CN113861707A

CN113861707A - Self-leveling asphalt cement for repairing pavement pit and slot and preparation method thereof

Info

Publication number: CN113861707A
Application number: CN202111214968.0A
Authority: CN
Inventors: 肖振勇; 庄恢将; 冼丽丽; 陈曙; 李云党
Original assignee: Guangzhou High Speed Operation Management Co ltd
Current assignee: Guangzhou High Speed Operation Management Co ltd
Priority date: 2021-10-19
Filing date: 2021-10-19
Publication date: 2021-12-31
Anticipated expiration: 2041-10-19
Also published as: CN113861707B

Abstract

The invention relates to the technical field of road engineering materials, in particular to a self-leveling asphalt cement for repairing pits in a pavement and a preparation method thereof. The asphalt cement comprises the following components in parts by weight: 100 parts of petroleum asphalt; 8-12 parts of SBS; 2-4 parts of MBS; 0.2-0.4 part of light stabilizer; 0.1-0.2 part of sulfur. The preparation method comprises the following steps: heating the petroleum asphalt to 160-200 ℃, adding SBS, stirring at a high speed of 300-500 r/min for 1-1.5 h, then mixing with MBS and light stabilizer in sequence, passing through a colloid mill, stirring for 30-60 min, finally adding sulfur, stirring and mixing uniformly to obtain the self-leveling asphalt cement for repairing pavement pits. The invention utilizes SBS and MBS composite modified asphalt cement and special light stabilizer to improve road performance and thermal oxidation aging resistance of asphalt cement.

Description

Self-leveling asphalt cement for repairing pavement pit and slot and preparation method thereof

Technical Field

The invention relates to the technical field of road engineering materials, in particular to a self-leveling asphalt cement for repairing pits in a pavement and a preparation method thereof.

Background

In the service process of the asphalt pavement, the cementing material is aged under the load action of sunlight, water, air and driving, the self-adhesion of the asphalt is reduced, and the cohesive failure is generated. Meanwhile, the water retained in the pavement continuously generates a flowing water scouring effect, so that the adhesion force between the asphalt and the aggregate is weakened, and finally the asphalt and the aggregate are peeled off to cause adhesion damage. Cohesive failure and adhesive failure simultaneously cause loose and falling of aggregates on the asphalt pavement, and finally pit grooves are formed. The pit not only seriously influences the running speed of vehicle traffic, reduces the comfort in the driving process, but also greatly harms the personal and property safety and easily causes safety accidents.

The patent CN109574550A discloses a repairing material for pits of an asphalt concrete pavement and a preparation method thereof, the repairing material comprises asphalt, reclaimed aggregates, a diluent, a modified filler and an anti-stripping agent, wherein the modified filler comprises expanded graphite, bentonite and other materials, and the diluent comprises kerosene, petroleum ether and other substances. According to the patent, the early strength of the pit repairing material is improved by adding modified fillers such as expanded graphite, bentonite and the like, but the volatilization speed of diluents such as kerosene, petroleum ether and the like is low, and the diluents remain in the mixture and can have adverse effects on the final strength and the water loss resistance of the material.

The patent CN109574548A discloses a low-temperature quick-maintenance pit repairing material and a preparation method thereof, the material comprises an epoxy resin cementing material and a wear-resistant aggregate, and the epoxy resin cementing material comprises a component A, a component B and a component C. According to the method, the epoxy resin is obtained by mixing three components of materials and is mixed with the aggregate to obtain the material for repairing the pit slot, and the material has strong compressive strength and bending strength. However, the epoxy resin has a fast reaction speed, the time of a construction window is short, the unevenness of a repaired surface is easily caused, and the attractiveness is affected.

