A cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent and its preparation method

Abstract

This invention discloses a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent and its preparation method. The micro-expansion agent prepared by this invention can effectively control the performance of asphalt and asphalt concrete. Component A can effectively control the ductility and viscosity of asphalt, which can be controlled between 200 and 1000 mm at 10℃, effectively improving the low-temperature crack resistance of asphalt concrete. It has good coating properties with coarse aggregate, with a coating area ≥ 4 / 5, and can significantly improve the water stability of cold recycled mixtures. Component B serves the purpose of micro-expansion, reducing the porosity of asphalt concrete. The porosity can be controlled within 8-13%, further improving the water damage resistance and strength of asphalt concrete. At the same time, component C can regulate the demulsification time of emulsified asphalt, and the demulsification rate can be controlled within 3-8 hours, fully meeting the requirements of mixing and construction.

Description

Technical Field

[0001] This invention relates to the field of asphalt concrete preparation technology, specifically to a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent and its preparation method. Background Technology

[0002] Urban roads are closely related to people's lives and the flow of goods, serving as a crucial indicator of a city's modernization. With my country's rapid economic development and accelerated urbanization, the total number of motor vehicles and transportation volumes in cities is increasing year by year, leading to a surge in asphalt pavement defects. Road intersections and bus stops, as important transportation hubs, are particularly prone to defects such as rutting, cracks, bulges, and alligator cracking due to high traffic volume, channelized traffic, frequent starts and stops (resulting in repeated shear stress on the pavement structure), heavy loads, and high summer temperatures. Rutting is the most severe of these defects. It causes vehicles to easily sway and skid when driving on these sections, posing a significant safety hazard to both vehicles and pedestrians. Therefore, it is urgent to address the problem of rutting and other defects on urban roads.

[0003] While traditional semi-rigid base courses offer improved strength compared to flexible base courses, water seeping into the base course after rain, under the influence of high-speed heavy vehicles, creates dynamic water pressure, causing the base course to loosen and break up, ultimately damaging the asphalt surface. Cement-stabilized crushed stone base courses, which have lower water stability than the three-slag grade, are prone to shrinkage cracks, which, when reflected back to the asphalt surface, still easily lead to damage. After years of service on the pavement, the properties of raw materials in emulsified asphalt mixtures will change under the combined effects of environmental factors and traffic loads. For example, residual asphalt after demulsification will age, some RAP (Rich Acid Asphalt) components bound by fine aggregates will gradually disperse, and the old and new asphalt on the RAP surface will slowly fuse. All of these factors will significantly affect the long-term performance of recycled asphalt mixtures, thus impacting the overall pavement performance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent and its preparation method. The present invention prepares a cost-effective micro-expansion agent that can prevent and solve various diseases of asphalt pavement, extend the service life of the pavement, reduce pavement maintenance costs, improve driving safety, and at the same time make the performance of asphalt concrete meet the relevant technical specifications as much as possible, thereby reducing engineering costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent, comprising component A, component B and component C, wherein component A is prepared as follows: by weight, 20-90 parts of fatty acid, 20-90 parts of lower alkyl ester, 1-5 parts of phosphoric acid and 2-6 parts of plasticizer are reacted at 120-165℃ for 2-6 hours to obtain component A;

[0007] The preparation method of component B is as follows: 100 parts by weight of water, 0.1-0.5 parts of iron compound, 0.1-0.5 parts of magnesium oxide, 0.1-0.5 parts of calcium compound and 0.1-0.5 parts of sodium salt are mixed evenly at room temperature to form a solution, thus obtaining component B;

[0008] The preparation method of component C is as follows: Mix 20-40 parts of tricarboxylic acid and 40-80 parts of fatty acid evenly according to the weight, then control the temperature at 150℃, add 10-20 parts of polyamine, raise the temperature to 220℃ and react for 1-2 hours to obtain component C.

[0009] Preferably, the fatty acids in component A are one or more of formic acid, acetic acid, oxalic acid, propionic acid, adipic acid, stearic acid, and oleic acid.

