JP2000128605A - Composition for imitation stone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve weather resistance against an alkali, ultraviolet rays or the like by regulating a mortar-cement ratio and a sand-cement ratio so as to be each within a specific range, adding a specified amount of a polymer, and using a polymeric staple as a reinforcing fiber. SOLUTION: This composition for an imitation stone is obtained by regulating the water-cement ratio in a mortar so as to be 25-35%, and the sand-cement ratio so as to be 50-120%. The polymer in the proportion of 3-7% based on the weight of the cement in the mortar is added thereto. A polymeric staple such as a vinylon fiber is preferably used as the reinforcing fiber to reduce the deterioration caused by the alkali of the cement component. The reinforcing fiber in the proportion of 2-8% based on the weight of the cement in the mortal is preferably added thereto. If necessary, an air-entraining agent can be added to the composition to miniaturize the babbles included in the component and to increase the resistance to freezing and thawing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a composition for artificial rock.

[0002]

2. Description of the Related Art When it is desired to secure a natural scenery in a leisure facility such as a park, a zoo, or an amusement park, or to exhibit a decorative effect as a natural scenery in an exhibition hall or the like, a shape similar to a natural rock is used. Pseudo rock with color is used.

[0003] In addition to concrete, this kind of artificial rock is made of glass fiber reinforced plastics (GFRP), glass fiber reinforced concrete or mortar (GFRC) in which glass fibers are mixed into concrete or mortar, in consideration of durability. ) And the like, and these production materials were sprayed or poured into a formwork to produce a pseudo rock.

However, if the artificial rock having such a composition is used for a long period of time outdoors in an area having severe weather conditions such as a cold region, there are technical problems as described below.

[0005]

That is, in the case of GFRP, exposure to ultraviolet rays not only degrades the glass fiber and causes a decrease in strength, but also causes discoloration to appear on the surface of the pseudo-rock and impairs aesthetic appearance. In the case of GFRC, the glass fiber is deteriorated by the alkali of the cement component, and the strength is reduced.

Furthermore, when the above-described composition for artificial rock is sprayed, there is a problem that large air bubbles (entrap air) are mixed into the composition, causing freezing and thawing, and further causing deterioration. .

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a composition for artificial rock having improved weather resistance to alkalis and ultraviolet rays. is there.

[0008] Another object of the present invention is to provide a composition for artificial rock having increased resistance to freezing and thawing.

[0009]

In order to achieve the above object, the present invention provides a composition for artificial rock containing mortar, reinforcing fiber and polymer, wherein the mortar has a water-cement ratio of 25 to 35%, The ratio was set to 50 to 120%, and the polymer was added to the cement in the mortar in an amount of 3 to 7% based on the weight of the cement. According to the composition for artificial rock configured as described above, since the polymer short fiber is used for the reinforcing fiber, there is no deterioration of the cement component due to alkali unlike the glass fiber, and the weather resistance to ultraviolet rays is high. In the composition for artificial rock of the present invention, the mortar has a water-cement ratio of 25 to 35%, which is smaller than that of ordinary concrete.
Since the unit water amount is small, shrinkage after curing is small, and the occurrence of cracks is reduced. In the composition for artificial rock of the present invention,
An air entrainer can be added as needed, and the addition of the air entrainer results in finer bubbles in the composition and increased resistance to freeze-thaw. As the polymer-based reinforcing fiber of the present invention, vinylon fiber can be used, and the fiber is used in an amount of 2 to 8 with respect to the weight of cement in the mortar.
% Is desirable. The amount of vinylon fiber added is 2
If the amount is less than 8%, the reinforcing effect of the strength by adding the fiber becomes insufficient, and if the amount exceeds 8%, troubles such as kneading occur and the economic disadvantage is increased.
It is desirable to set within this range.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
Prepared a simulated rock panel 10 using the simulated rock composition according to the present invention, subjected the material to a laboratory test (quality test, freeze-thaw resistance test, drying shrinkage test) and a cold test. It is explanatory drawing of the test body which performed the land exposure test.

The artificial rock panel 10 is provided in a formwork as shown in Table 1 below.
By filling the composition shown in and curing this,
It was formed into a curved surface having a thickness of about 40 mm and a size of 1800 × 700 mm.

Into the artificial rock panel 10, inserts for mounting the separators 12 were previously embedded at intervals of 40 cm. The artificial rock panel 10 is supported by the separator 12 and the internal steel material 14, and is filled with post-cast concrete 18 between the artificial rock panel 10 and a substrate 16 provided on the back side of the artificial rock panel 10,
The thickness was 500 mm at the thinnest part.

