JP4744210B2 - Method for producing recycled asphalt mixture - Google Patents

Description

  The present invention relates to a method for producing a regenerated asphalt mixture for regenerating an already laid asphalt mixture.

  For example, when repairing an existing asphalt road, it is known to pave the road using a regenerated asphalt mixture that is a mixture of new asphalt material and asphalt generating material generated when the existing asphalt is crushed. (For example, see Patent Document 1).

  In order to better understand the present invention, a conventional reclaimed asphalt mixture manufacturing apparatus and method will be described with reference to FIGS.

  In FIG. 3, the regenerated asphalt mixture manufacturing apparatus (manufacturing plant) includes an asphalt plant 1, a regenerated aggregate heating apparatus 2, a dust and smoke emission treatment device 3, and a dust and smoke emission line L.

  The asphalt plant 1 includes a mixing tower comprising a hot bin 12 having a screen 11 at the top, a weighing device 13 provided below the hot bin 12, and a mixer 14 provided below the weighing device 13. M is installed.

  A dryer 15 is installed beside the mixing tower M, and new aggregate is put into the dryer 15 by a conveyor 17 from a material stock hopper 16.

  Aggregate heated by the dryer 15 is put into the hot bin 12 by an aggregate conveying elevator 18.

  On the other hand, the recycled aggregate heating device 2 has a recycle dryer 24, and recycled aggregate, that is, asphalt generating material recovered from the repaired pavement, is passed from the recycled aggregate hopper 21 through the belt conveyor 22. The elevator 23 is configured to be put into the recycle dryer 24.

Here, the asphalt generating material collected from the repaired pavement is firstly sorted into a 40 mm or less object and a 40 mm or more object by a grizzly feeder (not shown) of a crushing plant (not shown).
Items of 40 mm or less are reused as they are for reclaimed crusher runs.
On the other hand, a part of 40 mm or more is mechanically crushed by a primary crusher (not shown), applied to a vibration sieving machine (not shown), and regenerated bone having a fine particle size by a secondary crusher (not shown) and a vibration sieving machine (not shown). Get the material.
Alternatively, after being crushed by a steam box type crusher (not shown), a recycled aggregate is obtained by using a vibrating sieve machine (not shown), or after being crushed by a hot water tank type crusher (not shown), the recycled aggregate is applied to a vibrating sieve machine (not shown). Furthermore, recycled aggregate is obtained by a hot air rotary kiln (not shown).
The recycled aggregates thus obtained are classified into, for example, three classes according to the size of the particle diameter, and the recycled aggregates having the three classes of particle diameters are put into the recycle dryer 24 at a prescribed ratio. .

  Furthermore, the recycled aggregate heating device 2 includes a skip elevator 25 and a surge bin 26 provided with a measuring means (not shown). The asphalt generating material charged in the recycle dryer 24 is heated by the recycle dryer 24, charged into the surge bin 26 by the skip elevator 25, weighed by a measuring means (not shown) of the surge bin 26, and then measured by the shooter S. It is configured to be fed into the mixer 14.

  A dry cyclone 27 and a blower 28 are installed beside the recycle dryer 24 so that dust generated by the recycle dryer 24 is captured by the dry cyclone 27 and the remaining exhaust gas is sent to a bug filter 31 described later by the blower 28. It is configured.

  One end of the dust line L is connected to the dryer 15, and a bag filter 31, an intake blower 32, a deodorizing device 33, and a smoke exhausting device 34 are interposed in the path, and the exhaust gas generated in the dryer 15 and the recycling dryer 24. The exhaust gas generated in is gradually dedusted and deodorized from the dust line L, and is discharged from the smoke exhaust device 34 to the atmosphere.

As shown in FIG. 4, the method for producing a regenerated asphalt mixture is as follows. First, in the asphalt plant 1, a new material, fine grain Ma1, aggregate “A” Ma2, and aggregate “B” Ma3, 3 are simultaneously heated by the dryer 15 (step Sa11).
The heating temperature at this time is set to 170 to 180 ° C., which is about the same as the temperature immediately after the production of the regenerative heating asphalt mixture Mx which is a product.