[0010] Preferably, the lower alkyl ester in component A has 4-16 carbon atoms, more preferably C8-C. 12 .

[0011] Preferably, the phosphoric acid in component A is one or more of orthophosphoric acid, metaphosphoric acid, and polyphosphoric acid.

[0012] Preferably, the plasticizer in component A is one or more of dioctyl phthalate, dibutyl phthalate, epoxidized soybean oil, citrate, and epoxidized butyl oleate.

[0013] Preferably, the iron compound in component B is ferric chloride and / or ferric oxide, the magnesium oxide is magnesium oxide and / or magnesium sulfate, the calcium compound is one or more of calcium silicate, calcium aluminosilicate, calcium sulfoaluminate, calcium sulfate, and calcium oxide, and the sodium salt is sodium sulfate or sodium chloride.

[0014] Preferably, the tricarboxylic acid in component C has 6-60 carbon atoms.

[0015] Preferably, the fatty acids in component C are one or more of acetic acid, oxalic acid, propionic acid, adipic acid, stearic acid, and oleic acid.

[0016] Preferably, the polyamine in component C is one or more of ethylenediamine, diethanolamine, and triethanolamine.

[0017] The present invention also provides a method for preparing the above-mentioned cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent, comprising the following steps: mixing component A, component B and component C evenly to obtain the micro-expansion agent.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The micro-expansion agent prepared by the present invention can effectively control the performance of asphalt and asphalt concrete. Component A can effectively control the ductility and viscosity of asphalt, which can be controlled between 200 and 1000 mm at 10°C, effectively improving the low-temperature crack resistance of asphalt concrete. It has good coating properties with coarse aggregate, with a coating area ≥ 4 / 5, which can significantly improve the water stability of cold recycled mixture. Component B plays the role of micro-expansion, reducing the porosity of asphalt concrete. The porosity can be controlled within 8 to 13%, further improving the water damage resistance of asphalt concrete and increasing the strength of asphalt concrete. At the same time, component C can regulate the demulsification time of emulsified asphalt. The demulsification speed can be controlled within 3-8 hours, which fully meets the requirements of mixing and construction.

[0020] (2) The micro-expansion agent provided by the present invention can be fully mixed with cement and aggregate to undergo a chemical reaction, and then demulsified and formed a semi-flexible binder together with cement. The initial strength is formed quickly and the strength continues to increase over time. On the other hand, the active groups in the micro-expansion agent interact with the active groups in the asphalt to form a high-strength viscoelastic material, which improves the cohesion and viscosity of the asphalt, reduces its temperature sensitivity, and thus improves the adhesion between the asphalt and aggregate. It not only forms a bridge between the asphalt and the aggregate, but also produces physical / chemical reactions between the asphalt, aggregate and micro-expansion agent, avoiding and slowing down the occurrence of reflective cracks, thereby significantly enhancing the ability of the asphalt mixture to resist external deformation and improving the high-temperature rutting resistance and low-temperature crack resistance of the mixture.

[0021] (3) The micro-expansion agent provided by the present invention can avoid and slow down the occurrence of reflective cracks, and at the same time play a healing role; it can avoid and control segregation or even demulsification during production, transportation and construction, and achieve the effect of controllable demulsification speed; the physicochemical interaction between the micro-expansion agent and asphalt and aggregates makes its viscosity and toughness much better than that of ordinary emulsified asphalt, and significantly improves the water stability performance of asphalt concrete.

[0022] (4) This invention uses recycled mixture as raw material, realizes the recycling of resources, improves its use value, and has significant economic and environmental benefits.

[0023] (5) This process is simple, reduces many processing steps, is highly operable, has low equipment and raw material costs, and has mild operating conditions. The temperature of the entire process is significantly reduced, which effectively reduces safety hazards in production. It is suitable for industrial production and has significant economic benefits. Detailed Implementation

[0024] The present invention will be further described in detail below through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0025] It should be noted that, unless otherwise specified, all chemical reagents involved in this invention were purchased through commercial channels.

[0026] The CAS number of the epoxidized soybean oil used in this invention is 8013-07-8.

