JP3070737B2 - How to spray asphalt emulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dispersing an asphalt emulsion for penetration used in, for example, a prime coat, a tack coat, a seal coat, an armor coat used as a road material or a waterproof film material.

[0002]

2. Description of the Related Art For example, asphalt emulsions for roads are mainly of cationic type, and some of them are nonionic, but few of them are anionic. Cationic asphalt emulsions are further classified into penetrating emulsions and mixing emulsions, and the characteristics of the emulsions differ depending on the application.

[0003] When building asphalt pavements, prime coats and tack coats are commonly used. Prime coat penetrates the surface of the crushed stone roadbed and stabilizes the part, preventing the penetration of surface water due to rainfall, blocking the capillary water of moisture from the roadbed, and the asphalt mixture installed on top It is constructed for the purpose of improving familiarity.

[0004] In general, using the PK-3, the amount used is 1 to 2 L / m ^2. After the application of the prime coat, it takes 2 to 3 hours in summer and 4 to 5 hours in winter until moisture evaporates and is sufficiently decomposed. The tack coat is used for the purpose of improving the adhesion between the asphalt mixture and the lower layer and the seam or the structure. In general, PK-4 is used, and the amount used is 0.3 to 0. 0.6 l / m ² . After the tack coat is applied, it usually takes 1 to 2 hours depending on the season and weather, etc., until the water evaporates and is sufficiently decomposed.

[0005] The seal coat is applied to the existing pavement surface with PK-
An armor coat is used for spraying two or more layers of a seal coat with the aggregates being scattered with the first and second grades. The asphalt emulsion for penetration as shown above requires a very long time to decompose the asphalt emulsion, and depending on the season and weather, a long one requires 4 to 5 hours. It becomes a blank time that can not be done, and especially in the case of nighttime repair work, shortening the curing time is a major problem due to time constraints.

[0006] It is also desirable to avoid construction when the temperature falls below 5 ° C. This is because it takes time to evaporate the water in the emulsion, and during severe cold, the water in the emulsion may freeze before the emulsion is decomposed. Therefore, there is a method for decomposing an emulsion using an electrolyte as a method for forcibly performing decomposition such that water in the asphalt emulsion separates from the asphalt and turns the asphalt into a film in a short time.

[0007] For example, when a cationic emulsion (cation is a cation) is hit with an anion, the interfacial potential of the asphalt emulsion is reduced by an ionic reaction, and water is separated from the emulsion to form an asphalt film. In other words, adding an anionic substance having the opposite ion to a cationic emulsion or adding a cationic substance to an anionic emulsion neutralizes the interfacial potential of the emulsion and separates water from the emulsion. become.

[0008] In the case of cationic emulsions, anionic substances having opposite ions as the emulsion decomposable substances generally fall under this category. Decomposition time and decomposition time depend on the constituents of the cationic emulsion and the alkalinity and amount of the decomposer. Of different degrees. As a decomposed substance of the cationic emulsion, NaOH is a representative substance. It is also known that anionic emulsions, cement, and lime can also be decomposed substances.

[0009]

As described above, it is the most important in road construction to form an asphalt film by quickly decomposing an asphalt emulsion, but the above NaOH is a substance designated as a deleterious substance and must be handled. There is a problem that is difficult. In addition, the method of using an anionic emulsion as a decomposer for a cationic emulsion can be carried out as a test study, but in practice, double use of asphalt emulsion causes a great waste and is not practical. .

[0010] Further, cement and lime have a problem that workability is poor and difficult to handle because they are powder.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for rapidly decomposing an asphalt emulsion by contacting a cationic asphalt emulsion using an emulsifier containing an amine as a main constituent by spraying a decomposing agent for a light metal electrolyte, It is characterized by separating water and forming asphalt into a film. Asphalt materials used in the present invention include straight asphalt, blown asphalt, semi-blown asphalt, natural asphalt, bituminous substances such as solvent deasphalted asphalt, tar and pitch, heavy oil (A, B, C) and the like. Or a mixture of two or more rubber latexes, synthetic polymer latexes, synthetic polymer emulsions, water-soluble synthetic resins, or the like, if necessary.