  The heated new material is heated by the dryer 15 and then put into the hot bin 12 by the aggregate conveying elevator 18, and the screen 11 of the hot bin 12 has a large particle size Ma11 and a medium size Ma12. It is sieved to class Ma13 (step Sa12), each is weighed by the weighing device 13 (step Sa13), and is put into the mixer 14.

  On the other hand, in a crushing plant (not shown), the asphalt generating material Mb1 recovered from the modified paved road is crushed by the method described above (step Sb11), and the class Mb11 having a particle size of 0 to 2.5 mm and 2 Sieve into three groups of class Mb12 of 5 to 5.0 mm and class Mb13 of 5.0 to 13.0 mm or greater than 13.0 mm (step Sb12). The cutting material Mc is divided into the same three groups without being crushed.

  The asphalt generating materials Mb11, Mb12, and Mb13 that have been sieved into the above three classes are weighing means (not shown) of the surge bin 26 of the recycled aggregate heating device 2, and each has an appropriate amount (for example, 10% for Mb11, 30% for Mb12, Mb13 is measured to 60% (step Sb13), and an appropriate amount is fed from the recycled aggregate hopper 21 of the recycled aggregate heating device 2 to the recycle dryer 24 via the belt conveyor 22 and the elevator 23. And it heats to 160-180 degreeC with the recycle dryer 24 (process Sb14).

  Class Mb11 having a particle diameter of 0 to 2.5 mm, class Mb12 having a particle diameter of 2.5 to 5.0 mm, and class having a particle diameter of 5.0 to 13.0 mm or 13 heated to 160 to 180 ° C. by the recycle dryer 24 Class Mb13 exceeding 0.0 mm is fed from the shooter S to the mixer 14 into which the new materials Mb11, Mb12, and Mb13 that have been sieved are placed in the asphalt plant 1 and mixed by the mixer 14 (step Sa14).

  A new asphalt is added to the mixture mixed by the mixer 14 (step Sa15), and further an additive is added (step Sa16), and the regenerated and heated asphalt mixture Mx as a product is completed.

  The temperature of the mixture immediately after completion of the regeneratively heated asphalt mixture Mx is 160 to 180 ° C.

However, in such recycled asphalt manufacturing apparatus and manufacturing method, the asphalt mixture, which is an aggregate used, has various properties, and some of them have a high viscosity with an asphalt softening point of 80 ° C. or higher.
FIG. 5 is a table showing the heating temperature for each material (type) of paving petroleum asphalt. That is, the softening point varies depending on the asphalt material for paving, and the optimum temperature is selected as the heating standard temperature within the range shown in the table of FIG.
Usually, in a drainage asphalt mixture, the viscosity is increased by a chemical substance such as a polymer (softening point is increased). When a highly viscous asphalt mixture is crushed and heated, a small particle size, for example, 2.5 mm or less, is an asphalt mortar adhering, that is, a mixture of asphalt, sand and stone powder. It melts and adheres to the heating device, and the deposit grows into a lump. As a result, the efficiency of the heating device is reduced, and the lump is heated for a long time, so that the asphalt is scorched and generates odor.
JP 2004-243150 A

  Accordingly, an object of the present invention is to provide a method for producing an asphalt mixture in which asphalt mortar does not adhere to a heating device even when a mixture using a highly viscous asphalt is used.

  According to the present invention, the existing asphalt generating material (Mb1) is crushed (step Sb1) and sieved (step Sb3), and the sieved crushed material is separated for each predetermined particle size (Mb11, Mb12, Mb13). (Step Sb4) and heated (step Sb6), on the other hand, the new aggregate for asphalt mixture (Ma1, Ma2, Ma3) is heated to 180-230 ° C. (step Sa1), and the heated aggregate is Weighing for each predetermined particle size (Ma11, Ma12, Ma13) (Step Sa3), mixing these weighed aggregates for new asphalt mixture (Ma11-Ma13) and the existing asphalt generating material (Mb11-13). (Step Sa4) In addition, the asphalt is further mixed (Step Sa5) to obtain a regenerated asphalt mixture (Mx). Asphalt generating material (Mb1) was crushed (step Sb1), and the asphalt, sand and stone powder adhering to it were peeled off (step Sb2), and the particle size was 2.5 mm or less (Mb11), 2.5 mm to 5.0 mm (Mb12), sieving into 3 groups of 5.0 mm or more (Mb13) (step Sb3), those with a particle size of 2.5 mm or less (Mb11) are forced-drying lines equipped with good ventilation or fans. (Step Sb5), particles having a particle size of 2.5 mm or more (Mb12, Mb13) are heated to 160 to 180 ° C. (Step Sb6), and each of the heated new asphalt aggregates (Ma11 to 13) is heated. Mix with.

