JPH0220762B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention aims to improve the flow resistance of asphalt pavement by making the surface of granules made of hydraulic powder with high oil absorption and hardenability, which is added to asphalt mixtures, elastic and temperature sensitive. The present invention relates to an oil-absorbing curing material coated with a rubber or resin having a high viscosity and a method for producing the same. [Conventional technology and its problems] Rutting has become a major problem in asphalt pavement damage in recent years. The main cause is
Due to the increase in traffic volume, larger vehicles, fixed passing positions, and the quality of asphalt mixtures, road surface deformations in the form of bands in the longitudinal direction of roads are occurring frequently. Ruts have a severe negative impact on the road environment and traffic safety, such as water splashing on roadsides and users, reduced skid resistance due to the hydroplane phenomenon when driving on expressways, and difficulty in driving. . The causes of ruts include external factors such as the quality and quantity of traffic and environmental conditions such as temperature, and internal factors such as pavement structure. In addition, when viewed from the perspective of phenomena, this can be roughly divided into permanent deformation in each layer including the subgrade, and compression, flow, and wear mainly in the ascon layer. Countermeasures for these are different; the former requires structural reinforcement and improved construction methods, and the latter, permanent deformation in the ascon layer accounts for a high proportion of rutting, and can be characterized as a viscoelastic body. Measures need to be taken in terms of materials and construction. According to the Asphalt Pavement Guidelines revised in June 1973, as a measure against flow, a special mixture is required to be designed for areas where ruts are concentrated. According to this, the quality of asphalt is generally modified with rubber or resin, or
Alternatively, try to deal with ruts by using asphalt with low penetration, that is, hard asphalt, reducing the temperature sensitivity due to the temperature-viscosity relationship of asphalt cement, and increasing the adhesion between aggregate particles. It is believed that. However, modified asphalt is expensive, and especially in the case of rubber-containing asphalt, the quality of the asphalt mixture and the amount of rubber added tend to vary. Furthermore, resin-filled asphalt has the disadvantage that it often fails to produce the expected results due to poor workability and poor dispersibility of the resin, and further improvements are desperately needed (note that Japanese Patent Application Laid-Open No. 55 In No. 9934, a method was proposed to stabilize the paved road surface by absorbing light oil in the asphalt after it was paved). [Means for Solving the Problem] As a result of repeated research in view of the current state of the technology as described above, the present inventor has discovered that hydraulic powder, a seed stone serving as a core, is mixed with an appropriate amount of water or water to which an admixture has been added. Mix and granulate with
Furthermore, it has been discovered that the problems of the prior art can be substantially or largely eliminated when coated with powdered rubber or thermoplastic resin powder or a mixture of both. That is, the present invention provides the following oil-absorbing curing material for asphalt pavement resistance to flow and its manufacturing method. The present invention provides a surface of a granular material formed by agitating and mixing a hydraulic powder and an appropriate amount of water or water to which an admixture has been added, and a surface made of a single resin or rubber or a mixture of the two. Particle size 20 with coating
It is an oil-absorbing curing material for flow resistance of granular or granular asphalt pavement of 1 mm or less in size, and the surface coating is made of resin or rubber alone or a mixture of both during or after mixing and granulation of hydraulic powder. This is a method for producing an oil-absorbing hardening material for flow resistance of asphalt pavement, which is characterized by adding a material to form a coating on the surface of the granulated particles. By setting the maximum particle size above to 20 mm, it can also be used in the chipping method, in which the asphalt pavement is sprayed and press-fitted, and by increasing the amount of sprayed per unit area, it has an improvement effect (improved dynamic stability). ) can be made sufficient. The oil-absorbing hardening material of the present invention is obtained by hydrating and granulating a hydraulic powder with high oil-absorbing properties, and its physical properties, particularly compressive strength, are equal to or higher than those of aggregate for asphalt, and When a core seed stone is added to a hydraulic powder that absorbs a large amount of light oil in an asphalt mixture and has oil-absorbing properties, the powder and the seed stone are sufficiently tightly adsorbed or adhered to each other. obtain. In addition, a product having a particle size smaller than the predetermined particle size of this product in the absence of the seed stone can also be used as an oil-absorbing hardening material. When these granules are mixed into an asphalt mixture, they exhibit a bearing effect because they are granular (including granules, the same applies hereinafter) or granular, and have the advantage of being very easy to disperse and lay in the mixture. Because of its high oil absorption performance, especially at high temperatures, it has the characteristic of significantly increasing its rutting prevention effect. In addition, when stirring and mixing the above powder, by adding water to which an admixture has been added, the optimum watering amount can be adjusted to 10 to 20%.
By reducing the amount of water sprayed by %, the oil absorption performance is improved by increasing the strength of the powder and increasing the pore space. Therefore, the present invention provides a surface coating material for particles by attaching a predetermined amount of powdered rubber, thermoplastic resin powder, or a mixture of both to the surface of the granules during production of the granules, which are then introduced into a mixer in an asphalt plant and used during mixing. The dispersibility of the rubber or resin is significantly improved, and an asphalt mixture with stable quality is obtained, and the high oil absorption of the hydraulic powder and the temperature sensitivity, elasticity, and toughness of the organic material are synergistically effective. It has a low price compared to conventional modified asphalt, and has the ability to greatly prevent ruts. According to this granulation method, the seed stone is used as the core of the granule, and the oil-absorbing granules are adsorbed or attached around the core, so the granule itself becomes a very porous structure. There is. Next, the present invention will be explained by giving examples. 1 Raw materials (1) Hydraulic powder with high oil absorption One or more of Portland cement, blast furnace cement, blast furnace slag powder, and gypsum is used. (2) Seed stone The seed stone should be natural aggregate or artificial aggregate with a particle size of 10 mm or less. An example of the properties of the artificial aggregate is shown in Table 3. (3) Surface covering material A surface covering material made of rubber powder, thermoplastic resin powder, or a mixture of both shall be used. 2. Conditions for producing oil-absorbing hardening material: Mix the above-mentioned hydraulic powder alone or with seed stone at a ratio of 0.3 to 0.7:0.7 to 0.3 (weight ratio), and spray an appropriate amount of water onto the raw material. Sprinkle with water or pre-impregnate the seed stone with an appropriate amount of water or a portion thereof, then stir and granulate it into granules, then sieve through a 20 mm sieve to produce products with a particle size of 20 mm or less. If the particle size is 20mm or more,
Break the frame to 20mm or less and make it into a product in the same way as above. In order to further apply a surface coating, an appropriate amount of a surface coating material made of rubber powder, resin powder, or a mixture thereof is added and coated using the surface moisture of the granules during granulation in the above manufacturing process or before and after sieving. . The amount of water to be sprinkled is approximately 10 to 16% of the total amount when using only hydraulic powder, taking into account the granulation conditions, and approximately 8 to 12% when consisting of hydraulic powder and seed stone. The amount of water to be sprinkled should be determined so that the granules do not become plate-like. Further, when an admixture for reducing the amount of water to be sprinkled, such as a water reducing agent or an AE water reducing agent, is added, the amount of water to be sprinkled is reduced by 10 to 20% of the above amount. 3 Test results of manufactured oil-absorbing curing materials Tests were conducted on the following seven types of formulations. (1) Composition The composition of raw materials is shown in Table-1.

