CN113666667B - A kind of anti-water damage sulfur modified asphalt mixture and preparation method thereof - Google Patents

Abstract

The invention discloses a water-damage-resistant sulfur-modified asphalt mixture. The components and their parts by weight include: 95-100 parts of aggregate, 1-5 parts of modified sulfur, and 3-8 parts of asphalt; Natural sulfur is made by polymerizing and modifying sulfur with dipentene and isooctyl acrylate. The raw materials used in the modified sulfur and their mass percentages include: sulfur 96-98%, dipentene 1-2% , 0-1% isooctyl acrylate, 0-1% external admixture. The sulfur-modified asphalt mixture of the present invention can greatly improve the problem of insufficient water stability of the sulfur-modified asphalt mixture while ensuring the good high-temperature performance of the sulfur-modified asphalt mixture, and the preparation method involved is relatively simple, Suitable for promoting applications.

Description

A kind of anti-water damage sulfur modified asphalt mixture and preparation method thereof

technical field

The invention belongs to the technical field of road building materials, and in particular relates to a water damage-resistant sulfur-modified asphalt mixture and a preparation method thereof.

Background technique

As early as the beginning of the 20th century, people began to use sulfur as a modifier to improve the road performance of asphalt mixture; however, due to the high price of sulfur at that time and the release of H ₂ during the production of sulfur-modified asphalt mixture The problem of sulfur-containing toxic gases such as S has seriously restricted the development of sulfur-to-asphalt technology. Until the early 1980s, the sulfur modifier SEAM researched and produced by the Rockbond Company of the United States solved the problem of sulfur-containing gas emissions during the production process, making sulfur-modified asphalt technology widely used again. During the decade from 1981 to 1990 in the United States and Canada, a number of highways were built using sulfur-modified asphalt mixtures. Since entering the 21st century, due to the rising international oil prices, the project cost of asphalt pavement has been increasing accordingly. Sulfur is used as a modifier of asphalt, and the method of internal mixing can replace part of asphalt, which can effectively relieve the pressure on resources on asphalt supply. In recent years, it has become a research hotspot in the industry.

Patent CN107523072A discloses a warm-mix sulfur asphalt, the warm-mix agent used is polyethylene wax as raw material, prepared by sweating process; the obtained warm-mix sulfur asphalt reduces the preparation temperature and use temperature of sulfur asphalt, and reduces harmful gases The amount of occurrence, while improving the high temperature stability of asphalt pavement. Patent CN1690126 discloses a sulfur-modified asphalt mixture, which is used to lay asphalt pavement, mainly by mixing sulfur, carbon, smog inhibitor and plasticizer to form modified sulfur, and then adding it to the asphalt mixture; the obtained mixture The construction process is that the mixing temperature is not higher than 150°C, and the rolling temperature is not lower than 90°C, which can effectively reduce harmful gases in the construction process. Greatly improve the road quality.

However, the existing sulfur-modified asphalt mixtures usually have serious problems such as insufficient water stability. Research on the asphalt vulcanization process believes that sulfur captures the hydrogen element in the asphalt during the vulcanization process and generates hydrogen sulfide. At the same time, sulfur-containing groups are formed during the cross-linking of sulfur and asphalt molecules, which changes the original composition of the asphalt. With properties, the average molecular weight of the modified asphalt increases, and its viscosity decreases, which leads to a decrease in the water stability of the asphalt. Therefore, further exploration of sulfur-modified asphalt mixture with better water stability has important research and application significance.

Contents of the invention

The main purpose of the present invention is to address the problems and deficiencies in the prior art, and provide a water damage-resistant sulfur-modified asphalt mixture, which has good high-temperature stability, can reduce the construction temperature by 20-30°C, and has better water resistance. The stability performance can effectively solve the problem of insufficient water stability performance of the existing road-use modified sulfur asphalt mixture; and the preparation method involved is simple, easy to operate, and suitable for popularization and application.

To achieve the above object, the technical solution adopted in the present invention is:

A water-damage-resistant sulfur-modified asphalt mixture, the components and their parts by weight include: 95-100 parts of aggregate, 1-5 parts of modified sulfur, and 3-8 parts of asphalt; wherein the modified sulfur uses It is obtained by polymerizing and modifying sulfur with dipentene and/or isooctyl acrylate.

