JPH0442423B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an emulsion-type modified recycled additive composition for paving recycled asphalt mixtures intended for high-grade pavements, simple pavements, bridge pavements, airport pavements, and the like.

BACKGROUND ART In recent years, with resource and energy conservation efforts, asphalt mixtures from aged or unused waste materials have been recycled.

The asphalt in the asphalt mixture, which is aged pavement waste, is produced by oxidation or polymerization of the maltene fraction (consisting of n-pentane-soluble polar fraction, aromatic fraction, and saturated fraction) in the asphalt. As a result, the maltene fraction is relatively insufficient in terms of chemical composition compared to the original asphalt. This causes the physical properties of the asphalt mixture to deteriorate and the stress relaxation performance to deteriorate. To this end, by adding to the asphalt mixture a regenerating additive that has physical properties close to those of the maltene fraction, the asphalt mixture is restored and regenerated to bring the physical properties close to those of the original asphalt.

There are two main types of regeneration for asphalt mixtures: central plant methods and on-road methods.
The central plant method is a method of recycling in a special or conventional type of plant, in which the waste asphalt mixture is accumulated in a stockyard, and then it is loosened and classified by crushing equipment or thermal crushing, either alone or as new aggregate, Add and mix straight asphalt and supplementary materials such as recycled additives.

In addition, in the on-road method, part or all of the asphalt mixture of the existing pavement is cut on site, and the cutting waste alone or supplementary materials such as aggregate, straight asphalt, asphalt mixture, and recycled additives are used. is added and mixed, and the mixture is spread and compacted.

However, in the case of such a central plant method or roadside method that uses recycled additives, the recycled additives, which are supplementary materials when producing recycled asphalt mixtures, can be melted by heating and sprayed through a nozzle. Since the viscosity is lowered to a viscosity that can form a film with the aggregate before use, there is a disadvantage that extra fuel and steps are required to heat the supplementary material.

In addition, in order to regenerate aged asphalt mixtures having such physical properties, if a regeneration additive mainly consisting of maltene fraction is added in the above-mentioned central plant method or on-the-road method, the asphalt mixtures will flow more easily at high temperatures than new asphalt mixtures. Deformation development is more likely to occur and abrasion phenomena are more likely to occur at low temperatures. Therefore, when a recycled asphalt mixture containing recycled additives is used as an asphalt mixture for paving, it is more likely than ordinary asphalt mixtures to cause flow deformation and abrasion phenomena on the road surface when subjected to repeated loads from automobile traffic. The drawback is that it is difficult to maintain a flat road surface for a long time.

The present invention solves the above-mentioned drawbacks, and has a wide range of applicability regardless of the degree of aging of the waste asphalt mixture. In addition, when producing a recycled asphalt mixture, the recycled additive material, which is a supplementary material, can be kept at room temperature without heating. The object of the present invention is to provide an emulsion-type modified regenerating additive composition for pavement use.

In order to achieve this object, the present invention is characterized in that a resin is added to a petroleum softener and then emulsified using an emulsion liquid to obtain an emulsion-type modified recycled additive composition for pavement.

The emulsion-type modified recycled additive composition for pavement according to the present invention will be explained below.

The present invention varies depending on the type of emulsifier used for emulsification, and includes anionic type petroleum softener emulsion, nonionic type petroleum softener emulsion, cationic type petroleum softener emulsion, clay type petroleum softener emulsion, etc. It is an oil-in-water emulsion made by emulsifying a petroleum softener in water.

First, the petroleum softener which is the main ingredient of the present invention is:
Distillate oil is obtained by separating low-boiling fractions from crude oil using an atmospheric distillation column, and distilling the heavy crude oil remaining at the bottom of the atmospheric distillation column under reduced pressure.
They are classified into paraffinic softeners, naphthenic softeners, and aromatic softeners depending on the treatment process and formulation, but all of these can be used in the present invention.

Among petroleum-based softeners, it is preferable to use one having a chemical composition close to that of the maltene fraction in asphalt.

As the resin, natural resins or various synthetic resins may be used alone or in combination. Its properties may be either solid or latex type, such as natural resins, petroleum resins, modified resins thereof, polyvinyl acetate, ethylene/vinyl acetate copolymers,
Vinyl acetate/acrylate copolymer, vinyl acetate/carboxylic acid vinyl ester copolymer, polyacrylate, ethylene/acrylate copolymer,
Polystyrene, styrene/acrylate copolymer, vinyl chloride/vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, vinylidene chloride/
Vinyl chloride copolymer, alkyd resin, maleate ester/vinyl acetate copolymer, etc. are used.

