CN110577750A - A kind of composite modified asphalt for road and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of road building materials, in particular to a composite modified asphalt for roads and a preparation method thereof. Aiming at the problem that the overall strength of the existing modified asphalt cannot be guaranteed, the following solutions are proposed, including main materials and Auxiliary material, the main material includes base asphalt, and the auxiliary material includes modifier, stabilizer, biological filler, SBS, SBR and PPA. The performance of SBS and SBR is enhanced by adding PPA and MAC modifiers. After the composite modifier formed by the combination of SBR and SBS is added to the asphalt, due to the cross-linking effect of macromolecules, the rubber and plastic materials form a higher proportion in the asphalt. A single SBR modifies a larger, more complex, random interpenetrating network structure, and the addition of PPA can significantly improve the high-temperature performance and flexibility of asphalt mixing. MAC modifier can improve the adhesion of biological fillers and asphalt. Improves water stability, fatigue resistance and aging resistance after mixing.

Description

A kind of composite modified asphalt for road and preparation method thereof

technical field

The invention relates to the technical field of road building materials, in particular to a composite modified asphalt for roads and a preparation method thereof.

Background technique

Asphalt is a black or dark black solid or semi-solid viscous substance composed of high molecular hydrocarbons and non-hydrocarbons. It has excellent properties such as water resistance, moisture resistance, wear resistance, electrical insulation and toughness. It is indispensable for modern road construction. important material. Due to weather, vehicle overloading and other reasons, asphalt pavement often has defects such as pavement subsidence, cracks, and flatness reduction. These defects often further accelerate the overall damage of asphalt pavement, thus causing potential harm to vehicle driving safety.

Due to the solid form of asphalt, its fluidity is poor, and it is a viscous object with strong viscosity. Therefore, it is often not well mixed with other aggregates, which brings great difficulties to road construction. At present, the main methods of mixing asphalt with aggregate are solvent method and heating and melting method. The solvent method uses a large amount of organic solvent to dissolve the asphalt, thereby increasing its fluidity and achieving the purpose of mixing with the aggregate evenly. Therefore, more and more composite modified asphalts appear on the market.

In order to give full play to the modification effect of waste rubber powder on asphalt, some technical measures are currently used to improve the stability of waste rubber powder in asphalt. For example, in the modified asphalt process, organic solvents are used to improve the compatibility of waste rubber powder in asphalt, or coupling agents are used to improve the interface between waste rubber powder and asphalt, but the use of these additives in the overall modified asphalt The strength cannot be guaranteed, and the strength increase is not obvious compared with the existing asphalt. Therefore, it is necessary to invent a composite modified asphalt for roads and a preparation method thereof.

SUMMARY OF THE INVENTION

The composite modified asphalt for road and its preparation method proposed by the invention solve the problem that the overall strength of the modified asphalt cannot be guaranteed.

In order to achieve the above object, the present invention adopts the following technical solutions:

A composite modified asphalt for road, including main material and auxiliary material, the main material includes base asphalt, and the auxiliary material includes modifier, stabilizer, biological filler, SBS, SBR and PPA, in the main material and auxiliary material Each component adopts the following proportions according to the mass parts: 82-90 parts of base asphalt, 6-10 parts of modifier, 3-7 parts of stabilizer, 12-16 parts of biological filler, 8-12 parts of SBS, 6-10 parts of SBR 10-14 servings of PPA.

Preferably, described matrix pitch selects one or more in coal tar pitch, petroleum pitch and natural pitch, described biological filler comprises RAP pitch, waste rubber powder and sludge, and each component ratio in described biological filler is 3: 2:1, the modifier selects MAC modifier.

Preferably, the present invention also provides a method for preparing composite modified asphalt for roads, which specifically includes the following steps:

Step 1: Select the matrix asphalt and the biological filler to be heated respectively, and the heating temperature is kept at 150-180 °C for 2-4 hours, and the heating process is continuously stirred and mixed;

Step 2: adding the heated biological filler into the base asphalt, adding a stabilizer to it, increasing the heating temperature to 180-220°C, and continuously stirring, adding SBS and SBR evenly during the stirring process;

Step 3: Add PPA to the base asphalt for stirring and heating, add modifier for heating for 4-6 hours after heating for 30-50 minutes, and gradually cool down at 30-50°C/h after the heating is completed until the temperature is lowered to room temperature to obtain Compound modified asphalt.