Patent CN 106810886A discloses a composite modified asphalt with excellent high and low temperature performance, which is prepared by vulcanizing gutta percha and then preparing the gutta percha and SBS into the composite modified asphalt, so that the high and low temperature performance of the composite modified asphalt is improved, and meanwhile, the amount of SBS is saved. However, the eucommia ulmoides gum has a single structure (polyisoprene), the improvement of high-temperature oxidation resistance and aging resistance of asphalt is limited, the softening point of the obtained modified asphalt is 57.3-82.2 ℃, the use scene of a pavement pit repairing material cannot be met, and the pavement performance is poor. Patent CN 102952407A discloses a MBS-asphalt composition with stable thermal storage and a preparation method thereof, and the MBS-asphalt composition with stable thermal storage is obtained by the mixing reaction of asphalt, MBS, a compatibilizer and an auxiliary agent. However, the single MBS has limited improvement on the high-temperature oxidation resistance and the aging resistance of the asphalt, and the obtained asphalt composition has a softening point of 60-72 ℃ and also has the problem of poor road performance.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, it is a primary object of the present invention to provide a self-leveling asphalt cement for repairing pavement pits. The asphalt cement of the invention adopts SBS and MBS to compound and modify, and can obviously improve the high temperature oxidation resistance and aging resistance of asphalt through the cross-linking effect of the SBS and MBS.

The invention further aims to provide a preparation method of the self-leveling asphalt cement for repairing the pits of the pavement.

In order to achieve the purpose, the invention adopts the following technical scheme:

a self-leveling asphalt cement for repairing pits in a pavement comprises the following components in parts by weight:

100 parts of petroleum asphalt;

8-12 parts of styrene-butadiene-styrene block copolymer (SBS);

2-4 parts of styrene-butadiene-methyl methacrylate terpolymer (MBS);

0.2-0.4 part of light stabilizer;

0.1-0.2 part of sulfur.

Further, the penetration of the petroleum asphalt at 25 ℃ is 60-80 dmm.

Further, the styrene-butadiene-styrene block copolymer has a star-shaped structure. The star polymer is one kind of non-linear structure polymer, and has several linear branches connected to the same central core via chemical bonds. In the invention, the self-leveling asphalt cementing material further adopts SBS with a star structure, which is easier to generate cross-linking reaction with the swollen MBS to form network structure filling, thereby effectively improving the strength retention rate of the cementing material under the high temperature condition and further slowing down the degradation of SBS phase.

Furthermore, the number average molecular weight of the styrene-butadiene-styrene block copolymer is 10-25 ten thousand, the styrene content is 38% -42%, and the elongation at break is more than or equal to 500%.

Further, the refractive index of the styrene-butadiene-methyl methacrylate terpolymer is 1.49-1.50%.

Further, the tensile strength of the styrene-butadiene-methyl methacrylate terpolymer is 30-35 MPa.

Further, the weight ratio of the styrene-butadiene-styrene block copolymer to the styrene-butadiene-methyl methacrylate terpolymer is 1: 0.25-0.35.

Further, the light stabilizer is benzotriazole ultraviolet absorbent UV928 or UV234, hindered amine radical scavenger LS111 or UV4050, light shielding agent LDHs or bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate, and more preferably bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate.

The preparation method of the self-leveling asphalt cement for repairing the pits of the pavement comprises the following preparation steps:

heating petroleum asphalt to 160-200 ℃, adding a styrene-butadiene-styrene block copolymer, stirring at a high speed of 300-500 r/min for 1-1.5 h, then mixing with a styrene-butadiene-methyl methacrylate terpolymer and a light stabilizer uniformly in sequence, passing through a colloid mill, stirring for 30-60 min, finally adding sulfur, stirring and mixing uniformly to obtain the self-leveling asphalt cement for repairing pits in the pavement.

