WO2012103691A1

WO2012103691A1 - Road asphalt modified by composite modifier and preparation method thereof

Info

Publication number: WO2012103691A1
Application number: PCT/CN2011/073230
Authority: WO
Inventors: 潘民光
Original assignee: 佛山惠幅化工有限公司
Priority date: 2011-02-02
Filing date: 2011-04-24
Publication date: 2012-08-09
Also published as: CN102061100B; CN102061100A

Abstract

A road asphalt modified by a composite modifier and the preparation method thereof are provided. The modified road asphalt is obtained by allowing a base asphalt to modify by a composite modifier of a vulcanized rubber powder mixing with a thermoplastic styrene-butadiene rubber (SBS). The preparation method comprises the steps of adding a certain amount ofvulcanized rubber powders into a base asphalt, adding a thermoplastic styrene-butadiene rubber (a modifier) and a stabilizing agent, and obtaining said road asphalt after shearing and grinding via a colloid mill. The modified road asphalt has excellent rutting resistance and low-temperature anti-cracking property.

Description

Composite modifier modified road asphalt and preparation method thereof

[0001] The present invention relates to a composite modifier modified road asphalt and a preparation method thereof, and belongs to the field of petrochemical industry.

Background technique

[0002] The continuous advancement of the city and the development of the social economy have made the quality, construction and construction of urban roads even more severely tested: for example, the speed of modern highways and road traffic and the frequency of driving have increased sharply, and the axle load of freight cars Increasingly, it is common to implement one-way driving in lanes, which requires further improvement of road surface resistance, that is, the ability to resist rutting at high temperatures; improving flexibility and elasticity, that is, the ability to resist cracking at low temperatures; improving wear resistance and extending service life . Asphalt, one of the main materials used for road paving, has been continuously focused on the optimization and improvement of its performance in road paving. After decades of research and practical application in engineering, the emergence of book-based asphalt has improved or overcome some of the defects of traditional asphalt, accelerating the development of the industry.

[0003] The modified asphalt is generally an external admixture (modifier) such as rubber, resin, high molecular polymer, ground rubber powder or other filler, mixed with asphalt, or lightly oxidized for asphalt. Such measures can be used to improve the performance of the asphalt or asphalt mixture, and the modification of the asphalt can be realized by changing the chemical composition of the asphalt or by uniformly distributing the modifier in the asphalt to form a certain spatial network structure.

[0004] A method for modifying asphalt by using waste tire rubber powder, since waste tires can be recycled and reused, and resource recycling is facilitated, thereby eliminating environmental pollution, and at the same time, the green rubber modified with waste tire rubber powder can also be used for The paving construction of noise-reducing pavement is beneficial to reduce urban traffic noise. In addition, the pavement paved with this modified asphalt has better heat resistance, cold resistance and anti-skid performance, and has the advantages of rich raw materials and high cost performance. Therefore, in recent times The year has also received extensive attention. For example, Chinese patents ZL 200410040237.9, ZL 200510016293.3, ZL200610023919.8, etc. have carried out related research on the production of rubber powder, the method and equipment of rubber powder modified asphalt and achieved good results.

[0005] However, the waste rubber powder is a vulcanized rubber powder because it comes from waste tires. Its structure is a three-dimensional network structure and contains various additives. The composition is complicated, and it is more common than conventional rubber powder or thermoplastic styrene-butadiene rubber. Polymers such as (SBS) are more difficult to swell and disperse in the asphalt. The existing waste tire rubber powder modified asphalt process often performs high temperature swelling, physical shearing, grinding and dispersing agitation of the waste tire rubber powder of a certain degree of fineness, which is affected by the reaction inertness of the waste tire rubber powder itself. The use of waste tire rubber powder to modify the asphalt will make the storage and stability of the asphalt poor, and the final modification effect is not satisfactory. In order to solve this problem, some methods have been proposed. For example, the patent CN1114258A proposes to cut waste rubber tire into thin strips or fine powder mixed with asphalt. This method is only used at the production site and fails to solve the actual storage stability. The problem is also proposed to use the desulfurization rubber powder to modify the asphalt, such as CN1597782, CN1441005 Instruction manual

Etc., but the method and process are more complicated and complicated, and the corresponding solvent or other polymer needs to be added, so that the cost is high. These methods using rubber powder modification have not solved the practical problems well, and thus the development of such methods is limited.

