JPH0553882B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Field of Application) The present invention relates to a base structure for an athletic stadium on which artificial turf is laid, and it is possible to provide a base structure that utilizes the local soil as it is. (Prior Art) Artificial turf has been used for baseball fields, soccer fields, volleyball courts, etc. because it is more durable and easier to maintain than natural turf. Recently, a method of filling the grain of an artificial lawn with dry sand to make the characteristics more similar to that of a natural lawn has attracted attention, and this method has become popular nationwide, mainly for tennis courts. (Problems to be Solved by the Invention) In the case of athletic fields constructed using these artificial lawns or artificial lawns filled with dry sand, the roadbed is first created by digging the roadbed, and then A layer of granular crushed stone was formed on top of the ground, and then asphalt mixture or concrete was poured on top of it to form the base, and an artificial lawn was laid on top of this. This required large-scale construction, high costs, and a long construction period, so improvements were desired. Therefore, an inexpensive and simple way to build a foundation is to use the so-called soil cement method, in which soil from the local roadbed is dug up and compacted with cement, lime, etc., and then artificial grass is laid on top of it. It is being considered. However, the soil cement foundation there
It has been pointed out that the alkali content gradually disappears, resulting in neutralization, that is, aging, which is particularly noticeable in areas where there is underground water, and has the drawback of aging and falling apart in six months to one year. Furthermore, since soil cement has no water permeability, it has the fatal drawback that during frost heaving in winter, the ground becomes uneven and cannot be used as a sports field. Therefore, the present inventors have arrived at the present invention as a result of various studies on a base structure for an artificial grass sports stadium that can use the local soil as it is and that can solve the drawbacks of conventional soil cement. (Means for Solving the Problems) That is, the present invention mixes soil and cement, and then mixes the mixture with inorganic salts of alkali metals and alkaline earth metals, the main components of which are chlorides of potassium, magnesium, sodium, and calcium. After spraying and stirring an aqueous solution of the mixture dissolved in water and solidifying by rolling,
This is a base structure for an artificial grass sports stadium characterized by laying artificial grass. The configuration of the present invention will be explained in detail below. First, potassium, magnesium, and sodium, which are the most important in creating the base structure of the present invention,
The chemical components of a mixture of inorganic salts of alkali metals and alkaline earth metals, the main component of which is calcium chloride, are shown in Table 1 below.

[Table] An example of the mixing ratio of the following mixture of inorganic salts of alkali metals and alkaline earth metals, soil, and cement is as follows: 1 ^m3 of soil: 150 kg of cement
and 1 kg of a mixture of inorganic salts of alkali metals and alkaline earth metals dissolved in 20 ml of water. Next, to explain the construction method for creating the base structure, first we survey the local soil and measure the frost heave depth, but the soil that is normally treated as the frost heave depth is 15
~70cm deep. Once the amount of soil to be treated is determined based on the depth of frost heaving, a grader or other tool is used to correct the unevenness of the field surface, then cement is spread on top of it, and a tractor, stabilizer, or other device is used to mix the soil and cement. An aqueous solution prepared by dissolving a mixture of inorganic salts of alkali metals and alkaline earth metals in water is sprayed onto the solution using a spreader, and the mixture is mixed again using a tractor, stabilizer, etc. Once this is completed, temporary compaction is carried out using tire rollers, macadam rollers, etc., then unevenness is corrected using bulldozers, etc., and main compaction is again carried out using tire rollers, etc., to complete the creation of the base foundation. Once the following work has been completed, an artificial turf is laid on the formed base, in the form of pile fibers planted on a corrosion-resistant base fabric, to complete the athletic field. In some cases, dry sand is filled within the grain of the lawn, which is ideal for sports fields. In addition, sometimes a water-permeable artificial lawn with holes provided therein is laid, and in this case, rainwater flows out under the artificial lawn. (Function) The base of the athletic field of the present invention formed as described above has a mixture of inorganic salts of alkali metals and alkaline earth metals completely electrolyzed in soil cement and attached to soil particles. Neutralizes organic acids and prevents them from reacting with Ca ²⁺ in cement paste to form an impermeable film.
It is possible to dissociate the floc structure formed between cement particles and soil particles, and as a result, cement hydrate is directly entrained between the soil particles and is infiltrated and coagulated in a network. 1/100～
It hardens with fine and continuous gaps as small as 1/300 mm, and like underwater concrete, it is hydraulic, so it will not fall apart as it ages, and is permeable to water. To explain an example of this water permeability, the water permeability coefficient of the base material of the present invention was 1.9 x 10 ^-4 at 10 days of age, while that of soil cement was 3.5 x 10 ^-5 . (Effects of the Invention) As described above, the present invention provides a mixture of inorganic salts of alkali metals and alkaline earth metals, which consists mainly of chlorides of potassium, magnesium, sodium, and calcium, by mixing soil and cement. The base structure of an artificial lawn sports stadium is characterized by spreading an aqueous solution of water, stirring it, solidifying it by compaction, and then laying an artificial lawn on it. can be created. Therefore, in the case of a tennis court, it is most suitable for converting a clay court into an artificial grass court. In addition, the base structure of the artificial turf sports stadium of the present invention is much cheaper than the conventional base structure made of granular crushed stone and asphalt mixture, and can shorten the construction period, making it economically superior. Compared to a cement base, it has permeability, so there is no unevenness due to frost heaving, and if you have a permeable artificial lawn, rainwater will permeate through the base and be drained away. Furthermore, it has many advantages such as not aging due to its hydraulic nature, making it ideal for creating athletic fields using artificial turf.

Claims (1)

[Scope of Claims] 1. An aqueous solution prepared by mixing soil and cement, and then dissolving in water a mixture of inorganic salts of alkali metals and alkaline earth metals, the main components of which are chlorides of potassium, magnesium, sodium, and calcium. A base structure for an artificial turf sports stadium, characterized in that an artificial turf is laid after being spread, stirred, and compacted. 2. The base structure of an artificial lawn sports stadium according to claim 1, wherein the artificial lawn is a water-permeable artificial lawn.