The aging of asphalt is caused by many reasons, among which the hardening of petroleum asphalt and the degradation of high polymers are the main factors for the aging of modified asphalt. SBS in asphalt has the possibility of degradation due to the presence of polybutadiene unsaturated segments on the main chain, but SBS modified asphalt has much less degradation than other types of modified asphalt due to the greater crosslinking effect per unit volume of SBS. The styrene-butadiene-methyl methacrylate terpolymer is used as an excellent anti-aging agent and an antioxidant, the added styrene-butadiene-methyl methacrylate terpolymer can generate a swelling reaction in the asphalt and is compounded with the styrene-butadiene-styrene block copolymer for use, a network structure is formed by utilizing the crosslinking reaction of the styrene-butadiene-methyl methacrylate terpolymer and the styrene-butadiene-styrene block copolymer, the effective filling is realized, the softening point of the asphalt cement is improved, and a certain strength retention rate is still maintained under the high-temperature condition, so that the degradation of SBS phase is further slowed down, and the thermal oxidation aging resistance of the asphalt is remarkably improved. And further discovers that the specific light stabilizer bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate can improve the heat resistance of the asphalt, delay the hardening of the petroleum asphalt and obviously reduce the aging degree of the modified asphalt under the action of hot oxygen.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention utilizes the swelling effect of the styrene-butadiene-methyl methacrylate terpolymer in the asphalt and the crosslinking effect of the styrene-butadiene-styrene block copolymer, and the asphalt cementing material is modified by compounding the styrene-butadiene-methyl methacrylate terpolymer and the styrene-butadiene-styrene block copolymer, compared with the modification of a single styrene-butadiene-styrene block copolymer or the modification of the styrene-butadiene-methyl methacrylate terpolymer, the thermal oxidation aging resistance is obviously improved.

(2) The invention further discovers that the specific light stabilizer bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate can improve the heat resistance of the asphalt, delay the hardening of the petroleum asphalt and obviously reduce the aging degree of the modified asphalt under the action of hot oxygen.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1

10 kg of Esso No. 70 asphalt with the penetration of 70dmm at 25 ℃ is taken, heated to 180 ℃, 1 kg of styrene-butadiene-styrene block copolymer (medium petrochemical SBS, model T171E; number average molecular weight is about 20 ten thousand, styrene content is 40.4%, elongation at break is 695%) is added, a high-speed shearing machine is started, the mixture is stirred at a high speed of 400r/min for 1.5h, then 0.3 kg of styrene-butadiene-methyl methacrylate terpolymer (refractive index is 1.50%, tensile strength is 32MPa) and 0.03 kg of bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate are sequentially added, mixed uniformly, passed through a colloid mill and stirred for 60min, and finally 0.015 kg of sulfur is added and stirred for 2h, so that the self-leveling asphalt cement for repairing pavement grooves in the embodiment is obtained. The obtained asphalt cement is heated in a rotary film oven at 163 ℃ and 193 ℃ respectively, the penetration, softening point and ductility of residues are tested, and the performance test results are shown in table 1.

Example 2

10 kg of Esso No. 70 asphalt with the penetration of 70dmm at 25 ℃ is taken, heated to 160 ℃, 0.8 kg of styrene-butadiene-styrene block copolymer (medium petrochemical SBS, model T171E; number average molecular weight is about 20 ten thousand, styrene content is 40.4%, elongation at break is 695%) is added, a high-speed shearing machine is started, high-speed stirring is carried out for 1.5h at the rotating speed of 300r/min, then 0.2 kg of styrene-butadiene-methyl methacrylate terpolymer (refractive index is 1.49%, tensile strength is 35MPa) and 0.02 kg of bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate are sequentially added, mixed uniformly, passed through a colloid mill, stirred for 30min, and finally 0.01 kg of sulfur is added and stirred for 2h, so that the self-leveling asphalt cement for repairing pavement grooves is obtained.

Example 3

10 kg of Esso No. 70 asphalt with the penetration degree of 70dmm at 25 ℃ is taken, heated to 200 ℃, 1.2 kg of styrene-butadiene-styrene block copolymer (medium petrochemical SBS, model T171E; number average molecular weight is about 20 ten thousand, styrene content is 40.4%, elongation at break is 695%) is added, a high-speed shearing machine is started, high-speed stirring is carried out for 1h at the rotating speed of 500r/min, then 0.4 kg of styrene-butadiene-methyl methacrylate terpolymer (refractive index is 1.50%, tensile strength is 30MPa) and 0.04 kg of bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate are sequentially added, mixed uniformly, passed through a colloid mill, stirred for 45min, and finally 0.02 kg of sulfur is added, and stirred for 2h, so that the self-leveling asphalt cement for repairing pavement grooves is obtained.

