JPH0699176B2 - Semi-flexible paving material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semi-flexible pavement material for constructing a semi-flexible pavement having intermediate properties between asphalt pavement (flexible pavement) and concrete pavement (rigid pavement).

[0002]

BACKGROUND ART Pavement materials are divided into asphalt pavement materials produced by mixing aggregate with asphalt and concrete pavement materials produced by mixing aggregate with cement. Generally, the former is used for paving. Flexible pavement is called pavement, and rigid pavement is constructed using the latter.

By the way, at present, a semi-flexible pavement having an intermediate property between the flexible pavement and the rigid pavement, that is, flexibility and moderate rigidity is laid. This semi-flexible pavement is an open particle size asphalt mixture
5 mm to 20% of the total weight is passed through the 2.5 mm sieve.
A mother formed by compacting the enclosure mixture)
In the void of the body asphalt concrete layer, special cement
Fill the cement milk and harden the cement milk
Be built by. And the semi-flexible pavement is
Since it has excellent heat resistance, oil resistance, acid resistance, and fluidity resistance, it is used in places contaminated with oil and chemicals, places where large loads are applied, and the like.

The semi-flexible pavement has the above-mentioned characteristics.
The reason is that it has the following configuration.
That is, the base asphalt concrete layer is asphalt
Asphalt joins the aggregates covered with slag
It is said to have been constructed. This structure is the viscosity of asphalt
Due to elasticity, when an external force acts, it deforms
Demonstrates the flexibility that is characteristic of pavement. This mother ass
Cement milk is filled in the voids of the peat concrete layer.
Aggregate movement due to deformation by filling and hardening
Restrains and causes a deformation resistance force. Half way like this
Paving is asphalt in the base asphalt concrete layer
The shape that binds the aggregate by the alt and restrains the movement of the aggregate.
Deflection by hardened cement milk filled with
It has the property that it has high deformation resistance while maintaining its properties.
Of .

However, since it was necessary to prevent the cement milk from coming into contact with the high-heat mixture and quickly setting it before permeating into the voids, the conventional pavement method for semi-flexible pavement used the paved open-grain size asphalt mixture. Waiting for the temperature to drop to a predetermined temperature, the cement milk kneaded at the site was sprinkled on the pavement surface, and while vibrating, the method was used to fill the voids on the pavement surface.

[0006] Therefore, in the conventional pavement method for semi-flexible pavement, two operations, that is, the paving work of the open-grain size asphalt mixture and the cement milk filling work are required, so that the work efficiency is poor and the cement milk is penetrated. The semi-flexible pavement could be laid only with an asphalt mixture having a limited size of voids, such as an open particle size asphalt mixture.

[0007] In order to deal with this, aggregates and aspha
It was mixed with Luto to make an open particle size asphalt mixture.
Then, cool it, and remove the aggregate and cement coated with asphalt.
By mixing the menth milk and compacting it
Therefore, a method of constructing a semi-flexible pavement is also conceivable. Only
And cool the cooled general asphalt mixture.
Even if it is hardened, the asphalt viscosity will increase due to cooling.
Therefore, the aggregates coated with asphalt will adhere and bond to each other.
Absent. Therefore, the structure of the base asphalt concrete layer
No structure could be formed .

Therefore, the viscosity of asphalt is reduced.
In order to use room temperature asphalt with cutback asphalt
Mix cement milk into the falt mixture and compact
A method can be considered, but when mixing with cement milk
Cutback asphalt mixes with each other.
The aggregates are not bonded to each other and the asphalt concrete
The structure of the coating layer was not formed.

[0009]

In consideration of such facts, the present invention does not mix the cement milk and the cutback asphalt even if the cement milk is mixed in advance, and the original strength of the asphalt mixture and the cement An object of the present invention is to provide a semi-flexible pavement material capable of exerting the hardening strength of milk.

[0010]

The semi-flexible pavement material according to claim 1 is obtained by kneading dry aggregate and cutback asphalt to coat the aggregate with cutback asphalt, and coating the cutback asphalt. 1 more face
~ Water and cement are added to a room temperature asphalt mixture which is coated with a trivalent organic acid, and slaked lime is added to the coated surface of the trivalent organic acid to form a coating layer containing the trivalent organic acid. It is characterized by being manufactured by kneading cement milk containing as a main component.

