JP6524857B2 - Stucco material, plaster and plaster panel - Google Patents

Description

  The present invention relates to a stucco material capable of forming a lightweight stucco having excellent toughness, and a stucco and stucco panel obtained by curing the stucco material.

  Stucco is made by kneading slaked lime with fibers of hemp fibers, moss fibers (sasa), herbs and seaweeds, water, etc. and is hardened as it absorbs carbon dioxide (air-hardenable) as a coated wall material It is done. In addition, plaster has properties such as waterproofness, humidity control and fire resistance, and has been used as a top coat for the inner and outer walls made of soil from castles, shrines, storages and houses since ancient times, but in recent years The range of use is limited. For this reason, stucco mixed with synthetic resin, pigment, etc. is commercialized, and, compared with the conventional low strength and brittle stucco, the strength of the stucco is improved, the strength developing property is improved, or the humidity control function or formaldehyde Attempts have been made to develop new products focusing on the original characteristics of stucco such as adsorptive decomposition function, and attempts have been made to expand the range of use and application of stucco.

For example, Patent Document 1 proposes a composition for stucco comprising γ-type 2CaO · SiO ₂ and calcium hydroxide as a composition for stucco which is less likely to cause cracking and flaking and has improved strength development. There is. Further, as disclosed in Patent Document 2, slaked lime or quicklime, and a mixed powder thereof are used as main materials, as a plaster-based adhesive cured material which can be hardened to high strength and be expanded regardless of air or water. A plaster-based adhesive / hardening material has been proposed which comprises one or more components selected from alkali silicate components and alkaline earth metal salts.

  In addition, in Patent Document 3, a plaster material containing scallop shell powder as a main component for effectively utilizing scallops discarded in large quantities as stucco having sufficient strength is disclosed in Patent Document 4 as a viscose. And as stucco which increases toughness, the stucco which mixed the powder of the shell in the main raw material of stucco is proposed.

  Stucco is considered to exhibit high strength and hardness over a long time because it has air-hardening properties, and this is accepted, but if excellent in strength development and early in time to exhibit predetermined strength and hardness For example, it is desirable to expand the use and application of wider plaster. Although Patent Document 1 describes that a composition for plaster having significantly improved strength development is provided, there is no particular data or explanation thereof, and the plaster materials described in Patent Literature 2 to 4 also improve strength development to some extent. It is not clear.

  In order to solve the above problems, the present inventors have developed a plaster material using a high Ca ion-containing aqueous solution as a plaster material excellent in strength development. The stucco can improve the bending strength by about 5 to 10 times and the compressive strength by about 5 times as compared with the conventional stucco (see, for example, Patent Document 5).

JP, 2006-104039, A JP 2000-72520 A JP 2007-284294 A JP-A-54-13537 Patent No. 4843733

  Although the plaster material containing the high Ca ion-containing aqueous solution described in Patent Document 5 is an excellent plaster material, further improvement is desired in order to expand usage destinations and applications of the plaster. For example, by improving resistance to shearing and bending, it is expected to promote the use as a wall material. The heavier ones are also the bottleneck for using plaster and expanding its application. Although it is relatively easy to cope with the weight reduction of the stucco, it has strength and toughness equal to or higher than those of the conventional stucco, and it is not easy to reduce the weight further.

  The present invention, in view of the demand for expanding the use and application of such stucco and conventional problems, a stucco material having high strength and toughness and capable of forming a lightweight stucco, and curing the stucco material Aims to provide a stucco and stucco panel.

The present invention is a plaster material mainly comprising quick lime and / or slaked lime, fine aggregate, bamboo powder and water, wherein the content of the bamboo powder is 30 to 50% by weight based on quick lime and / or slaked lime. is there.

In the plaster material of the present invention , a high Ca ion-containing aqueous solution is used instead of the water, and the Ca ion concentration of the high Ca ion-containing aqueous solution is preferably 6 to 20 g / L.

In plaster material of the present invention, before the KiHoso aggregate can be used lime made sand, the content of the lime-made sand, preferably from 300% by weight relative to the quick lime and / or slaked lime .

In plaster material of the present invention, the quick lime and / or slaked lime, Ru can be used after firing oyster shells at 900 to 1200 ° C..

The present invention is a stucco formed by kneading and curing the stucco material , wherein the volume change rate is within ± 1% when the ratio of the volume change before and after curing to the volume before curing is the volume change rate. It is a stucco.

Further, the present invention is a plaster panel in which the plaster material is kneaded and hardened, and the volume change ratio is ± 1% when the ratio of the volume change before and after hardening to the volume before hardening is the volume change ratio. within an der Ru transportable-formed plaster panel.

  According to the present invention, it is possible to provide a stucco material having high strength and toughness and capable of forming a lightweight stucco. In addition, it is possible to provide a stucco and stucco panel which has high strength and toughness and is reduced in weight.

It is a weight change rate measurement result of the bamboo powder stucco described in Example 1 of this invention. It is a volume change rate measurement result of the bamboo powder stucco described in Example 1 of this invention. It is a density measurement result of the bamboo powder stucco described in Example 1 of this invention. It is a bending strength and compressive strength measurement result of the bamboo powder stucco described in Example 1 of this invention. It is a figure which shows the relationship of bending strength and compressive strength measurement of the bamboo powder stucco described in Example 1 of this invention. It is a weight change rate measurement result of the bamboo powder high Ca stucco described in Example 2 of this invention. It is a volume change rate measurement result of the bamboo powder high Ca stucco described in Example 2 of this invention. It is a density measurement result of the bamboo powder high Ca plaster described in Example 2 of this invention. It is a figure which shows the carbonation progress state of the test body 55 days after air curing of bamboo powder high Ca plaster described in Example 2 of this invention. It is a bending strength and compressive strength measurement result of bamboo powder high Ca plaster described in Example 2 of this invention. It is a figure which shows the relationship of bending strength and compressive strength measurement of bamboo powder high Ca stucco described in Example 2 of this invention.

  In the present invention, various types of stucco are defined as follows. As with conventional stucco, those using water as a liquid to knead stucco material including lime and fine aggregate are used as ordinary stucco, and instead of water, an aqueous solution containing high Ca ion (high Ca ion containing aqueous solution) is used What uses water as the liquid to knead plaster material containing high Ca plaster, bamboo powder Use to bamboo powder plaster, liquid using kneader material containing bamboo powder to use high Ca ion containing aqueous solution Is called bamboo powder high Ca stucco.

  The stucco material according to the first embodiment of the present invention is a stucco material comprising quick lime and / or slaked lime, fine aggregate and bamboo powder, and is a bamboo powder stucco material to which water is added and kneaded and used. . The present plaster material is characterized in that it contains bamboo powder. In addition to the above components, the present plaster material may also contain, for example, fibers of hemp fibers and straw (sass) commonly used in stucco, adhesives obtained from grasses and seaweeds, adhesives made of synthetic resin, etc. Good.

  As the lime in the present plaster material, quick lime or slaked lime or a mixture of quick lime and slaked lime can be used. As a raw material of quick lime or slaked lime, what baked shells, such as oyster shell and scallops, can also be used. The fine aggregate is not particularly limited, but mountain sand, river sand, lime sand or the like can be used.

  Bamboo powder is obtained by pulverizing bamboo into powder, and one having an average particle diameter of about 300 μm can be suitably used. The kind of bamboo which is a raw material of bamboo powder is not particularly limited.

  In the present plaster material, as the content of bamboo powder increases, the drying speed when hardened becomes faster, and the volume change rate becomes smaller. Also, as the content of bamboo powder increases, the density decreases and the stucco is reduced in weight. Furthermore, as the content of bamboo powder increases, carbonation tends to proceed, and the strength increases. On the other hand, when the content of bamboo powder is extremely large, coating becomes difficult.

  From the above, the content of bamboo powder is 20 to 50 parts by weight to 100 parts by weight of lime, preferably 20 to 40 parts by weight to 100 parts by weight of lime, more preferably 30 to 40 parts by weight to 100 parts by weight of lime It is a department. Hereinafter, ○ parts by weight of bamboo powder to 100 parts by weight of lime is referred to as bamboo powder concentration ○%. When 30 parts by weight of bamboo powder is contained with respect to 100 parts by weight of lime, the bamboo powder concentration is 30%.

  The plaster material having the above-mentioned structure is faster in drying than conventional plaster, so it can be suitably used as a wall material or the like, and when manufacturing plaster panels, productivity is improved. In addition, the plaster material having a bamboo powder concentration of 30 to 50% has a very small change in volume when hardened, and in particular if the plaster material having a bamboo powder concentration of 40 to 50% is hardened, no shrinkage occurs without volume change. The stucco of can be obtained (see the examples described below). Therefore, it can be suitably used as a material for wall materials and plaster panels that do not like large shrinkage.

The density of a plaster obtained by curing a plaster material having a bamboo powder concentration of 30 to 50% as shown in the below-mentioned examples is about 1.6 to 1.68 g / cm ³ . On the other hand, the density of ordinary stucco is about 1.88 g / cm ³ , and the difference is about 0.2 to 0.28 g / cm ³ in proportion of about 10 to 15%. Thus, the stucco formed by curing the present stucco material has a low density, so that it is easy to transport even if it is a stucco panel, and a portable stucco panel can be easily produced.

  The bending strength of the stucco formed by curing the present stucco material is 2 to 3.5 times higher than that of ordinary stucco when the bamboo powder concentration is 30 to 50% as shown in the examples described later. The compressive strength also increases in proportion to the concentration of bamboo powder, and has several times the strength of conventional stucco. Since the stucco formed by curing the present stucco material in this manner is excellent in toughness, it can be suitably used for a portion subjected to a shearing force such as a wall material or for a stucco panel.

  The stucco material according to the second embodiment of the present invention is a stucco material further comprising a high Ca ion-containing aqueous solution in addition to the stucco material according to the first embodiment of the present invention. That is, the plaster material according to the present invention is a bamboo powder high Ca plaster material characterized in that a high Ca ion-containing aqueous solution is used as a liquid for kneading quick lime and / or slaked lime with fine aggregate and bamboo powder. Here, the high Ca ion-containing aqueous solution means a liquid containing a high concentration of Ca ions. In the same manner as the plaster material of the first embodiment of the present invention, the present plaster material also has, other than the above-mentioned components, an adhesive obtained from hemp fibers or rattan fibers (sins) generally used in plaster, herbaceous or seaweed The adhesive etc. which consist of synthetic resins may be contained.

According to published data (for example, http://www.takenet-eco.co.jp/pages/jitsurei/sokai_senjo.html, http://www.questions.gr.jp/chem/odoroki1.htm) Limestone (CaO) and calcium hydroxide (Ca (OH) ₂ ) are said to be dissolved by about 0.2% in pure water at a weight percentage concentration. In the plaster material of the present embodiment, CaO or Ca (OH) _{2 which} is dissolved more than 0.2% is used. For this reason, for example, a stock solution is first prepared by dissolving CaO in an aqueous acetic acid solution or the like which is easily dissolved.

  Then, this stock solution or an aqueous solution obtained by diluting this stock solution with water is produced, and these are added to a plaster material containing bamboo powder and kneaded. The aqueous solution used for this kneading has a high concentration of Ca ions. Therefore, in the present invention, it is referred to as a high Ca ion-containing aqueous solution. The water is not particularly limited, and may be any of pure water, ionic water, pure water and the like.

For example, when using a 10% aqueous acetic acid solution, the high Ca ion-containing aqueous solution can dissolve CaO at a weight percentage concentration at room temperature and about 3.2% (32 g / L) based on Ca. Sodium bicarbonate (NaHCO ₃ ) can be added if dissolution of CaO or Ca (OH) ₂ is difficult. Moreover, you may dissolve CaO and / or Ca (OH) ₂ using acidic aqueous solutions, such as a citric acid aqueous solution and a formic acid aqueous solution, other than an acetic acid aqueous solution. However, an aqueous solution of acetic acid is preferable in view of the dissolution ability and the like. In addition, the pH of the high Ca ion-containing aqueous solution can be adjusted during use.

The CaO and / or Ca (OH) ₂ used in the preparation of the high Ca ion-containing aqueous solution is not limited to a specific CaO and / or Ca (OH) ₂ as shown in the examples described later The oyster shell powder baked at 900-1200 degreeC can be used. Instead of oyster shells, other shells can be fired and used.

  The amount of Ca ion in the high Ca ion-containing aqueous solution can be used without being limited to a specific value, and Ca ion of about 2 to 20 g / L can be used, among which Ca ion concentration An aqueous solution containing 6 to 20 g / L of a high Ca ion can be suitably used. The stucco obtained by using such a high Ca ion-containing aqueous solution has high bending strength and excellent toughness as compared with the conventional stucco.

  Also in the present plaster material containing a high Ca ion-containing aqueous solution, the bamboo powder concentration is 20 to 50%, preferably 20 to 40%, more preferably 30 to 40%, similarly to the plaster material of the first embodiment.

  The present plaster material may be used by separately stocking components such as quick lime, fine aggregate, bamboo powder, and a high Ca ion-containing aqueous solution, and kneading these at the time of use and may be used in advance. The aqueous dispersion containing high Ca ions may be added to components such as fine aggregate and bamboo powder. In addition, what added the high Ca ion containing aqueous solution to components, such as a quick lime, a fine aggregate, a bamboo powder, beforehand is packed airtightly, is stored, and is used after kneading at the time of use.

  The stucco material having the above-described configuration has a very small volume increase / decrease rate when cured, as in the stucco material of the first embodiment, and in particular, if the stucco material having a Ca ion concentration of 6 to 20 g / L is cured. It can be suitably used for wall materials and plaster panels that resist shrinkage.

As shown in the below-mentioned example, the stucco made by curing the stucco material having a bamboo powder concentration of 30% has a density as small as about 1.43 to 1.48 g / cm ³ except for the Ca ion concentration of around 10 g / L. Therefore, even if it is a plaster panel, transportation is easy, and a portable plaster panel can be easily manufactured.

  The flexural strength of the stucco formed by curing the present stucco material increases with the increase of the Ca ion concentration as shown in the examples described later. It turned out that it increases 2 to 2.5 times of high Ca plaster over 5 to 16 g / L of Ca ion concentration, and increases about 3.5 to 4 times of Ca ion concentration 18 to 20 g / L. The compressive strength also increases with the increase of the Ca ion concentration, and is generally more than three times the compressive strength of high Ca stucco. Moreover, the stucco which hardens this stucco material leaves the shape as it is even after compression fracture. This also shows that the bond between the stucco is strong and it is a very tenacious stucco.

  It is considered that the bending strength and compressive strength of the stucco formed by curing the present stucco material increase with the increase of the Ca ion concentration is related to the progress of the neutralization. The neutralization of the stucco made by curing the present plaster material proceeds faster as the Ca ion concentration is higher. As carbonation progresses, the test body used for the strength test is reinforced by calcium carbonate around the test body, that is, it is considered that calcium carbonate plays a role like a reinforcing bar and flexural strength and compressive strength increase.

  As described above, bamboo powder high Ca stucco has the role of accelerating the progress of neutralization of Ca ions, and the fibrous bamboo powder playing a role of bonding between lime and aggregate, and of course, high stucco as well as high calcium. It is excellent in bending strength and compressive strength as compared with stucco. The bamboo powder high Ca stucco which hardens such a stucco material can be suitably used for a wall material and a plaster panel like a bamboo powder stucco.

  While the preferred embodiments have been described above, one of ordinary skill in the art, upon viewing the specification, will readily envision various changes and modifications within the obvious scope. Accordingly, such changes and modifications are to be construed as being within the scope of the invention as defined in the appended claims.

Example 1: Bamboo powder stucco material and bamboo powder stucco A preparation procedure of a representative bamboo powder stucco material is shown. 100 parts by weight of quicklime (made by Nakayama Lime Industry Co., Ltd .; particle size of 0.15 mm or less) shown in Table 1, 300 parts by weight of lime sand, 30 parts by weight of bamboo powder having an average particle diameter of 300 μm, and 120 parts by weight of water The mixture was mixed to obtain a bamboo powder stucco material having a bamboo powder concentration of 30%. In the same manner, bamboo powder plaster materials having bamboo powder concentrations of 5%, 7.5%, 10%, 20%, 40 and 50% were obtained. Also, in the same manner, an ordinary plaster material containing no bamboo powder was obtained.

  A test sample of bamboo powder stucco was prepared in the following manner. Pour the bamboo powder stucco material obtained by the above procedure into half of the formwork in half, and push it evenly with a push rod so that the bamboo powder stucco material spreads to every corner of the formwork, then take the formwork to full bamboo Powdered plaster material was poured in, and the bottom of the stab sticks out all the way to the previous 1/3 depth. Furthermore, bamboo powder plaster material was poured in and allowed to stand for several hours until the surface of the mold was hidden. Thereafter, the upper part of the mold was cut with a parallel bar, taken out of the mold, placed in a curing case, and air cured for a predetermined number of days in an air curing room to obtain a test body. The test body is a prism of 40 × 40 × 160 mm. The test body of ordinary stucco was produced using the ordinary stucco material in the same manner as the test body of bamboo powder stucco.

The measurement results of weight change rate, volume change rate, and density of bamboo powder stucco are shown in FIGS. 1 to 3. The weight change rate was a weight ratio after 30 days of atmospheric curing to the weight of the specimen at the time of demolding. The rate of increase or decrease in volume is determined by measuring the length, width and height of the test specimen after 30 days of air curing using a digital caliper, determining the volume of the test specimen under these, and based on the volume at demolding, It calculated | required using (1).
Volume change rate (%) = (volume at demolding-volume at the elapsed days) / volume at demolding x 100
... (1)
The density was determined by measuring the weight of the test specimen after 30 days of air curing and dividing the weight by the volume calculated in the above manner.

  As shown in FIG. 1, the weight increase and decrease rate tends to increase as the bamboo powder concentration increases from 0 to 7.5%, but when the bamboo powder concentration is 10 to 30%, it is approximately -12%. When the concentration of bamboo powder is 40 to 50%, it remains around -5.5%, and the dry weight reduction rate decreases.

  In addition, during the air curing period of bamboo powder stucco, it was found from the result of weight measurement carried out daily that the higher the bamboo powder concentration, the shorter the period to dry.

  As shown in FIG. 2, the rate of increase or decrease in volume decreases as the concentration of bamboo powder increases. In particular, when the bamboo powder concentration is 7.5% and 40 to 50%, the volume change rate is approximately 0%, and it can be said that the plaster has a small volume shrinkage. As shown in FIG. 2, since the volume change rate of ordinary stucco is -5%, the difference is obvious.

As shown in FIG. 3, the density is about 1.60 to 1.68 g / cm ² in the range of bamboo powder concentration of 20 to 50%, and it is about 0.2 to 0.28 g as compared with the density of ordinary stucco / Cm ^{2 was} low. Overall, the density tended to decrease as the bamboo powder concentration increased. This is because while the weight of the plaster decreases as the bamboo powder concentration increases, the volume reduction rate is small.

  The results of the strength test are shown in FIG. 4 and FIG. The curing period of the test body is 30 days. The strength test was conducted by a method according to JIS A 1171 (test method for polymer cement mortar).

  As shown in FIG. 4, the bending strength is almost the same as that of ordinary stucco until the bamboo powder concentration is 5 to 20%, but when the bamboo powder concentration is 30 to 50%, it is 2-3 compared to the ordinary stucco It was found to increase .5 times. The compressive strength tends to increase as the bamboo powder concentration increases, as shown in FIG. 4. The bamboo powder concentration was about 1.4 times the compressive strength of ordinary stucco at 40 to 50%. Further, from FIG. 5, in the case of bamboo powder stucco, the bending strength was in proportion to the compressive strength as in the case of the conventional stucco.

Example 2: Bamboo powder high Ca stucco material and bamboo powder high Ca stucco The preparation procedure of the bamboo powder high Ca stucco material is shown. 100 parts by weight of quicklime (made by Nakayama Lime Industry Co., Ltd .; particle size of 0.15 mm or less) shown in Table 1, 300 parts by weight of lime sand, 30 parts by weight of bamboo powder having an average particle diameter of 300 μm, and a high Ca ion-containing aqueous solution 120 By mixing with parts by weight, bamboo powder high Ca plaster material was obtained. The high Ca ion concentration was 0, 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 g / L. In addition, high Ca ion concentration 0 is a bamboo powder stucco material whose bamboo powder concentration is 30%. The test piece of bamboo powder high Ca stucco was produced in the same manner as the bamboo powder stucco described in Example 1.

  The high Ca ion-containing aqueous solution was prepared as follows. White color obtained by firing oyster shell at 1200 ° C. in an aqueous acetic acid solution (10% by weight concentration) in which 100 g of acetic acid (1st grade by Wako Pure Chemical Industries, Ltd., code No. 014-00266) is added to 900 g of pure water 30 g of the powder of the above was added in several portions and dissolved completely. After leaving this solution to stand for half a day, the supernatant was collected and used as a high Ca ion-containing aqueous solution (stock solution). Water was added to the above stock solution to obtain a high Ca ion-containing aqueous solution. The firing temperature of the oyster shell can be 900 to 1200 ° C. The component analysis results of the white powder obtained by firing the oyster shell at 1200 ° C. are shown in Table 2.

  The measurement results of weight change rate, volume change rate, and density of bamboo powder high Ca stucco are shown in FIGS. 6 to 8. The definition of weight change rate, volume change rate, density, and measurement procedure are the same as the bamboo powder stucco described in the first embodiment. However, the measurement was carried out 55 days after air curing.

As shown in FIG. 6, the weight increase / decrease rate tends to decrease as the Ca ion concentration increases, but the weight greatly decreases when the Ca ion concentration is 12 g / L. Moreover, it remained substantially the same to 14 to 20 g / L of Ca ion concentration. The above characteristics are considered to be a factor that prevents the weight loss, as the Ca ion concentration increases and the CO ₂ absorption capacity increases. In addition, the CO ₂ absorption capacity is considered to be substantially constant after the Ca ion concentration of 14 g / L.

  As shown in FIG. 7, the volume increase / decrease rate shows a tendency to be slightly expanded after the Ca ion concentration is 6 g / L, while the volume increase / decrease rate decreases as the Ca ion concentration increases. . When the Ca ion concentration is 6 to 20 g / L, the volume increase / decrease rate is approximately 0%, which can be said to be a plaster material having a small volume shrinkage.

As shown in FIG. 8, the density tends to increase in proportion to the Ca ion concentration in the range of 0 to 10 g / L of Ca ion concentration, and gradually decreases in the range of 10 to 20 g / L of Ca ion concentration. The density of bamboo powder high Ca stucco is about 1.43 to 1.48 g / cm ³ except Ca ion concentration around 10 g / L, and comparing this with the density of high Ca stucco, bamboo powder high Ca stucco It was found that the density was lower by 0.2 to 0.35 g / cm ³ and the density difference was further increased as the Ca ion concentration was increased. This is a characteristic obtained by mixing bamboo powder with low density and the mutual effect with the Ca ion aqueous solution.

  FIG. 9 is a view showing the progress of the carbonation of the test sample 55 days after atmospheric curing of bamboo powder high Ca stucco. This figure is a figure obtained by spraying a phenolphthalein solution on the bending fracture surface of each test body by a bending test of a test body after 55 days of air curing of bamboo powder high Ca stucco. The white part is a neutralization part and is calcium carbonate. The red part is the part which is not neutralized yet, and is calcium hydroxide.

  From FIG. 9, in the range of the Ca ion concentration of 0 to 12 g / L, the top, bottom, left, and right of the stucco are slightly white, but they are substantially the same. On the other hand, in the range of the Ca ion concentration of 14 to 20 g / L, it can be seen that the whitened parts in the upper, lower, left, and right areas increase with the increase of the Ca ion concentration, and the neutralization progresses. The part of calcium carbonate plays a role like rebar, and greatly affects the strength because it reinforces the red part.

  The results of the strength test are shown in FIG. 10 and FIG. The curing period of the test body is 55 days. The strength test was conducted by a method according to JIS A 1171 (test method for polymer cement mortar).

  As shown in FIG. 10, the bending strength tends to increase with the increase of the Ca ion concentration. In the range of 6 to 16 g / L of Ca ion concentration, 2 to 2.5 times the bending strength of high Ca plaster, and in the range of 18 to 20 g / L of Ca ion concentration, the bending strength of high Ca plaster of about 3.5 to It was found to increase fourfold.

  Further, as shown in FIG. 10, the compressive strength also tends to increase with the increase of the Ca ion concentration. The compressive strength of bamboo powder high Ca stucco was, in the range of 2 to 20 g / L of Ca ion concentration, approximately three or more times the compressive strength of high Ca stucco. The high compressive strength and flexural strength of bamboo powder high Ca stucco compared to high calcium stucco is thought to be due to the fact that bamboo powder is fibrous and that it bonds between lime and aggregate. .

  In addition, in the case of bamboo powder high Ca plaster, the test body after compression test does not fall apart. From this, it can be seen that the viscosity of bamboo powder high Ca plaster is high. As shown in FIG. 11, in the case of bamboo powder high Ca stucco, the bending strength and the compressive strength were in proportion as in the conventional stucco. When the dependence of the Ca ion concentration on the flexural strength and the compressive strength was compared, the compressive strength was larger.

Claims (6)

Main components are quick lime and / or calcium hydroxide, fine aggregate, bamboo powder and water,
The plaster material whose content of the said bamboo powder is 30 to 50 weight% with respect to quick lime and / or slaked lime . Instead of the water, a high Ca ion-containing aqueous solution is used,
The plaster material according to claim 1 , wherein the Ca ion concentration of the high Ca ion-containing aqueous solution is 6 to 20 g / L. The stucco material according to claim 1 or 2 , wherein the quick lime and / or the slaked lime is obtained by firing an oyster shell at 900 to 1200 ° C. The fine aggregate is sand made of lime,
The plaster material according to any one of claims 1 to 3 , wherein the content of the lime sand is 300% by weight with respect to quick lime and / or slaked lime . A stucco formed by kneading and curing the stucco material according to any one of claims 1 to 4,
Stucco in which the volume increase or decrease rate is within ± 1%, where the volume increase or decrease rate is the ratio of the volume change before and after curing to the volume before curing . It is a plaster panel in which the plaster material according to any one of claims 1 to 4 is kneaded and hardened,
The stucco panel formed so as to be transportable , wherein the volume change rate is within ± 1% when the ratio of the volume change before and after curing to the volume before curing is taken as the volume change rate .