[0027] Example 1

[0028] A method for preparing a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent, comprising the following steps:

[0029] Preparation of component A: 20 parts by weight of acetic acid, 80 parts by weight of methyl hexanoate, 2 parts by weight of phosphoric acid, 2 parts by weight of dioctyl phthalate and 3 parts by weight of dibutyl phthalate were reacted at 120°C for 6 hours to obtain component A.

[0030] The preparation method of component B is as follows: 100 parts by weight of water, 0.1 parts by weight of FeCl3, 0.1 parts by weight of iron oxide, 0.1 parts by weight of magnesium oxide, 0.1 parts by weight of calcium oxide and 0.1 parts by weight of sodium chloride are mixed evenly at room temperature to form a solution, thus obtaining component B;

[0031] The preparation method of component C is as follows: Mix 20 parts of citric acid and 40 parts of stearic acid evenly according to the weight, then control the temperature at 150℃, add 15 parts of ethylenediamine, raise the temperature to 220℃ and react for 1 hour to obtain component C.

[0032] Mix components A, B, and C thoroughly to obtain the micro-expansion agent.

[0033] According to the Chinese standards "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011) and "Technical Specifications for Construction of Asphalt Pavement on Highways" (JTGF40-2004), after adding 1% of the micro-expansion agent of this invention, the prepared asphalt concrete freeze-thaw splitting residual strength ratio (dry-wet splitting ratio) is 87%, the porosity is 13.2%, the coarse aggregate has good coating properties with a coating area ≥4 / 5, and the demulsification rate is 5h.

[0034] Example 2

[0035] A method for preparing a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent, comprising the following steps:

[0036] Preparation of component A: 30 parts by weight of acetic acid, 70 parts by weight of methyl hexanoate, 2 parts by weight of phosphoric acid, 2 parts by weight of dioctyl phthalate and 2 parts by weight of dibutyl phthalate were reacted at 130°C for 6 hours to obtain component A.

[0037] The preparation method of component B is as follows: 100 parts by weight of water, 0.1 parts of iron oxide, 0.1 parts of magnesium oxide, 0.2 parts of calcium aluminosilicate and 0.1 parts of sodium chloride are mixed evenly at room temperature to form a solution, thus obtaining component B;

[0038] The preparation method of component C is as follows: Mix 30 parts of citric acid and 40 parts of stearic acid evenly according to the weight, then control the temperature at 150℃, add 15 parts of ethylenediamine, raise the temperature to 220℃ and react for 1 hour to obtain component C.

[0039] Mix components A, B, and C thoroughly to obtain the micro-expansion agent.

[0040] According to the Chinese standards "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011) and "Technical Specifications for Construction of Asphalt Pavement on Highways" (JTGF40-2004), after adding 1% of the micro-expansion agent of this invention, the prepared asphalt concrete freeze-thaw splitting residual strength ratio (dry-wet splitting ratio) is 96%, the porosity is 10.6%, the coarse aggregate has good coating properties with a coating area ≥4 / 5, and the demulsification rate is 6h.

[0041] Example 3

[0042] A method for preparing a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent, comprising the following steps:

[0043] Preparation of component A: 40 parts by weight of acetic acid, 60 parts by weight of methyl hexanoate, 1 part by weight of metaphosphoric acid, 2 parts by weight of dioctyl phthalate and 2 parts by weight of epoxidized soybean oil were reacted at 140℃ for 6 hours to obtain component A.

[0044] The preparation method of component B is as follows: 100 parts by weight of water, 0.1 parts of iron oxide, 0.1 parts of magnesium oxide, 0.2 parts of calcium sulfoaluminate and 0.1 parts of sodium chloride are mixed evenly at room temperature to form a solution, thus obtaining component B;

[0045] The preparation method of component C is as follows: Mix 30 parts of citric acid and 60 parts of oleic acid evenly according to the weight, then control the temperature at 150℃, add 15 parts of diethanolamine, raise the temperature to 220℃ and react for 2 hours to obtain component C.

[0046] Mix components A, B, and C thoroughly to obtain the micro-expansion agent.

[0047] According to the Chinese standards "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011) and "Technical Specifications for Construction of Asphalt Pavement on Highways" (JTGF40-2004), after adding 1% of the micro-expansion agent of this invention, the prepared asphalt concrete freeze-thaw splitting residual strength ratio (dry-wet splitting ratio) is 95.6%, the porosity is 13.6%, the coarse aggregate has good coating properties with a coating area ≥4 / 5, and the demulsification rate is 8h.

[0048] Example 4

[0049] A method for preparing a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent, comprising the following steps:

[0050] Preparation of component A: 50 parts by weight of acetic acid, 50 parts by weight of methyl hexanoate, 1 part by weight of polyphosphoric acid, 2 parts by weight of butyl oleate and 2 parts by weight of epoxidized soybean oil were reacted at 160℃ for 6 hours to obtain component A.

[0051] The preparation method of component B is as follows: 100 parts by weight of water, 0.1 parts of iron oxide, 0.1 parts of magnesium oxide, 0.3 parts of calcium sulfoaluminate and 0.1 parts of sodium chloride are mixed evenly at room temperature to form a solution, thus obtaining component B;

[0052] The preparation method of component C is as follows: Mix 40 parts citric acid and 80 parts oleic acid evenly according to the weight, then control the temperature at 150℃, add 5 parts ethylenediamine and 15 parts triethanolamine, raise the temperature to 220℃ and react for 2 hours to obtain component C.

[0053] Mix components A, B, and C thoroughly to obtain the micro-expansion agent.

[0054] According to the Chinese standards "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011) and "Technical Specifications for Construction of Asphalt Pavement on Highways" (JTGF40-2004), after adding 1% of the micro-expansion agent of this invention, the prepared asphalt concrete freeze-thaw splitting residual strength ratio (dry-wet splitting ratio) is 99.6%, the porosity is 9.3%, the coarse aggregate has good coating properties with a coating area ≥4 / 5, and the demulsification rate is 7h.

[0055] Example 5

[0056] A method for preparing a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent, comprising the following steps:

[0057] Preparation of component A: 60 parts by weight of acetic acid, 40 parts by weight of methyl hexanoate, 1 part by weight of polyphosphoric acid, 1 part by weight of dioctyl phthalate, 2 parts by weight of butyl oleate and 2 parts by weight of epoxidized soybean oil were reacted at 165°C for 6 hours to obtain component A.

[0058] The preparation method of component B is as follows: 100 parts by weight of water, 0.2 parts by weight of iron oxide, 0.1 parts by weight of magnesium oxide, 0.3 parts by weight of calcium sulfoaluminate and 0.1 parts by weight of sodium chloride are mixed evenly at room temperature to form a solution, thus obtaining component B;

[0059] The preparation method of component C is as follows: Mix 40 parts of citric acid and 80 parts of oleic acid evenly according to the weight, then control the temperature at 150℃, add 10 parts of ethylenediamine and 10 parts of triethanolamine, raise the temperature to 220℃ and react for 2 hours to obtain component C.

[0060] Mix components A, B, and C thoroughly to obtain the micro-expansion agent.

[0061] According to the Chinese standards "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011) and "Technical Specifications for Construction of Asphalt Pavement on Highways" (JTGF40-2004), after adding 1% of the micro-expansion agent of this invention, the prepared asphalt concrete freeze-thaw splitting residual strength ratio (dry-wet splitting ratio) is 99.7%, the porosity is 9.5%, the coarse aggregate has good coating properties with a coating area ≥4 / 5, and the demulsification rate is 8h.

[0062] Example 6

[0063] A method for preparing a cement-emulsified semi-flexible high-strength asphalt concrete micro-expansion agent, comprising the following steps:

[0064] Preparation of component A: 70 parts by weight of acetic acid, 30 parts by weight of methyl hexanoate, 2 parts by weight of phosphoric acid, 1 part by weight of polyphosphoric acid, 1 part by weight of dioctyl phthalate and 2 parts by weight of epoxidized soybean oil were reacted at 155°C for 5 hours to obtain component A.

