JPS62282B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of paving stadiums, sports courts, promenades, etc. In the past, the ground of playgrounds, sports courts, and walking paths was compacted with rollers, but recently it has become an all-weather type that can be used for sports, whether it rains or is dry, and is aesthetically pleasing. Paving methods that use resin as a binder have been adopted to achieve harmonious and colorful results. The construction of this pavement requires a pot life of the binder of at least 30 minutes, preferably about 1 hour, including pavement finishing, and a compressive strength of at least 3 Kg/cm ² after about 24 hours. Preferably 5Kg/
The desired condition is that the material exhibits a strength of at least 1 cm ² ), allowing workers to perform repair or topcoat work on the constructed surface. The curing rate and pot life of a binder are contradictory. That is, if the curing speed is increased, the pot life becomes too short, and conversely, if the pot life is lengthened, the product remains uncured even the next day. Therefore, the curing speed and pot life are adjusted by changing the type of curing agent, the amount added, and the operating temperature to suit the above-mentioned pavement construction conditions. However, if the surfaces of playgrounds, sports courts, promenades, etc. are different, even if the binder is adjusted on one side, it will not necessarily meet the conditions of pavement construction on the other. This is because the properties of the soil used as aggregate are different. Therefore, in the construction of resin binder pavement, it is not possible to maintain a consistent standard of work, such as allowing the next work to be done the day after paving, which is a major drawback for civil engineering work, which has an important construction schedule. The inventor of the present invention has conducted intensive research on a paving method that can maintain a constant work standard even in a variety of different soil types, and has developed a method to prevent the expression of the original properties of the aggregate by coating the aggregate with a material whose properties are known in advance. For example, we focused on the fact that the properties of the aggregate can be changed to the fixed properties of the covering material, and based on this knowledge, we have accomplished the present invention. That is, the present invention is a paving method consisting of the following three steps. (b) The process of forming a plastic coating on aggregate. (b) Adding a binder to the aggregate having a plastic coating to form a mixture thereof. (c) A step of applying pressure from above the applied mixture by applying the mixture onto the paved base within the pot life of the binder. The plastic according to the invention may be any material capable of coating dry or wet aggregate. After the coating is formed on the aggregate, it is preferable that the plastic coating has elasticity and stretchability at room temperature, and is resistant to discoloration or has a light color. In the case of a type of plastic that is cured during film formation, it is desirable for the efficiency of paving work to be one that cures within 10 minutes, preferably within about 4 to 6 minutes, depending on the working environment conditions such as temperature. Any plastic that meets the above conditions may be used, such as phenolic resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, or polyurethane resin. A preferred embodiment of the invention is to use a polyurethane resin, which is the reaction product of a polyisocyanate and a compound having two or more active hydrogens in the molecule, as the plastic coating the aggregate. This is a so-called two-component type, in which a hardening agent is mixed before forming a coating on the aggregate. As the polyisocyanate, polyisocyanates commonly used in polyurethane resin synthesis, such as tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and hexamethylene diisocyanate, are used. Compounds with two or more active hydrogens in the molecule include polyols, such as polyesters and polyethers with terminal OH groups, polyvinyl alcohol, phenolic resins, epoxy resins, carboxy-modified latexes, and water, amines, and amine derivatives. is used. Of these,
Amines and amine derivatives, especially aliphatic amines, cure quickly and can be used for coatings. The method of covering the plastic with the aggregate should be one that is compatible with the selected plastic. In an embodiment using a polyurethane resin, a polyisocyanate and a compound having active hydrogen are added to the aggregate simultaneously or sequentially and kneaded in a mixer until hardened to uniformly coat the aggregate. The amount of polyurethane resin added is sufficient to stop the expression of the original properties of the aggregate. In the present invention, an accelerator can be used to adjust the curing speed of the polyurethane resin. As this accelerator, metal compounds such as dibutyltin dilaurate, tin octylate, dimethyltin dichloride, cobalt naphthenate, zinc naphthenate, triethylamine, triethylenediamine, N
-Tertiary amines such as methylmorpholine and pentamethyldiethylenetriamine are used. When used in combination with an aqueous system, tin compounds such as dibutyltin laurate are preferred, and when used in combination with a polyol system, tertiary amines such as triethylenediamine are preferred. Furthermore, the strength may be significantly improved by adding an aminosilane coupling agent or an epoxysilane coupling agent in an amount of 0.1 to 1.0% based on the coating plastic. It is advisable to add the accelerator and silane coupling agent to the active hydrogen-containing compound in advance. The binder according to the present invention may be one that binds aggregate coated with plastic. For example, acrylic resins, unsaturated alkyd resins, phenolic resins, methacrylic resins, polyurethane resins, etc. are used as binders. preferable. In addition, it is desirable that the curing rate of the binder can be easily adjusted according to the working environment conditions such as temperature so that the paving can be carried out within the pot life of the binder and the curing is completed before the next construction schedule. A preferred embodiment of the invention is to use as a binder a polyurethane resin which is the reaction product of a polyisocyanate and a compound having two or more active hydrogens in the molecule. It is a two-component type, and a curing agent is mixed before use as a binder. The polyisocyanate may be one commonly used for polyurethane resin synthesis, such as TDI and MDI. Examples of compounds having two or more active hydrogens in the molecule include polyols (polyesters and polyethers having an OH group at the end), polyvinyl alcohol, carboxy-modified latex, and the like. However, amines and amine derivatives, especially aliphatic amines, react too quickly and cannot be controlled, making them unsuitable as binders. The amount of binder added varies depending on the type of binder and the desired pavement strength, but if polyurethane resin is used to prevent dust, approximately the amount of aggregate will be added.