In the above scheme, the raw materials used in the modified sulfur and their mass percentages include: sulfur 96-98%, dipentene 1-2%, isooctyl acrylate 0.1-1%, external admixture 0-1% %.

Preferably, in the raw material of the modified sulfur, the mass percentage of isooctyl acrylate is 0.3-0.7%.

More preferably, in the raw material of the modified sulfur, the mass percentage of isooctyl acrylate is 0.3-0.5%.

In the above scheme, the external admixture is composed of zinc stearate and zinc hydroxystannate in a mass ratio of 1:(1~2).

In the above scheme, the preparation method of the modified sulfur comprises the following steps: uniformly mixing sulfur, dipentene, isooctyl acrylate and external admixture, heating to 130~170°C, reacting for 2~6h, cooling to room temperature, Get modified sulfur.

In the above scheme, the asphalt is road petroleum asphalt.

In the above scheme, the components in the mineral material and their mass percentages include: 85-99% of the aggregate, and 1-10% of the mineral powder.

In the above scheme, the aggregate can be blended with one or more of aggregates commonly used in road engineering such as basalt, limestone, limestone, and steel slag aggregate. Requirements for the recommended range of technical specifications; fillers can be finely ground mineral powder of limestone, cement, slaked lime, etc.

Preferably, the mass percentage of the isooctyl acrylate in the modified sulfur raw material is 0.1-0.7%.

Preferably, the mass percentage of the external admixture in the modified sulfur raw material is 0.1-1%.

More preferably, the sulfur composite modified asphalt mixture according to the present invention is mainly made of the following raw materials in parts by weight: 95 parts of mineral aggregate, 3.4 parts of asphalt, and 1.4 parts of modified sulfur;

Wherein the percentages in the mineral material are: aggregate 97%, mineral powder 3%;

The percentage of modified sulfur is: 97% sulfur, 2% dipentene, 0.5% isooctyl acrylate, and 0.5% external admixture.

The preparation method of the above-mentioned a kind of anti-water damage sulfur modified asphalt mixture comprises the following steps:

1) Weigh each raw material according to the ratio;

2) Dry the weighed aggregate, then add modified sulfur under heating conditions, and stir evenly; then add asphalt and mineral powder in turn, stir evenly, and obtain the water damage-resistant sulfur-modified asphalt mixture.

In the above scheme, the heating temperature in step 1) is 120-140°C.

Compared with prior art, the beneficial effect of the present invention is:

1) In the present invention, sulfur is polymerized with dipentene and isooctyl acrylate under high temperature conditions, and small molecules of sulfur are connected into long chains of macromolecules, which are fully fused with asphalt during the subsequent mixing process of the mixture, and are wrapped on the surface of the mixture , can effectively improve its water stability; based on the functional group modification of dipentene and isooctyl acrylate, it can simultaneously improve the water stability, mechanical properties and high temperature performance of the resulting mixture;

2) The melting points of dipentene, isooctyl acrylate and sulfur are not much different. Under high temperature conditions, several substances can be better integrated with each other to promote a more uniform and sufficient reaction;

3) The anti-water damage sulfur-modified asphalt mixture obtained in the present invention can further significantly improve the water stability performance under the premise of maintaining and further effectively improving the good road performance of the sulfur-modified asphalt mixture, which has important application and promotion significance;

4) The preparation method involved in the present invention is relatively simple, easy to operate, and suitable for popularization and application.

detailed description

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

In the following examples, the aggregate used is limestone; the synthetic gradation of the mineral material is the AC13 class collection that meets the requirements of the recommended range of the current road asphalt pavement construction technical specifications in my country; the filler is the finely ground mineral powder of limestone;

The asphalt used is No. 70 base asphalt;

In the following examples, the external admixture used is composed of zinc stearate and zinc hydroxystannate in a mass ratio of 1:1.

Example 1

A kind of anti-water damage sulfur modified asphalt mixture, its preparation method comprises the following steps:

1) Preparation of modified sulfur; weigh each component in proportion, each component and its mass percentage are: 97.5% sulfur, 2% dipentene, 0.5% external dopant; the weighed sulfur, bis Pentene and external admixture are mixed evenly, placed in a reaction kettle, heated to 170°C for 4 hours, and then cooled to room temperature to obtain modified sulfur:

2) Preparation of asphalt mixture; Weigh each raw material according to the ratio, each raw material and its share by weight are: 95 parts of mineral aggregate (97% of aggregate, 3% of mineral powder), 3.4 parts of asphalt, 1.4 parts of modified sulfur part; dry the weighed aggregate in an oven at 140°C for 4 hours, then pour it into a mixing pot at 140°C, add modified sulfur, and stir for 60 seconds; add asphalt and continue stirring for 60 seconds;

Then add mineral powder and continue to stir for 120 seconds to obtain the anti-water damage sulfur-modified asphalt mixture.

