JPS58201847A - Regenerated additive composition for pavement - Google Patents

Abstract

PURPOSE:To prepare the titled additive composition usable independent of the aging degree of waste materials, and giving durability and flow resistance to regenerated asphalt mixture, by compounding a rubber and an ethylene-vinyl acetate copolymer to a petroleum-type softening agent. CONSTITUTION:100pts.wt. of a petroleum-type softening agent is mixed with 1- 30pts.wt. of a polymer mixture composed of an ethylene-vinyl acetate copolymer preferably having vinyl acetate content of 10-35wt% and a melt index of 1- 40 and 20-100pts.wt., based on 100pts.wt. of the copolymer, of a rubber, preferably a solid or latex rubber having a Mooney viscosity of 10-100. For example, the rubber is added slowly to the petroleum-type softener molten by heating e.g. at 90-160 deg.C, the mixture is heated under agitation to remove water, and the ethylene-vinyl acetate copolymer is added to the mixture heated at 130- 180 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a recycled additive composition for pavement of recycled asphalt mixtures intended for high-grade pavement, simple pavement, bridge surface pavement, airport pavement, etc.

In recent years, recycling of aged or unnecessary asphalt mixtures has been reconsidered due to the trend toward resource and energy conservation.

For recycling of asphalt mixtures,
Broadly speaking, there are central plant methods and on-road methods.

The central plant method is a method of recycling in a special or US-based plant, in which waste materials are collected in a stockyard, then loosened and classified by crushing or thermal crushing using crushing equipment, and recycled into new aggregates and straight materials. Add and mix supplementary materials such as asphalt and recycled additives.

In addition, in the on-site method, part or all of the existing asphalt mixture is cut at the site, and supplementary materials such as aggregate, straight asphalt, and recycled additives are added to the cutting waste and mixed. Then, it is leveled and compacted.

However, when a recycled asphalt mixture containing straight asphalt or recycled additives is used as an asphalt mixture for paving, compared to a general asphalt mixture, when subjected to repeated traffic such as vehicles, flow deformation occurs on the road surface. It is difficult to maintain a flat road surface for a long period of time because it is prone to wear and tear phenomena.

The reason for this is that in the asphalt in the asphalt mixture, which is waste material from existing pavement, the maltene fraction in the asphalt (refers to that consisting of a polar fraction soluble in n-pentane, an aromatic fraction, and a saturated fraction). ) is oxidized or polymerized and transferred to asphaltone (referring to n-pentane insoluble matter), resulting in a relative shortage of maltene fraction compared to the original straight asphalt in terms of chemical composition.

The physical properties of the asphalt in aged waste asphalt mixtures are observed to be lower in penetration, elongation and higher softening point compared to the original straight asphalt.

An aged asphalt mixture with such physical properties is
), when a low-viscosity additive containing mainly maltene fraction is added, the flow deformation phenomenon occurs at high temperatures and wear angle is more likely to occur at low temperatures compared to a good asphalt mixture. When straight asphalt is added for regeneration, it is necessary to add a large amount to restore the physical properties of the original straight asphalt.
As a result, as the amount of asphalt in the recycled asphalt mixture becomes excessive, there is a drawback that flashing and flowing phenomena tend to occur.

The present invention has been developed to overcome the above-mentioned drawbacks, and its purpose is to be able to be used in a wide range of applications regardless of the age of waste materials, and to add durability to internal asphalt mixtures. An object of the present invention is to provide a paving additive composition that can provide flow resistance.

In order to achieve the above-mentioned object, the present invention provides a total amount of rubber at a ratio of 20 to 100 parts by weight per 100 parts by weight of ethylene/vinyl acetate copolymer (hereinafter referred to as EVA). is characterized in that the amount of the recycled additive is 1 to 30 parts by weight per 100 parts by weight of the petroleum softener.

Examples of the reclaimed pavement additive composition according to the present invention will be described below.
It consists of three components: A and rubber.

1 A distillate oil obtained by separating a low boiling point fraction from crude oil using a petroleum softener using an atmospheric distillation column, and distilling the heavy crude oil remaining at the bottom of the atmospheric distillation column under reduced pressure. type of crude oil,
Depending on the treatment process and formulation, they are separated into paraffinic softeners, naphthenic softeners, and 3-aromatic softeners, but all of these can be used in the present invention.

Such a petroleum softener has a chemical composition close to that of the maltene fraction in asphalt.

2. EVA preferably contains 10 to 35% by weight of vinyl acetate and has a melt intex of 1 to 40. In addition, EVA [in which the vinyl acetate content is 1
If it is less than 0%, the solubility in aged asphalt is poor;
And its properties at low temperatures are poor.

3. Various synthetic rubbers including natural rubber can be used as the rubber, and one type or a mixture of two or more types can be used. Its properties are solid or latex type, and good results can be obtained when the Mooney viscosity of the rubber is about 0 to 100. In addition, synthetic rubber, chloroprene rubber, styrene-isoprene copolymer rubber, polyisoprene rubber.

Polybutadiene rubber, styrene pot butadiene copolymer rubber, etc. are used.

The composition of the present invention is usually obtained as follows.

4- First, EVA], rubber is 20 to 10 per 00 weight part
Prepare both at a ratio of 0 parts by weight, and further add a total amount of 1 to 1 to 100 parts by weight of the petroleum softener.
Prepare 30 parts by weight of EVA, rubber, and petroleum softener, respectively.

Then, a predetermined amount of rubber, such as rubber latex or solid rubber, is gradually added to a predetermined amount of petroleum softener heated and melted at a temperature of 90 to 160°C, and water is removed by heating while stirring to form a rubber. Use petroleum-based softener.

