JP6650165B2 - Pavement mixture and method for producing the same - Google Patents

Description

  The present invention relates to a pavement mixture and a method for producing the same, and more particularly, to a pavement mixture that can be stored for a long time and a method for producing the same.

  Generally, asphalt mixtures can be broadly divided into heated asphalt mixtures and room temperature asphalt mixtures.

  The heated asphalt mixture is produced by mixing coarse aggregate, fine aggregate, filler and asphalt in a heated state. Specifically, the heated asphalt mixture produced in the production plant is prepared by heating and mixing the asphalt for pavement and aggregate made of crushed stone, sand, and filler using a large asphalt mixing mixer or the like installed in the plant. Manufactured. Thereafter, the manufactured heated asphalt mixture is transported to a construction site while maintaining a heated state, and is used for pavement such as roads and ground surfaces, or for repairing these.

  Further, the heated asphalt mixture includes one using a new aggregate and one using a recycled asphalt concrete aggregate. The recycled asphalt concrete aggregate is obtained by crushing and classifying a waste asphalt mixture generated by removing an existing pavement or the like. In the following description, asphalt concrete recycled aggregate is referred to as “recycled aggregate”.

  In some cases, the asphalt mixture for paving is reused depending on the construction. In this case, apply heat to the construction site, scrape it with special equipment, manufacture an asphalt mixture for pavement using additives, etc., or put the waste asphalt mixture into special equipment and heat it to heat the asphalt mixture. By being manufactured, it is used for pavement on roads and ground surfaces, or for repairing these.

  Furthermore, in the method for producing a preservation asphalt mixture, a dedicated facility is used immediately after the production of a heated asphalt mixture produced in a general plant, and the preservation asphalt mixture produced by rapidly cooling is applied. It is used for pavement on roads, ground surfaces, etc., or for repairing these by heating by an appropriate method on site.

  On the other hand, the room temperature asphalt mixture can be prepared by mixing coarse aggregate, fine aggregate and the like with an asphalt emulsion or the like at room temperature, and paving at room temperature (100 ° C. or lower). The room temperature asphalt mixture is generally slightly inferior in durability to the heated asphalt mixture, but can be stored, so that it is used as a simple pavement material or a repair material.

http: // www. askyo. JP / knowledge / 06-1. html (November 10, 2017) JP 2000-317434 A JP 2012-126865 A

  However, a heated asphalt mixture produced in a plant is produced using a production apparatus such as a large-sized mixing mixer, so that the production amount per batch is at least several hundred kg. Therefore, in the case of small-scale pavement or repair, the remaining asphalt mixture for pavement must be disposed of, which not only increases the cost but also has a problem in terms of environmental protection.

  Further, it is necessary to strictly control the amount of the heated asphalt mixture to be shipped from the plant and the time required to carry it in until it reaches the construction site after the shipment. Furthermore, if the construction was stopped due to a sudden change in the weather or the like, the entire production had to be disposed of. In any case, since the heated asphalt mixture corresponds to an asphalt mixture for paving exceeding a certain amount or more, it is difficult to install a plant economically in an area where demand is low, There was a drawback that the plant could not be operated economically during periods of low demand.

  Furthermore, the heated asphalt mixture produced at the construction site has no waste asphalt mixture, but it is difficult to use for step correction, repair of potholes, ruts, etc., or small-scale new pavement. . In addition, for small-scale pavement and repair in remote areas such as remote islands, heavy equipment and dedicated equipment for scraping and digging must be carried, which is costly and uneconomical.

  In addition, asphalt mixture for preservation is to melt and mix the surface of the mixture by applying heat.However, during high temperature, the petroleum asphalt for pavement softens and this mixture blocks, resulting in a lump mixture. There was a problem that it was difficult to melt by heating. Further, petroleum asphalt for paving belongs to a drying oil, and in particular, in long-term storage, etc., may deteriorate due to oxidation and may not be able to obtain predetermined performance.

  Furthermore, the asphalt mixture for preservation is easy to produce as a single crushed stone of No. 6 crushed stone (4.75 mm to 13.2 mm) aggregate or No. 7 crushed stone (2.36 mm to 4.75 mm) aggregate. However, it is difficult to produce fine aggregates having a diameter of 2.5 mm or less, and lightweight aggregates do not separate from each other and are aggregated. In addition, it is difficult to produce various pavement mixtures synthesized from No. 6 crushed stone aggregate, No. 7 crushed stone aggregate, fine aggregate and filler. In addition, a dedicated facility must be installed in a conventional pavement petroleum asphalt mixture production plant, so that it cannot be easily produced.

  On the other hand, the room temperature asphalt mixture can be stored at room temperature, but is premised on being used as a simple pavement material or repair material. Therefore, it is difficult to use the cold asphalt mixture as a substitute for the heated asphalt mixture.