The performance test results of the asphalt mixture obtained in this example are shown in Table 1.

Table 1 Performance test results of asphalt mixture obtained in Example 1

Marshall Stability (KN) Water immersion residual stability (%) Splitting strength (MPa) Freeze-thaw splitting strength ratio (%) Dynamic stability (times/mm) Example 1 15.21 85.4 1.12 82.3 2714 experiment method T0709-2011 T0709-2011 T0729-2000 T0729-2000 T0719-2011

Example 2

A kind of anti-water damage sulfur modified asphalt mixture, its preparation method comprises the following steps:

1) Preparation of modified sulfur; weigh each component in proportion, each component and its mass percentage are: 97% sulfur, 2% dipentene, 0.5% isooctyl acrylate, and 0.5% external admixture; Mix the weighed sulfur, dipentene and external admixture evenly, place in a reaction kettle, heat to 170°C for 4 hours, and then cool to room temperature to obtain modified sulfur:

2) Preparation of asphalt mixture; Weigh each raw material according to the ratio, each raw material and its share by weight are: 95 parts of mineral aggregate (97% of aggregate, 3% of mineral powder), 3.4 parts of asphalt, 1.4 parts of modified sulfur part; dry the weighed aggregate in an oven at 140°C for 4 hours, then pour it into a mixing pot at 140°C, add modified sulfur, and stir for 60 seconds; add asphalt and continue stirring for 60 seconds; then add mineral powder and continue Stir for 120 seconds to obtain the anti-water damage sulfur-modified asphalt mixture.

The performance test results of the asphalt mixture obtained in this example are shown in Table 2.

Table 2 Performance test results of the asphalt mixture obtained in Example 2

Marshall Stability (KN) Water immersion residual stability (%) Splitting strength (MPa) Freeze-thaw splitting strength ratio (%) Dynamic stability (times/mm) Example 2 16.64 90.2 1.35 88.9 2852 experiment method T0709-2011 T0709-2011 T0729-2000 T0729-2000 T0719-2011

Example 3

The preparation method of the anti-water damage sulfur-modified asphalt mixture described in this example is roughly the same as in Example 1, except that the components in the modified sulfur and their mass percentages are: 97.2% sulfur, dipentamyl 2% alkene, 0.3% isooctyl acrylate, and 0.5% external admixture.

The performance test results of the obtained asphalt mixture are shown in Table 3.

Table 3 Performance test results of asphalt mixture obtained in Example 3

Marshall Stability (KN) Water immersion residual stability (%) Splitting strength (MPa) Freeze-thaw splitting strength ratio (%) Dynamic stability (times/mm) Example 5 16.03 88.5 1.29 84.6 2831 experiment method T0709-2011 T0709-2011 T0729-2000 T0729-2000 T0719-2011

Example 4

The preparation method of the anti-water damage sulfur-modified asphalt mixture described in this example is roughly the same as in Example 1, except that the components in the modified sulfur and their mass percentages are: 96.8% sulfur, dipentamyl 2% alkene, 0.7% isooctyl acrylate, and 0.5% external admixture.

The performance test results of the obtained asphalt mixture are shown in Table 4.

Table 4 Performance test results of asphalt mixture obtained in Example 4

Marshall Stability (KN) Water immersion residual stability (%) Splitting strength (MPa) Freeze-thaw splitting strength ratio (%) Dynamic stability (times/mm) Example 5 14.23 87.2 1.06 80.4 2498 experiment method T0709-2011 T0709-2011 T0729-2000 T0729-2000 T0719-2011

Comparative example 1

A common sulfur-modified asphalt mixture, the preparation method of which is roughly the same as in Example 1, except that sulfur is directly used instead of the modified sulfur described in Example 1; the performance test results of the obtained asphalt mixture are shown in Table 5.

