Dry mortar, hardened dry mortar, and method for manufacturing hardened dry mortar.

Abstract

To provide a dry mortar with an improved balance of workability and strength after hardening. [Solution] The solution includes cement and sand, and the air permeability time t [seconds] measured in accordance with JIS R5201:2015 and the Blaine specific surface area S [cm²] calculated in accordance with JIS R5201:2015. 2 A dry mortar in which [ / g] satisfies all of the following equations (1) to (4). Formula (1): S≧100×t 0.55 Formula (2): S≦230×t 0.58 Formula (3): S≦10,000 Formula (4): t≦750

Description

[Technical Field]

[0001] The present invention relates to dry mortar, a hardened dry mortar, and a method for producing a hardened dry mortar. [Background technology]

[0002] To reduce the effort required for weighing at the construction site, dry mortar, which is pre-mixed with cement, sand, and additives, is sometimes used. Examples of technologies related to dry mortar include those described in Patent Document 1.

[0003] Patent Document 1 discloses a cement premix product that is resistant to collapse, comprising a cement composition containing cement and fine aggregate, and a paper packaging bag, wherein the angle difference (angle of repose - angle of collapse) when the cement composition is measured with a powder property evaluation device is 25 degrees or less, and the thickness of the paper is 1000 μm or less. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-141662 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] This invention provides a dry mortar with an improved balance between workability and strength after hardening. [Means for solving the problem]

[0006] The present invention provides a dry mortar, a hardened dry mortar, and a method for producing a hardened dry mortar, as described below.

[0007] [1] Cement and sand, and The air permeability time t [seconds] measured in accordance with JIS R5201:2015 and the Blaine specific surface area S [cm 2 / g] calculated in accordance with JIS R5201:2015 satisfy all of the following formulas (1) to (4): dry mortar. Formula (1): S ≥ 100 × t 0.55 Formula (2): S ≤ 230 × t 0.58 Formula (3): S ≤ 10,000 Formula (4): t ≤ 750 [2] The dry mortar according to [1], wherein the air permeability time t further satisfies the following formula (5). Formula (5): t ≥ 2 [3] When the content of the sand in the dry mortar is s mass% and the total content of the binder in the dry mortar is b mass%, The dry mortar according to [1] or [2], wherein the ratio of s to b (s / b) is 4.50 or less. [4] The density measured by the constant volume expansion method is 1.50 g / cm 3 or more and 3.50 g / cm 3 or less: the dry mortar according to any one of [1] to [3]. [5] The dry mortar according to any one of [1] to [4], wherein the porosity calculated by the following (Method 1) is 0.10 or more and 0.60 or less. (Method 1) Put the dry mortar into a cell, then measure the mass of the dry mortar put into the cell, and then calculate the porosity from the following formula (P). Formula (P): (Porosity) = 1 - [(mass of the dry mortar) / {(volume of the cell) × (density of the dry mortar)}] [6] The dry mortar according to any one of [1] to [5], wherein the sand contains one or more selected from the group consisting of lime sand, silica sand, lightweight aggregate, and heavyweight aggregate. [7] The dry mortar according to any one of [1] to [6], wherein the sand content in the dry mortar is 5% by mass or more and 95% by mass or less when the total amount of the dry mortar is 100% by mass. [8] The dry mortar according to any one of [1] to [7], wherein the cement content in the dry mortar is 5% by mass or more and 95% by mass or less when the total amount of the dry mortar is 100% by mass. [9] A dry mortar according to any one of [1] to [8], further comprising one or more selected from the group consisting of expansives, accelerating agents, powdered silica fume, powdered polymers, retarders, and dispersants.

[10] A dry mortar according to any of the above [1] to [9], wherein the flow value according to the following (Method 2) is 110 mm or more and 1000 mm or less. (Method 2) A mixture is prepared by mixing 2000g of the dry mortar and 320g of water. Then, the flow value is measured using the mixture in accordance with the flow test described in JIS R 5201:2015.

[11] The compressive strength after 28 days, as shown below (Method 3), was 20 N / mm². 2 More than 500N / mm 2 The dry mortar described in any of the above [1] to

[10] , which is as follows: (Method 3) A test specimen measuring 4 cm × 4 cm × 16 cm is prepared by mixing 2000 g of the dry mortar and 320 g of water. Then, the compressive strength after 28 days is measured using the test specimen in accordance with the strength test described in JIS R 5201:2015.

