JP2019085322A - Paving mixture and production method thereof - Google Patents

Abstract

To provide a paving mixture capable of storing for a long period of time and developing strength equivalent to a hot asphalt mixture by heating and a production method thereof.SOLUTION: The paving mixture 10 contains an aggregate 11 and a coating layer 12 coating a surface of the aggregate 11. The coating layer 12 contains, from the inside, an asphalt layer 13, an adhesion layer 14, and a separation layer 15. The separation layer 15 is a layer formed by adding a demulsifier 19 to the asphalt emulsion 18.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a paving mixture and a method of manufacturing the same, and more particularly to a paving mixture capable of long-term storage and a method of manufacturing the same.

  In general, asphalt mixtures can be broadly divided into heated asphalt mixtures and cold 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 heated and mixed with aggregate made of crushed stone, sand, filler, etc. and asphalt for paving 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 paving such as roads and ground surfaces or for the repair of these.

  Further, the heated asphalt mixture includes one using a new aggregate and one using an asphalt concrete recycled aggregate. Asphalt concrete recycled aggregate is obtained by crushing and classifying a waste asphalt mixture generated by removing existing pavement and the like. In the following description, asphalt concrete recycled aggregate is described as "regenerated aggregate".

  In addition, the asphalt mixture for paving may be reused by construction. In this case, heat is applied to the construction site and the mixture is scraped with a dedicated device, and a paving asphalt mixture is produced using additives and the like, or the waste asphalt mixture is introduced into a dedicated device and heated to heat the heated asphalt mixture. By manufacturing, it is used for the pavement of roads, the ground surface, etc., or repair of these.

  Furthermore, in the method of producing the asphalt mixture for storage, the asphalt mixture for storage produced by rapid cooling using a dedicated facility immediately after the production of the heated asphalt mixture produced in a general plant is applied. By heating by the appropriate method on the site, it is used for the pavement of roads, ground surfaces, etc., or repair of these.

  On the other hand, the normal temperature asphalt mixture can be paved at normal temperature (100 ° C. or less) by mixing coarse aggregate, fine aggregate and the like with asphalt emulsion etc. at normal temperature. A cold asphalt mixture is generally used as a simple paving material or a repair material because it can be stored although its durability is generally somewhat inferior to that of a heated asphalt mixture.

http: // www. askyo. JP / knowledge / 06-1. html (November 10, 2017) JP 2000-317434 A Unexamined-Japanese-Patent No. 2012-126865

  However, since the heating asphalt mixture produced in the plant is produced using a production apparatus such as a large mixing mixer, the production amount per batch is at least several hundreds kg. Therefore, in the case of small-scale paving and repair, the remaining paving asphalt mixture has to be disposed of, which is not only expensive but also has problems in terms of environmental protection.

  Further, the heated asphalt mixture needs to strictly control the shipment amount from the plant and the delivery time until the construction site arrives after the shipment. Furthermore, when construction was suspended due to sudden change of weather, etc., it was necessary to dispose of the whole produced. In any case, since the heating asphalt mixture corresponds to the amount of paving asphalt mixture exceeding a certain amount or more, installation of the plant is economically difficult in an area where the demand is small, snowfall time, etc. In the low demand period, the plant can not be operated economically.

  Furthermore, although the heated asphalt mixture produced at the construction site does not generate waste asphalt mixture, it is difficult to use it for level difference correction, pothole, weir repair, or new scale pavement etc. . In addition, it is necessary to carry heavy equipment and special equipment for scraping and digging small-scale pavements and repairs in remote areas such as remote islands, which is costly and uneconomical.

  In addition, the asphalt mixture for preservation is to melt and apply the surface of the mixture by applying heat, but the petroleum asphalt for paving is softened in the high temperature season and this mixture is blocked, resulting in a lumped mixture There is a difficult task of heating and melting. In addition, petroleum asphalt for paving belongs to a drying oil, and in particular, in long-term stocks etc., it may be deteriorated by oxidation and a predetermined performance may not be obtained.

  Furthermore, the asphalt mixture for storage is easy to produce with crushed stone No. 6 crushed stone (4.75 to 13.2 mm) aggregate or crushed stone No. 7 aggregate (2.36 mm to 4.75 mm) aggregate. However, with fine aggregate having a diameter of 2.5 mm or less, manufacture is difficult and lightweight aggregates do not separate and form aggregates. In addition, it is difficult to produce various paving mixtures synthesized from No. 6 crushed aggregate, No. 7 crushed aggregate, fine aggregate, filler and the like. In addition, it is necessary to install a dedicated facility in the conventional asphalt-asphalt mixture production plant for paving, which can not be easily produced.