  An object of the present invention based on the above-mentioned problems is to provide a pavement mixture which can be stored for a long period of time and has a strength equivalent to a heated asphalt mixture by heating, and a method for producing the same.

The pavement mixture of the present invention comprises an aggregate, and a coating layer that covers the periphery of the aggregate, wherein the coating layer includes an asphalt layer made of asphalt that covers the periphery of the aggregate, and the asphalt. An adhesive layer covering the periphery of the layer and containing the asphalt, the asphalt emulsion and the demulsifier, and a separation layer covering the periphery of the adhesive layer and containing the demulsifier that has not reacted with the asphalt emulsion. Yes, and the pH of the separation layer, characterized in that 8.0 to 11.0 or less.

The present invention relates to a pavement mixture for forming an asphalt layer, an adhesive layer and a separation layer on the surface of the novel aggregate by mixing a novel aggregate, asphalt, an asphalt emulsion, and a demulsifier. A manufacturing method, a step of mixing the asphalt with the new aggregate, a step of mixing the asphalt emulsion with the asphalt and the new aggregate, the asphalt, the new aggregate and the asphalt emulsion, Mixing the demulsifier, and the step of mixing the demulsifier, by adding the demulsifier containing alcohol with a hydrogen ion concentration of reaction equivalent or more to the asphalt emulsion, Forming the separation layer containing the demulsifier not reacted with the asphalt emulsion and having a pH of 8.0 or more and 11.0 or less . And features.

The present invention relates to a pavement for forming an adhesive layer and a separation layer on the surface of the asphalt concrete recycled aggregate by mixing an asphalt concrete recycled aggregate, an oil component , an asphalt emulsion, and a demulsifier. A method for producing a mixture, a step of adding the oil component to the asphalt concrete recycled aggregate, a step of mixing the asphalt emulsion with the asphalt concrete recycled aggregate and the oil component, and a step of mixing the asphalt concrete recycled aggregate. Mixing the oil component and the asphalt emulsion with the demulsifier, wherein the step of mixing the demulsifier has a hydrogen ion concentration of a reaction equivalent or more with respect to the asphalt emulsion and alcohol. By adding the above-mentioned demulsifier, it has reacted with the asphalt emulsion Wherein the pH include have the demulsifier generating the separation layer is 8.0 to 11.0 or less.

The pavement mixture of the present invention comprises an aggregate, and a coating layer that covers the periphery of the aggregate, wherein the coating layer includes an asphalt layer made of asphalt that covers the periphery of the aggregate, and the asphalt. An adhesive layer covering the periphery of the layer and containing the asphalt, asphalt emulsion and demulsifier, and a separation layer covering the periphery of the adhesive layer and containing the demulsifier that has not reacted with the asphalt emulsion. Yes, and the pH of the separation layer, characterized in that 8.0 to 11.0 or less. Therefore, since the outermost periphery of the coating layer covering the aggregate has a separation layer containing a demulsifier that has not reacted with the asphalt emulsion, contact between the asphalt layer and the adhesive layer and the external atmosphere is suppressed, Oxidation of these layers is suppressed. Therefore, the paving mixture can be stored for a long time. In addition, when a pavement mixture is used for pavement or repair, the separation layer is evaporated by heating. Furthermore, the asphalt layer and the adhesive layer are integrated by being heated and melted, and the heated and melted asphalt layer is formed, thereby having the same structure as the heated asphalt mixture, and can be used as a so-called heated mixture. Therefore, the paving mixture of the present invention can be stored at room temperature for a long period of time like a room temperature asphalt mixture, and has sufficient strength like a heated asphalt mixture. Further, when the pH of the separation layer is 8.0 or more, each aggregate can be maintained in a separated state, and when the pH of the separation layer is 11.0 or less, the worker handling the pavement mixture can be maintained. Safety can be ensured.

The present invention relates to a pavement mixture for forming an asphalt layer, an adhesive layer and a separation layer on the surface of the novel aggregate by mixing a novel aggregate, asphalt, an asphalt emulsion, and a demulsifier. A manufacturing method, a step of mixing the asphalt with the new aggregate, a step of mixing the asphalt emulsion with the asphalt and the new aggregate, the asphalt, the new aggregate and the asphalt emulsion, Mixing the demulsifier, and the step of mixing the demulsifier, by adding the demulsifier containing alcohol with a hydrogen ion concentration of reaction equivalent or more to the asphalt emulsion, Forming the separation layer containing the demulsifier not reacted with the asphalt emulsion and having a pH of 8.0 or more and 11.0 or less . And features. Therefore, the water generated by adding the demulsifier containing alcohol having a hydrogen ion concentration of the reaction equivalent or more and the alcohol contained in the demulsifier are mixed, and a separation layer having lubricity in a mixture of both is formed. Can be generated. Further, a separation layer can be suitably formed on the outermost peripheral portion of the new aggregate.