[12] A hardened dry mortar according to any of the above [1] to

[11] .

[13] A method for producing a hardened dry mortar, comprising the step of mixing the dry mortar described in any of [1] to

[11] above with water. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide dry mortar with an improved performance balance between workability and strength after curing.

Brief Description of the Drawings

[0009] [Figure 1] It is a diagram showing the relationship between the air permeability time t and the Blaine specific surface area S in the examples. [Figure 2] It is a diagram showing the relationship between the air permeability time t and the Blaine specific surface area S in the examples. [Figure 3] It is a diagram showing the relationship between the air permeability time t and the Blaine specific surface area S in the examples.

Mode for Carrying Out the Invention

[0010] Regarding each component of this embodiment, one kind may be used alone, or two or more kinds may be used in combination. Also, "~" representing a numerical range represents "above" and "below", and includes both the upper limit value and the lower limit value.

[0011] Hereinafter, the present invention will be described based on embodiments.

[0012] [Dry Mortar] The dry mortar of this embodiment contains cement and sand. In the dry mortar of this embodiment, the air permeability time t [seconds] measured in accordance with JIS R5201:2015 and the Blaine specific surface area S [cm 2 / g] calculated in accordance with JIS R5201:2015 satisfy all of the following formulas (1) to (4). Formula (1): S ≧ 100 × t 0.55 Formula (2): S ≦ 230 × t 0.58 Formula (3): S ≦ 10,000 Formula (4): t ≦ 750 By having the above-described configuration, the present invention can provide dry mortar with an improved performance balance between workability and strength after curing. In this embodiment, workability can be evaluated, for example, by the fluidity of the dry mortar after mixing with water.

[0013] The inventors investigated and found that, although the reason is not entirely clear, evaluating dry mortar using air permeation time t and Blaine specific surface area S, which have not been conventionally used as evaluation methods for dry mortar, allows for the distinction between dry mortar with an improved balance of workability and strength after hardening and dry mortar with one that does not. Based on this finding, the inventors further investigated and discovered for the first time that dry mortar with an improved balance of workability and strength after hardening lies within a specific region on a graph with air permeation time t on the horizontal axis and Blaine specific surface area S on the vertical axis, thus completing the present invention.

[0014] In the dry mortar of this embodiment, from the viewpoint of improving the balance between workability and strength after hardening, the air permeability time t [seconds] measured in accordance with JIS R5201:2015 and the Blaine specific surface area S [cm²] calculated in accordance with JIS R5201:2015 are used. 2 / g] satisfies all of equations (1) to (4).

[0015] In the dry mortar of this embodiment, the air permeability time t and the Blaine specific surface area S can be adjusted, for example, by adjusting the cement content, sand content, and other component content, the drying method of the raw materials used, and by excluding fine particles in the raw materials used.

[0016] In this embodiment, the workability of the dry mortar can be improved by satisfying the relationship between the air permeation time t and the Blaine specific surface area S given by equation (1). From the viewpoint of further improving the workability of the dry mortar, equation (1) preferably has S ≥ 125 × t 0.55 Therefore, more preferably S ≥ 150 × t 0.55 That is the case.

[0017] In this embodiment, the workability of the dry mortar can be improved by ensuring that the air permeation time t and the Blaine specific surface area S satisfy the relationship given by equation (2).

[0018] In this embodiment, the dry mortar can be improved in terms of workability and strength after hardening by satisfying the Blaine specific surface area S of equation (3).

[0019] In this embodiment, by ensuring that the air permeation time t satisfies equation (4), the balance between workability and strength after hardening of the dry mortar can be improved.

[0020] In this embodiment, the air permeation time t preferably further satisfies the relationship of equation (5) from the viewpoint of further improving the balance between workability and strength after curing. Formula (5): t≧2 Equation (5) is more preferably t≧3, even more preferably t≧4, and even more preferably t≧5, from the viewpoint of further improving the balance between workability and strength after curing.

[0021] In this embodiment, the strength of the dry mortar after hardening can be further improved by ensuring that the air permeation time t satisfies equation (5).

[0022] In this embodiment, the Blaine specific surface area S preferably further satisfies the relationship of equation (6) from the viewpoint of further improving the balance between workability and strength after curing. Formula (6): S≧200 Equation (6) is more preferably S≧300, even more preferably S≧400, and even more preferably S≧500, from the viewpoint of further improving the balance between workability and strength after curing.