[0065] The preparation method of component B is as follows: 100 parts by weight of water, 0.2 parts by weight of iron oxide, 0.1 parts by weight of magnesium oxide, 0.3 parts by weight of calcium aluminosilicate and 0.1 parts by weight of sodium chloride are mixed evenly at room temperature to form a solution, thus obtaining component B;

[0066] The preparation method of component C is as follows: Mix 30 parts citric acid and 60 parts oleic acid evenly according to the weight, then control the temperature at 150℃, add 5 parts ethylenediamine and 5 parts triethanolamine, raise the temperature to 220℃ and react for 2 hours to obtain component C.

[0067] Mix components A, B, and C thoroughly to obtain the micro-expansion agent.

[0068] According to the Chinese standards "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011) and "Technical Specifications for Construction of Asphalt Pavement on Highways" (JTGF40-2004), after adding 1% of the micro-expansion agent of this invention, the prepared asphalt concrete freeze-thaw splitting residual strength ratio (dry-wet splitting ratio) is 99.8%, the porosity is 12.5%, the coarse aggregate has good coating properties with a coating area ≥4 / 5, and the demulsification rate is 6h.

[0069] Finally, it should be noted that the above embodiments do not limit the present invention in any way. Those skilled in the art can make modifications and improvements based on the present invention. Therefore, any modifications or improvements made without departing from the spirit of the present invention are within the scope of protection claimed by the present invention.

Claims

1. A cement-emulsified semi-flexible high-strength asphalt concrete micro-expanding agent, characterized by, The micro-expanding agent comprises A component, B component and C component, wherein the A component is prepared by the following method: 20-90 parts of fatty acid, 20-90 parts of lower alkyl ester, 1-5 parts of phosphoric acid and 2-6 parts of plasticizer are mixed at 120-165 ℃ for 2-6 h to obtain the A component; The B component is prepared by the following method: 100 parts of water, 0.1-0.5 parts of iron compound, 0.1-0.5 parts of magnesia, 0.1-0.5 parts of calcium compound and 0.1-0.5 parts of sodium salt are mixed at room temperature to form a solution, thereby obtaining the B component; The C component is prepared by the following method: 20-40 parts of tricarboxylic acid and 40-80 parts of fatty acid are mixed, and then 10-20 parts of polyamine is added at 150 ℃, and the temperature is increased to 220 ℃ and reacted for 1-2 h to obtain the C component; The fatty acid in the A component is one or more of formic acid, acetic acid, propionic acid, stearic acid and oleic acid. The lower alkyl ester in the A component has 4-16 carbon atoms.

2. The cement-emulsified semi-flexible high-strength asphalt concrete micro-expanding agent according to claim 1, characterized by, The plasticizer in the A component is one or more of dioctyl phthalate, dibutyl phthalate, epoxy soybean oil, citric acid ester and butyl epoxy oleate.

3. The cement-emulsified semi-flexible high-strength asphalt concrete micro-expanding agent according to claim 1, characterized in that, The iron compound in the B component is iron chloride and / or iron oxide, the magnesia is magnesium oxide and / or magnesium sulfate, the calcium compound is one or more of calcium silicate, calcium aluminate, calcium sulphoaluminate, calcium sulfate and calcium oxide, and the sodium salt is sodium sulfate or sodium chloride.

4. The cement-emulsified semi-flexible high-strength asphalt concrete micro-expanding agent according to claim 1, characterized by, The tricarboxylic acid in the C component has 6-60 carbon atoms.

5. The cement-emulsified semi-flexible high-strength asphalt concrete micro-expanding agent according to claim 1, characterized by, The fatty acid in the C component is one or more of acetic acid, propionic acid, stearic acid and oleic acid.

6. The cement-emulsified semi-flexible high-strength asphalt concrete micro-expanding agent according to claim 1, characterized by, The polyamine in the C component is one or more of ethylenediamine, diethanolamine and triethanolamine.

7. The method for preparing the cement-emulsified semi-flexible high-strength asphalt concrete micro-expanding agent according to any one of claims 1-6, characterized in that, The micro-expanding agent is prepared by mixing the A component, the B component and the C component.