  On the other hand, although a cold asphalt mixture can be stored at normal temperature, it is premised that it is used as a simple paving material and repair material to the last. Thus, cold asphalt mixtures are difficult to use as a substitute for hot asphalt mixtures.

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

  The paving mixture according to the present invention comprises aggregate, and a covering layer covering the periphery of the aggregate, wherein the covering layer is an asphalt layer comprising asphalt covering the periphery of the aggregate, and the asphalt An adhesive layer which covers the periphery of the layer and which contains the asphalt, the asphalt emulsion and the demulsifier, and a separation layer which covers the periphery of the adhesive layer and which does not react with the asphalt emulsion It is characterized by having.

  Furthermore, in the paving mixture according to the present invention, the separation layer is formed by adding the demulsifier containing an alcohol and having a hydrogen ion concentration equal to or more than a reaction equivalent to the asphalt emulsion. .

  Furthermore, in the paving mixture according to the present invention, the pH of the separation layer is 8.0 or more and 11.0 or less.

  Furthermore, in the paving mixture of the present invention, the pH of the separation layer is characterized by being 9.0 or more and 10.0 or less.

  Furthermore, the present invention is a method for producing a paving mixture comprising a novel aggregate, asphalt, an asphalt emulsion, and a demulsifier, wherein an alcohol has a hydrogen ion concentration equal to or more than the reaction equivalent to the asphalt emulsion. By forming the separated layer containing the demulsifier which has not reacted with the asphalt emulsion.

  Furthermore, in the method of producing a mixture for paving according to the present invention, the pH of the separation layer is 8.0 or more and 11.0 or less.

  Furthermore, in the method of producing a mixture for paving according to the present invention, the pH of the separation layer is 9.0 or more and 10.0 or less.

  Furthermore, the method for producing a paving mixture according to the present invention is characterized in that the asphalt emulsion and the demulsifier are mixed after the asphalt is mixed with the novel aggregate.

  Furthermore, the mixture for paving according to the present invention is a method for producing a mixture for paving which mixes asphalt concrete recycled aggregate, asphalt, an asphalt emulsion, and a demulsifier with a reaction equivalent or more with respect to the asphalt emulsion. By adding the demulsifier having a hydrogen ion concentration and containing an alcohol, a separated layer containing the demulsifier which has not reacted with the asphalt emulsion is produced.

  Furthermore, in the method of producing a mixture for paving according to the present invention, the pH of the separation layer is 8.0 or more and 11.0 or less.

  Furthermore, in the method of producing a mixture for paving according to the present invention, the pH of the separation layer is 9.0 or more and 10.0 or less.

  Furthermore, the method for producing a paving mixture according to the present invention is characterized in that the asphalt emulsion and the demulsifier are mixed after the oil component is added to the regenerated aggregate at normal temperature.

  The paving mixture according to the present invention comprises aggregate, and a covering layer covering the periphery of the aggregate, wherein the covering layer is an asphalt layer comprising asphalt covering the periphery of the aggregate, and the asphalt An adhesive layer which covers the periphery of the layer and which contains the asphalt, the asphalt emulsion and the demulsifier, and a separation layer which covers the periphery of the adhesive layer and which does not react with the asphalt emulsion It is characterized by having. Therefore, since the outermost layer of the coating layer covering the aggregate has a separation layer containing a demulsifier that has not reacted with the asphalt emulsion, the contact between the asphalt layer and the adhesive layer with the external atmosphere is suppressed. Oxidation of these layers is suppressed. Thus, the paving mixture can be stored for a long time. Moreover, when using the mixture for paving for paving or repair, a separation layer evaporates by heating. Furthermore, the asphalt layer and the adhesive layer are integrated by being heated and melted, and by forming the heated and molten asphalt layer, the same structure as the heated asphalt mixture is obtained, and it can be used as a so-called heating mixture. Therefore, the paving mixture of the present invention can be stored for a long time at normal temperature like a cold asphalt mixture, and further has sufficient strength like a heated asphalt mixture.

  Furthermore, in the paving mixture according to the present invention, the separation layer is formed by adding the demulsifier containing an alcohol and having a hydrogen ion concentration equal to or more than a reaction equivalent to the asphalt emulsion. . Therefore, the water generated by adding a demulsifier containing an alcohol and having a hydrogen ion concentration equal to or higher than the reaction equivalent and the alcohol contained in the demulsifier mix to form a separated layer having lubricity with a mixture of both can do.