[0023] In this embodiment, the strength of the dry mortar after hardening can be further improved by ensuring that the Blaine specific surface area S satisfies equation (6).

[0024] In this embodiment, the density of the dry mortar measured by the constant volume expansion method is preferably 1.50 g / cm³, from the viewpoint of further improving the balance between workability and strength after hardening. 3 More than 3.50g / cm 3 The following, and more preferably 1.60 g / cm³ 3 More than 3.40g / cm 3 The following, and more preferably 1.70 g / cm³ 3 More than 3.30g / cm 3 The following, and more preferably 1.80 g / cm³ 3 More than 3.20g / cm 3 The following, and more preferably 1.90 g / cm³ 3 More than 3.10g / cm 3 The following applies: The density of the dry mortar can be measured specifically by the method described in the examples.

[0025] With respect to the dry mortar of this embodiment, the porosity calculated by the following (Method 1) is preferably 0.10 to 0.60, more preferably 0.20 to 0.55, even more preferably 0.25 to 0.50, and even more preferably 0.30 to 0.45, from the viewpoint of further improving the balance between workability and strength after hardening. (Method 1) The dry mortar is placed in a cell, the mass of the dry mortar in the cell is measured, and then the porosity is calculated from the following formula (P). Equation (P): (Porosity) = 1 - [(Mass of dry mortar) / {(Volume of cell) × (Density of dry mortar)}] Furthermore, the porosity of dry mortar can be measured more specifically by the method described in the examples.

[0026] Next, we will explain the components of dry mortar with specific examples. The dry mortar of this embodiment contains cement and sand. The dry mortar of this embodiment may consist of cement and sand, or it may contain components other than cement and sand. The dry mortar of this embodiment may further contain other components, such as additives, binders other than cement, etc.

[0027] The dry mortar of this embodiment contains cement. The type of cement used in this embodiment is not particularly limited, and various types of cement and mixtures thereof can be used.

[0028] Examples of cements used in this embodiment include Portland cement, blended cement, eco-cement, special cement, and mixtures thereof. Examples of Portland cement include ordinary Portland cement, rapid-hardening Portland cement, ultra-rapid-hardening Portland cement, moderate-heat Portland cement, low-heat Portland cement, sulfate-resistant Portland cement, and white Portland cement. Examples of blended cement include blast furnace cement, silica cement, and fly ash cement. Examples of eco-cement include ordinary eco-cement and fast-setting eco-cement. Examples of special cement include alumina cement, ultra-fast-setting cement, grout cement, oil well cement, and cements that do not conform to JIS standards.

[0029] The cement of this embodiment preferably includes Portland cement, and more preferably includes one or more types selected from the group consisting of ordinary Portland cement and rapid-hardening Portland cement, from the viewpoint of further improving the balance between workability and strength after hardening.

[0030] The cement content in the dry mortar of this embodiment is preferably 5% to 95% by mass, more preferably 10% to 90% by mass, even more preferably 15% to 85% by mass, even more preferably 20% to 80% by mass, and even more preferably 25% to 75% by mass, when the total amount of dry mortar is considered as 100% by mass.

[0031] The dry mortar of this embodiment contains sand. The type of sand used in this embodiment is not particularly limited, and various types of sand and mixtures thereof can be used.

[0032] Examples of sand used in this embodiment include river sand, river gravel, mountain sand, mountain gravel, crushed stone, crushed sand, limestone aggregate, limestone sand, silica sand, colored sand, artificial aggregate, blast furnace slag aggregate, sea sand, sea gravel, lightweight aggregate, artificial lightweight aggregate, heavy aggregate, and the like.

[0033] The sand in this embodiment preferably includes one or more types selected from the group consisting of lime sand, silica sand, lightweight aggregate, and heavy aggregate, from the viewpoint of further improving the balance between workability and strength after hardening.

[0034] The sand content in the dry mortar of this embodiment is preferably 5% to 95% by mass, more preferably 10% to 90% by mass, even more preferably 15% to 85% by mass, even more preferably 20% to 80% by mass, and even more preferably 25% to 75% by mass, when the total amount of dry mortar is considered as 100% by mass.

[0035] When the total amount of dry mortar in this embodiment is set to 100% by mass, the sand content in the dry mortar is denoted as s% by mass, and the total binder content in the dry mortar is denoted as b% by mass.