The present invention relates to a pavement for forming an adhesive layer and a separation layer on the surface of the asphalt concrete recycled aggregate by mixing an asphalt concrete recycled aggregate, an oil component , an asphalt emulsion, and a demulsifier. A method for producing a mixture, a step of adding the oil component to the asphalt concrete recycled aggregate, a step of mixing the asphalt emulsion with the asphalt concrete recycled aggregate and the oil component, and a step of mixing the asphalt concrete recycled aggregate. Mixing the oil component and the asphalt emulsion with the demulsifier, wherein the step of mixing the demulsifier has a hydrogen ion concentration of a reaction equivalent or more with respect to the asphalt emulsion and alcohol. By adding the above-mentioned demulsifier, it has reacted with the asphalt emulsion Wherein the pH include have the demulsifier generating the separation layer is 8.0 to 11.0 or less. Therefore, the water generated by adding the demulsifier containing alcohol having a hydrogen ion concentration of the reaction equivalent or more and the alcohol contained in the demulsifier are mixed, and a separation layer having lubricity in a mixture of both is formed. Can be generated. Furthermore, since recycled aggregate is used, asphalt attached around the recycled aggregate can be reused, which can contribute to resource saving. Furthermore, the energy required for the method for producing a paving mixture can be reduced.

It is a figure which shows the mixture for paving which concerns on embodiment of this invention, (A) is sectional drawing which shows the mixture for paving, (B) is the expanded sectional view. It is a figure showing the mixture for paving concerning an embodiment of the invention, and (A) and (B) are enlarged sectional views of the mixture for paving. It is a figure showing the mixture for paving concerning an embodiment of the invention, and (A) and (B) are enlarged sectional views of the mixture for paving. It is a figure showing the mixture for paving concerning an embodiment of the invention, and is an enlarged sectional view of the mixture for paving. BRIEF DESCRIPTION OF THE DRAWINGS It is the flowchart which shows the manufacturing method of the paving mixture using the novel aggregate which concerns on embodiment of this invention, and sectional drawing which shows the state of the paving mixture in each process. BRIEF DESCRIPTION OF THE DRAWINGS It is the flowchart which shows the manufacturing method of the paving mixture using the recycled aggregate which concerns on embodiment of this invention, and sectional drawing which shows the state of the paving mixture in each process. It is a table | surface which shows the physical property of the mixture for paving which concerns on embodiment of this invention. It is a table | surface which shows the result of having verified the physical property of the separation liquid formed on the surface of the paving mixture which concerns on embodiment of this invention.

  Hereinafter, a pavement mixture 10 according to an embodiment of the present invention and a method for producing the same will be described in detail with reference to the drawings. In the following description, the same reference numerals are used for the same members in principle, and the repeated description is omitted.

<Configuration of paving mixture 10>
The configuration of the paving mixture 10 will be described with reference to FIG. FIG. 1A is a cross-sectional view showing a paving mixture 10, and FIG. 1B is an enlarged cross-sectional view thereof.

  Referring to FIG. 1A, pavement mixture 10 has aggregate 11 and coating layer 12 that covers the surface of aggregate 11. As described later, the paving mixture 10 can be stored at room temperature for a long period of time, for example, in a state of being packaged every several tens of kg. Further, the paving mixture 10 is heated, so that the coating layer 12 is melted and the paving mixture 10 is bonded to each other, and the coating layer 12 is hardened by cooling in the bonded state. Demonstrate. That is, the paving mixture 10 has excellent preservability like a normal-temperature asphalt mixture, and can obtain high strength equivalent to that of a heated asphalt mixture. The paving mixture 10 can be used in the construction or repair of roads or ground surfaces.

  The aggregate 11 is made of a stone or the like adjusted to have a predetermined particle size. It is assumed that the particle size of the aggregate 11 conforms to, for example, the “Pavement Construction Handbook” determined by the Japan Road Association. The aggregate 11 is made of crushed stone, sand, filler, and the like.

  The coating layer 12 covers the periphery of the aggregate 11. As will be described later, the coating layer 12 is formed by adding asphalt emulsion 18 and demulsifier 19 to asphalt, and its oxidation is suppressed even when stored for a long period of time.

  FIG. 1B schematically shows an enlarged cross-sectional view of the boundary between the paving mixtures 10. The coating layer 12 that covers the aggregate 11 has an asphalt layer 13, an adhesive layer 14, and a separation layer 15 from the inside. Further, the separation layer 15 which is the outermost layer of the coating layer 12 may be shared by the paving mixture 10 on the right side of the drawing and the paving mixture 10 on the left side of the drawing. Further, the contact point between the separation layer 15 of the paving mixture 10 on the right side on the paper surface and the separation layer 15 of the paving mixture 10 on the left side on the paper surface is indicated by a dotted line (contact portion 17) on the paper surface.