In the semi-flexible pavement material according to claim 2, the dry aggregate and the cutback asphalt are kneaded to coat the aggregate with the cutback asphalt, and the coated surface of the cutback asphalt is further 1-3. Coating with an inorganic material containing a valent organic acid and containing silica and alumina as the main components, and adding slaked lime to the coated surface of the inorganic material containing a 1-3 valent organic acid and containing silica and alumina as the main components. 1-3
Manufactured by kneading water and cement milk containing cement as a main component to a room temperature asphalt mixture containing a coating layer containing an inorganic material containing silica and alumina as a main component containing a valent organic acid. Is characterized by.

The semi-flexible pavement material according to claim 3 is characterized in that it is produced mainly by kneading cement in place of cement milk.

[0013]

In the semi-flexible pavement material having the above construction, the aggregate and the cutback asphalt dried in the mixer are kneaded, and the aggregate is covered with the cutback asphalt. Thereafter, a monovalent to trivalent organic acid is put into the mixer and kneaded to form a coat surface of the cutback asphalt to a coat surface of the monovalent to trivalent organic acid. Further, slaked lime is put into the mixer and kneaded. This slaked lime reacts with a monovalent to trivalent organic acid to form a coating layer containing the monovalent to trivalent organic acid. This coating layer has water repellency and includes cutback asphalt that coats the aggregate together with a monovalent to trivalent organic acid. Therefore, even when the cement milk is kneaded with the room temperature asphalt mixture produced in this way, the cement milk and the cutback asphalt do not mix.

Further, when the semi-flexible pavement material is laid and compacted at a pavement site, the coating layer is crushed and the aggregates are fixed to each other by cutback asphalt without interposing water. This results in a structure in which the cement milk is filled in the voids of the normal semi-flexible pavement, and the semi-flexible pavement is completed. Therefore, the work of filling the cement milk can be omitted.

Further, as a material which reacts with slaked lime to form a coating layer, an inorganic material mainly containing silica and alumina containing a monovalent to trivalent organic acid is also applicable. This one
The inorganic material containing silica and alumina as main components, which contains a trivalent organic acid, is obtained by refining the waste generated from the industrial production process. Furthermore, if the room temperature asphalt mixture with the coating layer formed is kneaded with cement that does not contain water, the cement will not harden, so that it can be stored, and if this is kneaded with water at the paving site,
A semi-flexible pavement material can be easily manufactured.

[0016]

EXAMPLE FIG. 1 shows a block diagram of an asphalt plant in which a semi-flexible pavement material 40 according to the first example is manufactured. A method of manufacturing the semi-flexible pavement material 40 will be described with reference to this block diagram.

From the aggregate hopper 12 in which the aggregate 10 is stored, the aggregate 10 is conveyed to the dryer 14 by a belt conveyor (not shown), and the aggregate 10 is heated. next,
The heat-dried aggregate 10 is screened by a hot elevator (not shown) above the hot bottle 16 and is sorted into a plurality of walls 16A according to the grain size of the aggregate 10 and stored in the hot bottle 16. .

The aggregate 10 stored in the hot bottle 16
The particle size is adjusted based on a predetermined blending design, and is charged into the first mixer 20. Next, the asphalt 33 and the cutback agent 35 are weighed by a weighing machine (not shown), separately injected into the first mixer 20, and mixed with the aggregate 10. As a result, the surface of the aggregate 10 is coated with the asphalt 33 and the cutback asphalt 34 generated by the cutback agent 35.

Next, when an organic acid 36 having a monovalent to trivalent carboxyl group is added and mixed, the organic acid 36 becomes
A cutback asphalt 34 covering the aggregate 10 is provided.
And coat them. Next, the slaked lime 22 is conveyed into the weighing machine 26 by an elevator (not shown), and is added into the first mixer 20 based on the composition design. Thus, by reacting calcium hydroxide 22 and the organic acid 36, cold asphalt mixture 38 covered with a coating layer 32 of a metal salt is prepared (see FIG. 2).

Thereafter, this room temperature asphalt mixture 38 is used.
Is charged into the second mixer 24. Then this second
To the mixer 24 of the cement 28 and the cement modifier 41
, And mix while adding water 30. This produces a semi-flexible pavement material 40, which is used by the second mixer 2
4 or et al is discharged, is transported to the paving site.

In the semi-flexible pavement material 40 thus manufactured, the cutback asphalt 34 for covering the aggregate 10 is covered with the metal salt coating layer 32. Therefore,
The cement-milk 29 produced by the cement 28 and the water 30 and the cutback asphalt 34 are not mixed. Further, since the room temperature asphalt mixture 38 is at a low temperature, the cement milk 29 does not rapidly set.