[0036] In this embodiment, the term "binder" refers to a material that reacts with water to produce a substance that contributes to the strength development of the mortar. Examples of binders include cement, expansives, quick-setting agents, silica fume, blast furnace slag powder, and fly ash. The binder of this embodiment includes cement. From the viewpoint of further improving the balance between workability and strength after hardening, the binder of this embodiment preferably further includes a binder other than cement, and more preferably further includes one or more selected from the group consisting of an expansive agent, a rapid-hardening agent, and silica fume.

[0037] In the dry mortar of this embodiment, the ratio of s to b (s / b) is preferably 4.50 or less, more preferably 4.25 or less, even more preferably 4.00 or less, even more preferably 3.75 or less, even more preferably 3.50 or less, even more preferably 3.25 or less, and even more preferably 3.00 or less, from the viewpoint of further improving the balance between workability and strength after hardening. In the dry mortar of this embodiment, the lower limit of the ratio (s / b) is not particularly limited, but may be, for example, 0.001 or more, 0.005 or more, 0.01 or more, 0.05 or more, or 0.1 or more.

[0038] The total binder content in the dry mortar of this embodiment is preferably 5% to 95% by mass, more preferably 10% to 90% by mass, even more preferably 15% to 85% by mass, even more preferably 20% to 80% by mass, and even more preferably 25% to 75% by mass, when the total amount of dry mortar is considered as 100% by mass.

[0039] The dry mortar of this embodiment may further contain additives. The additives of this embodiment are components added to the dry mortar for the purpose of improving various properties of the dry mortar. The additives of this embodiment are not particularly limited, and various additives can be used depending on the purpose.

[0040] Examples of additives in this embodiment include leavening agents, hardening agents, setting regulators, powdered silica fume, powdered polymers, retarders, water-reducing agents, AE (Air Entraining) agents, AE water-reducing agents, high-performance water-reducing agents, high-performance AE water-reducing agents, thickeners, rust inhibitors, antifreeze agents, hydration heat inhibitors, polymer emulsions, clay minerals, ion exchangers, oxides, sulfates, phosphates, boric acid, fluorite, wollastonite, shrinkage reducing agents, fluidizing agents, accelerators, foaming substances, water-repellent agents, antibacterial agents, colorants, defoaming agents, fibers, limestone powder, fly ash, blast furnace granulated slag powder, blast furnace slow-cooled slag powder, sewage sludge incineration ash, molten slag from sewage sludge incineration ash, municipal solid waste incineration ash, molten slag from municipal solid waste incineration ash, pulp sludge incineration ash, etc. Examples of clay minerals include bentonite and montmorillonite. Examples of ion exchangers include zeolites, hydrotalcite, and hydrocalmite. Examples of oxides include calcium oxide, silicon dioxide, and titanium dioxide. Examples of sulfates include alum, aluminum sulfate, and sodium sulfate.

[0041] The dry mortar of this embodiment further comprises, preferably, one or more additives selected from the group consisting of expansives, accelerating agents, powdered silica fume, powdered polymers, retarders, and dispersants.

[0042] The additive content in the dry mortar of this embodiment is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 6% by mass or less, and even more preferably 4% by mass or less, from the viewpoint of further improving the balance between workability and strength after hardening, when the total amount of dry mortar is considered as 100% by mass. The lower limit of the additive content in the dry mortar of this embodiment is not particularly limited when the total amount of dry mortar is considered to be 100% by mass, but may be, for example, 0% by mass or more, 0.01% by mass or more, or 0.1% by mass or more.

[0043] The flow value of the dry mortar in this embodiment according to the following (Method 2) is preferably 110 mm or more, more preferably 115 mm or more, even more preferably 120 mm or more, and even more preferably 130 mm or more, from the viewpoint of further improving the balance between workability and strength after hardening. The flow value of the dry mortar according to the following method (Method 2) in this embodiment is not particularly limited, but for example it may be 1000 mm or less, 500 mm or less, 400 mm or less, 350 mm or less, or 300 mm or less. The flow value of the dry mortar of this embodiment according to the following (Method 2) is preferably 110 mm to 1000 mm, more preferably 115 mm to 500 mm, even more preferably 120 mm to 400 mm, even more preferably 130 mm to 350 mm, and even more preferably 130 mm to 300 mm, from the viewpoint of further improving the balance between workability and strength after hardening.