  The asphalt layer 13 is a petroleum asphalt for pavement, and further, a recycled asphalt obtained by adding a regeneration additive to asphalt contained in a waste asphalt mixture discharged from a construction site or the like can be adopted. For example, it is desirable to use a regeneration additive that conforms to the “Pavement Regeneration Handbook” specified by the Japan Road Association. In addition, since asphalt is already attached around the recycled aggregate, the asphalt content of the asphalt emulsion 18 to be added later can be changed so that the manufactured paving mixture 10 can be adjusted to meet the specification of the asphalt amount%. No additional asphalt is required.

  The adhesive layer 14 is a layer generated by adding an asphalt emulsion 18 to asphalt for pavement forming the asphalt layer 13 and is a layer that exhibits an adhesive force. Here, as the asphalt emulsion 18, generally sold and used petroleum asphalt cationic emulsion (JIS K 2208), generally sold and used various petroleum asphalt cation emulsions, or petroleum asphalt amphoteric having both polarities Ionized emulsions can be employed.

  The separation layer 15 is a layer containing the demulsifier 19 that has not reacted with the asphalt emulsion 18 by adding the demulsifier 19 to the asphalt emulsion 18. Specifically, for example, the asphalt emulsion 18 is decomposed by adding and mixing a cationic asphalt emulsion 18 and a demulsifier 19 having a hydrogen ion concentration higher than the reaction equivalent to the asphalt emulsion 18 and containing alcohol. Asphalt particles 16 adhere to the similar asphalt layer 13 and the decomposed water is mixed with the unreacted demulsifier 19.

  The above-mentioned asphalt emulsion 18 is a petroleum asphalt cationic emulsion, which is a cationic ionic emulsion generally used and sold, such as a cationic emulsion (JIS K 2208) or a variety of generally sold and used cationic ionic emulsions. A petroleum asphalt amphoteric ionized emulsion having properties can be used. Among the asphalt emulsions 18, an emulsion having an optimum asphalt content and asphalt penetration can be selected according to the purpose of use and the degree of deterioration of the asphalt adhering to the recycled aggregate. Further, the asphalt emulsion 18 can adjust the asphalt physical properties of the final mixture to the physical properties (such as penetration, softening point, and elongation) of asphalt within a desired standard. When adjusting the amount of the asphalt emulsion 18 to be added, the water content of the asphalt emulsion 18 and the water content of the demulsifier 19 are not more than 2% of the total amount excluding the volatile matter after the pavement mixture 10 is formed. Is desirable.

  The above-described demulsifier 19 is prepared by adding at least one of alkali metal compounds or alkali metal earth compounds to an aqueous solution having a hydrogen ion concentration of pH 11.0 or more and a flash point of 100 ° C to 170 ° C. It is obtained by adding at least one kind of trihydric alcohol or trihydric alcohol having a flash point of 100 ° C. or more and 170 ° C. or less. In addition, the water decomposed from the asphalt emulsion 18 is mixed with the demulsifier 19 and remains as the separation layer 15 having alcohol lubricity.

  The aqueous solution contained in the demulsifier 19 is preferably an aqueous solution of a relatively general-purpose compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate, and potassium metasilicate. As for sodium hydroxide and potassium hydroxide, an aqueous solution corresponding to a general substance having a concentration of 5% or less is desirable.

  The alcohol contained in the demulsifier 19 has miscibility with viscous high-boiling water used for lubricants, humectants, antifreezes, and the like. Specifically, ethylene glycol, diethylene glycol, propylene glycol, dipropylene Glycol, glycerin and the like are desirable.

  Since the amount of the demulsifier 19 varies depending on the asphalt content and the hydrogen ion concentration of the asphalt emulsion 18 used, the water content of the asphalt emulsion 18 and the water content of the demulsifier 19 are changed after the pavement mixture 10 is formed. It is adjusted so that it is 2% or less of the total amount of the mixture excluding volatile components, the hydrogen ion concentration shows a weak alkaline region of pH 8.0 or more and pH 11.0 or less, and the amount of residual alcohol is 1% or less of the total amount of the mixture. It is desirable. The adjustment for this can be easily performed by measuring the hydrogen ion concentration of the decomposed liquid by a beaker test in which the demulsifier 19 is added to the asphalt emulsion 18 to be used at a temperature of 100 ° C. or less. Further, if the molar concentration of the asphalt emulsion 18 to be used is known, the molar concentration of the demulsifier 19 to be used can be calculated, and adjustment can be made by deriving an equimolar amount.

  The separation layer 15 is made of, for example, 2% or less of residual moisture and 1% or less of residual alcohol, and the separation layer 15 in the weakly alkaline region is 0.5% or more and 3% or less of the total amount of the pavement mixture 10. Is desirable. Further, the separation layer 15 is hardly volatile, having repulsion of the same kind of ions and lubricity of dihydric and trihydric alcohols, and is not affected by pressure due to load or temperature change in a normal temperature range. In addition, since the separation layer 15 exhibits weak alkalinity, oxidation of the adhesive layer 14 and the like is prevented, and deterioration of the paving mixture 10 is suppressed, so that long-term storage is possible.