[0006] Our national standard 70#, 90# heavy-duty asphalt, its softening point is around 50 °C, in actual use in the higher (summer) or lower temperature (winter, especially the north) environment, the performance appears Can not meet the use requirements. In order to solve this problem, the popular practice at home and abroad is to use SBS as a modifier for asphalt to improve the high temperature and low temperature performance of heavy asphalt.

[0007] With SBS as a modifier, there are currently two problems. One is the high cost. The price of SBS currently on the market is about 20,000 yuan / ton, such as 4.5% of the amount of feed, (the amount of modified asphalt modifier is generally 4% - 5%) per ton of modified asphalt modifier It is around 900 yuan; the second is poor anti-aging performance. The rubber section of SBS is raw rubber that has not been vulcanized and crosslinked, so the aging resistance is definitely poor; in addition, SBS has a smaller share of the entire modified asphalt body. For these reasons, the use of SBS alone to improve the performance of road asphalt does have some of the above-mentioned problems that are difficult to solve.

Summary of the invention

[0008] In view of the above deficiencies, the present invention provides a composite modifier modified road asphalt and a preparation method thereof, and the composite modifier modified road asphalt is compounded with a vulcanized rubber powder and a thermoplastic styrene-butadiene rubber (SBS). The new method is obtained by adding a certain amount of vulcanized rubber powder to the matrix asphalt, and using SBS and stabilizer to carry out composite modification of the asphalt, which is obtained by shearing and grinding after colloid grinding. The modified road asphalt has the characteristics of low production cost, simple process, high product quality, anti-rutting and low-temperature crack resistance, and environmental protection.

[0009] The technical solution adopted by the present invention is as follows:

1. Take the matrix asphalt, which accounts for 7%-10% of the mass of the matrix asphalt, and the thermoplastic styrene-butadiene rubber (SBS), which accounts for 5.1%-7% of the mass of the matrix asphalt, accounts for 1% of the matrix asphaltene. -2%. The stabilizer is used as the composition of the road asphalt modified by the composite modifier of the present invention.

[0010] 2. The composite modifier modified road asphalt of the present invention is prepared by the following steps:

(1) mixing the vulcanized rubber powder, which accounts for 7%-10% of the mass of the matrix asphalt, with the matrix asphalt in the reactor VI, and stirring while heating to form a fully plasticized, uniformly mixed mixture A;

(2) When the temperature rises to 250 °C, stop heating. Open the pump, draw the mixture A into the reaction vessel V2, add the thermoplastic styrene-butadiene rubber (SBS) containing 5.1%-7% of the matrix asphalt quality, stir while feeding, after the addition is completed, continue to stir for 25 minutes to obtain the mixture B;

(3) After the stirring is completed, the colloid mill is started, the temperature is controlled at 180 ° C - 200 ° C, and the mixture B is sheared and ground on the colloid grinding disc, and circulated 2-3 times; the mixture B is sheared by the colloid mill. When added, it accounts for 1% of the mass of the matrix asphalt. -2%. The stabilizer is co-milled, and the composite modifier is used to modify the road asphalt after the completion of the grinding. Instruction manual

[0011] The beneficial effects of the present invention over the prior art are:

Due to the new method of composite modification of vulcanized rubber powder and thermoplastic styrene-butadiene rubber (SBS), adding rubber powder to the asphalt can reduce the amount of SBS participation, thereby greatly reducing the cost. The synergy between the two can also improve the asphalt. The high and low temperature properties; the added stabilizer is beneficial to promote the dispersion of the vulcanized rubber powder in the asphalt and improve the stability of the asphalt; in addition, the modified road asphalt produced by the composite modification method has complete experimental results. In line with national standards, anti-rutting and low temperature anti-cracking performance is more prominent, and product quality is improved.

detailed description

The invention is further illustrated by the following examples, which are intended to illustrate the invention and not to limit the scope of the invention.