Table 5 Performance test results of asphalt mixture obtained in Comparative Example 1

Marshall Stability (KN) Water immersion residual stability (%) Splitting strength (MPa) Freeze-thaw splitting strength ratio (%) Dynamic stability (times/mm) Comparative example 1 14.98 82.5 1.15 78.9 2688 experiment method T0709-2011 T0709-2011 T0729-2000 T0729-2000 T0719-2011

Comparative example 2

The preparation method of the anti-water damage sulfur-modified asphalt mixture described in this example is roughly the same as that of Example 1, except that the components and their mass percentages in the modified sulfur are: sulfur 96%, dipentene 2%, isooctyl acrylate 1.5%, external admixture 0.5%. The performance test results of the obtained asphalt mixture are shown in Table 6.

The preparation method is similar to Example 1.

Table 6 Performance test results of asphalt mixture obtained in Comparative Example 2

Marshall Stability (KN) Water immersion residual stability (%) Splitting strength (MPa) Freeze-thaw splitting strength ratio (%) Dynamic stability (times/mm) Comparative example 2 9.09 72.8 0.61 37.7 1618 experiment method T0709-2011 T0709-2011 T0729-2000 T0729-2000 T0719-2011

The above results show that: the anti-water damage sulfur-modified asphalt mixture prepared by the scheme of the present invention can significantly improve the water stability of sulfur-modified asphalt, and simultaneously ensure other performance; especially when the amount of isooctyl acrylate When it is 0.5%, the soaking residual stability of the obtained asphalt mixture is as high as 90.2%, the splitting strength can reach 1.35 MPa, the freeze-thaw splitting strength ratio can reach 88.9%, and the dynamic stability can reach 2852 times/mm. Improve the water stability, mechanical properties and high temperature performance of the obtained asphalt mixture.

The above-mentioned embodiments are only examples made for the purpose of clearly illustrating, and are not intended to limit the implementation. For those of ordinary skill in the art, on the basis of the above description, other different forms of changes or changes can also be made, and it is not necessary and impossible to exhaustively list all the implementation modes here, so the obvious changes or changes extended Still within the scope of protection of the present invention.

Claims (8)

1. The water loss resistant sulfur modified asphalt mixture is characterized by comprising the following components in parts by weight: 95-100 parts of mineral aggregate, 1-5 parts of modified sulfur and 3-8 parts of asphalt; wherein the modified sulfur is prepared by polymerizing and modifying sulfur by utilizing dipentene and isooctyl acrylate;

the modified sulfur comprises the following raw materials in percentage by mass: 96 to 98 percent of sulfur, 1 to 2 percent of dipentene, 0.1 to 0.7 percent of isooctyl acrylate and 0 to 1 percent of external admixture.

2. The water damage resistant sulfur modified asphalt mixture according to claim 1, wherein the external additive is prepared by compounding zinc stearate and zinc hydroxystannate according to a mass ratio of 1 (1) - (2).

3. The water damage resistant sulfur modified asphalt mixture according to claim 1, wherein the preparation method of the modified sulfur comprises the following steps: uniformly mixing the sulfur, the dipentene, the isooctyl acrylate and the admixture, heating to 130-170 ℃, reacting for 2-6 h, and cooling to room temperature to obtain the modified sulfur.

4. The water damage resistant sulfur modified asphalt mixture according to claim 1, wherein the asphalt is one or more of road petroleum asphalt, polymer modified asphalt, lake asphalt and rock asphalt.

5. The water damage resistant sulfur modified asphalt mixture according to claim 1, wherein the mineral aggregate comprises the following components in percentage by mass: 85 to 99 percent of aggregate and 1 to 15 percent of mineral powder.

6. The water damage resistant sulfur modified asphalt mixture according to claim 5, wherein the aggregate is one or more of basalt, limestone, glauconite and steel slag aggregate.

7. The preparation method of the water damage resistant sulfur-modified asphalt mixture according to any one of claims 1 to 6, which is characterized by comprising the following steps:

1) Weighing the raw materials according to the proportion;

2) Drying the weighed aggregate, adding modified sulfur under the heating condition, and uniformly stirring; and sequentially adding asphalt and mineral powder, and uniformly stirring to obtain the water loss resistant sulfur modified asphalt mixture.

8. The method for preparing a polyurethane foam according to claim 7, wherein the heating temperature in the step 2) is 120 to 140 ℃.