CN108752945A - High performance modified bitumen based on graphene and production method - Google Patents

Abstract

The present invention proposes a graphene-based high-performance modified asphalt and a preparation method thereof, wherein the high-performance modified asphalt is composed of 70# matrix asphalt, graphene and stearamide; 70# matrix asphalt, graphene and stearic acid The mass ratio relationship of amides is as follows: the mass of graphene is 20‰ of the mass of 70# matrix pitch, and the mass of stearamide is 1% of the mass of graphene. The beneficial technical effects of the present invention are: a graphene-based high-performance modified asphalt suitable for industrial production and a production method are proposed.

Description

Graphene-based high-performance modified asphalt and its preparation method

technical field

The invention relates to a modified asphalt production technology, in particular to a graphene-based high-performance modified asphalt and a production method.

Background technique

Highway construction is an important indicator to measure the development of the national economy. In recent years, my country's highway construction has made great progress. By the end of 2014, the total mileage of my country's highways had exceeded 4.45 million kilometers, ranking first in the world; among all highway construction mileage, asphalt The pavement occupies the vast majority. Due to factors such as increased traffic volume, large-scale vehicles, heavy vehicle loads, and temperature differences, rutting and cracking on the asphalt pavement may occur from time to time, resulting in a decline in the performance of the asphalt pavement. Higher requirements are put forward for the performance and quality of the asphalt pavement. It is hoped that the application and innovation of new materials and new technologies will be accelerated to reduce early damage to asphalt pavement and other diseases.

At present, the development of SBS modified asphalt is the most beneficial to the improvement of asphalt pavement; practice shows that adding SBS modifier to base asphalt can significantly improve the high temperature stability, fatigue resistance and temperature sensitivity of the pavement; but in practice In application, SBS modified asphalt has problems such as high requirements for preparation conditions, unstable storage (easy to delaminate, coagulate or segregate), and difficult mixing construction, which leads to poor controllability of the quality of asphalt and asphalt mixture, which affects to a certain extent performance on asphalt roads.

Graphene is a nano-material with huge specific surface area and super surface activity. Experiments have proved that adding graphene to asphalt can have a special effect on the physical and chemical properties of asphalt, thereby improving the performance of asphalt; however, in In actual production, it is impossible to directly add graphene to asphalt: experiments have shown that when the amount of graphene added reaches a certain level, graphene will have serious agglomeration problems, and graphene cannot be dispersed evenly in asphalt, resulting in graphene being unable to It can modify asphalt.

Contents of the invention

In order to solve the problems in the background technology, the inventor has adopted multiple surfactants and basic solvents (can be miscible with asphalt or easily separated with asphalt, so as to observe the dispersion effect of graphene) to test, finally find a kind of Graphene is uniformly dispersed surfactant-stearamide, and its corresponding basic solvent is trichlorethylene; In order to determine the optimal proportioning and optimal process conditions of asphalt, surfactant and basic solvent, the inventor has carried out the following test:

1) Using the uniform design method, the amount of graphene (the ratio of the mass of graphene to the mass of 70# matrix pitch) is changed in the range of 2‰～20‰, and the amount of stearamide (the ratio of the mass of stearamide to the mass of graphene ratio) in the range of 1% to 10%, the shear rate in the range of 2000 to 6500 rpm, the shear time in the range of 30min to 180min, the shear temperature in the range of 110°C to 150°C; the experimental design The factor level table is shown in Table 1, the uniform design table is shown in Table 2, and the experimental arrangement is shown in Table 3;

Table 1

Table 2

table 3

The performance indexes of the graphene-modified asphalt obtained in each test are shown in Table 4;

Table 4

Adopt mathematical statistics software to analyze test data, obtain 3 groups of optimized material formulations (i.e. the optimized solution in Table 5) as shown in Table 5;

table 5

optimal solution Shear rate (r.p.m.) Shearing time (min) Graphene content (‰) Stearamide content (%) Shear temperature (℃) 1 6500 30 20 10 150 2 7000 200 20 8.26 160 3 6500 180 20 1 140

The graphene-modified asphalt was prepared according to the three groups of optimized material formulas, and the performance indexes of the three groups of modified asphalt obtained are shown in Table 6;

Table 6

It can be seen from Table 6 that compared with optimized material formula 1 and optimized material formula 2, the low-temperature crack resistance of graphene-modified asphalt obtained from optimized material formula 3 is more significant, so optimized material formula 3 is selected as the optimal material formula; The comparison of the performance indexes of the graphene-modified asphalt and base asphalt prepared according to the optimal material formula is shown in Table 7;

Table 7

It can be seen from Table 7 that compared with the base asphalt, the graphene-modified asphalt prepared according to the optimal material formula has 10.4 times the ductility work (low temperature crack resistance) at 5 °C and 10.4 times the creep recovery rate (delayed elastic recovery ability) increased by 9.2 times, the softening point (high temperature resistance ability) increased by 6.2°C, and the performance of modified asphalt has been significantly improved.