  Furthermore, the separation layer 15 is a mixture of the above-described alkaline aqueous solution, alcohol and water decomposed from the asphalt emulsion 18, and the pH of the mixture is such that the aggregates 11 solidify even when the pavement mixture 10 is stored for a long period of time. By doing so, it is possible to maintain the health and safety environment of the workers involved in the production of the paving mixture 10 without blocking. Specifically, the preferable range of the pH of the separation layer 15 is, for example, 8.0 or more and 11.0 or less. When the pH of the separation layer 15 is 8.0 or more, each aggregate 11 can be maintained in a separated state, and when the pH of the separation layer 15 is 11.0 or less, the work of handling the paving mixture 10 is performed. The safety of the staff can be ensured. Further, a particularly preferable range of the pH of the separation layer 15 is, for example, 9.0 or more and 10.0 or less. By setting the content in such a range, the above-described effect can be remarkable.

  As described above, the pavement mixture 10 has the separation layer 15 on the outermost periphery thereof. The separation layer 15 is formed from the aqueous alkali solution, the alcohol, and the water decomposed from the asphalt emulsion 18. Therefore, when the paving mixture 10 is stored, the quality of the paving mixture 10 is not affected by the pressure due to the load or the temperature change in the normal temperature range. Furthermore, since the separation layer 15 shows weak alkalinity, oxidation of the asphalt layer 13 is prevented, and deterioration of the paving mixture 10 is suppressed. Therefore, the pavement mixture 10 can be stored for a long time, and can be adapted to various pavements by heating and mixing at the construction site.

  Further, since the separation layer 15 is negatively charged, the separation layer 15 formed around the left aggregate 11 and the separation layer formed around the right aggregate 11 Layer 15 repels each other. Therefore, even when the paving mixture 10 is stored in a storage bag for a long period of time, it is possible to suppress the blocking of the paving mixture 10 from occurring.

  Further, since the pavement mixture 10 can be stored in a bag for a long period of time, it is suitable for stockpiling for disasters and for repairing and preparing remote areas such as remote islands and roads in snowy season when the plant does not operate. Furthermore, by heating and mixing the pavement mixture 10 by an appropriate method according to the situation at the site, a petroleum asphalt mixture for pavement having a particle size range in which quality control is performed, which conforms to standards of various places regarding pavement, can be easily produced. . Further, it can be produced relatively easily in existing pavement petroleum asphalt production plants without adding equipment, and the materials to be used can be provided universally and easily because they are easily available.

  Next, with reference to FIGS. 2 to 4, a description will be given of a reaction that occurs around the aggregate 11 when the paving mixture 10 is manufactured. Each of FIGS. 2 to 4 is an enlarged sectional view showing a boundary portion between the aggregates 11.

  Referring to FIG. 2A, first, the surface of aggregate 11 is covered with asphalt layer 13. Around the asphalt layer 13, an asphalt emulsion 18 and a demulsifier 19 are present. Asphalt emulsion 18 contains asphalt particles 16 that are positively charged. The demulsifier 19 has alkalinity by having a hydrogen ion concentration higher than the reaction equivalent to the asphalt emulsion 18 as described above, and is negatively charged.

  Referring to FIG. 2 (B), the asphalt emulsion 18 and the demulsifier 19 are mixed with each other, so that the asphalt emulsion 18 and the demulsifier 19 are mixed at a molecular level, and the asphalt particles contained in the asphalt emulsion 18 are mixed. 16 are electrically neutralized. Further, as described above, since the hydrogen ion concentration is equal to or higher than the reaction equivalent to the asphalt emulsion 18, the layer formed by mixing the asphalt emulsion 18 and the demulsifier 19 exhibits weak alkalinity.

  Referring to FIG. 3A, asphalt particles 16 contained in asphalt emulsion 18 are electrically neutralized as described above, so that asphalt particles 16 adhere to the surface of similar asphalt layer 13. I do.

  As a result, as shown in FIG. 3B, an adhesive layer 14 composed of asphalt particles 16 attached to the surface of the asphalt layer 13 is formed. Then, a weakly alkaline separation layer 15 that is negatively charged is formed outside the adhesive layer 14. Since the left separation layer 15 and the right separation layer 15 repel each other on the paper, the occurrence of blocking under storage conditions is suppressed.

  Referring to FIG. 4, when performing road construction or the like using the paving mixture 10, the paving mixture 10 is heated by a burner or the like. As a result, the separation layer 15 evaporates. Further, the asphalt layer 13 and the adhesive layer 14 become an integrated heat-melted asphalt layer 20, and the heated-melt asphalt layer 20 bonds the pavement mixtures 10 together.

