CN102976649B - Warm-mixing agent used for waste-rubber-powder-modified asphalt, and preparation method thereof - Google Patents

Abstract

The invention relates to a warm mix agent for waste rubber powder modified asphalt and a preparation method thereof. Through the compounding of substances containing ethylene structure with a melting point range of 100-150°C, esters with a melting point range of 50-100°C, monoamides with a melting point range of 50-100°C, oleic acid, aromatic oil and other components, the waste The viscosity of rubber powder modified asphalt is greatly reduced to meet the requirements of warm mixing, and at the same time, the low temperature ductility and high temperature softening point of modified asphalt are improved to a certain extent.

Description

Warm mix agent for waste rubber powder modified asphalt and preparation method thereof

Technical field:

The invention relates to a warm mix agent for waste rubber powder modified asphalt and a preparation method thereof.

Background technique:

Warm mix asphalt technology is a type of asphalt mixing whose mixing temperature is between hot mix asphalt technology (150-180°C) and cold mix asphalt technology (10-40°C), and the performance reaches (or is close to) hot mix asphalt mixture Energy-saving new technology. Usually, the most common implementation method of warm mix technology is to add warm mix agent. Compared with standard hot mix asphalt technology, the temperature of warm mix asphalt technology can be reduced by 20°C to 30°C. Warm mix asphalt technology has many advantages: Firstly, the production and construction temperature of asphalt mixture can be reduced, which can save energy consumption by more than 20%. At the same time, the storage temperature of asphalt mixture is lowered, and the fluidity at lower temperature is enhanced. Second, reduce emissions. Warm mix asphalt can greatly reduce the types and quantities of gas emissions during asphalt mixing. In addition, the construction period of asphalt pavement is extended and the application range is expanded.

The additives used at home and abroad for base asphalt warm mixing include the following: 1. Aspha-Min ^R zeolite. The method uses a synthetic zeolite to add the powdered material during asphalt mixing to generate foam in the binder. The foam effect can increase the coating rate of asphalt on the aggregate surface at a lower temperature, and at the same time, the foaming reaction in the liquid phase binder acts as a lubricant to make the asphalt mixture workable at low temperature. 2. Sasobit synthetic wax. It is a fine crystal, which exists in the form of flakes or powder at room temperature, and its melting point is about 99 ° C. When it exceeds 116 ° C, it can be completely dissolved in the asphalt binder, thereby producing a large amount of liquid to reduce the viscosity of the asphalt binder. Effect. 3. Liquid warm mixing agent. Usually an emulsifier is used to prepare a certain concentration of aqueous solution (soap), which is sprayed into the solution during the mixing of asphalt and aggregates (the soap is preferably in contact with the asphalt first), and the warm asphalt mixture is produced after full stirring.

In the 21st century, large-scale waste tire products will bring huge black pollution to the world. The application of waste rubber powder modified asphalt technology can solve the waste of resources caused by the accumulation of waste tires, and waste rubber powder modified asphalt has high and low temperature performance that cannot be compared with ordinary asphalt. However, due to the incorporation of rubber powder, the modified asphalt has a higher viscosity than ordinary base asphalt, resulting in a 30-50°C higher paving temperature than base asphalt, which not only increases the cost of paving, but also causes environmental damage. pollute.

In order to make waste rubber powder modified asphalt widely used on a large scale, it is imperative to use a suitable warm mix agent. The above-mentioned several traditional warm mix agents are widely used in reducing the viscosity of base asphalt and improving certain properties, but there are the following disadvantages when applied to waste rubber powder modified asphalt: First, the superior performance of waste rubber powder modified asphalt , mainly depends on the residual network chain structure of waste rubber powder. After adding the traditional warm mix agent, it will interact with the waste rubber powder, which will inevitably damage the network chain structure to a certain extent and reduce its low-temperature performance. Secondly, the viscosity of waste rubber powder modified asphalt is much higher than that of base asphalt, which will inevitably lead to an increase in the amount of traditional warm mix agent, resulting in an increase in cost. In addition, the moisture in the liquid warm mixing agent will not only cause certain damage to the instrument, but also the residual moisture will generate air bubbles, which will also have a great impact on the performance of the modified asphalt.