Embodiment 1

The vulcanized rubber powder having a mass of 7% of the base asphalt is mixed with the 90# heavy-duty asphalt in the reactor VI, and stirred while being heated to form a mixture A which is sufficiently plasticized and mixed. When the temperature rises to 250 °C, stop heating. The mixture A was pumped to the reactor V2, and a thermoplastic styrene-butadiene rubber (SBS) having a mass of 5.1% of the matrix pitch was added, and the mixture was stirred while being added. After the addition was completed, stirring was continued for 25 minutes to obtain a mixture B. After the stirring is completed, the colloid mill is started, the temperature is controlled at 185 ° C, the mixture B is sheared and ground on the grinding disc, and the cycle is repeated twice. At the last cycle, the mass of the matrix asphalt is added by 1%. The sulphur is sulphur, and the finished end of the modified road asphalt is finished.

[0014] Example 2

The vulcanized rubber powder of 8% by mass of the base asphalt is mixed with the 70# heavy-duty asphalt, and stirred while being heated to form a fully plasticized, uniformly mixed mixture A. When the temperature rises to 250 °C, stop heating. The pump was opened, and the mixture A was pumped to the reaction vessel, and a thermoplastic styrene-butadiene rubber (SBS) having a mass of 5.5% of the matrix pitch was added, and the mixture was stirred while being added. After the addition was completed, stirring was continued for 25 minutes to obtain a mixture B. After the stirring is completed, the colloid mill is started, the temperature is controlled at 18 CTC, and the mixture B is sheared and ground on the grinding disc, and the cycle is repeated twice. At the first cycle, the mass of the matrix asphalt is added by 1.5%. The sulphur, the end of the cycle, is finished with modified road asphalt.

[0015] Example 3

The vulcanized rubber powder having a mass of 9% of the base asphalt was mixed with 70# heavy-duty asphalt, and stirred while being heated to form a fully plasticized, uniformly mixed mixture A. When the temperature rises to 250 ° C, the heating is stopped. The pump was opened, and the mixture A was pumped to the reaction vessel, and a thermoplastic styrene-butadiene rubber (SBS) having a mass of 7% of the base pitch was added, and the mixture was stirred while being added. After the addition was completed, stirring was continued for 25 minutes to obtain a mixture B. After the stirring was completed, the colloid mill was started, the temperature was controlled at 190 ° C, and the mixture B was sheared, ground, and circulated three times on the grinding disc. At the first cycle, the mass of the matrix pitch was 1.5%. The sulphur, the end of the cycle has a modified road asphalt finished product. Instruction manual

[0016] Example 4

The vulcanized rubber powder having a base asphalt mass of 10% is mixed with 90# heavy-duty asphalt, and stirred while being heated to form a fully plasticized, uniformly mixed mixture A. When the temperature rises to 250 °C, stop heating. The pump was opened, and the mixture A was pumped to the reaction vessel, and a thermoplastic styrene-butadiene rubber (SBS) having a mass of 6.5% of the matrix pitch was added thereto, and the mixture was stirred while being fed. After the addition was completed, stirring was continued for 25 minutes to obtain a mixture B. After the stirring is completed, the colloid mill is started, the temperature is controlled at 200 ° C, the mixture B is sheared and ground on the grinding disc, and the cycle is repeated 3 times. At the second cycle, the mass of the matrix asphalt is added 2%. The surfactant, recycled to the finished road asphalt finished product.