<Method for producing pavement mixture 10>
Next, a method for manufacturing the paving mixture 10 having the above-described configuration will be described with reference to the flowcharts of FIGS. The case where a new aggregate is adopted as the aggregate 11 will be described with reference to FIG. Further, a case where recycled aggregate is employed as the aggregate 11 will be described with reference to FIG.

  Referring to FIG. 5, the method for producing pavement mixture 10 using the novel aggregate of the present embodiment includes a step S10 of mixing aggregate 11 and asphalt, a step S11 of mixing asphalt emulsion 18, and a separation layer And generating step S15. Further, the produced paving mixture 10 is stored in step S13, and in step S14, the paving mixture 10 is used for construction. In this figure, a schematic cross section of the aggregate 11 at each step is shown beside each step.

  In this step, it is not necessary to specially prepare a dedicated plant for producing the paving mixture 10 according to the present embodiment, and the paving mixture 10 is used in a general-purpose plant for producing a heated asphalt mixture or a room temperature asphalt mixture. Can be manufactured.

  First, in step S10, the aggregate 11 and the asphalt are mixed. As described above, a mixture of crushed stone, sand, and filler can be used as the aggregate 11. In practice, after the aggregate 11 having an appropriately adjusted particle size is dried and heated to an appropriate temperature, the aggregate 11 having a desired particle size range is put into a mixer, and the filler in the normal temperature range and the heated petroleum asphalt for the pavement are sequentially arranged. Add and mix. In this step, since the temperature of the aggregate 11 is desirably 100 ° C. or less, the aggregate 11 is dried as much as possible, the drying heating temperature is adjusted, and the filler in the normal temperature range is heated to an appropriate temperature. After adding and mixing the paved petroleum asphalt, it is added and mixed. By doing so, the mixture can be produced lubricated without any load on the equipment and the like. The mixing in this step is performed, for example, in a situation where the temperature of each material is 80 ° C. or higher.

  In step S11, the asphalt emulsion 18 is added to the mixture of the aggregate 11 and the asphalt layer 13 and mixed. The type of the asphalt emulsion 18 is as described above. For example, a petroleum asphalt cationic emulsion as the asphalt emulsion 18 is added at room temperature. By this step, the aggregate 11 is covered with the asphalt layer 13 and the asphalt emulsion 18. Here, when a so-called new aggregate is used as the aggregate 11, step S10 of attaching asphalt around the new aggregate is essential, while when a recycled aggregate is used as the aggregate 11, step S10 is performed. It becomes unnecessary. This is because the recycled aggregate has asphalt already attached around the recycled aggregate.

  In step S12, a demulsifier 19 is added to and mixed with the mixture of the aggregate 11, the asphalt layer 13, and the asphalt emulsion 18. The type and amount of the demulsifier 19 are as described above. For example, an appropriate amount of a demulsifier 19 for a petroleum asphalt cationic emulsion is charged and mixed at room temperature. By this step, the aggregate 11 is covered with the asphalt layer 13, the asphalt emulsion 18, and the demulsifier 19. Here, the asphalt emulsion 18 and the demulsifier 19 can be charged and added from a charging port provided in a mixer portion of the plant. Further, commonly used asphalt additives and pigments are similarly introduced.

  Further, by mixing the asphalt emulsion 18 and the demulsifier 19 in step S12, the reaction described with reference to FIGS. 2 to 3 occurs, and the asphalt layer 13 and the adhesive layer 14 are formed on the surface of the aggregate 11. And the separation layer 15 is formed. Here, the adhesive layer 14 can be regarded as a decomposed asphalt layer after demulsification.

  Here, in the present embodiment, a demulsifier 19 having a hydrogen ion concentration equal to or higher than the reaction equivalent to the asphalt emulsion 18 and containing alcohol is added and mixed. By doing so, the asphalt emulsion 18 is decomposed, and similar decomposed asphalt particles adhere to the asphalt layer 13.

  Further, in this step, a preferable range of the pH of the separation layer 15 is, for example, 8.0 or more and 11.0 or less. The amount of the demulsifier 19 to be added is adjusted so that the pH of the separation layer 15 falls within such a range. When the pH of the separation layer 15 is 8.0 or more, each aggregate 11 can be maintained in a separated state, and when the pH of the separation layer 15 is 11.0 or less, the work of handling the paving mixture 10 is performed. The safety of the staff can be ensured. Further, a particularly preferable range of the pH of the separation layer 15 is, for example, 9.0 or more and 10.0 or less. By setting the content in such a range, the above-described effect can be remarkable.

  In step S13, the paving mixture 10 produced by the above-described process is stored in a bag every several tens of kg. In the pavement mixture 10 according to the present embodiment, since the separation layer 15 described above is formed on the surface thereof, blocking of the pavement mixture 10 is suppressed, and oxidation of the asphalt layer 13 and the like formed on the surface is prevented. It is prevented and long-term storage is possible.