In addition, asphalt is used as a modifier (SBR, E
VA, SBS, SIS, etc.) to form a modified asphalt and then emulsify to obtain a modified asphalt emulsion. Alternatively, add a modifier to an emulsifier and emulsify the asphalt to obtain a modified asphalt emulsion. It can also be.
When asphalt is used, a penetration of about 10 to 300 is used. The evaporation residue (solid content) of the asphalt emulsion is generally about 50 to 70%, but the present invention can be applied to an asphalt emulsion having a concentration of 10 to 70%.

The decomposing agent used is preferably a substance harmless to the human body. Since the reaction mechanism is a chemical reaction, the decomposition time is not affected by the outside air temperature, and the material can be decomposed even in winter before moisture in the emulsion freezes. The decomposing agent is a light metal electrolyte, and desirable metal ions include Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺
Particularly effective substances are sodium hydrogen carbonate (NaHCO ₃ ) and potassium hydrogen carbonate (KHCO ₃ ), and such an electrolyte powder, preferably an aqueous solution, is used. The concentration of the aqueous solution is about 1% to a saturated solution.

[0014] The decomposing agent is applied to the asphalt emulsion with a sprayer or the like. The contact may be carried out after spraying the asphalt emulsion or in the air during the spraying of the asphalt emulsion.

[0015]

Embodiments of the present invention will be described below. A common asphalt emulsion used for road pavement is one in which asphalt or the like and an aqueous emulsifier solution are emulsified by a colloid mill or the like. Here, the emulsification will be described. Emulsification refers to dispersing one liquid (dispersed phase) in fine particles in another liquid (continuous phase) that is immiscible with it, and the resulting dispersion is called an emulsion. In many cases,
Emulsions are composed of water and oil (a generic term for liquids that are immiscible with water). When the amount of oil is about 1% or less, a stable emulsion is formed without adding a stabilizer,
For higher amounts of the dispersed phase, stabilizers must be added to obtain a stable emulsion. The third substance added for stabilizing such an emulsion is called an emulsifier. Therefore, an emulsion is generally a system composed of a continuous phase, a dispersed phase, and an emulsifier.

Asphalt Emulsions The amines that can be used in asphalt emulsions are primary and secondary amines.
Grades, tertiary amines and quaternary ammonium salts, polyamines and mixed amines obtained by mixing these. After dispersing these emulsifiers in warm water, a mineral acid (hydrochloric acid and the like) is added to neutralize the emulsifier to obtain an amine salt as a cationic surfactant.

If the amount of surfactant in the emulsion required for emulsification is 0.1 wt% or more, an asphalt emulsion can be produced, but the storage stability and mechanical stability of the asphalt emulsion are possible. In consideration of the dissolution property, mixing stability and the like, and taking into account the decomposition characteristics after asphalt emulsion is sprayed, 0.1 to 5.
0 wt% is desirable. Using these emulsifiers, 130-
Emulsify the asphalt heated to 180 ° C.

Decomposing agent As a decomposing agent for the asphalt emulsion, a light metal electrolyte is used. At this time, it is desirable that the pH of the light metal aqueous solution is near neutrality and does not affect the environment and the human body. For example, NaHCO ₃ , KHCO _{3 and the} like can be mentioned. In particular, NaHCO ₃ has no concern about environmental problems, and is the most excellent in terms of economy and in terms of asphalt decomposition characteristics.

It is also possible to use the light metal electrolyte alone without using the decomposing agent as an aqueous solution. Method of using decomposing agent The asphalt emulsion produced by the above method is sprayed on a roadbed, a base layer, or a surface layer, and simultaneously with or after the spraying, the decomposing agent is sprayed on the asphalt emulsion and brought into contact.

The above-mentioned simultaneous means that the asphalt emulsion to be sprayed is brought into contact with the road surface before it reaches the road surface. As a result, the asphalt emulsion is decomposed in about 1 to 5 minutes after contact with the decomposing agent, water floats, and the asphalt is formed into a film. Adjustment of the decomposition time can be adjusted by the type, concentration, and application amount of the decomposition agent.