[0013] A cushioning material is wound around the outer peripheral surface of each separator 12 in order to cut an edge between the concrete 12 and the post-cast concrete 18, so that restraint by the separator 12 is reduced. On the back surface of the artificial rock panel 10, urethane resin is applied as a trimming material to a thickness of about 2 mm, and silica sand is applied to the resin at 1 kg / m ^2.
By spraying to the extent, the restraint by the post-cast concrete 18 was reduced.

Table 1 below shows the materials and composition examples of the composition for pseudo rock used in the pseudo rock panel 10.

[0015]

[Table 1]

Here, the composition of the composition for artificial rock of the present invention will be described in detail. In the composition for artificial rock containing mortar, reinforcing fiber and polymer, first, the water-cement ratio of the mortar is in the range of 25 to 35%. Must be set within

The reason is that when the water cement ratio is less than 25%, the fluidity of the mortar is reduced, and when the water cement ratio exceeds 35%, the required strength cannot be obtained. Set.

The mortar has a water-cement ratio of 25-3.
If it is 5%, the water-cement ratio is smaller than that of ordinary concrete, so that the strength after hardening is increased, the unit water amount is reduced, the shrinkage after hardening is reduced, and the occurrence of cracks is reduced.

On the other hand, the mortar has a sand-cement ratio of 50 to 50.
It must be set within the range of 120%.

The reason is that when the sand-cement ratio is less than 50%, the unit water content is large, the shrinkage after curing becomes large, and when the sand-cement ratio exceeds 120%, the fluidity is reduced. Set within the range.

Further, it is necessary to add the polymer within a range of 3 to 7% based on the weight of the cement in the mortar. The reason is that if it is less than 3%, the required strength cannot be obtained, and if it exceeds 7%, the viscosity increases, so it is set within this range.

As the reinforcing fibers, it is necessary to use, for example, high polymer short fibers such as vinylon and Kevlar. When a polymer short fiber is used as the reinforcing fiber, the cement component is less likely to be degraded due to alkali like glass fiber.

When vinylon fibers are used as the reinforcing fibers, it is desirable to add 2 to 8% of the vinylon fibers based on the weight of cement in the mortar. If the added amount of vinylon fiber is less than 2%, the reinforcing effect of the strength by adding the fiber becomes insufficient, and if the added amount exceeds 8%, troubles such as kneading occur, which is economically disadvantageous. Since the profit is also increased, it is desirable to set within this range.

Further, an air entraining agent (AE agent) can be added to the artificial rock composition of the present invention, if necessary. When the air entraining agent is added, air bubbles contained in the composition become fine. And increased resistance to freeze-thaw.

Table 2 below shows the results of a mortar quality test of the composition for artificial rock shown in Table 1.

[0026]

[Table 2]

The quality test of the composition for the artificial rock was carried out based on the flow and air volume in the fresh property and the compressive and flexural strength at the age of 28 days. As is clear from the results shown in Table 2, the flow and the amount of air were fresh properties suitable for spraying.

The compression and flexural strength at 28 days of age also satisfied the required performance.

The freeze-thaw resistance test of the pseudo rock panel 10 was performed in accordance with the "freeze-thaw test method for concrete" (JSCE-G501-1986, Japan Society of Civil Engineers).

FIG. 2 shows the test results of the relative dynamic elastic modulus (index indicating the ratio of the strength of concrete subjected to freeze-thawing to the initial strength) in the freeze-thaw resistance test. According to the test results, the relative dynamic elastic modulus at 600 cycles was 100
% Or more, and it was confirmed to have excellent freeze-thaw resistance.

Incidentally, in the case of ordinary concrete and fiber reinforced concrete which are usually blended, the relative dynamic elastic modulus is generally about 60 to 80%.

The drying shrinkage test of the simulated rock panel 10 is performed according to JIS.
A 1129-1993 "Mortar and concrete length change test method", 4 cm x 4 cm x 16
When a square pillar specimen of cm was cured under the conditions of a temperature of 20 ° C. and a humidity of 60%, the rate of change of length with respect to one day of age was measured. FIG. 3 shows the measurement results of the drying shrinkage test.