Furthermore, the above-mentioned rubber-containing petroleum softener is heated to a temperature of 130 to 180°C.
The mixture is heated to a temperature of 0.degree. C., and a predetermined amount of EVA is added thereto and dissolved to obtain the reclaimed pavement additive composition of the present invention.

By using the present invention thus obtained in a central ground system, on-road system, etc., a recycled asphalt mixture can be produced.

Incidentally, an anti-peeling agent or the like may be added if necessary.

Hereinafter, non-inventive embodiments will be described in detail.

First, in the first example, ethylene vinyl acetate copolymer resin (28% vinyl acetate in solid content) was added to 100 parts by weight of a petroleum softener heated and melted at a temperature of 140 to 160°C.
What it contains. Add 40 parts by weight of chloroprene rubber latex, stir with a whisk to make it uniform, dissolve it, then add 17 parts by weight of chloroprene rubber latex in terms of solid content, stir to remove moisture, stir to make it uniform, stir with a whisk to dissolve) qf By doing so, the pavement recycling additive composition according to the present invention is obtained.

In this invention, when 10 parts by weight of the recycled pavement additive composition of the present invention is added to 100 parts by weight of aged asphalt extracted from a waste asphalt mixture and mixed,
The properties shown in Table 1 below are obtained.

In the comparative example shown in Table 1, 15 parts by weight of a mineral oil-based aromatic oil was added and mixed with 100 parts by weight of aged asphalt extracted from a waste asphalt mixture.

In the second example, a petroleum-based softener 1. heated and melted at a temperature of 1.40 to 160°C was used. Ethylene vinyl acetate copolymer resin (28% vinyl acetate in solid content) per 0 parts by weight
What it contains. Add 40 parts by weight of 1 part of ) and stir until uniformly dissolved. Styrene/isoprene copolymer rubber latex (45% solids, containing 70% imprene in the solids). Converting to solid content is 122
The recycled additive composition for pavement according to the present invention is obtained by adding a heavy weight, stirring, removing water, and stirring and dissolving it uniformly.

In the present invention, when 111 parts by weight of the reclaimed pavement additive composition of the present invention is added to a measured part of aged asphalt extracted from a waste asphalt mixture (I Oox) and mixed, the properties shown in Table 1 below are obtained. .

In the third example, 40% of ethylene vinyl acetate copolymer resin (containing 28% vinyl acetate in solid content) was added to 00Mtt part of petroleum softener heated and melted at a temperature of 140 to 160°C. Add parts by weight, stir until homogeneous,
After dissolving, add 10 parts by weight of the styrene-butadiene copolymer rubber latex in terms of total solid content, stir to remove moisture, and stir until uniform by stirring with an ox to dissolve. Such a recycled pavement additive composition is obtained.

In the present invention, when 13 parts by weight of the reclaimed pavement additive composition of the present invention is added to 100 parts by weight of aged asphalt extracted from a waste asphalt mixture and mixed, the following table--
Properties exhibiting IK can be obtained.

Cloth-1 As described above, according to the reclaimed pavement additive composition according to the present invention, 20 to 10 parts of rubber is added to 100 parts by weight of EVA.
The total amount of both petroleum softeners is 10 parts by weight in a ratio of 0 parts by weight.
By adjusting the amount to 1 to 30 parts by weight compared to 0 parts by weight,
When the present invention is used as a regenerating additive for waste materials, malten fraction is sufficiently added to the waste materials, restoring aged asphalt to a state close to its original chemical composition, and adding EVA and rubber. Due to the increase in durable viscosity and increased adhesiveness,
It exhibits great resistance to flow, embrittlement and abrasion, and can form safe and smooth traffic routes.

Furthermore, since a large amount of the present invention is not required for waste materials, the recycling rate of the waste materials is significant, which is a significant effect.
Master) January 251, 1981 (Mr. Kazuo Wakasugi, Commissioner of the Patent Office, 1, Indication of the case, 1983 Patent Application No. 068854, 2, Title of invention: Recycled additive composition for pavement 3, Person making amendment case) Relationship Patent applicant address: 7-3-7 Roppongi, Minato-ku, Tokyo Name
(Toa Road Industry Co., Ltd. (abbreviation)) Representative Director Iwa 34 Kawaguchi, Representative 7 Contents of Amendment 1 Page 2, line 11 to page 3, line 20 of the specification are amended as follows.

[The reason for adding this IfiK straight asphalt and recycled additives is that the maltene fraction (n-pentane soluble polar fraction, The aromatic fraction and the saturated fraction) are oxidized or polymerized and transferred to asphaltone (referring to the n-pentane insoluble fraction), which is chemically compositionally asphalt compared to the original straight asphalt. This is due to the relative lack of maltene fraction in the asphalt, and therefore, the physical properties of this asphalt include the degree of penetration compared to the original straight asphalt.
An increase in elongation and softening point is observed.

However, in order to regenerate an aged asphalt mixture having such physical properties, a low viscosity regeneration additive mainly composed of maltene fraction is added in the central plant method or road method. Compared to new asphalt mixtures, flow deformation phenomena are more likely to occur at high temperatures, and abrasion phenomena are more likely to occur at low temperatures.

Furthermore, when straight asphalt is added to regenerate aged asphalt mixtures, it is necessary to add a large amount to restore the physical properties of the original straight asphalt, and as a result, the asphalt in the regenerated asphalt mixture becomes excessive. There is a drawback that flash phenomena and flow phenomena tend to occur as the temperature increases.

Claims (1)

[Claims] ■ The ratio of rubber to 100 parts by weight of ethylene red vinyl acetate copolymer is 20 to 100 parts by weight, and the total amount of both is 1 to 30 parts by weight to 100 parts by weight of petroleum softener. A recycled additive composition for pavement.