JP2000302516A - Mixing type semiflexible paving material and semiflexible paving structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixing type semi-flexible paving material and semi- flexible paving structure capable of improving flexibility and easily, cheaply producing an asphalt adhered aggregate keeping a conventional basic effect which is capable of a thick layer construction method and contributory to saving manpower and the like. SOLUTION: The mixing type semi-flexible paving material 21 is obtained by mixing an asphalt adhered aggregate 31 in which 3-15 pts.wt. asphalt is adhered to a 100 pts.wt. aggregate, a cement paste 32 which is so combined that volume ratios of the asphalt adhered aggregate 31 and the cement paste 32 are 60-90 and 40-10 respectively and a polymer for cement as an additive. The semi-flexible paving structure 1 comprises a semi-flexible paving body 12 which is formed by rolling out the mixing type semi-flexible paving material 21 with a roller after spreading the material 21 with an asphalt finisher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixed semi-flexible pavement material and a semi-flexible pavement structure having improved durability by making use of the flexibility of an asphalt pavement structure and the rigidity of a concrete pavement structure. Regarding improvement.

[0002]

2. Description of the Related Art As a conventional semi-flexible pavement structure, for example, a semi-flexible pavement structure of an infiltration type is known. In this method, an open-grain asphalt mixture having a large porosity (hereinafter referred to as "open-grain ascon") is laid on a base, and then the cement milk for infiltration penetrates into the voids. Such a semi-flexible pavement structure by infiltration type
It has the advantage of higher rigidity and superior durability compared to asphalt pavement structures.

[0003] However, in the semi-flexible pavement structure of the infiltration type, since the construction method of infiltrating cement milk having a predetermined viscosity from the pavement surface of open-grained ascon is taken, the pavement thickness that can be constructed with one layer is reduced. 10c
m. In particular, in the case of using cement milk containing fine aggregate from the viewpoint of improving the slip resistance, the inconvenience has been remarkable because the permeability deteriorates. In addition, the semi-flexible pavement structure by the infiltration method needs to be constructed in two steps, namely, a step of laying open-grained ascon and a step of injecting cement milk, which poses a problem from the viewpoint of labor saving and shortening of the step. there were.

As means for solving such technical problems, a semi-flexible pavement structure of a mixed type has been conventionally known (for example, Japanese Patent Publication No. 2-10109). In this method, a mixed semi-flexible pavement material obtained by mixing asphalt-attached aggregate with asphalt and a cement mixture fluid is laid on a roadbed.

[0005] That is, in the semi-flexible pavement structure of the mixed type, a thick layer construction can be performed as in ordinary asphalt pavement, and the construction can be performed by only one step of paving the mixed type semi-flexible pavement material. Since labor saving and shortening of the process are achieved, and fine aggregate is optionally included, slip resistance can be improved.

[0006]

However, in the semi-flexible pavement structure of the mixed type, unlike the semi-flexible pavement structure of the infiltration type which has a basic structure of contact between asphalt-attached aggregates, asphalt Since the degree of contact between the attached aggregates is weak, the bending strength and the static modulus of elasticity are increased as compared with the semi-flexible pavement structure by the infiltration method, and the flexibility is reduced accordingly.

On the other hand, in the current method of producing asphalt-attached aggregate by a water-cooling method (a method of mixing heated aggregate and asphalt, bathing in cooling water, and separating each particle), the particles are separated. Since it has the property that it does not separate for each particle even if it is finely exposed to cooling water, it is difficult to apply it to fine aggregate, and if it is forcibly applied, the production cost increases.

Accordingly, an object of the present invention is to improve the flexibility while maintaining the basic effect of a conventional mixed-type semi-flexible pavement structure capable of thick layer construction and contributing to labor saving. It is an object of the present invention to provide a mixed semi-flexible pavement material and a semi-flexible pavement structure capable of producing asphalt-attached aggregate easily and at low cost.

[0009]

In order to achieve the above object, among the present invention, the mixed semi-flexible pavement material according to the first invention is 3 to 15 parts by weight per 100 parts by weight of aggregate. Asphalt-attached aggregate on which asphalt is applied,
The asphalt-attached aggregate has a volume ratio of 60 to 90, and the cement paste blended such that the volume ratio of the cement paste is 40 to 10 and a cement polymer as an additive are mixed. Features.