Although the embodiment has been described with reference to an example in which the present invention is applied to a road, the present invention can be carried out in exactly the same manner in spraying and waterproofing a slope or a wall, and can be applied as a mixture. Table 1 below shows practical examples according to the above embodiments.

[0022]

[Table 1]

Practical Example 1 When magnesium sulfate as a decomposing agent was sprayed and contacted with an asphalt emulsion containing an emulsifier containing a primary amine as a main component, the asphalt emulsion was decomposed in about 1 minute to form a good asphalt film. did. Practical Example 2 When sodium bicarbonate as a decomposing agent was sprayed and contacted with an asphalt emulsion using an emulsifier containing a secondary amine as a main component, the asphalt emulsion was decomposed in about 1 minute, and a good asphalt film was formed.

Practical Example 3 When sodium bicarbonate as a decomposing agent was sprayed and contacted with an asphalt emulsion using an emulsifier containing a tertiary amine as a main component, the asphalt emulsion was decomposed in about 1 minute, and a good asphalt film was formed. Formed. Practical Example 4 When sodium bicarbonate as a decomposing agent was sprayed and contacted with an asphalt emulsion using an emulsifier containing a quaternary ammonium salt as a main component, the asphalt emulsion was decomposed in about 1 minute, and a good asphalt film was formed. .

Practical Example 5 When sodium bicarbonate as a decomposing agent was sprayed on and contacted with an asphalt emulsion containing an emulsifier containing a polyamine as a main component, the asphalt emulsion was decomposed in about 1 minute to form a good asphalt film. . Practical Example 6 When potassium hydrogen carbonate was sprayed and contacted as a decomposing agent, the asphalt emulsion was decomposed in about 1 minute, and a good asphalt film was formed.

Practical Example 7 When potassium bicarbonate as a decomposing agent was sprayed and contacted with an asphalt emulsion using an emulsifier of a mixed amine, the asphalt emulsion was decomposed in about 1 minute, and a good asphalt film was formed.

[0027]

According to the present invention described in detail above, by using an asphalt emulsion and a suitable decomposing agent, the asphalt emulsion is decomposed in about 1 to 5 minutes after contact with the decomposing agent to form an asphalt film. It has the effect of doing.
In addition, since this decomposition mechanism is a chemical reaction, the decomposition time is hardly affected by the outside air temperature, the asphalt emulsion can be rapidly and reliably decomposed even in winter, and the construction time can be greatly reduced. It has the effect of. This construction method can also be used for spraying and waterproofing slopes and wall surfaces.

Further, the decomposing agent has no effect on the environment or the human body, and has an effect of being excellent in workability since it can be used in an aqueous solution.

Continuation of the front page (56) References JP-A-9-21102 (JP, A) JP-B-6-60043 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) E01C 7 / 35 E01C 19/16

Claims (5)

(57) [Claims] An asphalt emulsion using a cationic asphalt emulsion using an emulsifier having an amine as a main constituent, and a decomposing agent for a light metal electrolyte, which is contacted after spraying the asphalt emulsion, rapidly decomposes the asphalt emulsion, And spraying the asphalt into a film by separating the asphalt emulsion. 2. Use of a cationic asphalt emulsion using an emulsifier containing an amine as a main constituent, and contacting a decomposing agent for a light metal electrolyte while the asphalt emulsion is in the air during the application of the asphalt emulsion. A method for spraying an asphalt emulsion, wherein the asphalt emulsion is rapidly decomposed and water is separated to form an asphalt film. 3. The method for spraying asphalt emulsion according to claim 1, wherein the decomposing agent is a metal ion such as Na ⁺ , K ⁺ , Mg ²⁺ or Ca ²⁺ . 4. The method for spraying asphalt emulsion according to claim 1, wherein the decomposing agent is NaHCO ₃ . 5. The method for spraying asphalt emulsion according to claim 1, wherein the decomposing agent is KHCO ₃ .