Invention content:

The object of the present invention is to provide a warm mix agent for waste rubber powder modified asphalt and a preparation method thereof. Through the reasonable compounding of the various components of the warm mix agent, the viscosity of the waste rubber powder modified asphalt is greatly reduced to meet the warm mix requirements, and at the same time, the low temperature ductility and high temperature softening point of the modified asphalt are improved to a certain extent.

A kind of warm mixing agent for waste rubber powder modified asphalt, its basic composition and mass parts are:

The substance containing ethylene structure in the melting point range of 100-150° C. is one of ethylene bis-stearic acid amide, ethylene bis-oleic acid amide or a mixture thereof. The ester having a melting point in the range of 50-100° C. is one of the following: diphenyl carbonate, glyceryl monostearate, glyceryl methacrylate, glyceryl behenate. The monoamide with a melting point of 50-100°C is one of the following substances or their mixture: oleic acid amide, erucic acid amide, acrylamide.

The present invention also provides a preparation method of the above-mentioned warm mixing agent: at room temperature, a substance containing an ethylene structure with a melting point in the range of 100-150°C, an ester with a melting point in the range of 50-100°C, and a unit with a melting point in the range of 50-100°C Amide, oleic acid and aromatic oil are initially mixed evenly in proportion. Then, put the primary mixture into the reaction kettle, stir at 100-150° C. for 10-15 minutes, the stirring speed is preferably 50-80 r/min, and then cool to room temperature to obtain the warm mixing agent.

The warm mix agent of the present invention can be directly added to the waste rubber powder modified asphalt when used.

The viscosity-reducing mechanism of the warm mixing agent of the present invention: First, from a physical point of view, the melting points of the substances used in the present invention are all below 140°C. When the temperature is higher than 140 °C, the above substances all exist in liquid form, and the presence of a large amount of liquid will inevitably reduce the viscosity of waste rubber powder modified asphalt, so as to meet the construction requirements. Secondly, from a chemical point of view, the reason why the viscosity of waste rubber powder modified asphalt increases is that the waste rubber powder absorbs and swells the light components (saturated components, aromatic components) in the asphalt, and acts as a light component of the solvent in the whole system. A decrease in content will inevitably lead to an increase in viscosity. The molecular weights of the main components in the warm mix agent of the present invention are all between 250-1500, while the molecular weight ranges of the saturated components and aromatic components (partial colloids) in the asphalt are all between 300-2000. Therefore, the addition of warm mix agent is equivalent to increasing the content of saturated and aromatic components in theory. For the entire asphalt system, as the content of saturated and aromatic components increases, it means that the solvent components increase, and the asphaltene and gum content increase. The concentration of the substance is relatively reduced, and the viscosity will also be reduced accordingly, so the addition of warm mixing agent will have the effect of reducing viscosity and warm mixing. In addition, the -C=O, -OH, and -NH groups contained in the warm mix agent can form hydrogen bonds with the -OH, _-NH2 and other functional groups in asphaltenes or colloids, and the non-polarity of the warm mix agent is long The chain structure is extended in the extension, and due to the mutual repulsion of the non-polar structure, it can disperse other asphaltenes or colloids and reduce the viscosity.

The invention can solve the problems caused by using the traditional warm mix agent for waste rubber powder modified asphalt. When the warm mix agent provided by the invention is applied to waste rubber powder modified asphalt, it will not affect the comprehensive performance of the asphalt at high and low temperatures. Due to the characteristics of the main components of the warm mix agent of the present invention, it will migrate to the surface of asphalt at low temperature, and when it is used to modify asphalt with waste rubber powder, it will not damage its internal waste rubber powder network chain structure, resulting in a decrease in its low-temperature performance. The warm mix agent of the present invention reduces viscosity from two aspects of physics and chemistry, is not only environmentally friendly and green, but also can ensure excellent viscosity reduction effect at a relatively low usage amount. The warm mixing agent of the present invention is a solid warm mixing agent, the operation is simple and easy, and the production equipment will not be damaged. In addition, the warm mixing agent of the present invention can also be used for traditional base asphalt viscosity-reducing warm mixing.