Comparative example 1

In this comparative example, the amount of the styrene-butadiene-styrene block copolymer added was reduced to 0.5 kg as compared with example 1, and the rest was the same.

10 kg of Esso No. 70 asphalt with the penetration degree of 70dmm at 25 ℃ is taken, heated to 180 ℃, 0.5 kg of styrene-butadiene-styrene block copolymer (medium petrochemical SBS, model T171E; number average molecular weight is about 20 ten thousand, styrene content is 40.4%, elongation at break is 695%) is added, a high-speed shearing machine is started, high-speed stirring is carried out for 1.5h at the rotating speed of 400r/min, then 0.3 kg of styrene-butadiene-methyl methacrylate terpolymer (refractive index is 1.50%, tensile strength is 32MPa) and 0.03 kg of bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate are sequentially added, mixed uniformly, passed through a colloid mill, stirred for 60min, and finally 0.015 kg of sulfur is added, and stirred for 2h, so as to prepare the modified asphalt. The asphalt is heated in a rotary film oven at 163 ℃ and 193 ℃, the penetration, softening point and ductility of the tested residues are shown in the table 1.

Comparative example 2

This comparative example compares to example 1 without the addition of the styrene-butadiene-methyl methacrylate terpolymer, the rest being identical.

10 kg of Esso No. 70 asphalt with the penetration of 70dmm at 25 ℃ is taken, heated to 180 ℃, 1 kg of styrene-butadiene-styrene block copolymer (medium petrochemical SBS, model T171E; number average molecular weight is about 20 ten thousand, styrene content is 40.4 percent, and elongation at break is 695%) is firstly added, a high-speed shearing machine is started, high-speed stirring is carried out for 1.5h at the rotating speed of 400r/min, then 0.03 kg of bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate is added, the mixture is uniformly mixed, then the mixture is passed through a colloid mill, then stirring is carried out for 60min, and finally 0.015 kg of sulfur is added, and stirring is carried out for 2h, thus preparing the modified asphalt. The asphalt is heated in a rotary film oven at 163 ℃ and 193 ℃, the penetration, softening point and ductility of the tested residues are shown in the table 1.

Comparative example 3

This comparative example is identical to example 1 except that bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate was not added.

10 kg of Esso No. 70 asphalt with the penetration of 70dmm at 25 ℃ is taken, heated to 180 ℃, 0.5 kg of styrene-butadiene-styrene block copolymer (medium petrochemical SBS, model T171E; number average molecular weight is about 20 ten thousand, styrene content is 40.4 percent, and elongation at break is 695%) is added, a high-speed shearing machine is started, high-speed stirring is carried out for 1.5h at the rotating speed of 400r/min, then 0.3 kg of styrene-butadiene-methyl methacrylate terpolymer (refractive index is 1.50 percent, tensile strength is 32MPa) is added, the mixture is uniformly mixed, then the mixture is passed through a colloid mill and stirred for 60min, and finally 0.015 kg of sulfur is added and stirred for 2h to prepare the modified asphalt. The asphalt is heated in a rotary film oven at 163 ℃ and 193 ℃, the penetration, softening point and ductility of the tested residues are shown in the table 1.

TABLE 1 asphalt cement Performance test results

The aging test for asphalt cement is mainly to prepare an aged material for performance test, such as a rotary film oven (RTFOT). The RTFOT test simulates the short term aging that occurs in asphalt during the mix production process. The RTFOT test adopts JTGE20 procedure T0610-2011 method of pitch rotating film heating test, the test temperature is 163 ℃, and the time is 85 min; in order to simulate the high-temperature use scene of the self-leveling material, the temperature is raised to 193 ℃ for 85 min.