  In step S14, construction of roads, ground surfaces, and the like is performed with the paving mixture 10. Specifically, the paving mixture 10 is used by heating it to a predetermined temperature at a construction site by an appropriate method. For example, depending on the amount of the paving mixture 10 to be used, a method of heating and mixing with a hand burner that can be held by one hand and a small shovel, a method of heating and mixing with a propane gas burner having a diameter of about 80 mm to 100 mm with a scoop, or various methods Various construction methods can be adopted according to the situation at the site, such as a method of heating and mixing using a heating mixer for a construction site. In addition, the temperature at the time of construction is the temperature at the time of spreading the petroleum asphalt mixture for paving, which is conventionally performed, and is generally desirably 110 to 140 ° C. Further, when the paving mixture 10 is heated in-situ, as shown in FIG. 4, the above-mentioned separation layer 15 evaporates by heating, and a heated molten asphalt layer 20 is formed.

  Referring to FIG. 6, a case where recycled aggregate is employed as the aggregate 11 will be described. The method for manufacturing the pavement mixture 10 using the recycled aggregate of the present embodiment includes a step S20 of adding a regeneration additive to the aggregate 11 and the recycled aggregate, a step S21 of mixing the asphalt emulsion 18, and a separation layer 15. Generating step S22. Further, the manufactured paving mixture 10 is stored in step S23, and the paving mixture 10 is used for construction in step S24.

  As described above, the method of manufacturing the paving mixture 10 here is roughly the same as the method of manufacturing described with reference to FIG. 5, and the difference is that in step S20, the aggregate 11 that is the recycled aggregate is used. Is to regenerate the asphalt attached to the surrounding area.

  In step S20, the regenerated aggregate adjusted to the particle size of the aggregate 11 to be manufactured is dried and heated to an appropriate amount at an appropriate temperature, and then put into a mixer, and a regenerating additive is added and mixed. As the regeneration additive, for example, those based on the “Pavement Regeneration Handbook” determined by the Japan Road Association can be used. In addition, since the asphalt is already attached around the recycled aggregate, the asphalt content of the asphalt emulsion 18 to be added later can be added to adjust the manufactured pavement mixture 10 to the specification of the asphalt amount%. No additional asphalt is required. In this step, the oil component may be added to the recycled aggregate under a heated condition, or the oil component may be added to the recycled aggregate at normal temperature. The temperature of the recycled aggregate is desirably 100 ° C. or lower. By using recycled aggregate that is as dry as possible, and adding and mixing an appropriate amount of a regeneration additive, it is possible to produce lubrication without load on equipment.

  Details of steps S21, S22, S23, and S24 are the same as steps S11, S12, S13, and S14 described with reference to FIG.

  As described above, by using recycled aggregate as the aggregate 11, the aggregate 11, asphalt, and thermal energy required for the method for manufacturing the paving mixture 10 can be reduced.

<Example>
With reference to the table of FIG. 7, it will be described that the hot-melt asphalt layer 20 of the pavement mixture 10 according to the present embodiment satisfies the asphalt standard used for the hot asphalt mixture. Here, the main items of the asphalt standard are penetration, softening point, elongation, flash point and density. The appropriate range of each item is defined for general areas and general area multi-transport.

  As described above, the present embodiment is an embodiment in which the pavement mixture 10 is manufactured using the new aggregate as the aggregate 11 and an embodiment in which the pavement mixture 10 is manufactured using the recycled aggregate as the aggregate 11. including. Therefore, the paving mixture 10 was manufactured using both embodiments, and the penetration, softening point, elongation, flash point and density of the heated and melted asphalt layer 20 were measured. As a result, in both embodiments, results satisfying almost all items of general area use and general area multi-transport are obtained.

  From the above, the hot-melt asphalt layer 20 of the paving mixture 10 according to the present embodiment, even if the aggregate 11 is a new aggregate, even if it is a recycled aggregate, almost meets the asphalt standard, It can withstand the actual construction of the paving mixture 10.

  With reference to the table of FIG. 8, an example of the method for manufacturing the paving mixture 10 described above will be described. Explaining the conditions of the example, the ambient temperature was 25 ° C., and the molecular weight of sodium hydroxide was 40. The aggregate 11 was not used, and an aqueous solution of an alkali compound (here, an aqueous solution of sodium hydroxide) contained in the asphalt emulsion 18 and the demulsifier 19 and an alcohol (here, ethylene glycol) contained in the demulsifier 19 were mixed in a beaker. As a result, the asphalt emulsion 18 and the demulsifier 19 are separated into the asphalt component of the asphalt emulsion 18 corresponding to the adhesive layer 14 and the liquid corresponding to the separation layer 15, and the hydrogen ion concentration (pH) of the separated liquid is separated. Was measured. Thereafter, the mixture was heated to 80 ° C. to 100 ° C. corresponding to the formation temperature of the paving mixture 10, cooled to room temperature, and the pH of the liquid was measured again. This liquid was cured at room temperature for 72 hours, and the pH of the liquid after curing was measured.