  Furthermore, in the paving mixture according to the present invention, the pH of the separation layer is 8.0 or more and 11.0 or less. Therefore, when the pH of the separation layer is 8.0 or more, the state in which each aggregate is separated can be maintained, and further, when the pH of the separation layer is 11.0 or less, the worker handling the paving mixture Security can be ensured.

  Furthermore, in the paving mixture of the present invention, the pH of the separation layer is characterized by being 9.0 or more and 10.0 or less. Therefore, it is possible to maintain the state in which the aggregates are separated, and to make the effect of ensuring the safety of the workers remarkable.

  Furthermore, the present invention is a method for producing a paving mixture comprising a novel aggregate, asphalt, an asphalt emulsion, and a demulsifier, wherein an alcohol has a hydrogen ion concentration equal to or more than the reaction equivalent to the asphalt emulsion. By forming the separated layer containing the demulsifier which has not reacted with the asphalt emulsion. Therefore, it is possible to easily form a separation layer that prevents oxidation of the asphalt layer and the adhesive layer formed around the aggregate. Furthermore, in the method for producing a paving mixture according to the present invention, the separation layer is formed by adding the demulsifier, which has a hydrogen ion concentration of a reaction equivalent or more and contains an alcohol, to the asphalt emulsion. It features. Therefore, the water generated by adding the demulsifier containing an alcohol having a hydrogen ion concentration equal to or higher than the reaction equivalent and the alcohol contained in the demulsifier are mixed, and a separation layer having lubricity with a mixture of both is obtained. Can be generated.

  Furthermore, in the method of producing a mixture for paving according to the present invention, the pH of the separation layer is 8.0 or more and 11.0 or less. Therefore, when the pH of the separation layer is 8.0 or more, the state in which each aggregate is separated can be maintained, and further, when the pH of the separation layer is 11.0 or less, the worker handling the paving mixture Security can be ensured.

  Furthermore, in the method of producing a mixture for paving according to the present invention, the pH of the separation layer is 9.0 or more and 10.0 or less. Therefore, it is possible to maintain the state in which the aggregates are separated, and to make the effect of ensuring the safety of the workers remarkable.

  Furthermore, the method for producing a paving mixture according to the present invention is characterized in that the asphalt emulsion and the demulsifier are mixed after the asphalt is mixed with the novel aggregate. Therefore, the separation layer can be suitably formed on the outermost periphery of the novel aggregate.

  Furthermore, the mixture for paving according to the present invention is a method for producing a mixture for paving which mixes asphalt concrete recycled aggregate, asphalt, an asphalt emulsion, and a demulsifier with a reaction equivalent or more with respect to the asphalt emulsion. By adding the demulsifier having a hydrogen ion concentration and containing an alcohol, a separated layer containing the demulsifier which has not reacted with the asphalt emulsion is produced. Therefore, it is possible to easily form a separation layer that prevents oxidation of the asphalt layer and the adhesive layer formed around the aggregate. Furthermore, in the method for producing a paving mixture according to the present invention, the separation layer is formed by adding the demulsifier, which has a hydrogen ion concentration of a reaction equivalent or more and contains an alcohol, to the asphalt emulsion. It features. Therefore, the water generated by adding the demulsifier containing an alcohol having a hydrogen ion concentration equal to or higher than the reaction equivalent and the alcohol contained in the demulsifier are mixed, and a separation layer having lubricity with a mixture of both is obtained. Can be generated. Furthermore, since the recycled aggregate is used, asphalt adhering to the periphery of the recycled aggregate can be reused, which can contribute to resource saving.

  Furthermore, in the method of producing a mixture for paving according to the present invention, the pH of the separation layer is 8.0 or more and 11.0 or less. Therefore, when the pH of the separation layer is 8.0 or more, the state in which each aggregate is separated can be maintained, and further, when the pH of the separation layer is 11.0 or less, the worker handling the paving mixture Security can be ensured.

  Furthermore, in the method of producing a mixture for paving according to the present invention, the pH of the separation layer is 9.0 or more and 10.0 or less. Therefore, it is possible to maintain the state in which the aggregates are separated, and to make the effect of ensuring the safety of the workers remarkable.