[0044] (Method 2) A mixture is prepared by mixing 2000g of dry mortar and 320g of water. Then, the flow value is measured using the mixture in accordance with the flow test described in JIS R 5201:2015. The flow value of the dry mortar can be measured more specifically by the method described in the examples.

[0045] The compressive strength of the dry mortar of this embodiment after 28 days, as determined by the following method (Method 3), is preferably 20 N / mm², from the viewpoint of further improving the balance between workability and strength after hardening. 2 The above is more preferable: 25 N / mm 2 The above is preferable, and more preferably 30 N / mm 2The above is preferable to 33 N / mm 2 The above is preferable to 35 N / mm 2 That's all. The upper limit of the compressive strength of the dry mortar in this embodiment after 28 days according to the following method (3) is not particularly limited, but for example, 500 N / mm². 2 The following applies: 300 N / mm 2 The following may also be true: 200 N / mm 2 The following may also be true: 150 N / mm 2 The following may also be true: 120 N / mm 2 The following may also be true: 100 N / mm 2 The following is also acceptable. The compressive strength of the dry mortar of this embodiment after 28 days, as determined by the following method (Method 3), is preferably 20 N / mm², from the viewpoint of further improving the balance between workability and strength after hardening. 2 More than 500N / mm 2 The following is more preferable: 25 N / mm 2 More than 300N / mm 2 The following, and more preferably 30 N / mm² 2 More than 200N / mm 2 The following, and more preferably 33 N / mm 2 More than 150N / mm 2 The following, and more preferably 35 N / mm² 2 More than 120N / mm 2 The following, and more preferably 35 N / mm² 2 Above 100 N / mm 2 The following applies:

[0046] (Method 3) A test specimen measuring 4cm x 4cm x 16cm is prepared by mixing 2000g of dry mortar and 320g of water. Then, the compressive strength after 28 days is measured using the test specimen in accordance with the strength test described in JIS R 5201:2015. Furthermore, the compressive strength of the dry mortar after 28 days can be measured more specifically by the method described in the examples.

[0047] <Method for manufacturing dry mortar> The method for producing dry mortar according to this embodiment includes the following steps. • Mixing process: Cement and sand are mixed to obtain dry mortar.

[0048] The dry mortar of this embodiment can be manufactured by mixing cement and sand. In the mixing process, additives, binders other than cement, etc. may be added to the dry mortar as needed.

[0049] The method of mixing the additives and binders other than cement in this embodiment is not particularly limited. For example, cement, sand, and additives may be uniformly mixed using a mixer, or the additives may be uniformly mixed into the resulting dry mortar using a mixer. Examples of mixers include V-type blenders, cone blenders, Nauter mixers, pan-type mixers, and omni mixers.

[0050] The dry mortar manufacturing method of this embodiment preferably further comprises the following steps, from the viewpoint of being able to adjust the air permeation time t and the Blaine specific surface area S to an appropriate range. • Drying process: The raw materials for the dry mortar are dried. • Fine particle removal process: Fine particles are removed from the raw materials of the dry mortar.

[0051] In the drying process, sand, one of the raw materials for dry mortar, is dried. From the viewpoint of adjusting the air permeability time t and the Blaine specific surface area S to an appropriate range, the drying conditions are preferably a temperature of 100-110°C and standing for 3 hours or more.

[0052] In the fine particle removal process, fine particles are removed from the sand, which is the raw material for dry mortar. This can be done, for example, by passing the sand, which is the raw material for dry mortar, through a sieve with a mesh size of 70-80 μm and removing the components that pass through the sieve.

[0053] [Hardened dry mortar] The hardened dry mortar of this embodiment can be obtained, for example, by mixing the dry mortar of this embodiment with water and allowing it to harden.

[0054] [Method for manufacturing hardened dry mortar] The method for manufacturing a hardened dry mortar body according to this embodiment includes the following steps. • Mixing process: Mix the dry mortar of this embodiment with water. • Curing process: The mixture obtained in the mixing process is cured.

[0055] In the mixing step, the dry mortar of this embodiment is mixed with water to obtain a mixture. The mixing method of this embodiment is not particularly limited. In the mixing step, components other than the dry mortar and water of this embodiment may be added as needed.

[0056] In the curing process, the mixture obtained in the mixing process is cured. In this embodiment, the curing of the mixture is carried out by letting the mixture stand.