The semi-flexible pavement material 40 of the first embodiment is used.
The compounding ratio of is as follows.

The amount of asphalt 33 is 3% to 5% (percentage relative to the total weight of the mixture). The amount of the asphalt 33 is determined by the Marshall test in the above range in consideration of the stability of the mixture. Volatile petroleum (gasoline, kerosene, etc.) is used as the cutback agent 35, and the cutback agent 5 is added to the asphalt 33 in an amount of 5
% To 20% is mixed. The amount of the cutback agent 35 mixed is usually determined in consideration of the storage period of the room temperature asphalt mixture 38. Instead of the cutback agent 35, a softening agent such as mineral oil or vegetable oil may be used. In the present embodiment, trimer acid is used as the organic acid 36 having a valence of 1 to 3, and 0.3% to 1 with respect to the weight of the aggregate 10.
It is said to be%. This is because, in this range, the coating layer 32 of the metal salt formed by reacting with the slaked lime 22 is reliably crushed by the compaction. In addition to trimer acid, dimer acid, monomer acid or the like may be used. In addition, an inorganic material containing silica and alumina as a main component containing a monovalent to trivalent organic acid can be used instead of the organic acid 36, but in this case, it is 0.5 with respect to the weight of the aggregate 10. By setting the content to be 3% to 3%, an appropriate thickness of the coating layer 32 can be formed.

The slaked lime 22 is 0.3% to 3% of the weight of the aggregate 10. This is 0.3%
If it is less than 3%, it does not react sufficiently with the organic acid 36, and is 3%.
This is because the unreacted slaked lime 22 is increased in the amount above. In addition, the result that the coating layer 32 is formed earlier by adding a minute amount of water to the slaked lime 22 is obtained.

The amount of cement milk 29 produced by mixing cement 28 and water 30 is determined by the following formula.
Cement milk amount = porosity (porosity of room temperature asphalt mixture) × cement milk specific gravity × loss rate (loss rate varies depending on the maximum particle size and particle size of the room temperature asphalt mixture, but in the present embodiment, 1.05 to 1. 20),
The water-cement ratio (W / C) of the cement milk 29 is preferably 35% to 50% in consideration of workability.

A powder or emulsion type resin is used as the cement modifier 41 for securing the required strength of the cement milk 29, and the addition amount is 1 with respect to the weight of the cement 28. % To 5%.

In consideration of economy, it may be replaced with silica sand or fly ash having a weight ratio of 20% to 30% with respect to the cement 28. Further, by adding 0.5% to 5% by weight of the fibrous material to the cement 28, the strength and flexibility are further improved.

Next, the semi-flexible pavement material 40 of the first embodiment.
The pavement method using is explained. The semi-flexible pavement material 40 manufactured in the plant is carried into the pavement site, and the semi-flexible pavement material 40 is spread on the pavement surface of the base layer 42 by a finisher or manually (see FIG. 3). Next, the pavement surface on which the semi-flexible pavement material 40 is spread is compacted with a vibration roller or the like. As a result, the metal salt coating 32 enclosing the cut-back asphalt 34 covering the aggregate 10 shown in FIG. 2 is crushed, and the aggregates 10 are separated from each other without interposing water between the aggregates 10. Bonded with cutback asphalt 34. In addition, the structure is such that the cement milk 29 is filled in the voids of the usual flexible pavement, and the cement milk 29 is hardened in the voids and restrains the aggregate 10. As a result, the work of filling the cement milk 29 is omitted, and a semi-flexible pavement having flexibility and rigidity is constructed. Finally, the cement milk 29 is cured until it has a predetermined strength, and the paving work is completed.

The water 3 that composes the cement milk 29
0 to 0.5% carboxymethyl cellulose
The result shows that the addition of ~ 3% also improves the workability during paving.

Further, in the semi-flexible pavement 40 of this embodiment, since it is not necessary to consider the injection work of the cement milk 29, it is not limited to the open particle size asphalt mixture having a certain void, but the amount of asphalt, the particle size and the maximum bone amount. Semi-flexible pavement material 4 with various asphalt mixtures with varying diameters
0 can be produced.

In addition, FIGS. 4 to 7 show a test piece for a semi-flexible pavement manufactured by a conventional method and a test piece for a semi-flexible pavement manufactured by using the semi-flexible pavement material 40 according to the present invention. The result of the strength test is shown.