Specific implementation plan:

The present invention will be further described below through examples and comparative examples, but not as a limitation to the protection scope of the present invention.

The asphalt used in the following examples and comparative examples is petroleum asphalt, and the grade meets the technical requirements for road asphalt in the technical specification for highway asphalt pavement construction promulgated by the Ministry of Communications. Among them, the test methods for viscosity, softening point, penetration, ductility, etc. all adopt the standards stipulated in the "Test Regulations for Asphalt and Asphalt Mixtures in Highway Engineering" (JTJ 052-2000).

Comparative example 1:

After melting the asphalt, heat it to 160°C, add waste rubber powder (60 mesh in Puyang, Henan Province) to the asphalt, and use a high-speed mixer to mix and premix at a stirring speed of 300r/min for 15 minutes, and then mix the premixed modified The asphalt is sheared at a high speed by a high-speed shearing machine, the shearing temperature is 160°C, the shearing time is 25-30min, and the shearing rate of the shearing machine is 9000r/min to obtain modified asphalt. The resulting viscosity is shown in Table 1, and other performance indicators are shown in Table 2.

Comparative example 2:

Add the traditional warm mix agent (Sasobit) to the modified asphalt obtained in Comparative Example 1 at a mass ratio of 1:50 to the modified asphalt, and stir with a high-speed mixer at 160° C. for 15 minutes at a stirring speed of 300 r/min. The resulting viscosity is shown in Table 1, and other performance indicators are shown in Table 2.

Example 1:

With 50 mass parts of ethylene bisoleic acid amide, 30 mass parts of diphenyl carbonate, 30 mass parts of oleic acid amide, 15 mass parts of oleic acid, aromatic oil (Zibo Taichang Lubricating Oil Co., Ltd., the following examples all adopt the same Aromatic oil) 5 parts by mass are preliminarily mixed to make it macroscopically uniform. Then, the primary mixture was put into a reactor (volume 5L, the same reactor was used in the following examples) for reaction and mixing, the stirring speed was 50r/min, and the treatment time was 15 minutes at 140°C, and cooled to room temperature. Get warm mix.

Add warm mix agent and modified asphalt to the modified asphalt prepared in Comparative Example 1 at a mass ratio of 1:50, and stir with a high-speed mixer at 160°C for 15 minutes at a stirring speed of 300r/min. The resulting viscosity is shown in Table 1, and other performance indicators are shown in Table 2.

Example 2:

50 parts by mass of ethylene bis stearic acid amide, 30 parts by mass of glyceryl monostearate, 30 parts by mass of oleic acid amide, 15 parts by mass of oleic acid and 5 parts by mass of aromatic oil are preliminarily mixed to achieve macroscopic uniformity. Then, put the primary mixture into the reaction kettle for reaction and mixing, the stirring speed is 50r/min, the treatment time is 15 minutes at 140°C, and cooled to room temperature to prepare the warm mixing agent.

Add warm mix agent and modified asphalt to the modified asphalt prepared in Comparative Example 1 at a mass ratio of 1:50, and stir with a high-speed mixer at 160°C for 15 minutes at a stirring speed of 300r/min. The resulting viscosity is shown in Table 1, and other performance indicators are shown in Table 2.

Example 3:

Preliminarily mix 50 parts by mass of ethylene bisoleamide, 30 parts by mass of glyceryl behenate, 30 parts by mass of erucamide, 15 parts by mass of oleic acid, and 5 parts by mass of aromatic oil to achieve macroscopic uniformity. Then, put the primary mixture into the reaction kettle for reaction and mixing, the stirring speed is 50r/min, the treatment time is 15 minutes at 140°C, and cooled to room temperature to prepare the warm mixing agent.