0.5% by weight, and at least about 5% by weight of the amount of aggregate to withstand 10 tons of wheel pressure. The method of mixing the plastic-coated aggregate and the binder may be any method that is compatible with the selected binder, as long as it can be mixed uniformly. In embodiments using a polyurethane resin, the polyisocyanate and the compound having active hydrogen may be added to the aggregate simultaneously or sequentially and mixed in a mixer. The pot life and curing speed of the binder are adjusted by changing the type and amount of the binder added depending on working environment conditions such as temperature. Usually, it has a pot life of about 30 to about 60 minutes and is adjusted to have a compressive strength of about 3 kg/cm ² or more after about 24 hours. When using polyurethane resin as a binder,
Accelerators to adjust the cure rate can be used as well as the coating polyurethane resin. Further, in order to improve the strength of the polyurethane resin as a binder, a silane coupling agent can be used in the same manner as the coating polyurethane resin, and the details of the accelerator and the silane coupling agent are as described above. There are no particular restrictions on the aggregate used in the present invention, and there are no particular limitations on the type of aggregate used as aggregate, such as sand,
Volcanic rubble, light soil, red clay, lime dust, etc. can be used, and dry or wet materials may be used. By the method of the present invention, even if various aggregates are used, the pot life of the binder can be varied depending on the working environment conditions such as temperature, since the aggregates are coated with plastics with different properties in advance. Moreover, the curing speed can be easily adjusted, and the work standard can be kept constant, for example, there is enough time for paving and the next work can be done the day after paving. Next, the present invention will be explained in detail by showing examples according to the present invention and comparative examples in which the aggregate was not coated with plastic. Example 1 Castor DA of 0.15Kg for 30Kg of Mogami sand
2661 (Dainippon Ink & Chemicals Co., Ltd. Product name, main ingredients:
Add urethane resin) and 1.0Kg of water to 100r.p.
Mix and coat for 5 minutes with a mixer. In addition, 0.3 kg of Castol DA-100-A (Dainippon Ink & Chemicals Co., Ltd. product name, main ingredient: polyol)
Add 0.3 kg of Castol DA-200 (Dainippon Ink & Chemicals Co., Ltd. product name, main ingredient: MD) and mix for 2 minutes with a mixer. Next, the sand was removed and preliminary leveling was performed on the tennis court, and 30 minutes later, the tennis court was leveled with a roller and paved. The gel time required for the plastic coating was approximately 4 minutes, and the pot life of the binder was approximately 30 minutes. The next day, a worker got on the construction surface and was able to apply top coat by mixing 1 kg of Castol DA-100-A and 1 kg of Castol DA-200 to 30 kg of red iron. Here, the gelation time refers to the time it takes for the viscosity to increase once during kneading and then to decrease until it reaches a relatively smooth viscosity. Example 2 Example 1 except that Enshu washed sand was used as the aggregate
It was carried out in the same way. The gelation time was approximately 5 minutes, and the pot life was 30 minutes, and workers were able to work on the construction surface the next day. Example 3 18Kg of mountain soil and 12Kg of lime dust were mixed with 0.15Kg of Castor DA-100-W (Dainippon Ink & Chemicals)
Co., Ltd. product name, main component: polyol) and 0.15 kg of DEITSUKUBOND M-4 (Dainippon Ink & Chemicals Co., Ltd. product name, main component: MDI) were added and mixed for 5 minutes with a mixer at 100 rpm. coated. In addition, 0.3Kg of Deitsku Bond V-201 (Dainippon Ink and Chemicals
Co., Ltd. (product name, main component: polyol)) and 0.3 kg of DEITSUKUBOND M-4 (Dainippon Ink & Chemicals Co., Ltd. product name, main component: MDI) were added and mixed for 3 minutes with a mixer. Next, sand removal and preliminary leveling were carried out, and 30 minutes later, the tennis court was leveled with a roller and paved.
The gel time required for the plastic coating was approximately 4 minutes, and the pot life of the binder was approximately 30 minutes. The next day, a worker got on the construction surface and was able to apply the top coat by mixing 30 kg of red iron with 1 kg of Dark Bond V-201, 1 kg of Dark Bond M-4, and 1 kg of water. Comparative Example 1 Same as Example 1, but without plastic coating, the amount required for this coating was added to the binder.
0.45Kg of Castor DA-100 and 0.45Kg of Castor DA-200 were added. The pot life was over 30 minutes, and the next day the worker was able to get on the construction surface and work as in Example 1. Comparative Example 2 Same as Example 2, but without plastic coating and the amount required for this coating was added to the binder.
0.45Kg of Castor DA-100 and 0.45Kg of Castor DA-200 were added. The pot life was over 30 minutes, but when a worker stepped on the construction surface the next day, footprints were found in some areas, making it impossible to work on the construction surface. Comparative Example 3 As in Example 3, but without plastic coating, the amount required for this coating was added to the binder.
0.45Kg of Daykbond V-201 and 0.45Kg of Daykbond M-4 were added. The pot life was over 30 minutes, and workers were unable to work on the construction surface because it remained uncured the next day. The temperature at the time of construction in Examples 1 to 3 and Comparative Examples 1 to 3 was 20°C. The same paving method as in Examples 1 to 3 and Comparative Examples 1 to 3 was used to construct the main mold with a diameter of 50 mm and a height of 50 mm, and the compressive strength was measured over time, and the results are shown in Table 1 below.
Shown below.