  Here, an ammonia-based emulsion was employed as the asphalt emulsion 18, sodium hydroxide was employed as a solute of the aqueous solution contained in the demulsifier 19, and the amount of the solute was changed to change the pH of the generated liquid. . Further, here, five liquids were generated by changing the amount of solute, and the pH immediately after heating and cooling and the pH after curing for 72 hours were measured for each liquid. The reason for measuring the pH after curing for 72 hours is to confirm that the reaction has subsided and the state is stable.

  As shown in this figure, five samples from sample 1 to sample 5 are generated here. Sample 1 has the highest pH of the generated liquid by adding the most solute of the aqueous solution contained in the demulsifier 19. On the other hand, the sample 5 has the lowest pH of the generated liquid by adding the least amount of solute of the aqueous solution contained in the demulsifier 19. That is, as the item number of the sample increases, the amount of added solute decreases, and the pH of the generated liquid decreases.

  Here, the pH of sample 1 after 72 hours is 11.25. When such a sample is applied to the production of the paving mixture 10, each aggregate 11 can be separated well. However, if the pH is 11.25, there is a possibility that the safety and hygiene of the worker handling the paving mixture 10 may not always be ensured.

  In Samples 2 and 3, the pH after 72 hours is 10.42 and 9.83. When such a sample is applied to the production of the paving mixture 10, the aggregates 11 are separated well. be able to. When the pH is within this range, the worker can safely handle the paving mixture 10.

  In Samples 4 and 5, the pH after 72 hours was 7.74 and 6.73. When such a sample was applied to the production of the paving mixture 10, each aggregate 11 was inadvertently adhered. Blocking has occurred. In particular, in the sample 5, the aggregates 11 adhere to each other. This is because the pH of the liquid generated as the separation layer 15 is close to neutral, so that the ion repulsion rate is low.

  From the above, the preferable range of the pH of the separation layer 15 composed of the generated liquid is 8.0 or more and 11.0 or less, and the particularly preferable range of the pH is 9.0 or more and 10.0 or less. Understand that there is.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and can be modified without departing from the purpose and spirit of the present invention.

  For example, in the above description, when producing the pavement mixture 10, the demulsifier 19 was added after the asphalt emulsion 18 was added, but the order of addition may be reversed.

  Further, as the aggregate 11 used for the paving mixture 10, a mixture of a new aggregate and a recycled aggregate can be employed.

DESCRIPTION OF SYMBOLS 10 Paving mixture 11 Aggregate 12 Coating layer 13 Asphalt layer 14 Adhesive layer 15 Separation layer 16 Asphalt particles 17 Contact part 18 Asphalt emulsion 19 Demulsifier 20 Heat-melted asphalt layer

Claims (3)

Aggregate, comprising a coating layer covering the periphery of the aggregate,
The coating layer,
An asphalt layer made of asphalt covering the periphery of the aggregate,
An adhesive layer covering the asphalt layer and including the asphalt, asphalt emulsion and a demulsifier,
Together covering the external surface of the adhesive layer, have a, a separation layer containing the demulsifier has not reacted with the bitumen emulsion,
The pavement mixture, wherein the pH of the separation layer is 8.0 or more and 11.0 or less . A method for producing a pavement mixture for forming an asphalt layer, an adhesive layer and a separation layer on the surface of the novel aggregate by mixing a new aggregate, asphalt, an asphalt emulsion, and a demulsifier. ,
Mixing the asphalt with the new aggregate;
Mixing the asphalt emulsion with the asphalt and the new aggregate,
Mixing the asphalt, the novel aggregate and the asphalt emulsion with the demulsifier,
In the step of mixing the demulsifier, the asphalt emulsion, by adding the demulsifier containing alcohol having a hydrogen ion concentration of a reaction equivalent or more, the demulsifier not reacted with the asphalt emulsion. A method for producing a paving mixture, comprising: forming the separation layer having a pH of 8.0 or more and 11.0 or less . A method for producing a pavement mixture for forming an adhesive layer and a separation layer on a surface of the asphalt concrete recycled aggregate by mixing an asphalt concrete recycled aggregate, an oil component , an asphalt emulsion, and a demulsifier. And
A step of adding the oil component to the asphalt concrete recycled aggregate,
Mixing the asphalt emulsion with the asphalt concrete recycled aggregate and the oil component,
Mixing the asphalt concrete recycled aggregate, the oil component and the asphalt emulsion with the demulsifier,
In the step of mixing the demulsifier, to the asphalt emulsion, by adding the demulsifier containing an alcohol having a hydrogen ion concentration of a reaction equivalent or more, the demulsifier not reacted with the asphalt emulsion. A method for producing a pavement mixture, comprising producing the separation layer having a pH of 8.0 or more and 11.0 or less .

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