As shown in the figure, the rate of change in length of 12 rounds shows a relatively large value of -0.14%, but the rate of change from 4 rounds onward is small. . From this, it is considered that if a curing period of about 4 weeks is provided from the production to the installation of the pseudo rock, cracks due to drying shrinkage of the pseudo rock panel 10 can be prevented.

Table 3 below shows the measurement results of the coefficient of linear expansion of the dummy rock panel 10.

The linear expansion coefficient is measured by 10 cm × 10 cm
An embedded strain gauge is embedded in a specimen of × 40 cm,
The amount of strain was measured while changing the temperature from 20 ° C to + 60 ° C. The linear expansion coefficient of concrete is generally 1
It was about 0 μ / ° C., and the linear expansion coefficient was larger than this.

[0036]

[Table 3]

FIG. 4 shows the measurement results of a material test of the trimming material applied to the back surface of the pseudo rock panel 10. This material test
This was performed to confirm the adhesive strength and elongation ability of the edge cutting material, and the above-mentioned edge material of urethane resin and silica sand was provided on the pseudo rock panel 10 having a diameter of 10 cm, and mortar was spliced thereon. A direct tensile test was performed.

FIG. 4 shows the results of this test in terms of the relationship between tensile stress and displacement. As is clear from the obtained results, the amount of deformation was large, and the adhesive force was maintained until the deformation was about 2 mm. It was confirmed that it had sufficient performance to absorb the displacement between the artificial rock panel 10 and the post-cast concrete 18 and prevent the panel 10 from peeling.

In the exposure test of the dummy rock panel 10 in a cold region, the dummy rock panel 10 in which the post-cast concrete 18 was cast was sent to Hidaka-cho, Hokkaido in Machida-shi, Tokyo, where the exposure test was performed.

The exposure condition was such that the dummy rock panel 10 was directed in the south direction, the exposure period was 75 days, and the maximum temperature during the period was 3 days.
0.5 ° C, minimum temperature -22.1 ° C. One month after the exposure, a surface heating test using a jet heater was performed.

FIG. 5 shows the dummy rock panel 10 after the exposure test.
The surface state of No. 1 was shown, and the occurrence of cracks was slight, the width of cracks was almost 0.1 mm or less, and no harmful cracks were observed.

This is presumably because the urging effect of the urethane resin applied to the back surface of the panel 10 was effectively exhibited.

[0043]

As described in detail in the above examples, according to the composition for artificial rock according to the present invention, weather resistance to alkalis and ultraviolet rays is improved, and resistance to freezing and thawing is also increased.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an explanatory view of a specimen of a pseudo rock panel prepared by using the composition for pseudo rock according to the present invention.

FIG. 2 is a graph showing test results of a freeze-thaw resistance test of the specimen shown in FIG.

FIG. 3 is a graph showing test results of a drying shrinkage test of the specimen shown in FIG.

FIG. 4 is a graph showing a test result of a tensile test of an edge-cut material of the specimen shown in FIG.

FIG. 5 is an explanatory diagram showing the occurrence of cracks in a cold area exposure test of the specimen shown in FIG. 1;

[Explanation of symbols]

 10 Pseudo rock material 12 Separator 18 Post-cast concrete

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Ryo Shinmura 2-3 Kandajicho, Chiyoda-ku, Tokyo Tokyo Obayashi Corporation Tokyo head office (72) Inventor Tomoko Urano 2-3 Kandajicho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office (72) Inventor Toyooki Sawada 4-25-12 Higashiikebukuro, Toshima-ku, Tokyo 8F Ikebukuro Imaizumi Building 8F Inside PlanTalk Inc. (72) Inventor Akira Imai 4-25-12 Higashiikebukuro, Toshima-ku, Tokyo 8F Ikebukuro Imaizumi Building F-term in PlanTalk Inc. (reference) 4G012 PA04 PB28

Claims (3)

[Claims] 1. A composition for simulated rock containing mortar, reinforcing fibers and a polymer, wherein the mortar has a water cement ratio of 25 to 35%, a sand cement ratio of 50 to 120%, and the polymer in the mortar. A composition for artificial rock, wherein 3-7% is added to the weight of cement, and a short fiber of a polymer type is used as the reinforcing fiber. 2. A composition for artificial rocks, characterized by adding an air entraining agent to the composition for artificial rocks according to claim 1. 3. The artificial rock according to claim 1, wherein the polymer-based reinforcing fiber is vinylon fiber, and the fiber is added in an amount of 2 to 8% based on the weight of cement in the mortar. Composition.