[0017] Example 5

The vulcanized rubber powder having a matrix asphalt mass of 8.5% was mixed with 90# heavy-duty asphalt, and stirred while being heated to form a fully plasticized, uniformly mixed mixture A. When the temperature rises to 250 °C, stop heating. The pump was opened, and the mixture A was pumped to the reaction vessel, and a thermoplastic styrene-butadiene rubber (SBS) having a mass of 5.5% of the matrix pitch was added, and the mixture was stirred while being added. After the addition was completed, stirring was continued for 25 minutes to obtain a mixture B. After the stirring is completed, the colloid mill is started, the temperature is controlled at 180 ° C, the mixture B is sheared and ground on the grinding disc, and the cycle is repeated 3 times. On the second cycle, the mass of the matrix asphalt is added 2%. The surfactant, the end of the cycle, the finished road asphalt finished product.

[0018] Example 6

The composite modifier modified asphalt was evaluated in accordance with the national standard test. The test results are shown in the following table.

Table -1 Test Results of Modified Asphalt Evaluation

Conclusion: The technical indexes of the modified asphalt are in compliance with the relevant provisions of the Technical Specification for Highway Asphalt Pavement Construction (JTG F40-2004) "Technical Requirements for Polymer Modified Asphalt" SBS (ID). Instruction manual

[0020] Example 7

Asphalt mixture performance evaluation test.

[0021] 1 water stability

1.1 Residual Marshall Stability Test

The Marshall test piece was prepared with the optimum asphalt dosage (oil-stone ratio) of 5.25%, and the AC-13F asphalt mixture was immersed in the Marshall test according to the JTJ052~2000 T0709-2000 procedure. The test results are shown in the AC-13F grade water-immersed Marshall test results. -2), the residual stability is 85.8%, which satisfies the requirement that the Marshall residual stability of the Marshall test mixture design index of the dense grade modified asphalt mixture is greater than 85%.

-2 AC-13F grade water immersion Marshall test results

1.2 freeze-thaw split test

马The Marshall test piece was prepared with the optimum asphalt dosage (oil-stone ratio) 5.25%, and the freeze-thaw split test of AC-13F asphalt mixture was carried out according to the JTJ052-2000 Τ0729-2000 procedure. The test results are shown in the AC-13F target mix ratio grading. The freeze-thaw split test results (Table-3) have a residual strength ratio of 82.3% in the freeze-thaw split test, which satisfies the requirements of the freeze-thaw splitting residual strength ratio of the modified asphalt concrete mix design test index greater than 80%.

[0023] Table-3 Asphalt Mixture Freeze-Thaw Split Test Results

Description

2 high temperature stability

2.1 National standard dynamic stability test

The rutting test piece was prepared by using 5.25% of asphalt, and the rutting test of AC-13F asphalt mixture was carried out according to JTJ052-2000 T0719-2000. The test results are shown in Table-4 AC- 13F asphalt mixture rutting test results, its dynamic stability DS = 5045 times / mm, to meet the requirements of the modified asphalt concrete mix design test indicators in the rutting test dynamic stability greater than 3000 times / mm.

-4 AC- 13F asphalt mixture rutting test results

2.2 CPN rutting test

Try a newer rutting test device, the CPN rudder (Rotary Loaded Wheel Tester or

RUTMETER) is also known as multi-wheeler funeral to evaluate the high temperature performance and rutting resistance of asphalt mixtures.

[0025] The test temperature is 60 ° C, the number of loadings is 16,000 times or the number of loadings when the rut depth is 6.35 mm. Oil-stone ratio

5.25% molding standard Marshall test piece, then use the high-precision double-sided saw to simultaneously cut the Marshall test piece into 50mm thick test piece for experiment. After measuring the volume parameter of the test piece, put it into the test piece and preheat it. The test was started after the heat was completed, and the test results are shown in Table-5. From the test results, the modified asphalt has good high temperature performance.