  Furthermore, the method for producing a paving mixture according to the present invention is characterized in that the asphalt emulsion and the demulsifier are mixed after the oil component is added to the regenerated aggregate at normal temperature. Therefore, the energy required for the method of producing the 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 a paving mixture concerning an embodiment of the present invention, and (A) and (B) are an expanded sectional view of a paving mixture. It is a figure showing a paving mixture concerning an embodiment of the present invention, and (A) and (B) are an expanded sectional view of a paving mixture. It is a figure which shows the mixture for paving which concerns on embodiment of this invention, and is an expanded sectional view of the mixture for paving. It is a flowchart which shows the manufacturing method of the mixture for paving using the novel aggregate which concerns on embodiment of this invention, and sectional drawing which shows the state of the mixture for paving in each process. It is a flowchart which shows the manufacturing method of the mixture for paving using the reproduction | regeneration aggregate which concerns on embodiment of this invention, and sectional drawing which shows the state of the mixture for paving 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 isolation | separation liquid formed on the surface of the mixture for paving which concerns on embodiment of this invention.

  Hereinafter, the mixture 10 for paving which concerns on one Embodiment of this invention, and its manufacturing method are demonstrated in detail based on drawing. In the following description, the same reference numerals will be used in principle for the same members, and repeated descriptions will be omitted.

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

  Referring to FIG. 1 (A), paving mixture 10 has aggregate 11 and a covering layer 12 for covering the surface of aggregate 11. The paving mixture 10 can be stored for a long time at normal temperature, for example, in a bag-packed state every several tens kg, as described later. Furthermore, the paving mixture 10 is heated so that the coating layer 12 melts and the paving mixture 10 adheres to each other, and since the coating layer 12 hardens by cooling in the adhered state, high strength is achieved. Demonstrate. That is, the paving mixture 10 has excellent storability such as a cold asphalt mixture, and can obtain the same high strength as the 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 stone or the like adjusted to have a predetermined particle size. The particle size of the aggregate 11 is based on, for example, the "paving construction manual" defined by the Japan Road Association. The aggregate 11 is made of crushed stone, sand, a filler and the like.

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

  In FIG. 1 (B), the boundary enlarged sectional view of the mixture 10 for pavements is shown typically. The covering layer 12 covering the aggregate 11 has, from the inside, an asphalt layer 13, an adhesive layer 14 and a separation layer 15. Moreover, the separation layer 15 which is the outermost layer of the covering layer 12 may be shared by the mixture 10 for paving on the right side on the paper surface and the mixture 10 for paving on the left side on the paper surface. Further, the contact point between the separation layer 15 of the paving mixture 10 on the right on the drawing and the separation layer 15 of the paving mixture 10 on the left on the drawing is indicated by a dotted line (contact portion 17) on the drawing.

  The asphalt layer 13 is a paving petroleum asphalt, and may further be a regenerated asphalt obtained by adding a regeneration additive to asphalt contained in a waste asphalt mixture discharged from a construction site or the like. As the regeneration additive, for example, it is desirable to use one that complies with the "Pavement Regeneration Handbook" defined by the Japan Road Association. In addition, since asphalt is already adhered around the recycled aggregate, the asphalt content of asphalt emulsion 18 to be added later can be changed to adjust the manufactured paving mixture 10 to be within the specification of asphalt amount%. , No additional asphalt input is required.

  The adhesive layer 14 is a layer formed by adding the asphalt emulsion 18 to the paving asphalt forming the asphalt layer 13, and is a layer that exhibits adhesion. Here, as the asphalt emulsion 18, petroleum asphalt cation emulsion (JIS K 2208) which is generally sold and used, various petroleum asphalt cation emulsions which are generally sold and used, or petroleum asphalt having both polarity are used. Ionized emulsions can be employed.

  The separation layer 15 is a layer containing the demulsifier 19 which 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 an alcohol. As the asphalt particles 16 adhere to the asphalt layer 13 which is similar, the decomposed water mixes with the unreacted demulsifier 19.

  The above-mentioned asphalt emulsion 18 is a petroleum asphalt cationic emulsion, and is a commercially available cationic emulsion (JIS K 2208) or a cationic emulsion such as various cationic emulsions which are generally marketed and used. Petroleum asphalt amphoteric ionizable emulsions can be employed. Among the asphalt emulsions 18, an emulsion having an optimum asphalt content and asphalt penetration degree can be selected according to the purpose of use and the degree of deterioration of asphalt adhering to the recycled aggregate. In addition, the asphalt emulsion 18 can adjust the asphalt physical properties of the final mixture to the physical properties (penetration degree, softening point, elongation, etc.) of asphalt within a desired standard. In addition, when adjusting the amount of asphalt emulsion 18 to be added, the water content of asphalt emulsion 18 and the water content of demulsifier 19 are 2% or less of the total except for volatile components after forming paving mixture 10 Is desirable.