FIG. 4 shows the results of comparison between the bending strength (solid line) of the semi-flexible pavement prepared by the conventional method and the bending strength (broken line) of the semi-flexible pavement according to the present invention, with the horizontal axis representing the number of curing days.
Shows the comparison of bending strain amount, FIG. 6 shows the comparison of uniaxial compressive strength, and FIG. 7 shows the comparison of uniaxial compressive strain amount.

As can be confirmed from these test results,
With a test piece of semi-flexible pavement prototyped by the conventional method,
With respect to the strength of the test piece of the semi-flexible pavement manufactured by using the semi-flexible pavement material 40 according to the present invention, only a difference of an experimental error is recognized.

Next, the semi-flexible pavement material 50 of the second embodiment.
Will be described. In the second embodiment, the bag-packable semi-flexible pavement material 50 is used in consideration of small-scale pavement work such as road surface repair.

In the semi-flexible pavement material 50, the water 30 is not added to the second mixer 24 shown in FIG.
The room temperature asphalt mixture 38, the cement 28 and the cement improver 41 are kneaded and manufactured. The empty kneaded semi-flexible pavement material 50 is packed in a bag and stored.

Therefore, the semi-flexible pavement material 50 is suitable as a repairing material because it can be laid easily by adding water 30 and kneading at the pavement site.

[0037]

As described above, the semi-flexible pavement material according to the present invention can be manufactured in advance in the plant because the cutback asphalt of the room temperature asphalt mixture is not mixed with the cement milk. As a result, it is possible to omit the cement milk injection work at the pavement site and to construct a semi-flexible pavement having the original characteristics of the asphalt mixture and the hardening strength of the cement milk.

[Brief description of drawings]

FIG. 1 is a block diagram of a plant in which a semi-flexible pavement material according to the present invention is manufactured.

FIG. 2 is a conceptual diagram showing a distribution state of each constituent of the semi-flexible pavement material according to the present invention.

FIG. 3 is a cross-sectional view showing a state after the semi-flexible pavement material according to the present invention has been paved.

[FIG. 4] Comparison of bending strength between a semi-flexible pavement manufactured by a conventional method and a test piece of a semi-flexible pavement manufactured by using the semi-flexible pavement material according to the present invention by changing curing days. It is a graph.

[FIG. 5] The amount of bending strain between the semi-flexible pavement prototype manufactured by the conventional method and the test piece of the semi-flexible pavement prototyped using the semi-flexible pavement material according to the present invention by changing the curing days. It is the graph which compared.

[FIG. 6] A uniaxial compressive strength between a semi-flexible pavement prototype manufactured by a conventional method and a test piece of a semi-flexible pavement prototyped using the semi-flexible pavement material according to the present invention, by changing the curing days. It is the graph which compared.

FIG. 7 shows the uniaxial compressive strain amount between the semi-flexible pavement made by the conventional method and the test piece of the semi-flexible pavement made by using the semi-flexible pavement material according to the present invention as the curing days. It is the graph which changed and compared.

[Explanation of symbols]

10 Aggregate 22 Slaked lime 29 Cement milk 28 Cement 34 Cut back asphalt 36 Organic acid

Claims (3)

[Claims] 1. A dry aggregate and cutback asphalt are kneaded to cover the aggregate with the cutback asphalt, and the coated surface of the cutback asphalt is further 1
~ Water and cement are added to a room temperature asphalt mixture which is coated with a trivalent organic acid, and slaked lime is added to the coated surface of the trivalent organic acid to form a coating layer containing the trivalent organic acid. A semi-flexible pavement material, which is manufactured by kneading cement milk containing as a main component. 2. The dried aggregate and the cutback asphalt are kneaded to coat the aggregate with the cutback asphalt, and the coated surface of the cutback asphalt is further 1
~ Coated with an inorganic material containing a trivalent organic acid and containing silica and alumina as the main components, and slaked lime on the coated surface of the inorganic material containing a monovalent organic acid containing silica and alumina as the main components. Kneading water and cement milk containing cement as a main component to a room-temperature asphalt mixture in which a coating layer containing an inorganic material containing silica and alumina as a main component, which contains an organic acid having a valence of 1 to 3 is added. A semi-flexible pavement material characterized by being manufactured by. 3. The semi-flexible pavement material according to claim 1, which is manufactured by mainly mixing cement instead of the cement milk.