Background Art A variety of ground materials have been developed to prevent dust scattering when parking at underground or outdoor parking places.

Desirable ground materials for that use must be easily applied and be water-resistant. Urethane-based ground materials, which are applied several times to a cement base, are currently available as a waterproof ground material. Urethane is widely used because of its resistance against tearing due to friction from automotive tires and its nature not to generate dust.

In general, a urethane-based ground material is coated on a cement base through several applications with a predetermined interval to allow for hardening. This process takes much time, anywhere from a few hours to a few days, and laborers are exposed to toxic urethane gas over the duration.

The urethane-based ground material has poor durability and flexibility and can be separated from the cement base over time or due to serious temperature variations. Therefore, the worn urethane-based ground material must be removed to reapply a new one after a period of time.

The removed urethane-based ground material cannot be recycled, so to dispose of it, it is either incinerated or buried in the ground.

However, this causes environmental concerns because urethane produces excess polluants during incineration and is hard to decompose in the ground.

Disclosure of the Invention To solve these problems, it is an object of the present invention to provide a waterproof ground material using waste tires and silica, both of which are ubiquitous, and capable of reducing environmental contamination and raising recycling efficiencies of the resources, and a method for preparing the waterproof ground material.

It is another object of the present invention to provide an easy-to-construct, semi-permanent, waterproof ground material and a method for preparing the ground material.

According to an aspect of the present invention, there is provided a waterproof ground material comprising waste tire particles, silica particles, and a liquid resin that is curable over time.

In the waterproof ground material according to the present invention, it is preferable that the waste tire particles and the silica particles are mixed in a ratio of about 1: 0.5-1: 1.5 by volume. It is preferable that urethane resin is used as the liquid resin for a soft waterproof ground construct. Alternatively, epoxy resin may be used as the liquid resin for a hard waterproof ground construct. It is preferable that the silica particles are colored to give a colored appearance using. a mixed solution of oil paint and a thinner in a ratio of about 1: 0.5-1: 2.

According to another aspect of the present invention, there is provided a method for preparing a waterproof ground material, the method comprising mixing waste tire particles, silica particles, and a liquid resin that is curable over time.

In the method for preparing the waterproof ground material according to the present invention, it is preferable that the waste tire

particles and the silica particles are mixed in a ratio of about 1: 0.5-1: 1.5 by volume. It is preferable that urethane resin is used as the liquid resin for a soft waterproof ground construct. Alternatively, epoxy resin may be used as the liquid resin for a hard waterproof ground construct.

It is preferable that the silica particles are soaked into a mixed solution of oil paint and a thinner in a ratio of about 1: 0.5-1: 2 to give a waterproof ground construct a colored appearance. It is preferable that an additional liquid resin layer is coated on the surface of a waterproof ground construct.

Brief Description of the Drawings FIG. 1 shows the structure of a waterproof ground material using waste tires according to the present invention.

Best mode for carrying out the Invention A waterproof ground material and a method for preparing the waterproof ground method will be described in greater detail with reference to the appended drawings.

Referring to FIG. 1, the waterproof ground material according to a preferred embodiment of the present invention is formed of a mixture of waste tire particles 1, silica particles 2, and a liquid resin 3. The waste tire particles 1 and the silica particles 2 may be mixed in a ratio of about 1: 0.5-1: 1.5 by volume. In the present embodiment, the waste tire particles 1 and the silica particles 2 are mixed in a ratio of 1: 1 by volume.

Hardening. time of the waterproof ground material after being applied to a base can be controlled by adjusting the amount of the liquid resin 3 added. Alternatively, colored silica particles may be used to give the resultant waterproof ground construct a colored appearance.

Hereinafter, a method for preparing a waterproof ground material according to the present invention will be described.

First, waste tires are ground into particles of a predetermined size.

Silica is ground into particles of a predetermined size. The waste tire particles 1 and silica particles 2 have indefinite shapes. The size of the waste tire particles 1 and silica particles 2 may be varied depending on the use of the resulting waterproof ground material. However, the waste tier particles 1 and silica particles 2 have a diameter of, preferably 1-5 mm.

Next, the waste tire particles 1 and the silica particles 2 are put into a mixer (not shown), and the liquid resin 3 that is curable over time is added into the mixture with stirring to be thoroughly mixed.

Here, the waste tire particles 1, the silica particles 2, and the liquid resin 3 are mixed in the following ratios by volume : waste tire particles : silica particles = 1 : 0.5-1: 1.5, waste tire particles : liquid resin = 2: 0.5-2: 3, and silica particles : liquid resin = 2: 0.5-2: 2.

In the present embodiment, the waste tire particles 1, the silica particles 2, and the liquid resin 3 are mixed in a ratio of about 2: 2: 1 by volume.

For a colored appearance of the waterproof ground material, the silica particles 2 are colored before being put into the mixer. In coloring the silica particles 2, oil paint of a particular color and a lacquer thinner are mixed in a ratio of about 1: 0.5-1: 2, and the silica particles 2 are soaked into the mixed solution with stirring. In the present embodiment, the oil paint and the lacquer thinner are mixed in a ratio of about 1: 1. In this case, the oil paint permeates through the surfaces of the silica particles 2, and thus the coloring of the silica particles 2 is not removed by water or friction.

A waterproof ground material according to the present invention is prepared in paste form by the method described above to be hardened

after a predetermined period of time lapses. For a hard waterproof ground construct after hardening, epoxy resin can be used as the liquid resin 3. For a soft waterproof ground construct, like a cushion, after hardening, urethane resin can be used as the liquid resin 3. Suitable epoxy resins include EPODEX, KE-600A, KE-600B, KE-800A, and KE-800B, all of which are product names from KANGNAM CHEMICAL CO., LTD. Suitable urethane resins include DUA, HB-250, TP-651, and HB-220, all of which are product names from KANGNAM CHEMICAL CO., LTD. However, any epoxy resin or urethane resin produced by other companies are available without limitation.

The waterproof ground material according to the present invention in paste form is applied to a cement base and plastered using, for example, a plasterer's scoop, mortarboard, trowel, etc. The waterproof ground material is hardened within about 6-12 hours, but may be varied depending on the amount of the liquid resin added.

Alternatively, an additional liquid resin layer may be coated on the surface of the resultant waterproof ground construct to give enhanced surface glossiness for a clean appearance.

The waterproof ground material according to the present invention prepared by the method described above uses non-recycling waste tires and thus is environmentally friendly. Once the waterproof ground material according to the present invention, including waste tire particles and silica particles as main components, is applied to form a ground construct, the ground construct can be utilized almost permanently because of its good durability and flexibility. Therefore, there is no need to remove a worn waterproof ground material and reapply a new one after a period of time, thereby eliminating environmental concerns about waste ground materials.

Since the waterproof ground material according to the present invention is prepared as paste, it can be easily applied to a base by, for

example, plastering. The waterproof ground material is hardened, like asphalt, as the liquid resin is dried.

Unlike conventional urethane-based ground materials that need to be applied several times to a base, the waterproof ground material according to the present invention can be conveniently applied by plastering only once, thereby substantially reducing working hours.

While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Industrial Applicability As described above, in a waterproof ground material and a method for preparing the waterproof ground material according to the present invention, waste tires are used as a main source of the waterproof ground material, so that environmental contamination from the waste tires can be suppressed. Furthermore, once the waterproof ground material according to the present invention is applied to form a ground construct, the ground construct can be utilized almost permanently, thereby eliminating environmental concerns about waste ground materials. The waterproof ground material according to the present invention can be conveniently applied to a base and is endurable against sudden changes in temperature or weather without deformation.