-5 Indoor Marshall sample CPN rutting test results (average value)

3 fatigue performance

40 X 30 X 7.5cm large asphalt mixture plate test piece was formed by Finnish vibrating wheel milling equipment, and 38 X 6.4X 5cm asphalt mixture trabe test piece was obtained by high-precision double-sided saw double-sided cutting technology. . Using the COOPER NU-14 Pneumatic Servo Test System and the American Highway Development Strategy Research Program, the asphalt mixture four-point bending strain fatigue test fixture is used for the strain control method of asphalt mixture fatigue test; the test temperature is the specified temperature of the asphalt pavement design specification in China. : 15 ° C. As a comparative study, the same strain level was chosen - 600 microstrain, and the test results are shown in Table -6. Instruction manual

Table -6 Strain fatigue test results of modified asphalt mixture at 600 microstrain (average value)

Remarks: Fatigue life is defined as the number of tests when the mixture stiffness modulus is 50% of the initial stiffness modulus.

[0028] 4 low temperature performance

The trabecular bending failure test was carried out in accordance with the standard conditions specified in JTJ052-2000 T0715-1993, Test Procedure for Highway Engineering Asphalt and Asphalt Mixture. The test results are shown in Table -7.

-7 Asphalt Mixture-10 Low Temperature Bending Test Results (Average)

Asphalt mixture performance evaluation test conclusion: As AC-13F asphalt mixture is a suspended dense structure, it can better reflect the performance of asphalt cement, and also select the common granite gravel in the south, which is representative, so the above test design evaluation Asphalt road performance is well represented. The composite modified asphalt can meet the relevant requirements of "Technical Specifications for Highway Asphalt Pavement Construction" (JTGF40-2004) "Technical Requirements for Polymer Modified Asphalt" SBS (ID); the water stability of asphalt mixture prepared by it can meet the "highway" Asphalt Pavement Construction Technical Specification (JTGF40-2004) "Technical Requirements for Asphalt Mixture Water Stability Inspection". The composite modified asphalt has high performance, high temperature stability, fatigue performance, low temperature crack resistance and meets the requirements of the specification.

Claims

Claim

A composite modifier modified road asphalt and a preparation method thereof, characterized in that the modified road asphalt has the following composition: matrix asphalt, vulcanized rubber powder accounting for 7%-10% of the mass of the matrix asphalt, accounting for the quality of the matrix asphalt 5.1%-7% of thermoplastic styrene butadiene rubber (SBS), accounting for 1% of matrix asphaltenes. -2%. Stabilizer.

2. A composite modifier modified road asphalt according to claim 1 and a method for preparing the same, characterized in that the method for preparing the modified road asphalt comprises the following steps:

(2) When the temperature rises to 250 °C, stop heating; turn on the pump, pump mixture A to reactor V2, add 5.1%-7% of thermoplastic styrene butadiene rubber (SBS) with matrix asphalt mass, stir while feeding After the addition is completed, stirring is continued for 25 minutes to obtain a mixture B;

(3) After the stirring is finished, start the colloid mill, control the temperature at 180 °C - 200 °C, cut the mixture B on the colloid grinding disc, grind and circulate 2-3 times; when the mixture B is sheared by the colloid mill Add 1% of the mass of the matrix asphalt. -2%. The stabilizer is co-milled, and the composite modifier is used to modify the road asphalt after the grinding is completed.

3. A composite modifier modified road asphalt according to claim 1 and a method for preparing the same, characterized in that the base asphalt is one of the national standard 70# and 90# heavy-duty asphalt.

The composite modifier modified road asphalt according to claim 2 and the preparation method thereof, characterized in that the base asphalt is one of the national standard 70# and 90# heavy-duty asphalt.

The composite modifier-modified road asphalt according to claim 1, wherein the particle size of the vulcanized rubber powder is a vulcanized rubber powder passing through an 80 mesh sieve.

The composite modifier-modified road asphalt according to claim 2, wherein the vulcanized rubber powder has a particle size of vulcanized rubber powder passing through an 80 mesh sieve.

7. A composite modifier-modified road asphalt according to claim 1, wherein the stabilizer is sulfur.

The composite modifier-modified road asphalt according to claim 2, wherein the stabilizer is a surfactant.

9. The preparation method according to claim 2, wherein the order of adding the stabilizer is added when the mixture B is subjected to any one cycle of the colloid mill.