That is, the first invention is an asphalt-attached aggregate in which 3 to 15 parts by weight of asphalt is attached to 100 parts by weight of aggregate, and the volume ratio of the asphalt-attached aggregate is 60 to 100 parts by weight. 90 and the cement paste volume ratio is 40
By mixing the cement paste having a composition of from 10 to 10 and a cement type polymer as an additive to a mixed semi-flexible pavement material, it is possible to construct a thick layer and to contribute to labor saving and the like. It is possible to improve flexibility while retaining the effect.

In the above technical means, the asphalt-attached aggregate is a fine aggregate if 3 to 15 parts by weight of asphalt is attached to 100 parts by weight of aggregate. It does not matter whether it is coarse aggregate or a mixture thereof. The manufacturing method may be freely selected. However, from the viewpoint of easier and inexpensive production, it is preferable to use asphalt-recycled aggregate as the asphalt-attached aggregate.

On the other hand, among the present invention, the semi-flexible pavement structure according to the second invention is characterized in that the mixed semi-flexible pavement material according to the first invention is spread by an asphalt finisher and then rolled by rollers. It is characterized by including a semi-flexible pavement.

That is, the second invention realizes a semi-flexible pavement structure including a semi-flexible pavement formed by spreading the mixed semi-flexible pavement material according to the first invention and then rolling the rollers. Accordingly, it is possible to improve the flexibility while maintaining the conventional basic effect that enables thick layer construction and contributes to labor saving.

[0014] In such technical means, as long as the mixed semi-flexible pavement material is used as the semi-flexible pavement and the paving method is adhered to, the effect of improving the flexibility is ensured. The Rukoto. However, from the viewpoint of ensuring not only the improvement of the flexibility but also the improvement of the resistance (the tenacity) against the flexure fracture, the semi-flexible pavement has a bending strain of 500 × 1.
It is preferably 0 ^-6.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings. First Embodiment FIG. 1 is a view schematically showing a semi-flexible pavement structure according to a first embodiment of the present invention (FIG. 1 (a) is a cross-sectional view, and FIG.
FIG.

As shown in FIG. 1, the semi-flexible pavement structure 1 according to the first embodiment has an asphalt pavement body 11 serving as a surface layer for distributing a traffic load and transmitting the traffic load to a lower layer, and a load applied to the surface layer serving as a lower layer. It is composed of a semi-flexible pavement 12 serving as a base layer that transmits the road uniformly, and a roadbed 13 that further disperses the traffic load transmitted from the upper layer and transmits the traffic load to the subgrade Y.

The semi-flexible pavement 12 is formed by spreading a mixed semi-flexible pavement material 21 with an asphalt finisher and then rolling it with rollers. In the first embodiment, the semi-flexible pavement 12 is spread on one layer by an asphalt finisher and subjected to roller rolling. This indicates that the semi-flexible pavement 12 can be constructed in a thick layer.

In this regard, the semi-flexible pavement 12 is significantly different from a semi-flexible pavement of the infiltration type. That is, in the infiltration type semi-flexible pavement, two or three divisional constructions are required due to the limitation of the pavement thickness that can be constructed with one layer. Can be rebuilt. In addition, in the infiltration type semi-flexible pavement, two steps (the step of laying open granular ascon and the step of injecting cement milk) are required for each construction, whereas the first embodiment requires only one step. Can be constructed. Therefore, according to the first embodiment, labor saving and process shortening can be achieved as compared with the infiltration type semi-flexible pavement.

The mixed semi-flexible pavement material 21 comprises:
The volume ratio of the asphalt-attached aggregate 31 to which 3 to 15 parts by weight of asphalt is applied, the volume ratio of the asphalt-attached aggregate 31 is 60 to 90, and the volume ratio of the cement paste 32 is 40 to 00 parts by weight of the aggregate. The cement paste 32 is mixed with a cement polymer (not shown) as an additive.

In the first embodiment, the asphalt-attached aggregate 31 includes an asphalt-attached coarse aggregate 31a and an asphalt-attached fine aggregate 31b. That is, in the first embodiment, as compared with the conventional mixed-type semi-flexible pavement material, the mortar does not include fine aggregates on which asphalt is not applied, but the asphalt-coated asphalt is applied. The fine aggregate 31b was positively used. Based on the principle that the amount of asphalt that can be applied is approximately proportional to the surface area of the aggregate, the use of fine aggregate as the target for asphalt is actively used to improve flexibility. is there.

The asphalt-attached aggregate is not limited to the asphalt-attached aggregate 31, and may be composed of only the asphalt-attached coarse aggregate, or may be composed of only the asphalt-attached fine aggregate. You may comprise.