  The above-described demulsifier 19 is an aqueous solution of at least one of an alkali metal compound or an alkali metal earth compound having a hydrogen ion concentration of pH 11.0 or more, and a flash point of 100 ° C. or more and 170 ° C. or less 2 A polyhydric alcohol or a trivalent alcohol having a flash point of 100 ° C. or more and 170 ° C. or less is added. Also, the water decomposed from the asphalt emulsion 18 mixes with the demulsifier 19 and remains as a separation layer 15 having alcohol lubricity.

  The aqueous solution contained in the demulsifier 19 is preferably an aqueous solution of relatively widely used compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium metasilicate and potassium metasilicate. Moreover, about sodium hydroxide and potassium hydroxide, the aqueous solution which corresponds to the general thing whose density | concentration is 5% or less is desirable.

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

  The amount of demulsifier 19 added varies with the asphalt content of the asphalt emulsion 18 used and the hydrogen ion concentration, so the water content of the asphalt emulsion 18 and the water content of the demulsifier 19 after the paving mixture 10 is formed Adjust volatiles so that it is 2% or less of the total mixture, the hydrogen ion concentration shows a weak alkaline area of pH 8.0 to pH 11.0, and the amount of residual alcohol is 1% or less of the total mixture. Is desirable. 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 at a temperature of 100 ° C. or less to the asphalt emulsion 18 to be used. In addition, if the molar concentration of the asphalt emulsion 18 to be used is known, it is possible to make adjustments by deriving an equivalent molar amount by calculating the molar concentration of the demulsifier 19 to be used.

  The separation layer 15 is composed of, for example, residual moisture of 2% or less and residual alcohol of 1% or less, and the separation layer 15 of this weak alkali region is 0.5% or more and 3% or less of the total amount of the paving mixture 10 Is desirable. Furthermore, the separation layer 15 is sparingly volatile having the repulsion property of the same type ion and the lubricity of the dihydric and trihydric alcohols, and is not influenced by the pressure due to the load or the temperature change in the normal temperature range. Moreover, 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, whereby 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 is such that the aggregate 11 coagulates even when the paving mixture 10 is stored for a long period of time It is considered as the range which can maintain the health and safety environment of the worker who is engaged in manufacture of the mixture 10 for paving, without blocking by doing. Specifically, a suitable range of the pH of the separation layer 15 is, for example, 8.0 or more and 11.0 or less. The state in which each aggregate 11 is separated can be maintained because the pH of the separation layer 15 is 8.0 or more, and the work of handling the paving mixture 10 because the pH of the separation layer 15 is 11.0 or less Safety of personnel can be secured. Moreover, the 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 it as such a range, the above-mentioned effect can be made remarkable.

  As described above, the paving mixture 10 has the separation layer 15 at the outermost periphery thereof, and the separation layer 15 is generated from an aqueous alkaline solution, alcohol, and water decomposed from the asphalt emulsion 18. Therefore, when the paving mixture 10 is stored, the quality of the paving mixture 10 is not influenced by the pressure due to the load or the temperature change in the normal temperature range. Furthermore, since the separation layer 15 exhibits weak alkalinity, oxidation of the asphalt layer 13 is prevented, and deterioration of the paving mixture 10 is suppressed. Therefore, the mixture 10 for pavement can be preserve | saved over a long period, and it can adapt to various pavements by carrying out heating mixing at a construction site.

  Further, since the separation layer 15 is negatively charged, the separation layer 15 formed around the left aggregate 11 and the separation formed around the right aggregate 11 in the drawing are separated. The layers 15 repel each other. Therefore, even when the paving mixture 10 is stored in a storage bag for a long time, blocking of the paving mixture 10 can be suppressed.

  Furthermore, since the paving mixture 10 can be stored in a bagged state for a long period of time, it is suitable for stockpiling for disasters, repairing or preparing a remote place such as a remote island, or a road in snowfall season without plant operation. Furthermore, according to the situation of the site, by mixing the paving mixture 10 by an appropriate method, it is possible to easily manufacture a paving petroleum asphalt mixture in a quality controled particle size range that conforms to the standards of various places for paving. . In addition, the existing paving oil asphalt manufacturing plant can be relatively easily produced without additional facilities, and the materials used can also be provided universally and easily, so that they can be provided economically without any load.

  Next, with reference to FIGS. 2 to 4, the reaction that occurs around the aggregate 11 when producing the paving mixture 10 will be described. Each of FIGS. 2 to 4 is a cross-sectional view showing a boundary portion between the aggregates 11 in an enlarged manner.