Emulsifiers used for emulsification include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, bentonite, and emulsifying aids.
By adding 0.2 to 5.0 parts by weight per 100 parts by weight, an alkali, an acid, a salt, and a protective colloid agent are also added as an emulsified liquid.

If the amount of emulsifier used is less than 0.2 parts by weight, the emulsion stability of the paving emulsion regenerating additive composition obtained by emulsification will deteriorate, making it difficult to obtain a homogeneous emulsion with good long-term stability. In addition, if the amount of emulsifier used is more than 5.0 parts by weight, it will be an economic disadvantage and the emulsion will be very stable when used at room temperature, so it will take a long curing time to obtain a reduced petroleum softener. There is a drawback.

The composition of the present invention can be obtained as follows.

A method of gradually adding a predetermined amount of solid type or latex type resin to a predetermined amount of heated and melted petroleum softener, and emulsifying the heated and dissolved resin using an emulsifying liquid while continuing to stir; There is a method of adding a latex type resin to an emulsion and emulsifying it with a petroleum softener.

Next, examples of the present invention will be described.

First Example To 100 parts by weight of tap water, 1 part by weight of a cationic emulsifier such as fatty diamine, 0.3 parts by weight of concentrated hydrochloric acid, and 0.5 parts by weight of calcium chloride were added, stirred and dissolved, and the cationic emulsion was heated to about 55°C. The emulsion obtained by
The cationic paving emulsion-type modified recycled additive composition of the present invention is obtained by adding 10 parts by weight of 10 parts by weight of the mixture and stirring until homogeneous, and introducing the resulting mixture into a Harrell type homogenizer.

Second Example An anionic emulsifier such as 1.5 parts by weight of beef tallow carboxylate and 0.45 parts by weight of caustic soda was added to 100 parts by weight of tap water, and the anionic emulsion was stirred and dissolved and heated to about 60°C. Add 10 parts by weight of ethylene/ethyl acrylate copolymer resin to the emulsion and 140 parts by weight of petroleum softener heated and melted at a temperature of 140 to 160°C, stir and dissolve until homogeneous. By introducing the mixture into a mold homogenizer and emulsifying it, the anionic emulsion-type paving emulsion-type modified reclaimed additive composition of the present invention is obtained.

Third Example An emulsion obtained by adding a nonionic emulsifier such as 3.0 parts by weight of POE benzyl sulfonate and 0.3 parts by weight of calcium chloride to 100 parts by weight of tap water, stirring and dissolving the nonionic emulsion and heating it to about 50°C. Then, 8 parts by weight of vinyl acetate and acrylate copolymer were added to 140 parts by weight of petroleum softener heated and dissolved at a temperature of 140 to 160°C, stirred until uniform, and dissolved in a Harrell type homogenizer. By introducing and emulsifying, the nonionic pavement emulsion-type modified reclaimed additive composition of the present invention is obtained.

As explained above, according to the present invention, by emulsifying the modified regenerating additive composition, it is no longer necessary to heat the modified regenerating additive composition to obtain a viscosity that can be sprayed through a nozzle and a viscosity that can be coated on aggregate. As a result, the process is greatly shortened, the construction time can be shortened, and fuel is not required at all.

Furthermore, according to the present invention, unlike a modified recycled additive composition mainly composed of maltene fraction, even under repeated automobile loads, the flow deformation phenomenon is less likely to occur, similar to a new asphalt mixture, and the friction phenomenon is also less likely to occur. This has the effect of maintaining a flat road surface for a long period of time.

Claims (1)

[Claims] 1 Petroleum-based softener 100 heated and dissolved at 140-160℃
Add and dissolve 1 to 30 parts by weight of a resin consisting of ethylene vinyl acetate copolymer resin, ethylene/ethyl acrylate copolymer resin, or vinyl acetate/acrylate copolymer resin based on the weight part, and dissolve the resulting product. After heating 60 parts by weight to approximately 150°C,
1. A method for producing an emulsion-type modified recycled additive composition for pavement use, which comprises emulsifying with 40 parts by weight of an emulsion liquid at 50 to 60°C.