In the first embodiment, the asphalt-attached aggregate 31 is manufactured by a method of crushing the asphalt block, so that there is no difficulty in attaching the asphalt to the fine aggregate having fine grains. Or because cheap asphalt recycled aggregate can be diverted,
Compared to a method of manufacturing by a water cooling method, it has become possible to manufacture considerably easier and at a lower cost.

The reason why the adhesion of asphalt of 3 parts by weight is set to the lower limit is that the adhesion of asphalt of less than 3 parts by weight cannot sufficiently exhibit the deformability following property which is a feature of flexibility. . This lower limit is also consistent with the empirical rule that in the case where the total amount of asphalt that can be deposited is the minimum is coarse aggregate, only 3 parts by weight of asphalt can be physically secured (the amount of asphalt that can be deposited). Is considered to be approximately proportional to the surface area of the aggregate).

On the other hand, the reason why the upper limit of 15 parts by weight of asphalt is set is that asphalt exceeding 15 parts by weight cannot secure structural stability in summer. Specifically, the decrease in strength at high temperatures, flow resistance, and the like becomes quite noticeable. Also, this upper limit is
This is consistent with the empirical rule that in the case where the total amount of asphalt that can be deposited is the maximum asphalt is only fine aggregate, only 15 parts by weight of asphalt can be physically secured.

The reason why the volume ratio of the asphalt-attached aggregate 31 is 60 (the volume ratio of the cement paste 32 is 40) as the lower limit is that the asphalt-attached aggregate 31 having a volume ratio of less than 60 has This is because the aggregates 31 do not come into contact with each other and float in the cement paste 32, so that the rolling by the rollers becomes impossible. Also, if the asphalt-attached aggregates 31 do not contact each other, the bending strength and the static modulus of elasticity become extremely large, resulting in insufficient flexibility.

On the other hand, the reason that the volume ratio of the asphalt-attached aggregate 31 is set to 90 (the volume ratio of the cement paste 32 is 10) as the upper limit is that the asphalt-attached aggregate 31 exceeds 90.
Is the volume ratio of the cement paste 32 corresponding to the minimum required amount of the cement paste 32 (consisting of the minimum amount of water required for kneading and the minimum amount of cement required for developing strength). This is because it cannot be secured.

Further, the reason for using the polymer for cement as an additive is to aim at effects such as a water reducing effect, an improvement in stability, and an improvement in adhesiveness between cement and asphalt. Therefore, even if the polymer for cement is not added, it does not mean that the basic effects of the present invention cannot be obtained.
However, the addition of a polymer for cement has the significance that the advantageous effects compared to the conventional semi-flexible pavement structure of the mixing type become more pronounced.

As the polymer for cement, an aqueous polymer dispersion, a re-emulsifiable powder resin, a water-soluble polymer, and a liquid polymer can be appropriately selected and used. In the conventional semi-flexible pavement of the mixing type, for example, a rubber latex of an aqueous polymer dispersion was used. In the first embodiment, a resin emulsion was used.

Next, regarding the performance of the semi-flexible pavement 12 according to the first embodiment, the specimen (hereinafter referred to as “mixing type SFP”) according to the semi-flexible pavement 12 and the conventional mixing type are used. When a specimen relating to a semi-flexible pavement (hereinafter referred to as “conventional SFP”) and a specimen relating to an injection-type semi-flexible pavement (hereinafter referred to as “TXP”) were subjected to a bending strength test and examined, The result shown in FIG. 2 was obtained. Here, FIG. 2A is a table showing the bending strength and the static elastic modulus on the age of 28 days. FIG. 2 (b)
Is a graph showing a bending stress to strain curve.

Here, the blending of the mixed type SFP is shown in the following table.

[0031]

[Table 1]

Subsequently, the formulation of the conventional SFP is shown in the following table.

[0033]

[Table 2]

Further, the composition of TXP is shown in the following table.

[0035]

[Table 3]

In this bending strength test, 5 × 5 × 30 c
The test was performed at a loading speed of 1 mm / min and a test temperature of 20 ° C. by a center loading method with a span of 20 cm using a cut-out specimen of m.

According to FIG. 2, the mixed-type SFP has about three times the bending strength and the static modulus of elasticity as compared with the TXP, and has the same strain at break, whereas the mixed-type SFP has the same degree of strain at break. It can be understood that the flexural strength and static elastic modulus are as small as about 70%, and the strain at break, that is, the amount of flexural strain, is about 1.8 times larger and 1100 × 10 ⁻⁶ or more.