Alternatively, the existing asphalt generating material (Mb1) is crushed (step Sb1) and sieved (step Sb3), and the crushed crushed material is measured for each predetermined particle size (Mb11, Mb12, Mb13). (Step Sb4) Heat (Step Sb51), and on the other hand, the new aggregate for asphalt mixture (Ma1, Ma2, Ma3) is heated to 200 to 300 ° C. (Step Sa1), and the heated aggregate has a predetermined particle size. Weighing (Ma11, Ma12, Ma13) (step Sa3) and mixing the weighed aggregates for new asphalt mixture (Ma11-13) and the existing asphalt generating material (Mb11-13) (step Sa4) Furthermore, in the manufacturing method of the regenerated asphalt mixture which mixes asphalt (step Sa5) to obtain the regenerated asphalt mixture (Mx), The soot generating material (Mb1) was crushed (step Sb1) and the asphalt, sand and stone powder adhering to it were peeled off (step Sb2), and the particle size was 2.5 mm or less (Mb11), 2.5 mm to 5.0 mm ( Mb12), sieved into 3 groups of 5.0 mm or more (Mb13) (step Sb3), those with particle size of 5.0 mm or less (Mb11, Mb12) are forced drying equipped with a good ventilation line or fan etc. Lines dried (step Sb61), those having a particle size of 5.0 mm or more (Mb13) are heated to 200-230 ° C. (step Sb51), and the heated new asphalt aggregates (Ma11-13), respectively, Mix.

  According to the present invention of the manufacturing method described above, the asphalt generating material (Mb1) is crushed (Sb1), and then, for example, the particle size is sieved into three classes (Sb3), which is conventionally heated by the heating device. In this case, the small particle size class in which the asphalt generating material was easily attached to the heating device due to heating was dried (Sb5, Sb61) and then mixed with the new material (Ma11, Ma12, Ma13) (Sa4). Therefore, even if a highly viscous asphalt generating material is used, the asphalt mixture does not adhere to the heating device.

  The asphalt mixture production apparatus can be used as it is by simply adding a drying line to the conventional equipment, and the new equipment investment can be minimized.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, a first embodiment will be described based on FIG.
In FIG. 1, reference symbols Sa <b> 1 to Sa <b> 6 denote processing steps in the asphalt plant 1, and reference symbols Sb <b> 1 to Sb <b> 6 denote processing of asphalt generating materials in the crushing plant 4, the regenerated aggregate heating device 2, and a drying line not clearly shown. The process is shown.

In the asphalt plant 1, as a new material, the fine-grained portion Ma1, the aggregate “A” Ma2, and the aggregate “B” Ma3 are simultaneously heated by a heater (see the dryer 15 of FIG. 3 in the prior art) (process) Sa1).
The heating temperature at this time is set to 180 to 230 ° C., which is 20 to 50 ° C. higher than the temperature 160 to 180 ° C. immediately after the production of the regenerative heating asphalt mixture Mx as a product.

  The new material after heating is sieved into a class Ma11 having a small particle size, a medium class Ma12, and a large class Ma13 (process Sa2), each of which is weighed (process Sa3), and a mixer (conventional technology). 3 (see reference numeral 14 in FIG. 3).

  On the other hand, in the crushing plant 4, the asphalt generating material Mb1 crushed and recovered from the repaired paved road is crushed (step Sb1), and the asphalt, sand and stone powder adhering to the surface of the crushed asphalt generating material are steamed. It peels using a type peeling device etc. (process Sb2).

  The asphalt generating material Mb1 from which the sand or stone powder adhered to the surface is peeled off is classified into a class Mb11 with a particle size of 0 to 2.5 mm, a class Mb12 with a particle size of 2.5 to 5.0 mm, and a class of 5.0 to 13.0 mm. Or it classifies with class Mb13 exceeding 13.0 mm (process Sb3).