  Referring to FIG. 2 (A), first, the surface of aggregate 11 is covered with asphalt layer 13. Asphalt emulsion 18 and demulsifier 19 are present around asphalt layer 13. Asphalt emulsion 18 contains positively charged asphalt particles 16. As described above, the demulsifier 19 exhibits alkalinity by having a hydrogen ion concentration equal to or higher than the reaction equivalent to the asphalt emulsion 18, and is negatively charged.

  Referring to FIG. 2 (B), next, asphalt emulsion 18 and demulsifier 19 are mixed on a molecular level by mixing asphalt emulsion 18 and demulsifier 19, and asphalt particles contained in asphalt emulsion 18 are mixed. 16 are electrically neutralized. Further, as described above, since the hydrogen ion concentration is higher than the reaction equivalent with respect 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, as described above, asphalt particles 16 contained in asphalt emulsion 18 are electrically neutralized, and therefore, asphalt particles 16 adhere to the surface of asphalt layer 13 which is similar. Do.

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

  Referring to FIG. 4, when performing road construction and 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 described above evaporates. Further, the asphalt layer 13 and the adhesive layer 14 described above become an integrated heat-melted asphalt layer 20, and the heat-melted asphalt layer 20 bonds the paving mixture 10 together.

<Method of Producing Mixture 10 for Pavement>
Next, with reference to the flowcharts of FIGS. 5 and 6, a method of manufacturing the paving mixture 10 having the above-described configuration will be described. The case where a new aggregate is adopted as the aggregate 11 will be described with reference to FIG. Moreover, with reference to FIG. 6, the case where a regenerated aggregate is employ | adopted as the aggregate 11 is demonstrated.

  Referring to FIG. 5, in the method for producing paving mixture 10 using the novel aggregate of this embodiment, step S10 of mixing aggregate 11 and asphalt, step S11 of mixing asphalt emulsion 18, and separation layer And 15) generating S15. Furthermore, the manufactured paving mixture 10 is stored at step S13, and the paving mixture 10 is used for construction at step S14. In this figure, next to each step, a schematic cross section of the aggregate 11 in that step is shown.

  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 a general-purpose plant for producing a heated asphalt mixture or a cold asphalt mixture. It can be manufactured.

  First, in step S10, the aggregate 11 and asphalt are mixed. As the aggregate 11, as described above, a mixture of crushed stone, sand and a filler can be adopted. In practice, after appropriately drying and heating the aggregate 11 of the appropriately adjusted particle size to an appropriate temperature, the aggregate 11 of the desired particle size range is introduced into the mixer, and the filler in the normal temperature range and the heated petroleum asphalt for paving are orderd Add and mix. In this step, it is desirable that the temperature of the aggregate 11 is 100 ° C. or less, so use the aggregate 11 as dry as possible, adjust the drying heating temperature, and further heat the filler in the normal temperature range to an appropriate temperature Add and mix after adding and mixing the paving petroleum asphalt. By doing this, there is no load on equipment and the like, and the mixture can be manufactured for lubrication. Moreover, the mixing of this step is performed, for example, under the condition that the temperature of each material is 80 ° C. or higher.

  In step S11, asphalt emulsion 18 is added to and mixed with the mixture of aggregate 11 and asphalt layer 13. The type and the like of the asphalt emulsion 18 are as described above. For example, a petroleum asphalt cation emulsion as asphalt emulsion 18 is added at normal temperature. Through 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 adopted as the aggregate 11, step S10 for adhering asphalt around the new aggregate is essential, while when a regenerated aggregate is adopted as the aggregate 11, the step S10 is It becomes unnecessary. This is because the recycled aggregate has asphalt adhering to the periphery of the recycled aggregate.

  In step S12, the 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, a demulsifier 19 of a petroleum asphalt cationic emulsion is charged and mixed in a proper amount at normal temperature. Through 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 added and added from the input port installed in the mixer portion of the plant. Furthermore, commonly used additives and pigments for asphalt are also introduced in the same manner.

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

  Here, in the present embodiment, a demulsifier 19 having a hydrogen ion concentration equal to or greater than the reaction equivalent to the asphalt emulsion 18 and containing an alcohol is added and mixed. In this way, the asphalt emulsion 18 breaks down and the broken asphalt particles that are similar adhere to the asphalt layer 13.

  Furthermore, in this step, the 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 in such a range. The state in which each aggregate 11 is separated can be maintained because the pH of the separation layer 15 is 8.0 or more, and the work of handling the paving mixture 10 because the pH of the separation layer 15 is 11.0 or less Safety of personnel can be secured. Moreover, the 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 it as such a range, the above-mentioned effect can be made remarkable.