[Table] Study of Examples and Comparative Examples In Comparative Examples 1 to 3, the compressive strength after 24 hours differs greatly depending on the type of aggregate, so it is difficult to standardize the pavement work standard. In contrast, Example 1
Concerning the compressive strength after 24 hours of Samples 3 to 3, the strength of poor aggregates (Examples 2 and 3) was improved, so the difference in strength became smaller. Therefore, it can be seen that it has become easier to standardize the pavement work standard. Furthermore, when high quality and expensive sand such as Mogami sand is used (Example 1 and Comparative Example 1), good performance is shown even without plastic coating. However, it is rare to use high-quality and expensive sand, and usually nearby mountain soil is used. By applying a plastic coating according to the invention to aggregates such as mountain soil, the consumption of binder can be substantially reduced compared to the case without plastic coating.

[Table] Isocyanate,

[Table] Paraffin diluted type,

[Table] Polyvinyl alcohol modified
styrene butane diene
synthetic rubber latex

Claims (1)

[Scope of Claims] 1. (a) A step of forming a plastic coating on the aggregate; (b) A step of adding a binder to the coated aggregate to form a mixture; A paving method comprising the following three steps: applying the mixture on the base to be paved within the usage time and applying pressure from above the mixture. 2. The method according to claim 1, wherein the plastic is a polyurethane resin. 3. The method according to claim 1 or 2, wherein the binder is a polyurethane resin.