[0057] The embodiments of the present invention have been described above, but these are merely examples, and various other configurations can also be adopted. Furthermore, the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that do not impair the effects of the present invention are included in the present invention. [Examples]

[0058] This embodiment will be described in detail below with reference to examples and other relevant information. However, this embodiment is not limited in any way to the descriptions of these examples.

[0059] [Examples 1-15, Comparative Examples 1-5] The dry mortar in each example was manufactured using the following <Dry Mortar Raw Materials> and the following <Dry Mortar Manufacturing Method>.

[0060] <Ingredients for dry mortar> (cement) • Cement 1 (ordinary Portland cement, manufactured by Denka Co., Ltd.) • Cement 2 (rapid-hardening Portland cement, manufactured by Denka Co., Ltd.)

[0061] (sand) ·Lime sand Limestone sand 1: Limestone sand prepared by the following method Limestone (mined by Denka Co., Ltd.) was crushed using a jaw crusher (manufactured by Yoshida Seisakusho Co., Ltd., 1023-A) and a drum crusher (manufactured by Yoshida Seisakusho Co., Ltd., 1025-HB) to produce crushed material. The crushed material was then passed through a sieve with a mesh size of 0.6 mm. The particles that passed through the sieve were collected and designated as limestone sand 1. Limestone sand 2: Limestone sand prepared by the following method Limestone (mined by Denka Co., Ltd.) was crushed using a jaw crusher (manufactured by Yoshida Seisakusho Co., Ltd., 1023-A) and a drum crusher (manufactured by Yoshida Seisakusho Co., Ltd., 1025-HB) to produce crushed material. The crushed material was then passed through a sieve with a mesh size of 1.2 mm. The particles that passed through the 1.2 mm sieve were collected and passed through a sieve with a mesh size of 0.6 mm. The particles remaining on the 0.6 mm sieve were collected and designated as limestone sand 2.

[0062] • Silica sand (pearl silica sand, manufactured by Tokai Ritec Co., Ltd.) • Lightweight framing Lightweight aggregate 1 (Perlite B-2V, manufactured by Hattori Corporation) Lightweight aggregate 2 (Cenolite SA, manufactured by Tomoe Kogyo Co., Ltd.) Lightweight aggregate 3 (Fuyolite No. 0, manufactured by Fuyo Perlite Co., Ltd.) ·Heavyweight aggregate Heavy aggregate 1 (Venus Sand, manufactured by Hyotanya Co., Ltd.) Heavy aggregate 2 (PS sand, manufactured by Okazaki Huttenas Albertus Chemical Co., Ltd.)

[0063] (Bonding agents other than cement) • Rapid-hardening material (manufactured by Denka Co., Ltd.): A mixture of calcium aluminate (CaO / Al2O3 molar ratio 2.1, amorphous) and natural anhydrous gypsum. • Expansion agent (p-CSA type-S, manufactured by Denka Co., Ltd.) • Powdered silica fume Silica Fume 1 (SF94-CLM, manufactured by Tomoe Engineering Co., Ltd.) (hereinafter also referred to as SF1.) Silica Fume 2 (zirconia-derived silica fume, SF Silica Fume, manufactured by Tomoe Engineering Co., Ltd.) (hereinafter also referred to as SF2).

[0064] (Additives) • Powdered polymer (ELOTEX WR4600, manufactured by Nurion Co., Ltd.) • Delaying agent (Setter D300, manufactured by Denka Co., Ltd.) • Dispersant (Selfflow 110P, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) • Slaked lime (slaked lime, manufactured by Ueda Lime Manufacturing Co., Ltd.)

[0065] <Method for manufacturing dry mortar> The raw materials for the dry mortar were mixed according to the formulations listed in Table 1 to produce the dry mortar for each example.

[0066] Specifically, the dry mortar was manufactured using the following method. Each type of sand, a raw material for dry mortar, was dried by standing at 105°C for 3 hours. Next, each type of dried sand was sieved through a 75 μm mesh to remove any components that passed through the sieve. The sieved sands, cement, non-cement binders, and additives were then mixed to obtain the dry mortars shown in Table 1.

[0067] <Checking whether equations (1) to (4) are satisfied> We checked whether each example satisfied all of equations (1) to (4). Figure 1 shows a graph with air permeation time t on the horizontal axis and Brain specific surface area S on the vertical axis, plotted with the results for each example and equations (1) to (4). In Figure 1, "●" marks the results of the example, and "▲" marks the results of the comparative example. Equations (1) to (4) are shown as solid black lines. The region that satisfies all of equations (1) to (4) is the shaded area. Note that Figure 1 is a log-log graph.