  In step S13, the paving mixture 10 manufactured by the above-described process is stored by bagging every several tens kg. The paving mixture 10 according to the present embodiment has the above-described separation layer 15 formed on the surface, so blocking of the paving mixture 10 is suppressed and oxidation of the asphalt layer 13 and the like formed on the surface is prevented. It is prevented and can be stored for a long time.

  In step S14, construction of a road, a ground surface, etc. is performed with the mixture 10 for paving. Specifically, the paving mixture 10 is used by heating to a predetermined temperature by an appropriate method at a construction site. For example, depending on the amount of the paving mixture 10 used, a method of heating and mixing with a hand burner that can be held with one hand and a small shovel, a method of heating and mixing with a propane gas burner and a scoop with an aperture of about 80 mm to 100 mm, or various methods Various construction methods can be adopted according to the situation of 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 which the paving oil-asphalt mixture is conventionally spread, and it is generally desired that the temperature be 110 ° C. to 140 ° C. In addition, when the paving mixture 10 is heated in situ, as described in FIG. 4, the separation layer 15 described above is evaporated by heating, and a heated molten asphalt layer 20 is formed.

  The case where a recycled aggregate is adopted as the aggregate 11 will be described with reference to FIG. In the method of producing the paving mixture 10 using the recycled aggregate of the present embodiment, the step S20 of adding a regeneration additive to the aggregate 11 and the recycled aggregate, the step S21 of mixing the asphalt emulsion 18, and the separation layer 15 And generating step S22. Furthermore, the manufactured paving mixture 10 is stored at step S23, and the paving mixture 10 is used for construction at step S24.

  As described above, the method for producing the paving mixture 10 in this case is roughly the same as the production method described with reference to FIG. 5, and the difference is the aggregate 11 which is the recycled aggregate in step S20. It is to regenerate asphalt adhering to the surroundings of

  In step S20, the regenerated aggregate adjusted to the particle size of the aggregate 11 to be produced is dried and heated to an appropriate temperature and an appropriate temperature, and then added to a mixer to add and mix a regeneration additive. As the regeneration additive, for example, those complying with the "Pavement Regeneration Handbook" defined by the Japan Road Association can be used. In addition, since asphalt is already adhered around the regenerated aggregate, the asphalt content of asphalt emulsion 18 to be added later can be added to adjust the manufactured paving mixture 10 to be within the specification of asphalt amount%. , No additional asphalt input is required. In this step, the oil component may be added to the regenerated aggregate under heated conditions, or the oil component may be added to the regenerated aggregate at normal temperature. The temperature of the regenerated aggregate is desirably 100 ° C. or less, and by using the regenerated aggregate as dry as possible, by adding and mixing an appropriate amount of regeneration additive, the equipment can be manufactured with no load and can be manufactured for lubrication.

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

  As described above, by employing the recycled aggregate as the aggregate 11, it is possible to reduce the aggregate 11, asphalt and thermal energy required for the method of manufacturing the mixture 10 for paving.

<Example>
With reference to the table | surface of FIG. 7, it demonstrates that the heating melting asphalt layer 20 of the mixture 10 for pavers concerning this embodiment mentioned above satisfy | fills the asphalt specification used for a heating asphalt mixture. Here, the main items of the asphalt standard are penetration, softening point, elongation, flash point and density. In addition, the appropriate range of each item is defined for general area and general area traffic.

  As mentioned above, this embodiment manufactures the mixture 10 for pavement using the novel aggregate for the aggregate 11, and the embodiment for manufacturing the mixture 10 for pavement using the reproduction aggregate for the aggregate 11 including. Therefore, the mixture 10 for pavement was manufactured using both embodiment, and the penetration, the softening point, the elongation, the flash point, and the density were measured about the heating fusion asphalt layer 20. As a result, in both embodiments, the results satisfying most items for general area and general area traffic are obtained.

  From the above, the heated molten asphalt layer 20 of the mixture 10 for paving according to the present embodiment substantially meets the asphalt standard whether the aggregate 11 is a new aggregate or a recycled aggregate, It can withstand the actual construction of the paving mixture 10.

  An example of the method for producing the paving mixture 10 described above will be described with reference to the table of FIG. The atmospheric temperature is 25 ° C., and the molecular weight of sodium hydroxide is 40. Further, the aggregate 11 is not used, and an asphalt emulsion 18, an aqueous solution of an alkali compound contained in the demulsifier 19 (here, an aqueous sodium hydroxide solution) and an alcohol contained in the demulsifier 19 (here ethylene glycol) are mixed in a beaker By separating the asphalt emulsion 18 and the demulsifier 19 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 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. In addition, this liquid was allowed to cure 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 the solute of the aqueous solution contained in the demulsifier 19, and the pH of the liquid produced was changed by changing the amount of the solute. . Furthermore, here, five liquids were produced by changing the amount of solute, and the pH immediately after heating and cooling and the pH after aging 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 is stable and stable.