[Table] ○ mark indicates that seed stone or surface coating material was used.
(2) Water absorption and oil absorption performance of oil-absorbing hardening materials The water absorption and oil-absorption performance of hydraulic powders (Examples 1 and 2) when unhydrated and when hydrated are measured when they are added to ordinary Portland cement and asphalt mixtures. Table 2 Comparison with that of stone powder
Shown below.

[Table] As is clear from the above table, it cannot be said that powdery materials with high water absorption (for example, stone powder) necessarily have high oil absorption. However, in Examples 1 and 2, the oil-absorbing hardening material according to the present invention is used as a flow-proofing measure for asphalt pavement after hydrating hydraulic powder, and the oil-absorbing performance is comparable to that of ordinary Portland cement or stone powder. When unhydrated and
When compared with the hydrated values of Examples 1 and 2, the oil absorption performance is about 1.5 to 2 times higher. This oil-absorbing curing material with high oil-absorbing performance absorbs light oil in the asphalt mixture and has the effect of improving the flow resistance of the asphalt pavement.

[Table] (3) Total void volume of oil-absorbing curing material Examples 3, 4, and 5 with the formulation shown in Table-1.
The total void volume of Example 6 was measured and Table 4
Shown below.

[Table] 4 Properties of asphalt mixture to which oil-absorbing hardening agent has been added (1) Relationship between particle size of oil-absorbing hardening agent and marshal stability of the mixture The asphalt mixture is a dense-grained Asphalt mixture (M-13) according to the Asphalt Paving Guidelines.
Table 5 shows the relationship between changes in the marshal value over time when the particle size of the oil-absorbing curing material was changed. The test conditions are 75 times of marshal tamping on both sides.
times, mixing temperature 165±5℃, rolling temperature 145±5
℃, and the curing temperature was 60±1℃.

【table】

[Table] As is clear from Table 5, the marshall values of asphalt mixtures to which oil-absorbing hardening agents of different particle sizes were added are almost the same, and there is almost no effect of particle size, and the mixtures to which oil-absorbing hardening agents are added have no effect. Compared to additives, it is superior in porosity, saturation, stability, and S/F, which are effective for flow resistance. (2) Wheel tracking test The asphalt mixture was a dense-grained Asphalt (M-13) according to the Asphalt Paving Guidelines, and a wheel tracking test was carried out after aging under 60°C curing conditions for oil-absorbing curing agent mixtures with different particle sizes and addition amounts. I went there. Table 6 shows the results.
and shown in FIG. Preparation of the specimen and running tests were carried out in accordance with the Civil Engineering Research Institute Act (draft) of the Ministry of Construction. The mixing temperature is 165±5℃, the compaction temperature is 145±5℃,
The curing temperature was 60±1°C.

【table】

[Table] Figure 1 shows the results of the wheel tracking test shown in Table 6, and shows the relationship between dynamic stability and curing days (curing temperature 60±1°C). In Fig. 1, the curve ×-× is specimen number 5. The curve ●-● is specimen number 2. The curve ○†a-ku.

Claims (1)

[Scope of Claims] 1 A single resin or rubber, or a mixture of both, is applied to the surface of a granulated material obtained by stirring and mixing a hydraulic powder and an appropriate amount of water or water to which an admixture has been added. An oil-absorbing curing material for flow-resistant asphalt pavement in the form of particles or granules with a particle size of 20 mm or less, provided with a surface coating material consisting of: 2. The oil-absorbing curing material for flow resistance of asphalt pavement according to claim 1, wherein the granules have a seed stone serving as a core inside. 3. A surface coating material made of resin or rubber or a mixture of both is added during or after mixing and granulation of the hydraulic powder to form a coating on the surface of the granulated particles. A method for producing an oil-absorbing hardening material for flow resistance of asphalt pavement.