[0068] From Figure 1, each embodiment was located within the shaded area. In other words, it was confirmed that each embodiment satisfies all of equations (1) to (4). Furthermore, each comparative example was located outside the shaded area. In other words, we confirmed that each comparative example did not satisfy any of equations (1) to (4).

[0069] Figure 2 is a graph of Figure 1 with equation (5) added. Equation (5) is shown as a solid black line. From Figure 2, we can see that each embodiment satisfies all of equations (1) to (5).

[0070] Figure 3 is a graph of Figure 2 with equation (6) added. Equation (6) is shown as a solid black line. From Figure 3, it was confirmed that each embodiment satisfies all of equations (1) to (6).

[0071] [Physical properties of dry mortar] The physical properties of the dry mortar in each example were measured using the following method. The measurement results are shown in Table 2.

[0072] <Density Measurement> Dry mortar was placed in a container attached to a density measuring device (Dry Automatic Densitometer Accupic II 1340, manufactured by Shimadzu Corporation). Next, the mass of the dry mortar in the container was measured. Then, the density was measured using the density measuring device by the constant volume expansion method. The average value of 10 measurements was taken as the density of the dry mortar.

[0073] <Calculation of Polosity> Dry mortar was placed in a cell attached to a Blaine specific surface area measuring device (Blaine air permeability device, manufactured by Tsutsui Rikagakukikai Co., Ltd.). The amount of dry mortar placed in the cell was adjusted according to the method described below (Method 4). Next, the mass of the dry mortar placed in the cell was measured. Then, the porosity was calculated from the above formula (P). The density of the dry mortar used was the density of the dry mortar measured by the <Density Measurement> procedure described above. (Method 4) First, a quantity of dry mortar was weighed that would prevent the upper end of the plunger (the φ20.6mm portion) from touching the top surface of the cell when the dry mortar was pushed in using the plunger. Next, the weighed dry mortar was placed in the cell and pushed in using the plunger. Then, it was confirmed that the upper end of the plunger did not touch the top surface of the cell after pushing in. Finally, the dry mortar was removed from the cell. Next, a smaller amount of dry mortar than the amount removed from the cell was weighed out. Then, the weighed dry mortar was placed in the cell and pushed in using a plunger. Next, it was checked whether the upper end of the plunger was in contact with the top surface of the cell after pushing it in. If the upper end of the plunger was not in contact with the top surface of the cell after pushing it in, the dry mortar was removed from the cell. The above procedure was repeated until the upper end of the plunger, after being pushed in, contacted the top surface of the cell. Once the upper end of the plunger, after being pushed in, contacted the top surface of the cell, the adjustment of the amount of dry mortar was completed. The plunger was pushed in vertically downwards for 3 seconds.

[0074] <Measurement of air permeability time t> For dry mortar, the air permeability time t was measured using a Blaine specific surface area analyzer (Blaine air permeability analyzer, manufactured by Tsutsui Chemical Machinery Co., Ltd.) in accordance with JIS R5201:2015. The average of three measurements was taken as the air permeability time t for the dry mortar. The volume occupied by the bed of the sample (dry mortar) in the cell attached to the Blaine specific surface area analyzer is 1.85 cm³. 3 The porosity of the sample bed was calculated using the results from the <Porosity Calculation> section described above. The density of the sample was calculated using the results from the <Density Measurement> section described above.

[0075] <Measurement of Braine specific surface area S> For dry mortar, the Blaine specific surface area S was measured in accordance with JIS R5201:2015 using a Blaine specific surface area analyzer (Blaine air permeation analyzer, manufactured by Tsutsui Chemical Machinery Co., Ltd.). The average of three measurements was taken as the Blaine specific surface area S for each example of dry mortar. The volume occupied by the bed of the sample (dry mortar) in the cell attached to the Blaine specific surface area analyzer is 1.85 cm³. 3 The porosity of the sample bed was calculated using the results from the <Porosity Calculation> section described above. The density of the sample was calculated using the results from the <Density Measurement> section described above. Furthermore, the standard material used for the specific surface area test was the standard material for specific surface area testing (ordinary Portland cement, manufactured by the Cement Association). The Blaine specific surface area S0 of the standard material was 3250 cm². 2 The density ρ0 is 3.15 g / cm³ / g. 3 The bed's porosity e0 was 0.500%, and the air permeability time t0 was 79.0 seconds.

