing process by more than 15%. The samples prepared by the present invention do not show water seepage, while when the control product is used for the test, although there is also a water-reducing effect, there will be a slight water seepage.

Claims

1. A method for preparing normal temperature sulfur powder asphalt, characterized in that: In terms of parts by mass, the preparation method comprises the following steps: S1. preparing asphalt components; S2, preparing a starch-based component; S3, material mixing; In the step S1, the preparation process of the asphalt component is to heat 100 parts of the base asphalt to a molten state and stir, add 2 to 5 parts of the Bian Ze reagent and stir evenly; The S2 step is specifically divided into: S2-1, preparation of acid-hydrolyzed starch milk; S2-2, preparation of a rubber powder starch-based mixture; S2-3, preparing a starch-based component through a free radical reaction; In the S3 step, specifically at room temperature, epoxy resin is added to the asphalt component and mixed evenly, starch-based components, sulfur powder and curing agent are added in sequence and mixed and stirred, and the solid content is adjusted to prepare the room temperature sulfur powder asphalt, and the mass ratio of asphalt component, starch-based component, epoxy resin, curing agent and sulfur is 10:1~2:0.5~1:0.02~0.04:0.02~0.

04.

2. The method for preparing normal temperature sulfur powder asphalt according to claim 1, characterized in that: In terms of parts by mass, the preparation of the S2-1, acid-hydrolyzed starch emulsion is specifically as follows: 5 to 10 parts of dry starch are added to prepare starch emulsion, stirred at a temperature of 38° C. to 42° C., a mixed solution of acetic acid and hydrochloric acid with a mass percentage of 8% to 10% of the mass of the dry starch is added dropwise, stirring is continued, and then 0.5 to 1 part of ferrous chloride is added to prepare the acid-hydrolyzed starch emulsion.

3. The method for preparing normal temperature sulfur powder asphalt according to claim 1, characterized in that: In terms of parts by mass, the preparation of the S2-2, rubber powder starch-based mixture is specifically as follows: 5 to 10 parts of rubber powder are dissolved in 20 parts of toluene, mixed with the acid-hydrolyzed starch milk, and stirred at room temperature to react to obtain the rubber powder starch-based mixture.

4. The method for preparing normal temperature sulfur powder asphalt according to claim 1, characterized in that: In terms of mass fractions, the process of preparing the starch-based component by free radical reaction in S2-3 is specifically as follows: S2-3-1, take 50 parts by weight of the rubber powder starch-based mixture, mix it evenly with 2.0-2.5 parts by weight of maleic anhydride and 0.1-0.2 parts of hydroquinone, and heat it to react to obtain a maleic anhydride-modified rubber powder starch-based mixture; S2-3-2. Add 0.5-1 parts by mass of ferrous sulfate and 4-5 parts by mass of acrylic acid to 30-50 parts by mass of polyether monomer, add 2-3 parts of hydrogen peroxide at room temperature, stir evenly, and then add the maleic anhydride-modified rubber powder starch-based mixture prepared in step S2-3-1 by continuous dropwise addition, and at the same time, add 0.3-0.8 parts by mass of vitamin C and 1.5-2.0 parts of mercaptopropionic acid mixed solution, react after completion of the addition, and adjust the pH to neutral with liquid alkali after the reaction to obtain a starch-based component.

5. The method for preparing normal temperature sulfur powder asphalt according to claim 4, characterized in that: In the step S2-3-1, the reaction temperature of the heating reaction is 95°C to 105°C, and the reaction time is 2h to 4h.

6. The method for preparing normal temperature sulfur powder asphalt according to claim 4, characterized in that: In the step S2-3-2, the continuous dropping method has a dropping time of 60 min to 90 min, and a reaction time of 40 min to 60 min after the dropping is completed.

7. The method for preparing normal temperature sulfur powder asphalt according to claim 4, characterized in that: In the step S2-3-2, the polyether monomer is ethylene glycol vinyl polyoxyethylene ether or 4-hydroxybutyl vinyl polyoxyethylene ether with a weight average molecular weight of 2500 to 3500.

8. The method for preparing normal temperature sulfur powder asphalt according to claim 1, characterized in that: The epoxy resin is a glycidylamine type epoxy resin; the curing agent is an aliphatic polyamine curing agent, specifically any one of dimethylaminopropylamine or diethylpropylamine; the Bian Ze reagent is an aqueous solution containing any one of Brij78, Brij35, and Brij56.

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