Preferably, in the first step, the biological filler needs to be preliminarily pulverized, and then the part with a larger internal volume is pulverized and then heated.

Preferably, the heating is continued for 2-4 hours after the addition of the auxiliary materials in the second step.

Compared with the prior art, the beneficial effects of the present invention are:

1. In the present invention, the performance of SBS and SBR is enhanced by adding PPA and MAC modifiers. After the composite modifier formed by the combination of SBR and SBS is added to the asphalt, due to the cross-linking effect of macromolecules, the rubber and plastics can be reduced. The material forms a larger, more complex, random interpenetrating network structure in asphalt than a single SBR modification. Adding PPA can significantly improve the high temperature performance and flexibility of asphalt mixing. MAC modifier can improve the biological filler and Adhesion of asphalt, improve water stability, fatigue resistance and aging resistance after mixing, stable state under low temperature conditions, to ensure the strength and service life during the use of road paving;

2. In the present invention, by selecting RAP asphalt, waste rubber powder and sludge as biological fillers, the chemical components of biological fillers and matrix asphalt and auxiliary materials are basically the same, which can be mixed together quickly, and at the same time can fill the matrix due to the difference in specific gravity. The voids in the asphalt reduce the generation of air bubbles and increase the overall strength. In addition, RAP asphalt, waste rubber powder and sludge are all wastes after production and use. The reprocessing and use of the wastes can save energy and cost and protect the environment. .

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

Example 1:

A composite modified asphalt for road, including main material and auxiliary material, the main material includes base asphalt, and the auxiliary material includes modifier, stabilizer, biological filler, SBS, SBR and PPA, in the main material and auxiliary material Each component adopts the following proportions according to the parts by mass: 82 parts of base asphalt, 6 parts of modifier, 3 parts of stabilizer, 12 parts of biological filler, 8 parts of SBS, 6 parts of SBR, and 10 parts of PPA.

The base asphalt is selected from one or more of coal tar pitch, petroleum pitch and natural pitch. The biological filler includes RAP asphalt, waste rubber powder and sludge, and the ratio of each component in the biological filler is 3:2:1 , the modifier selects MAC modifier.

The invention also provides a preparation method of composite modified asphalt for road, which specifically comprises the following steps:

Step 1: Select the matrix asphalt and the biological filler to be heated separately. The biological filler needs to be preliminarily pulverized, and the larger internal volume is pulverized and then heated. The heating temperature is kept at 150 ° C for 2 hours, and the heating process is uninterrupted. to stir and mix;

Step 2: Add the heated bio-filler to the base asphalt, add stabilizer to it, increase the heating temperature to 180°C, and continue stirring. During the stirring process, SBS and SBR are evenly added to it, and the auxiliary materials are added. Then continue to heat for 2h;

Step 3: Add PPA to the base asphalt for stirring and heating, add modifier for 4 hours after heating, and gradually cool down at 30°C/h after heating until the temperature drops to room temperature to obtain composite modified asphalt.

Embodiment 2:

A composite modified asphalt for road, including main material and auxiliary material, the main material includes base asphalt, and the auxiliary material includes modifier, stabilizer, biological filler, SBS, SBR and PPA, in the main material and auxiliary material Each component adopts the following proportions according to the parts by mass: 90 parts of base asphalt, 10 parts of modifier, 7 parts of stabilizer, 16 parts of biological filler, 12 parts of SBS, 10 parts of SBR, and 14 parts of PPA.

The base asphalt is selected from one or more of coal tar pitch, petroleum pitch and natural pitch. The biological filler includes RAP asphalt, waste rubber powder and sludge, and the ratio of each component in the biological filler is 3:2:1 , the modifier selects MAC modifier.

The present invention also provides a preparation method of composite modified asphalt for road, which specifically comprises the following steps:

Step 1: Select the matrix asphalt and the biological filler to be heated separately. The biological filler needs to be preliminarily pulverized, and then the larger internal volume is pulverized and then heated. The heating temperature is kept at 180 °C for 4 hours, and the heating process is uninterrupted. to stir and mix;

Step 2: Add the heated bio-filler to the base asphalt, add stabilizer to it, increase the heating temperature to 220°C, and continue stirring. During the stirring process, SBS and SBR are evenly added to it, and the auxiliary materials are added. Then continue heating for 4h;

Step 3: Add PPA to the base asphalt for stirring and heating, add modifier for 6 hours after heating, and gradually cool down at 50°C/h after heating until the temperature drops to room temperature to obtain composite modified asphalt.