[0076] [Evaluation of dry mortar] The dry mortar in each example was evaluated using the following method. The evaluation results are shown in Table 2.

[0077] <Evaluation of workability> Workability was evaluated using flow values ​​(hereinafter also referred to as flow values) in accordance with the flow test described in JIS R 5201:2015. Flow values ​​were measured using the following method. Mixtures were prepared by combining 2000g of dry mortar and 320g of water for each example. The flow value was then measured using the mixture in accordance with the flow test specified in JIS R 5201:2015. The flow value was measured in indoor air at a temperature of 20°C and a relative humidity of 80% RH.

[0078] <Evaluation of strength after hardening> The strength after hardening was evaluated by the compressive strength at 28 days of age (hereinafter also referred to as the 28-day compressive strength) in accordance with the strength test described in JIS R 5201:2015. The 28-day compressive strength was measured by the following method. For each example, 2000g of dry mortar and 320g of water were mixed to prepare a 4cm × 4cm × 16cm test specimen. Then, the compressive strength after 28 days was measured using the test specimen in accordance with the strength test specified in JIS R 5201:2015. The 28-day compressive strength measurement was performed in indoor air at room temperature. A compressive strength measuring device (product name: 500kN uniaxial compression tester, manufactured by Marui Co., Ltd.) was used for the 28-day compressive strength measurement.

[0079] [Table 1]

[0080] [Table 2]

Claims

1. It contains cement and sand, The air permeability time t [seconds] measured in accordance with JIS R5201:2015 and the Braine specific surface area S [cm²] calculated in accordance with JIS R5201:2015. ２ A dry mortar in which [ / g] satisfies all of the following formulas (1) to (4). Equation (1): S ≧ 100 × t ０．５５ Equation (2): S≦230×t ０．５８ Formula (3): S≦10,000 Formula (4): t≦750

2. The dry mortar according to claim 1, wherein the air permeation time t further satisfies the following formula (5). Formula (5): t≧2

3. When the sand content in the dry mortar is s by mass%, and the total content of the binder in the dry mortar is b by mass%, The dry mortar according to claim 1, wherein the ratio of s to b (s / b) is 4.50 or less.

4. The density measured by constant volume expansion is 1.50 g / cm³. ３ 3.50g / cm or more ３ The dry mortar according to claim 1, which is as follows:

5. The dry mortar according to claim 1, wherein the porosity calculated by the method described below (Method 1) is 0.10 or more and 0.60 or less. (Method 1) The dry mortar is placed in a cell, the mass of the dry mortar in the cell is measured, and then the porosity is calculated from the following formula (P). Formula (P): (the porosity) = 1 - [(the mass of the dry mortar) / {(the volume of the cell) × (the density of the dry mortar)}]

6. The dry mortar according to claim 1, wherein the sand comprises one or more types selected from the group consisting of lime sand, silica sand, lightweight aggregate, and heavy aggregate.

7. The dry mortar according to claim 1, wherein the content of the sand in the dry mortar is 5% by mass or more and 95% by mass or less when the total amount of the dry mortar is 100% by mass.

8. The dry mortar according to claim 1, wherein the cement content in the dry mortar is 5% by mass or more and 95% by mass or less, when the total amount of the dry mortar is 100% by mass.

9. The dry mortar according to claim 1, further comprising one or more selected from the group consisting of an expansive agent, a hardening agent, powdered silica fume, powdered polymer, a retarder, and a dispersant.

10. The dry mortar according to claim 1, wherein the flow value by the following method (method 2) is 110 mm or more and 1000 mm or less. (Method 2) A mixture is prepared by mixing 2000 g of the dry mortar and 320 g of water. Then, the flow value is measured using the mixture in accordance with the flow test described in JIS R 5201:2015.

11. The compressive strength after 28 days, as shown below (Method 3), was 20 N / mm². ２ More than 500N / mm ２ The dry mortar according to claim 1, which is as follows: (Method 3) A test specimen measuring 4 cm × 4 cm × 16 cm is prepared by mixing 2000 g of the dry mortar and 320 g of water. Then, the compressive strength after 28 days is measured using the test specimen in accordance with the strength test described in JIS R 5201:2015.

12. A hardened dry mortar according to any one of claims 1 to 11.

13. A method for producing a hardened dry mortar, comprising the step of mixing the dry mortar according to any one of claims 1 to 11 with water.

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