  Among the asphalt generating materials screened into three classes, class Mb11 having a particle size of 0 to 2.5 mm is weighed to an appropriate amount (step Sb4), and the appropriate amount is dried, for example, with good ventilation. Drying is performed using a line or a forced drying line equipped with a fan or the like (step Sb5). However, you may heat by a hot air etc. in that case.

  On the other hand, among the asphalt generating materials screened into three classes, the class Mb12 having a particle size of 2.5 to 5.0 mm and the class Mb13 exceeding 5.0 to 13.0 mm or exceeding 13.0 mm For example, in the recycled aggregate heating device 2, each is measured to an appropriate amount (step Sb4), and the appropriate amount is heated to 160 to 180 ° C. by, for example, a recycle dryer (see reference numeral 24 in FIG. 3 of the prior art). (Step Sb6).

  Class Mb11 having a dried particle size of 0 to 2.5 mm, Class Mb12 having a particle size of 2.5 to 5.0 mm heated by a recycle dryer, and a class of 5.0 to 13.0 mm or 13.0 mm Is added to a mixer (see reference numeral 14 in FIG. 3 of the prior art) into which the screened new materials Ma11, Ma12, and Ma13 are charged and mixed by the mixer (step Sa4).

  Here, it should be noted that the new materials Ma11, Ma12, Ma13, the asphalt generating material Mb11 dried with a particle size of 0 to 2.5 mm, and the asphalt generating materials Mb12, Mb13 heated to have a larger particle size than that. The timing of charging into the mixer is to be the same period when the heated and heated materials are not cooled.

  A new asphalt is added to the mixture mixed by the mixer (step Sa5), and an additive is further added (step Sa6), and the regenerated and heated asphalt mixture Mx as a product is completed.

  The temperature of the mixture immediately after completion of the regeneratively heated asphalt mixture Mx is 160 to 180 ° C.

  Here, there is a close relationship between the asphalt mixture new aggregate, asphalt generating material and additive, and the mixing ratio of each class divided into three according to the particle size in the asphalt generating material, As an example, if the recycled asphalt mixture is shipped at a temperature of 180 ° C. and the mixing rate of the asphalt generating material at that time is 50% (asphalt mixture new aggregate 50%), Mb1 of 0 to 2.5 mm 10%, Mb2 of 2.5 to 5.0 mm is 5%, Mb3 of 5.0 to 13.0 mm is 35%, and the additive is 0.13%.

Next, based on FIG. 2, a second embodiment will be described with reference to FIG.
In the first embodiment of FIG. 1, in the recycled aggregate heating apparatus, the particle size of the asphalt generating material to be dried is set to class Mb11 from 0 to 2.5 mm. However, in the second embodiment of FIG. The particle size of the generated material is set to two classes, class Mb11 from 0 to 2.5 mm and class Mb12 from 2.5 to 5.0 mm. However, in this case as well, heating may be performed during drying.

  The particle size of the asphalt generating material to be dried is the same as that of the first embodiment of FIG. 1 except that the particle size is classified into two classes, class Mb11 and class Mb12, and the heating temperature.

  As described above, according to the embodiment of the present invention, after the asphalt generating material Mb1 is crushed (Sb1), for example, the class Mb11 having a particle size of 0 to 2.5 mm and the class of 2.5 mm to 5.0 mm are used. Mb12 and class Mb13 exceeding 5.0 to 13.0 and / or 13.0 mm are screened into three classes (Sb3), and asphalt is used for heating when heating with the conventional recycle dryer 24 The generated material Mb1 is easy to adhere to the recycle dryer 24 and has a small particle size (class Mb11 having a particle size of 0 to 2.5 mm, or a particle size of 0 to 2.5 mm and 2.5 to 5.0 mm. Class Mb12) is dried (Sb5, Sb61) by a different route from the recycle dryer and then mixed (Sa4) with new materials (Ma11, Ma12, Ma13). In, even with asphalt generating material Mb1 high viscosity, the asphalt mixture recycle dryer 24 does not adhere.