Embodiment three:

A composite modified asphalt for road, including main material and auxiliary material, the main material includes base asphalt, and the auxiliary material includes modifier, stabilizer, biological filler, SBS, SBR and PPA, in the main material and auxiliary material Each component adopts the following proportions according to the parts by mass: 86 parts of base asphalt, 8 parts of modifier, 5 parts of stabilizer, 14 parts of biological filler, 10 parts of SBS, 8 parts of SBR, and 12 parts of PPA.

The base asphalt is selected from one or more of coal tar pitch, petroleum pitch and natural pitch. The biological filler includes RAP asphalt, waste rubber powder and sludge, and the ratio of each component in the biological filler is 3:2:1 , the modifier selects MAC modifier.

The invention also provides a preparation method of composite modified asphalt for road, which specifically comprises the following steps:

Step 1: Select the matrix asphalt and the biological filler to be heated respectively. The biological filler needs to be preliminarily pulverized, and the larger part of the internal volume is pulverized before heating. The heating temperature is kept at 165 °C for 3 hours, and the heating process is uninterrupted to stir and mix;

Step 2: Add the heated bio-filler to the base asphalt, add stabilizer to it, increase the heating temperature to 200°C, and continue stirring. During the stirring process, SBS and SBR are evenly added to it, and the auxiliary materials are added. Then continue to heat for 3h;

Step 3: Add PPA to the base asphalt for stirring and heating, add modifier for 5 hours after heating, and gradually cool down at 40°C/h after heating until the temperature drops to room temperature to obtain composite modified asphalt.

Embodiment 4:

For the composite modified asphalt prepared in the above-mentioned embodiment, the required raw materials are adjusted and processed under different requirements, and compared with the existing road asphalt, the specific data are as follows:

It can be concluded from the above experimental data that the composite modified asphalt proposed by the present invention and the composite modified asphalt prepared by the preparation method thereof are improved in various properties compared with the existing asphalt, and the bonding strength, The shear strength and solid content are significantly enhanced, which increases the overall internal strength of the asphalt and ensures the strength and service life during road paving.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. The equivalent replacement or change of the inventive concept thereof shall be included within the protection scope of the present invention.

Claims (5)

1. The composite modified asphalt for the road comprises a main material and an auxiliary material, and is characterized in that the main material comprises matrix asphalt, the auxiliary material comprises a modifier, a stabilizer, a biological filler, SBS, SBR and PPA, and the main material and the auxiliary material are prepared from the following components in parts by mass: 82-90 parts of matrix asphalt, 6-10 parts of modifier, 3-7 parts of stabilizer, 12-16 parts of biological filler, 8-12 parts of SBS, 6-10 parts of SBR and 10-14 parts of PPA.

2. The composite modified asphalt for the road according to claim 1, wherein the base asphalt is one or more of coal tar asphalt, petroleum asphalt and natural asphalt, the biological filler comprises RAP asphalt, waste rubber powder and sludge, the biological filler comprises the components in a ratio of 3:2:1, and the modifier is an MAC modifier.

3. The preparation method of the composite modified asphalt for the road is characterized by comprising the following steps:

The method comprises the following steps: selecting matrix asphalt and biological filler to respectively heat, keeping the heating temperature at 150-;

Step two: adding the heated biological filler into the matrix asphalt, adding a stabilizer, increasing the heating temperature to 180-220 ℃, continuously stirring, and uniformly adding SBS and SBR into the mixture in the stirring process;

step three: adding PPA into the matrix asphalt, stirring and heating, heating for 30-50min, adding the modifier, heating for 4-6h, and gradually cooling at a speed of 30-50 ℃/h after heating until the temperature is reduced to room temperature to obtain the composite modified asphalt.

4. the method for preparing the composite modified asphalt for the road as claimed in claim 1, wherein the first step is to perform a preliminary pulverization process on the biological filler, pulverize the larger part of the internal volume of the biological filler, and then heat the pulverized biological filler.

5. the method for preparing the composite modified asphalt for the road as claimed in claim 1, wherein in the second step, the heating is continued for 2-4h after the auxiliary materials are added.