As can be seen from Table 1, the self-leveling asphalt cement prepared in example 1 has a high road performance index without aging, is a binder with excellent performance, and has small reduction of penetration, ductility and softening point after short-term aging of RTFOT, which indicates that the asphalt of example 1 has excellent thermal oxidation aging resistance. Although MBS is added into the asphalt sample obtained in the comparative example 1, all indexes are lower than those of the asphalt sample obtained in the example 1 due to the reduction of the SBS mixing amount, and the pavement performance is relatively poor. The single MBS or SBS mixing amount insufficient modified asphalt cement is difficult to meet the use scene of the pavement pit repairing material. Compared with the example 1, the indexes of the comparative example 2 are similar to those of the example 1 without adding the styrene-butadiene-methyl methacrylate terpolymer, but after the RTFOT is aged for a short time, the indexes of penetration, ductility and softening point are greatly reduced, which shows that the asphalt is gradually oxidized in the heating and aging process of the comparative example 2, SBS is degraded, and the aging resistance is poor. The swelling effect of the MBS in the asphalt and the synergistic crosslinking effect of the MBS and the SBS are proved to obviously improve the anti-aging performance of the asphalt cement. Comparative example 3 compared with example 1, the indexes of the original sample are similar to those of example 1 without adding bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate, but after the short-term aging of RTFOT, the indexes of penetration, ductility and softening point are greatly reduced, which shows that asphalt is gradually oxidized in the heating aging process of comparative example 3, SBS is degraded, and the aging resistance is poor.

The results show that compared with single SBS modification or MBS modification, the SBS and MBS composite modified asphalt cement has obviously improved softening point and thermal oxidation aging resistance. And further finds that the bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate can improve the heat resistance of the asphalt, delay the hardening of the petroleum asphalt and obviously reduce the aging degree of the modified asphalt under the action of hot oxygen.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims

1. The self-leveling asphalt cement for repairing pits in pavements is characterized by comprising the following components in parts by weight:

2. the self-leveling asphalt cement for repairing a pit in a road surface according to claim 1, wherein: the penetration of the petroleum asphalt at 25 ℃ is 60-80 dmm.

3. The self-leveling asphalt cement for repairing a pit in a road surface according to claim 1, wherein: the styrene-butadiene-styrene block copolymer is of a star-shaped structure.

4. The self-leveling asphalt cement for repairing a pit in a road surface according to claim 1, wherein: the styrene-butadiene-styrene block copolymer has the number average molecular weight of 10-25 ten thousand, the styrene content of 38-42% and the elongation at break of more than or equal to 500%.

5. The self-leveling asphalt cement for repairing a pit in a road surface according to claim 1, wherein: the refractive index of the styrene-butadiene-methyl methacrylate terpolymer is 1.49-1.50%.

6. The self-leveling asphalt cement for repairing a pit in a road surface according to claim 1, wherein: the tensile strength of the styrene-butadiene-methyl methacrylate terpolymer is 30-35 MPa.

7. The self-leveling asphalt cement for repairing a pit in a road surface according to claim 1, wherein: the weight ratio of the styrene-butadiene-styrene block copolymer to the styrene-butadiene-methyl methacrylate terpolymer is 1: 0.25-0.35.

8. The self-leveling asphalt cement for repairing a pit in a road surface according to claim 1, wherein: the light stabilizer is benzotriazole ultraviolet absorbent UV928 or UV234, hindered amine free radical trapping agent LS111 or UV4050, light shielding agent LDHs or bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate.

9. The self-leveling asphalt cement for repairing a pit in a road surface according to claim 1, wherein: the light stabilizer is bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate.

10. The preparation method of the self-leveling asphalt cement for repairing the pits in the pavement according to any one of claims 1 to 9, which is characterized by comprising the following preparation steps: