JP4843733B1 - Stucco material and method for producing stucco - Google Patents

Abstract

An object of the present invention is to provide a stucco material having excellent strength development and increased bending strength and compressive strength, and a method for producing the stucco.
A stucco material according to the present invention is a stucco material mainly composed of quick lime and / or slaked lime and fine aggregate, and comprises the stucco material and an aqueous solution containing high Ca ions. The method for producing a stucco according to the present invention is a method for producing a stucco excellent in strength development, and kneads a stucco material mainly composed of quick lime and / or slaked lime and fine aggregate and a high Ca ion-containing aqueous solution. Can be implemented.
[Selection] Figure 1

Description

  The present invention relates to a stucco material and a method for producing a stucco, and particularly relates to a stucco material kneaded using a high Ca ion-containing aqueous solution and a method for producing a stucco.

  Plaster is made by mixing kneaded lime with hemp fibers, straw fibers, adhesives obtained from herbs and seaweed, water, etc., and is known as a coating material that hardens while absorbing carbon dioxide (air-hardness) It has been. In addition, plaster has properties such as waterproofness, humidity control, and fire resistance, and has been used as a coating material for inner and outer walls made of castles, shrines, storehouses and houses from ancient times. The range of use is limited. For this reason, plaster mixed with synthetic resins and pigments has been commercialized, and compared to conventional low-strength and brittle stucco, the improvement of stucco strength, improvement of strength development, or humidity control function and formaldehyde Attempts have been made to develop new products that focus on the original characteristics of plaster, such as the adsorption decomposition function, and attempts have been made to expand the range and applications of plaster.

  For example, Patent Document 1 proposes a stucco composition comprising γ-type 2CaO · SiO2 and calcium hydroxide as a composition for stucco that is less prone to cracking and flaking and has improved strength development. . And in the description, 0.5 parts thickener, 1.5 parts fiber material, 1 part dispersant, and 0.3 part defoamer are added to 100 parts total of γC2S and calcium hydroxide and γC2S and calcium hydroxide. The stucco workability and cracking of a sample prepared by mixing 50 parts of water with 100 parts of the stucco composition and mixing the stucco with a thickness of 3 mm on a concrete board. The results of measurement of resistance, presence / absence of flaking, and hardness are shown.

Patent Document 2 proposes a plaster-based adhesive curing material that can be hardened regardless of whether it is in the air or underwater, has high strength, and can be used for expanding its applications. That is, a plaster-based adhesive curing material comprising slaked lime or quicklime and a mixed powder thereof as a main raw material, and one or more components selected from alkali silicate components and alkaline earth metal salts are blended therein. Proposed. And in the specification, No. 2 sodium silicate, anhydrous magnesium chloride, polyester fiber, and depending on the sample, a sample obtained by pouring or extruding a sample obtained by adding and mixing clay, adding water appropriately and kneading it into a mold, 28 days flexural strength of 18~73kgf / cm ² after training, compressive strength is 125~290kgf / cm ^2, CMC in conventional slaked lime compressive strength of (carboxymethylcellulose) the plaster was added 8~12kgf / cm ² It is described that the mechanical strength is very excellent compared to the above.

  Patent Document 3 proposes a stucco material mainly composed of scallop shell powder for effective use of scallops discarded in large quantities. Stucco material containing scallop shell powder, slaked lime, sasa and pigment, etc. Is described as having a humidity control action, a deodorizing action, an antifungal action, and a formaldehyde adsorbing action. In addition, the composition of scallop shell powder is almost the same as natural slaked lime, and tiles with scallop shell powder have a bending strength of 12 to 45 N / cm and have sufficient strength as interior tiles for walls. Etc. are described.

  Patent Document 4 proposes a plaster in which shell powder is mixed in the main raw material of plaster, and the shell powder is a powder obtained by baking the outer shell of shellfish, eggs, salmon, etc. Oyster shells are the best shell. And since this shell is familiar with slaked lime and contributes to the binding force, it is described that the viscosity and toughness of the whole raw material are enhanced.

JP 2006-104039 A JP 2000-72520 A JP 2007-284294 A JP 54-13537

  Stucco is said to exhibit high strength and hardness over a long time because it has air hardness, and this is accepted, but it is excellent in strength development and if it exhibits predetermined strength and hardness at an early stage For example, it is desired to expand the use and application of wider plaster. However, there are few prior arts describing the improvement of the strength development of stucco, and there is a description in Patent Document 1 that a composition for stucco with significantly improved strength development is provided. It is not clear how much the strength development of the composition has been improved.

  Further, the plaster composition described in Patent Document 1 requires γ-type 2CaO · SiO2, and the plaster adhesive hardener described in Patent Document 2 requires special silicate components and alkaline earth metal salts. There is a problem of requiring ingredients.

  The stucco material described in Patent Document 3 and the stucco described in Patent Document 4 are obtained by firing shells such as scallops and oysters, which are currently discarded in large quantities from the calcium component that is the main component of stucco. It is based on quicklime and is desirable from the viewpoint of resource protection and economy. However, the stucco material described in Patent Document 3 has a problem that it requires a finely divided sieve of scallop shell powder, and it is not clear how much strength and strength expression are. Regarding the plaster described in Patent Document 3, there is no description of its strength and strength development.

  The present invention is to provide a method for producing a plaster material and a plaster that are excellent in strength development and have improved bending strength and compressive strength in view of the request for expansion of use / use of such plaster and conventional problems. Objective.

  The plaster material which concerns on this invention is a plaster material which has quick lime and / or slaked lime, and a fine aggregate as a main component, Comprising: This plaster material and high Ca ion containing aqueous solution are comprised.

  In the above invention, the high Ca ion-containing aqueous solution is preferably one obtained by dissolving quick lime and / or slaked lime in an acidic aqueous solution at a concentration percentage by weight of 0.6 to 2.0%.

  In the above invention, the acidic aqueous solution may be an acetic acid aqueous solution.

  Moreover, in the said invention, the quick lime and / or slaked lime can use what baked the oyster shell at 900-1200 degreeC, and can use lime sand as a fine aggregate.

  The method for producing a stucco according to the present invention is a method for producing a stucco excellent in strength development, and kneads a stucco material mainly composed of quick lime and / or slaked lime and fine aggregate and a high Ca ion-containing aqueous solution. Can be implemented.

  Moreover, the manufacturing method of the stucco which concerns on this invention is a manufacturing method of the stucco which raised intensity | strength, Comprising: The stucco material which has quick lime and / or slaked lime, and a fine aggregate as a main component, and high Ca ion containing aqueous solution are knead | mixed. Can be implemented.

  ADVANTAGE OF THE INVENTION According to this invention, the stucco which has outstanding intensity | strength development property can be provided, the bending strength and compressive strength of a stucco can be raised, and the surface strength and peeling strength of a stucco wall can be raised.

It is a graph which shows the relationship between Ca ion water concentration, bending strength, and compressive strength. It is a photograph which shows an example of a neutralization test. It is a graph which shows the relationship between Ca ion water concentration and carbonation rate. It is a graph which shows the relationship between Ca ion water density | concentration, carbonation rate, bending strength, or compressive strength. It is a graph which shows the relationship between Ca ion water concentration, Ca ion water amount, and bending strength. It is explanatory drawing which shows the shape of a peeling test body. It is explanatory drawing which shows the load condition of a peeling test body. It is a graph which shows the relationship between Ca ion water density | concentration, Ca ion water amount, and peeling load. It is a graph which shows the relationship between Ca ion water concentration and flow amount. It is a graph which shows the relationship between material age, Ca ion water concentration, and the amount of drying shrinkage.

  Hereinafter, modes for carrying out the present invention will be described. The plaster material which concerns on this invention is a plaster material which has quick lime and / or slaked lime, and a fine aggregate as a main component, Comprising: This plaster material and high Ca ion containing aqueous solution are comprised. Quicklime and / or slaked lime means that the plaster material of the present invention can use quicklime, slaked lime, or a mixture of quicklime and slaked lime as its main component. As a raw material of quicklime or slaked lime, one obtained by baking shells such as oyster shells or scallop shells can be used. Although the fine aggregate is not particularly limited, mountain sand, river sand, lime sand and the like can be used. The high Ca ion-containing aqueous solution is particularly limited in the present invention, and will be described below. In addition, in the present plaster material, in addition to the above components, hemp fibers and straw fibers generally used in plaster, adhesives obtained from herbs and seaweeds, or adhesives made of synthetic resins can be used. .

According to published data (eg http://www.takenet-eco.co.jp/pages/jitsurei/sokai_senjo.html, http://www.questions.gr.jp/chem/odoroki1.htm) Quick lime (CaO) and slaked lime (Ca (OH) ₂ ) are said to be dissolved in pure water at a concentration of about 0.2% by weight. In the present invention, a solution in which CaO or Ca (OH) ₂ is dissolved more than 0.2% is used. For this reason, for example, first, a stock solution in which CaO is easily dissolved in an acetic acid aqueous solution or the like is prepared. And the aqueous solution which diluted this in water is manufactured, this aqueous solution is added to plaster materials, such as quicklime and a fine aggregate, and knead | mixing is performed. The aqueous solution used for this kneading has a high concentration of Ca ions. For this reason, in this invention, it calls the high Ca ion containing aqueous solution. That is, in the present invention, the stucco material is kneaded using a high Ca ion-containing aqueous solution. In addition, water is not specifically limited, Any may be clean water, ionic water, or pure water.

As the high Ca ion-containing aqueous solution, for example, when a 10% aqueous acetic acid solution is used, CaO can be dissolved at about 2% at a normal temperature at a weight percentage concentration. In the present invention, it is preferable to use a high Ca ion-containing aqueous solution in which CaO and / or Ca (OH) ₂ is dissolved by 0.6 to 2.0%. In addition, when it is difficult to dissolve CaO or Ca (OH) ₂ , sodium hydrogen carbonate (NaHCO ₃ ) can be added. In addition to the aqueous acetic acid solution, CaO and / or Ca (OH) ₂ may be dissolved using an acidic aqueous solution such as an aqueous citric acid solution or an aqueous formic acid solution. However, an aqueous acetic acid solution is preferable in view of dissolution ability and the like. In use, the pH of the high Ca ion-containing aqueous solution can be adjusted.

CaO and / or Ca (OH) ₂ used in the production of a high Ca ion-containing aqueous solution is not limited to specific CaO and / or Ca (OH) ₂ , as shown in the examples below. Oyster shell powder fired at 900-1200 ° C. can be used. Instead of oyster shells, other shells can be fired and used.

  This plaster material may be prepared by separately stocking components such as quick lime and fine aggregate and an aqueous solution containing high Ca ions, and kneading them at the time of use. What added components, such as material, and the high Ca ion containing aqueous solution may be used. In addition, what added components, such as quick lime and a fine aggregate, and high Ca ion containing aqueous solution previously, is airtightly packed and stored, and is used after re-kneading at the time of use.

  A stucco specimen was prepared from stucco obtained by adding a high Ca ion-containing aqueous solution to quicklime and fine aggregate, and subjected to a strength test, a peel test, a flow test, and a drying shrinkage test. The quicklime and lime sand used in the test were those manufactured by Nakayama Lime Industry Co., Ltd. Quick lime had a particle size of 0.15 mm or less and the composition was as shown in Table 1. Lime sand had a particle size of 2.5 mm or less. The fine aggregate was Chinese mountain sand. The amount of fine aggregate was 358 parts by weight with respect to 100 parts quicklime. In the case of a peeling test, a peeling test was also performed on a stucco specimen prepared from a stucco material using lime sand as a fine aggregate.

  A high Ca ion-containing aqueous solution was prepared as follows. That is, white obtained by baking oyster shells at 1200 ° C. in an acetic acid aqueous solution (10% concentration) in which 100 g of acetic acid (first grade manufactured by Wako Pure Chemical Industries, Ltd., code No.014-00266) was added to 900 g of pure water. 20 g of the powder was added and completely dissolved. After allowing this solution to stand for half a day, a supernatant was collected and added to each pure water as a stock solution to prepare a high Ca ion-containing aqueous solution having a predetermined Ca ion water concentration. Here, for the high Ca ion-containing aqueous solution, for example, the 1% Ca ion water concentration means that 1 g of oyster shell calcined powder is dissolved in 100 g of the high Ca ion-containing aqueous solution. In addition, in this test, in order to investigate how the amount of high Ca ion-containing aqueous solution affects stucco, it was changed to 100 parts, 110 parts, 120 parts, and 130 parts for 100 parts of quicklime. A high Ca ion-containing aqueous solution was prepared and kneaded, and various tests were performed on the prepared plaster specimen. A commercially available CaO powder can be used as the CaO powder. Moreover, the baking temperature of oyster shell can be 900-1200 degreeC. Table 2 shows the component analysis results of the white powder obtained by baking oyster shells at 1200 ° C.

<Strength test>
The results of the strength test are shown in FIGS. FIG. 1 is a graph showing the results of a bending strength test and a compressive strength test of a plaster specimen. The stucco specimen was prepared from stucco kneaded using 120 parts of a high Ca ion-containing aqueous solution with various changes in Ca ion water concentration for 100 parts of quicklime, and after curing for 28 days or 90 days. . In FIG. 1, the horizontal axis represents Ca ion water concentration, and the vertical axis represents bending strength or compressive strength. The parameter B120-90 in the figure indicates the bending strength of a stucco specimen with 120 parts of a high Ca ion-containing aqueous solution and a 90-day curing (age). C120-90 refers to the compressive strength of a stucco specimen with a high Ca ion-containing aqueous solution of 120 parts and an age of 90 days. The shape of the bent stucco specimen was 40 × 40 × 160 mm prismatic, and the shape of the compression stucco specimen was φ50 mm × 100 mm cylindrical. Curing was done by air curing. The preparation of the stucco specimen, the bending strength test, the compressive strength test, and the neutralization test were performed in accordance with JIS A1171 (Test method for polymer cement mortar).

  According to FIG. 1, both the bending strength and the compressive strength increase as the Ca ion water concentration increases, and the bending strength and the compressive strength are generally observed to be proportional to the Ca ion water concentration. However, when observing the bending strength curve and compressive strength curve in detail, when the age is 90 days, the bending strength curve rises stepwise in the range of Ca ion water concentration from 0.6% to 1.2%, 1.2% It is almost horizontal when crossing over. The compressive strength curve is almost linear as a whole although the slope of the curve increases at 1.0% Ca ion water concentration. However, the slope becomes smaller when it exceeds 1.6%, and when it exceeds 2.0% or 2.0%, it is expected to become horizontal like a bending strength curve. On the other hand, when the age is 28 days, the bending strength curve and the compressive strength curve are in a rising state even at 2.0% Ca ion water concentration, and are not observed to be constant values.

  In FIG. 1, when the bending strength curves of B120-90 and B120-28 are compared, the B120-28 curve is generally shaped such that the B120-90 curve is shifted to the right. For example, the B120-90 curve is 1 MPa when the Ca ion water concentration is 1.0%, and the B120-28 curve is 1 MPa at the 1.2% Ca ion water concentration. That is, it can be seen that the strength development of the stucco specimen can be improved by adjusting the Ca ion water concentration.

  The bending strength is 0.2 MPa at 0% Ca ion water concentration for B120-28 and 0.4 MPa for B120-90. On the other hand, at a 2.0% Ca ion water concentration, it is 2 MPa for B120-28 and 2.45 MPa for B120-90. That is, according to the present invention, the bending strength can be improved about 5 to 10 times by adjusting the Ca ion water concentration. On the other hand, the compressive strength is 0.65 MPa for B120-28 at 0% Ca ion water concentration, 1.0 MPa for B120-90, and 2.7 MPa for B120-28 at 2.0% Ca ion water concentration, B120 In case of -90, it is 4.8MPa. Further, according to the present invention, the compressive strength can be improved by about 5 times by adjusting the Ca ion water concentration.

The improvement in strength or strength of such a plaster specimen according to the present invention is related to the fact that in the present invention, the carbonation of the calcium (Ca) component in the plaster, that is, the formation of CaCO ₃ is promoted. Guessed. The carbonation of the Ca component in the plaster will be described below. Fig. 2 shows the fracture surface of the plaster specimen (0.6% Ca ionic water concentration of B120-90) subjected to the strength test shown in Fig. 1 immersed in a 1% alcohol solution of phenolphthalein (neutral) It is a photograph of a chemical conversion test. As shown in FIG. 2, there is a circular red portion (a portion surrounded by an alternate long and short dash line) in the center of the cross section of the plaster specimen, and the edge has a slightly reddish rock-like fracture surface. . That is, it can be seen that the central part of the plaster specimen is a part that remains Ca (OH) ₂ (not yet CaCO ₃ or carbonized), and the edge is carbonated. The ratio between the area of carbonation (S) and the total area (S ₀ ) of the cross section is defined as the carbonation rate, and a graph showing the relationship between the carbonation rate of the plaster specimen and the Ca ion water concentration is shown in FIG. Show.

  In FIG. 3, the horizontal axis represents the Ca ion water concentration, and the vertical axis represents the carbonation rate. In FIG. 3, the parameters indicate the amount and age of the high Ca ion-containing aqueous solution. For example, the 120-28 curve shows the carbonation rate of a stucco specimen with 120 parts of a high Ca ion-containing aqueous solution and a material age of 28 days with respect to 100 parts of quicklime. According to FIG. 3, each carbonation rate curve is linear with almost the same gradient, and it can be seen that the carbonation rate is proportional to the Ca ion water concentration. It can also be seen that the 120-28 curve has a 100% carbonation rate at 2.0% Ca ionic water concentration, and the 120-90 curve has a 100% carbonation rate at 0.6% Ca ionic water concentration.

  FIG. 4 is a graph showing the relationship between the bending strength and compressive strength of 90 days of age and the carbonation rate based on the data of FIGS. 1 and 3. In FIG. 4, the horizontal axis represents the Ca ion water concentration, and the vertical axis represents the carbonation rate, bending strength, or compressive strength. According to FIG. 4, the bending strength curve and the compressive strength curve are linear in the range of 0 to 1.0% Ca ionic water concentration, and the carbonation rate curve is linear in the Ca ionic water concentration range of 0 to 0.6%. The Ca ion water concentration reaches 100%. When these curves are compared, it can be said that the bending strength or compressive strength is proportional to the carbonation rate, and the slope of the bending strength curve and the compressive strength curve is smaller than the slope of the carbonation rate curve. Further, it can be seen that the bending strength and compressive strength are still increased even at a Ca ion water concentration of 0.6% or more at which the carbonation rate reached 100%.

  FIG. 5 is a stucco test specimen prepared from a stucco kneaded using 100 parts, 120 parts or 130 parts of a high Ca ion-containing aqueous solution with respect to 100 parts of quicklime, and a stucco test at an age of 90 days The result of the bending strength test of a body is shown. In FIG. 5, the horizontal axis indicates the Ca ion water concentration, the vertical axis indicates the bending strength, and the parameters indicate the same display as in FIG. According to Fig. 5, the bending strength curves of B110-90 and B120-90 are almost constant at Ca ion water concentration of 1.4% or more, and the values are 5MPa and B120-90 curves for B110-90 curve. In the case of 3MPa. On the other hand, the bending strength curve of B130-90 is almost straight in the range of 0 to 2.0% Ca ionic water, and the bending strength is 2 MPa at 2.0% Ca ionic water. Comparing these bending strength curves, it is presumed that the amount of the high Ca ion-containing aqueous solution in the present plaster material has an optimum amount depending on the purpose of use.

<Peeling test>
The exfoliation test was performed by applying a shear load to the exfoliation test body and determining the magnitude of the shear load (exfoliation load) when the plaster applied on both sides thereof was exfoliated.
As shown in FIG. 6, the peel test specimen is 20 mm thick on both surfaces of a core material formed by striking a square material of 30 mm width × 15 mm thickness at a pitch of 45 mm on both surfaces of 2350 × 250 mm × 50 mm plate material. The thing which applied the plaster of was used. As shown in FIG. 7, a load was applied to the peel test body in increments of 250 N, and the load at which cracks occurred was defined as the peel load.

  The result of the peeling test is shown in FIG. In FIG. 8, the horizontal axis represents the Ca ion water concentration, the vertical axis represents the peeling load, and the parameter represents the amount of the high Ca ion-containing aqueous solution. 110-Lime sand has 100 parts of quick lime, 358 parts of lime sand instead of mountain sand, 110% of test specimens made of exfoliated specimens prepared from plaster kneaded using 110 parts of high Ca ion-containing aqueous solution Indicates. The age of each test specimen is 28 days. According to FIG. 8, it can be seen that the peeling load is substantially proportional to the Ca ion water concentration, and according to the present invention, the surface strength and the peeling strength of the lacquer ware wall can be increased by adjusting the Ca ion water concentration. Also, the effect of the amount of the high Ca ion-containing aqueous solution is not clear unlike the bending strength. It can be seen that the 110-lime sand curve is on the upper side (high peel load side) of the figure and has a high peel load even at 0% Ca ion water concentration.

<Flow test>
The flow test was performed based on the flow test of JISR5201 (cement physical test method). FIG. 9 shows a flow test of stucco kneaded with 120 parts of a high Ca ion-containing aqueous solution for 100 parts of quicklime. In FIG. 9, the horizontal axis represents the Ca ion water concentration, the vertical axis represents the flow amount, and the parameters represent the flow amount before applying the drop motion (S) and after applying the drop motion (E). As shown in FIG. 9, the flow amount is observed to be proportional to the Ca ion water concentration, but at least the flow amount is higher at the high Ca ion water concentration than the low Ca ion water concentration. .

<Drying shrinkage test>
The drying shrinkage test was performed by measuring the interval between metal chips embedded in a 40 × 40 × 160 mm prismatic specimen with a contact gauge and determining the change with time (dry shrinkage). FIG. 10 shows the results of a dry shrinkage test of plaster kneaded with 100 parts of quicklime using 120 parts of a high Ca ion-containing aqueous solution. In FIG. 10, the horizontal axis indicates the age of the material, the vertical axis indicates the amount of drying shrinkage, and the parameter indicates the Ca ion water concentration. According to FIG. 10, it can be seen that the drying shrinkage amount becomes constant after 10 days of age at 0 to 2.0% Ca ion water concentration. It can also be seen that the higher the Ca ion water concentration, the greater the amount of drying shrinkage, and the longer the age of the material at which the amount of drying shrinkage becomes a constant value.

Claims (7)

  A stucco material mainly composed of quick lime and / or slaked lime and fine aggregate, comprising the stucco material and a high Ca ion-containing aqueous solution.   The stucco material according to claim 1, wherein the high Ca ion-containing aqueous solution is obtained by dissolving quick lime and / or slaked lime in an acidic aqueous solution in a weight percentage concentration of 0.6 to 2.0%. The plaster material according to claim 2 , wherein the acidic aqueous solution is an aqueous acetic acid solution.   The said quicklime and / or slaked lime are what baked the oyster shell at 900-1200 degreeC, The stucco material as described in any one of Claims 1-3 characterized by the above-mentioned.   The stucco material according to any one of claims 1 to 4, wherein the fine aggregate is lime sand. A method for producing stucco with excellent strength development,
A method for producing stucco, characterized by kneading a stucco material mainly composed of quicklime and / or slaked lime and fine aggregates and a high Ca ion-containing aqueous solution. A method for producing stucco with increased strength,
A method for producing stucco, characterized by kneading a stucco material mainly composed of quicklime and / or slaked lime and fine aggregates and a high Ca ion-containing aqueous solution.