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

  Here, the sample 1 has a pH of 11.25 after 72 hours, and when such a sample is applied to the production of the paving mixture 10, the respective aggregates 11 can be separated well. However, if the pH is 11.25, the safety and health of the worker who handles the mixture 10 for paving may not necessarily be ensured.

  In Samples 2 and 3, the pH after 10.72 hours is 10.42 and 9.83, and when such samples are applied to the formation of the paving mixture 10, each aggregate 11 is separated well be able to. Also, if the pH is in this range, the worker can handle the paving mixture 10 safely.

  The samples 4 and 5 had pHs of 7.74 and 6.73 after 72 hours, and when such samples were applied to the formation of the mixture 10 for pavement, each aggregate 11 was carelessly adhered Blocking has occurred. In particular, in the sample 5, the respective aggregates 11 are in close contact. This is because the pH of the liquid produced as the separation layer 15 is close to neutral, and the ion repulsion rate is low.

  From the above, the preferable range of the pH of the separation layer 15 composed of the liquid to be produced is 8.0 or more and 11.0 or less, and the particularly preferable pH range is 9.0 or more and 10.0 or less I understand that there is.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, It can change in the range which does not deviate from the objective of this invention, and the meaning.

  For example, in the above description, the demulsifier 19 is added after the asphalt emulsion 18 is added in producing the paving mixture 10, but the order of addition can be reversed.

  Moreover, as the aggregate 11 used for the mixture 10 for paving, the mixture of a novel aggregate and a regenerated aggregate is also employable.

10 pavement mixture 11 aggregate 12 coating layer 13 asphalt layer 14 adhesive layer 15 separation layer 16 asphalt particle 17 contact portion 18 asphalt emulsion 19 demulsifier 20 heating melting asphalt layer

Claims (12)

Comprising an aggregate and a covering layer covering the periphery of the aggregate;
The covering layer is
An asphalt layer comprising asphalt coating the periphery of the aggregate;
An adhesive layer covering the periphery of the asphalt layer and containing the asphalt, an asphalt emulsion and a demulsifier;
And a separation layer which covers the periphery of the adhesive layer and which contains the demulsifier which has not reacted with the asphalt emulsion.   The paving mixture according to claim 1, wherein the separation layer is formed by adding the demulsifier containing an alcohol and having a hydrogen ion concentration of a reaction equivalent or more to the asphalt emulsion. .   The mixture for paving according to claim 1 or 2, wherein the pH of the separation layer is 8.0 or more and 11.0 or less.   The pavement mixture according to claim 3, wherein the pH of the separation layer is 9.0 or more and 10.0 or less. A method of producing a paving mixture comprising a novel aggregate, asphalt, an asphalt emulsion, and a demulsifier,
The separation layer containing the demulsifier which has not reacted with the asphalt emulsion is formed by adding the demulsifier which has a hydrogen ion concentration of the reaction equivalent or more and contains an alcohol to the asphalt emulsion. Method of producing a mixture for paving.   The pH of the said separated layer is 8.0 or more and 11.0 or less, The manufacturing method of the mixture for paving of Claim 5 characterized by the above-mentioned.   The pH of the said separated layer is 9.0 or more and 10.0 or less, The manufacturing method of the mixture for paving of Claim 6 characterized by the above-mentioned.   The method for producing a paving mixture according to any one of claims 5 to 7, wherein the asphalt emulsion and the demulsifier are mixed after the asphalt is mixed with the novel aggregate. The asphalt concrete recycled aggregate, asphalt, asphalt emulsion, and demulsifier mixing method of the paving mixture,
The separation layer containing the demulsifier which has not reacted with the asphalt emulsion is formed by adding the demulsifier which has a hydrogen ion concentration of the reaction equivalent or more and contains an alcohol to the asphalt emulsion. Method of producing a mixture for paving.   The method according to claim 9, wherein the pH of the separation layer is 8.0 or more and 11.0 or less.   The method according to claim 10, wherein the pH of the separation layer is 9.0 or more and 10.0 or less.   The method for producing a pavement mixture according to any one of claims 9 to 11, wherein the asphalt emulsion and the demulsifier are mixed after adding an oil component to the regenerated aggregate at normal temperature.

Images