  The asphalt mixture production equipment can be used as it is by simply adding a drying line with good ventilation or a forced drying line equipped with a fan to the existing equipment. Is minimized.

  It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.

The block diagram of 1st Embodiment of the reproduction | regeneration asphalt mixture manufacturing method of this invention. The block diagram of 2nd Embodiment of the reproduction | regeneration asphalt mixture manufacturing method of this invention. The block diagram of the reproduction | regeneration asphalt manufacturing apparatus in a prior art. The block diagram explaining the reproduction | regeneration asphalt manufacturing method in a prior art. A table showing the heating temperature by material (type) of paving petroleum asphalt.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Asphalt plant 2 ... Recycled aggregate heating device 3 ... Dust and flue gas treatment device 11 ... Screen 12 ... Hot bottle 13 ... Metering device 14 ... Mixer 15 ... Dryer 16 ... Material stock hopper 17 ... Conveyor 18 ... Aggregate transport elevator 21 ... Recycled aggregate hopper 22 ... Belt conveyor 23 ... Elevator 24 ... Recycle dryer 25 ..Skip elevator 26 ... Surge bin 27 ... Dry cyclone 28 ... Blower 31 ... Bug filter 32 ... Blower 33 ... Deodorizer 34 ... Smoke cylinder

Claims (2)

  The existing asphalt generating material (Mb1) is crushed (step Sb1) and sieved (step Sb3), and the crushed crushed material is measured for each predetermined particle size (Mb11, Mb12, Mb13) (step) Sb4) heating (step Sb6), on the other hand, the new aggregate for asphalt mixture (Ma1, Ma2, Ma3) is heated to 180-230 ° C. (step Sa1), and the heated aggregate has a predetermined particle size (Ma11). , Ma12, Ma13) (step Sa3), and the measured aggregates for new asphalt mixture (Ma11-13) and the existing asphalt generating material (Mb11-13) are mixed (step Sa4). In the manufacturing method of the regenerated asphalt mixture to obtain the regenerated asphalt mixture (Mx) by mixing asphalt (step Sa5), the existing asphalt generation (Mb1) peels the asphalt, sand and stone powder adhering after crushing (step Sb1) (step Sb2), and the particle size is 2.5 mm or less (Mb11), 2.5 mm to 5.0 mm (Mb12), Sieve into 3 groups of 5.0 mm or more (Mb13) (step Sb3), and those with a particle size of 2.5 mm or less (Mb11) are dried in a forced drying line equipped with a ventilation line or a fan with good ventilation ( Step Sb5), those having a particle size of 2.5 mm or more (Mb12, Mb13) are heated to 160-180 ° C. (Step Sb6) and mixed with the heated new asphalt aggregates (Ma11-13), respectively. A method for producing a recycled asphalt mixture.   The existing asphalt generating material (Mb1) is crushed (step Sb1) and sieved (step Sb3), and the crushed crushed material is measured for each predetermined particle size (Mb11, Mb12, Mb13) (step) Sb4) is heated (step Sb51), on the other hand, the new aggregate for asphalt mixture (Ma1, Ma2, Ma3) is heated to 200-300 ° C. (step Sa1), and the heated aggregate is given a predetermined particle size (Ma11). , Ma12, Ma13) (step Sa3), and the measured aggregates for new asphalt mixture (Ma11-13) and the existing asphalt generating material (Mb11-13) are mixed (step Sa4). In the method for producing a regenerated asphalt mixture, the regenerated asphalt mixture (Mx) is obtained by mixing asphalt (step Sa5). The material (Mb1) is crushed (step Sb1) and the asphalt, sand and stone powder adhering thereto are peeled off (step Sb2), and the particle size is 2.5 mm or less (Mb11), 2.5 mm to 5.0 mm (Mb12) , Sieved into three groups of 5.0 mm or more (Mb13) (step Sb3), and those having a particle size of 5.0 mm or less (Mb11, Mb12) are drying lines with good ventilation or forced drying lines equipped with fans, etc. Dried (step Sb61), those having a particle size of 5.0 mm or more (Mb13) are heated to 200-230 ° C. (step Sb51), and mixed with the above-mentioned new aggregate for asphalt mixture (Ma11-13). A method for producing a recycled asphalt mixture characterized by comprising:

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