Add warm mix agent and modified asphalt to the modified asphalt prepared in Comparative Example 1 at a mass ratio of 1:50, and stir with a high-speed mixer at 160°C for 15 minutes at a stirring speed of 300r/min. The resulting viscosity is shown in Table 1, and other performance indicators are shown in Table 2.

Example 4:

50 mass parts of ethylene bis stearic acid amide, 30 mass parts of glyceryl methacrylate, 30 mass parts of acrylamide, 20 mass parts of oleic acid, and 5 mass parts of aromatic oil are preliminarily mixed to make it reach macro uniform. Then, put the primary mixture into the reaction kettle for reaction and mixing, the stirring speed is 50r/min, the treatment time is 15 minutes at 140°C, and cooled to room temperature to prepare the warm mixing agent.

Add warm mix agent and modified asphalt to the modified asphalt prepared in Comparative Example 1 at a mass ratio of 1:50, and stir with a high-speed mixer at 160°C for 15 minutes at a stirring speed of 300r/min. The resulting viscosity is shown in Table 1, and other performance indicators are shown in Table 2.

Example 5:

50 parts by mass of ethylene bis-oleic acid amide, 30 parts by mass of ethylene bis-stearic acid amide, 30 parts by mass of glycerol monostearate, 10 parts by mass of acrylamide, 40 parts by mass of oleic acid amide, and 40 parts by mass of oleic acid 20 parts by mass and 5 parts by mass of aromatic oil are preliminarily mixed to achieve macroscopic uniformity. Then, put the primary mixture into the reaction kettle for reaction and mixing, the stirring speed is 50r/min, the treatment time is 15 minutes at 140°C, and cooled to room temperature to prepare the warm mixing agent.

Add warm mix agent and modified asphalt to the modified asphalt prepared in Comparative Example 1 at a mass ratio of 1:50, and stir with a high-speed mixer at 160°C for 15 minutes at a stirring speed of 300r/min. The resulting viscosity is shown in the table, and other performance indicators are shown in table 2.

Table 1: Comparison of the viscosity properties (mpa s) of the examples of the present invention and the comparative examples at different temperatures

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative example 1 Comparative example 2 135°C 5253 3824 4783 3551 3371 10803 8211 150℃ 3003 2417 2862 2245 2256 6020 4577 165°C 2102 1715 1520 1413 1513 3571 2883 180°C 1411 1263 1193 1126 1009 2423 2415

Table 2: The performance index contrast of embodiment of the present invention and comparative example

The data in the above two tables show that adding the warm mix agent will affect the viscosity and other properties of the waste rubber powder modified asphalt. Compared with the waste rubber powder modified asphalt obtained in Comparative Example 1 without adding warm mix agent, the viscosity reduction effect of Examples 1-5 using the warm mix agent of the present invention is remarkable, and the viscosity reduction range exceeds 50%, and other properties also have certain The viscosity can be reduced to 3000mpa·s or lower at 150°C, and other performance index tests can also meet the engineering requirements. However, the range of viscosity reduction in Comparative Example 2 with the addition of traditional warm mixing agent was less than 25%.

Claims (2)

1. A kind of warm mix agent for waste rubber powder modified asphalt, its basic composition and mass parts are:

The substance containing an ethylene structure in the melting point range of 100-150°C is one of ethylene bis-stearic acid amide, ethylene bis-oleic acid amide, or a mixture thereof; The ester with a melting point in the range of 50-100°C is one of diphenyl carbonate, glyceryl monostearate, glyceryl methacrylate or glyceryl behenate; The monoamide with a melting point of 50-100° C. is one of the following substances or a mixture thereof: oleic acid amide, erucic acid amide, and acrylamide. 2. A preparation method of warm mixing agent for waste rubber powder modified asphalt according to claim 1, at room temperature, the melting point range is 100-150 ° C containing ethylene structure material, the melting point range is 50-100 ° C Esters, monoamides with a melting point of 50-100°C, oleic acid and aromatic oils are preliminarily mixed in proportion; then, the primary mixture is added to the reactor, stirred at 100-150°C for 10-15 minutes, and cooled to room temperature Get warm mix.