Then, the present invention has drawn following scheme:

A graphene-based high-performance modified asphalt, its innovation is: the high-performance modified asphalt is composed of 70# base asphalt, graphene and stearamide; the quality of 70# base asphalt, graphene and stearamide The proportioning relationship is: the quality of graphene is 20‰ of the quality of 70# matrix pitch, and the quality of stearamide is 1% of the quality of graphene.

In order to make the performance index of the high-performance modified asphalt better, the present invention also proposes the following preferred scheme: the specific surface area of the graphene is 300-400m2/ ^g , the single-layer ratio of the graphene is greater than 80%, and the graphene The carbon content is greater than 98.9%.

A method for preparing high-performance modified asphalt, the innovation of which is that the method includes:

1) adding trichlorethylene to stearamide until the stearamide is completely dissolved to obtain a mixed solution;

2) In a closed state, the mixed solution was subjected to ultrasonic vibration treatment for 1.5 hours;

3) Add the mixed solution into the 70# base asphalt, and then let it stand in a closed environment until the mixed solution and the 70# base asphalt are completely fused to obtain the mixture A;

4) Use a rotary evaporator to evaporate the mixture A, evaporate trichlorethylene from the mixture A to obtain the mixture B; the conditions for the evaporation operation are: oil bath temperature 110°C, rotation speed 85-90 rpm;

5) Shear the mixture B to obtain high-performance modified asphalt; the shear rate is 6500 rpm, the shear temperature is 140°C, and the shear time is 180 minutes;

In the foregoing method, the quality of graphene is 20‰ of the quality of 70# matrix pitch, and the quality of stearylamide is 1% of the quality of graphene.

Using the scheme of the present invention to produce graphene-modified asphalt can effectively solve the problem of graphene agglomeration in the production process, so that graphene can be evenly dispersed in the asphalt and play a corresponding modification role, especially suitable for graphene-modified asphalt mass production.

The beneficial technical effects of the present invention are: a graphene-based high-performance modified asphalt suitable for industrial production and a production method are proposed.

Detailed ways

A graphene-based high-performance modified asphalt, its innovation is: the high-performance modified asphalt is composed of 70# base asphalt, graphene and stearamide; the quality of 70# base asphalt, graphene and stearamide The proportioning relationship is: the quality of graphene is 20‰ of the quality of 70# matrix pitch, and the quality of stearamide is 1% of the quality of graphene.

Further, the specific surface area of the graphene is 300-400m ² /g, the single-layer ratio of the graphene is greater than 80%, and the carbon content of the graphene is greater than 98.9%.

A method for preparing high-performance modified asphalt, the innovation of which is that the method includes:

1) adding trichlorethylene to stearamide until the stearamide is completely dissolved to obtain a mixed solution;

2) In a closed state, the mixed solution was subjected to ultrasonic vibration treatment for 1.5 hours;

3) Add the mixed solution to the 70# base asphalt, and then let it stand in a closed environment until the mixed solution and the 70# base asphalt are completely fused to obtain the mixture A;

4) Use a rotary evaporator to evaporate the mixture A, evaporate trichlorethylene from the mixture A to obtain the mixture B; the conditions for the evaporation operation are: oil bath temperature 110°C, rotation speed 85-90 rpm;

5) Shear the mixture B to obtain high-performance modified asphalt; the shear rate is 6500 rpm, the shear temperature is 140°C, and the shear time is 180 minutes;

The quality of the graphene is 20‰ of the quality of 70# matrix pitch, and the quality of stearylamide is 1% of the quality of the graphene.

Claims (3)

1. a kind of high performance modified bitumen based on graphene, it is characterised in that：The high performance modified bitumen is dripped by 70# matrix Green, graphene and stearmide composition；The quality proportioning relationship of 70# matrix pitches, graphene and stearmide is：Graphene Quality is the 20 ‰ of 70# matrix pitch quality, and the quality of stearmide is the 1% of graphene quality.

2. the high performance modified bitumen according to claim 1 based on graphene, it is characterised in that：The ratio of the graphene Surface area is 300~400m²The single layer rate of/g, graphene are more than 80%, and the phosphorus content of graphene is more than 98.9%.

3. a kind of method preparing high performance modified bitumen, it is characterised in that：The method includes：

1) trichloro ethylene to stearmide is added into stearmide to be completely dissolved, obtains mixed solution；

2) under air-tight state, the ultrasonic vibration carried out 1.5 hours to mixed solution is handled；

3) mixed solution is added in 70# matrix pitches, is then stood under closed environment, until mixed solution and 70# matrix Pitch merges completely, obtains mixture A；

4) operation is evaporated to mixture A using Rotary Evaporators, trichloro ethylene is evaporated from mixture A, is mixed Close object B；The condition of evaporation operation is：110 DEG C of oil bath temperature, 85~90 revs/min of rotary speed；

5) mixture B is sheared, obtains high performance modified bitumen；6500 revs/min of shear rate, 140 DEG C of shear temperature, Shear time 180 minutes；

The quality of the graphene is the 20 ‰ of 70# matrix pitch quality, and the quality of stearmide is the 1% of graphene quality.