Therefore, the semi-flexible pavement 12 according to the first embodiment, which has substantially the same configuration as that of the mixed type SFP, is different from the conventional type SFP.
Compared with the conventional mixed-type semi-flexible pavement having almost the same configuration as FP, it was confirmed that the flexibility was improved and the resistance (toughness) to the flexure fracture was also improved. did.

Therefore, according to the semi-flexible pavement structure 1 according to the first embodiment, since the semi-flexible pavement 12 is included, it is possible to perform a thick-layer construction and to contribute to labor saving and the like. In addition to possessing, the flexibility is further improved. That is, in the semi-flexible pavement structure 1, the contact between the asphalt-attached aggregates 31 is enhanced, and the semi-flexible pavement structure 1 approximates the properties of the semi-flexible pavement structure by the injection method. The properties as a pavement structure became more prominent.

Embodiment 2 FIG. 3 is a view schematically showing a semi-flexible pavement structure according to Embodiment 2 of the present invention (FIG. 3 (a) is a sectional view, and FIG. 3 (b) is A
FIG. Note that components similar to those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and detailed description thereof is omitted here.

The basic configuration of the semi-flexible pavement structure 2 according to the second embodiment includes a semi-flexible pavement 12 (having a different pavement thickness) having substantially the same configuration as the first embodiment. It is substantially the same as the semi-flexible pavement structure 1 according to the first embodiment, except that the semi-flexible pavement 12 is used not in the base layer but in the surface layer, and asphalt pavement is used in the base layer. This is different from the first embodiment in the point.

According to the semi-flexible pavement structure 2, since the semi-flexible pavement 12 is used in the surface layer, compared with the first embodiment in which the asphalt pavement 11 is used in the surface layer, the flow resistance, It is excellent in that it can meet requirements such as oil resistance, light color and landscape.

Therefore, the semi-flexible pavement structure 2 according to the second embodiment includes the semi-flexible pavement 12 having substantially the same configuration as that of the first embodiment. In addition to obtaining the effect, the use of the semi-flexible pavement body 12 in the surface layer enables to further meet demands for fluid resistance, oil resistance, lightness and the like.

[0044]

According to the present invention, while having the above-described structure, the basic effect of the conventional semi-flexible pavement structure of the mixed type, which enables thick layer construction and contributes to labor saving, etc., is maintained. It becomes possible to improve the flexibility and to produce asphalt-attached aggregate easily and at low cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing a semi-flexible pavement structure according to Embodiment 1 of the present invention.

FIG. 2 is a table and a graph showing experimental results.

FIG. 3 is a sectional view schematically showing a semi-flexible pavement structure according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Semi-flexible pavement structure (Embodiment 1) 2 ... Semi-flexible pavement structure (Embodiment 2) 11 ... Asphalt pavement 12 ... Semi-flexible pavement 13 ... Roadbed 21 ... Mixed type semi-flexible pavement material 31 ... Asphalt-attached aggregate 31a ... Asphalt-attached coarse aggregate 31b ... Asphalt-attached fine aggregate 32 ... Cement paste Y ... Roadbed

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme Court ゛ (Reference) C04B 24:24) (72) Inventor Yasuhiro Yoshino 3-13-1, Kyobashi, Chuo-ku, Tokyo Yuraku Building Taisei Rotec Co., Ltd. (72) Inventor Mandai Fukuda 3-13-1, Kyobashi, Chuo-ku, Tokyo Yuraku Building Taisei Rotec Co., Ltd. F-term (reference) 2D051 AA08 AF01 AF02 AG01 AG11 AH02 AH05 EA01 EA07 4G012 PA23 PC11 PC14

Claims (4)

[Claims] 1 to 3 parts to 15 parts per 100 parts by weight of aggregate
Asphalt-attached aggregate to which asphalt is attached by weight, and the cement paste blended so that the volume ratio of the asphalt-attached aggregate is 60 to 90 and the volume ratio of the cement paste is 40 to 10 A mixed semi-flexible pavement material comprising a mixture of a cement polymer as an additive and a cement polymer. 2. An asphalt-recycled aggregate is used as the asphalt-attached aggregate.
The mixed semi-flexible pavement material according to 1. 3. A semi-flexible pavement obtained by spreading the mixed semi-flexible pavement material according to claim 1 or 2 using an asphalt finisher, and then rolling with a roller. , Semi-flexible pavement structure. 4. The semi-flexible pavement according to claim 3, wherein a bending strain amount is 500 × 10 ⁻⁶ or more.
The semi-flexible pavement structure according to 1.