Aerated composite material

Abstract

Provided is an aerated composite material which can be reduced in CFP, has high mechanical properties, has a large size, is homogeneous, and has a plurality of voids resulted from the carbonation of a calcium silicate composition. This aerated composite material comprises: a binding matrix in which a silica / calcium silicate continuous phase and a calcium carbonate continuous phase coexist, wherein a silica continuous phase is formed around a plurality of calcium silicate particles in the silica / calcium silicate continuous phase and the calcium silicate particles are dispersed substantially uniformly in the binding matrix; and a plurality of voids which are pores inside the binding matrix and are bubble-shaped or interconnected channels formed in the binding matrix. The aerated composite material is characterized in that the porosity is 50 vol% to 90 vol% inclusive, the sum of three outer dimensions, i.e., a longitudinal dimension, a horizontal dimension and a height dimension, is 700 mm or more, the coefficient of variation of partial bulk density is 10% or less, and the compressive strength in terms of density of 0.5 is 3.00 N / mm2 or more.

Description

cellular composite material

[0001] The present invention relates to a cellular composite material. More specifically, the present invention relates to a cellular composite material having large, uniform voids and high mechanical properties, which can reduce the carbon footprint and is made by carbonated calcium silicate composition, and a method for producing the same.

[0002] Autoclaved lightweight aerated concrete (hereinafter referred to as "AAC"), or commonly referred to as "ordinary ALC"), has many advantages over conventional concrete, including light weight, moisture control, strength-to-weight ratio, fire resistance, corrosion resistance, resistance to termites and mold, and excellent thermal insulation and sound deadening properties. AAC is also highly durable and easy to maintain. Its light weight and high strength make it easy to handle even relatively large composites, and it can be efficiently assembled without the need for additional special equipment. The lightweight nature of AAC also helps reduce transportation costs. The compressive strength of AAC depends on its total void volume, but its equivalent compressive strength (ECS) at density 0.5 is 1.5 times higher than conventional concrete. ０．５ ) at approximately 5N / mm ２ This fully meets the strength requirements for building materials.

[0003] Furthermore, AAC is a monolithic building material with sufficient strength and uniform physical properties, making it easy to design into building components and structures. It can also be easily manufactured into lightweight, large-sized pieces compared to brick or natural stone, making construction quick and easy. It has therefore been widely used. Examples of practical sizes include panels measuring 35-300 mm x 300-900 mm x 1600-6000 mm, blocks measuring 200 mm x 300 mm x 600 mm, and lintels measuring 250 mm x 300 mm x 1800 mm. AAC can be manufactured as a composite material with embedded reinforcing bars, such as rebar, and is efficiently produced by foaming the material together in a large mold and cutting it into multiple pieces during the process.

[0004] AAC is a type of precast concrete due to its manufacturing process. The raw materials used in the production of AAC are limestone materials such as cement and quicklime (CaO), silica (SiO ２ ), silica sand (SiO ２ siliceous materials such as gypsum (CaSO ４ The main raw materials used are aluminum metal or other foaming agents, surfactants to stabilize the bubbles, and other fillers. The foaming agents create voids in the matrix, increasing the porosity of the material. This increases the volume and reduces the density of the expanded material. The expanded material is pre-cured and then fully cured in an autoclave using hot steam at high temperature and pressure (e.g., 190°C, 12 atm) for 6 to 8 hours to produce AAC.

[0005] As described above, AAC uses a large amount of ordinary cement as a raw material, thereby achieving good foaming behavior during the process and good changes in rheological properties during pre-curing. However, as mentioned above, the use of a large amount of AAC and the need for high-temperature steam for its main curing pose a problem of high carbon footprint (hereinafter also referred to as CFP).

[0006] In the following Patent Document 1 (inventor: Liman Richard Yi et al.), it is stated that conventional ceramic materials such as cement, concrete and other similar materials are hard to be bonded to the material, for example, CaO.2SiO in hydrated Portland cement. ２ ・4H ２ O and CaO·H ２ To avoid the problem that the mechanical properties become weak due to the often weak hydrate bonds such as O, which ultimately leads to fracture, ceramic materials have been disclosed in which the bonding matrix has improved mechanical properties. Patent Document 1 discloses in detail that industrial wastes and the like can be used as precursor particles for the bonding matrix, and the mechanical properties of the bonding matrix itself obtained by carbonating a calcium silicate composition, but does not disclose how to produce a high-strength cellular composite of a large, practical size.

[0007] The following Patent Document 2 (inventors: Omkar Deo et al.) discloses a carbonated cellular composite material (hereinafter also referred to as carbonate-cured ALC) containing a plurality of voids obtained by carbonate-curing a calcium silicate composition in order to reduce CFP during production, and a method for producing the same. The cellular composite material described in Patent Document 2 has a porosity of 50% to 80% by volume, which allows it to have a strength of 300 kg / m ３ ~1500 kg / m ３ Density of 2.0 N / mm ２ ~8.5N / mm ２ Compression strength of 0.4 N / mm ２ ~1.7N / mm ２ However, although Patent Document 2 generally describes that industrial waste such as slag and silica fume may be used as raw material filler particles in addition to lime, quartz, and wollastonite, when general limestone fine powder or fly ash is used as the raw material, the bending strength of the composite is reduced to 0.5 density (ECS ０．５ ) to 3.0 N / mm ２ The above-mentioned strength has not been achieved, and the strength does not reach the level of AAC. Furthermore, the cellular composite material actually produced is only a laboratory-level size, with the total external dimensions of length, width, and height being 150 mm + 150 mm + 100 mm = 400 mm, and there is no disclosure at all about how to produce a large, practical size, high-strength cellular composite.

[0008] In the following Patent Document 3 (by Atakhan Bahit et al.), in order to further improve the strength, the volume of pores having a radius of 0.004 μm to 10.0 μm in the composite material is 0.30 ml / g or less, and the density 0.5 converted compressive strength (ECS ０．５ ) 2.0 N / mm ２The above publications disclose a cellular composite material with a carbonation degree of 67.2% or higher and a method for producing the same using a wet slurry with a water / solids ratio of 0.45 or lower. The described composite cellular material achieves strength levels comparable to AAC. However, although Patent Document 3 generally mentions that industrial waste, lime, slag, silica fume, etc. may be used as raw filler particles, it does not disclose how to produce large, practically sized cellular composites. Furthermore, the method disclosed in Patent Document 3, which reduces the water / solids ratio to 0.45 or lower, has the problem of lacking uniformity in physical properties and making it difficult to obtain molded bodies of practical sizes when scaling up production to obtain composites. This is due to the high viscosity of the mixed slurry, which makes it difficult to mix, foam, and pour a fixed amount into a mold.

[0009] The following Patent Document 4 (inventor: Arnett Junayt Tas) discloses that a manufacturing method using a magnesium additive changes the calcium carbonate crystalline phase generated by carbonation into a crystalline phase containing aragonite, improving strength and uniformity of physical properties. This enabled the production of a molded body measuring 700 x 600 x 650 mm, and in terms of strength, ECS0.5 had a strength of 3.0 N / mm ２ to 3.5 N / mm ２ Although there are general statements that industrial waste materials such as slag and silica fume may be used as raw material filler particles in addition to lime, quartz, and wollastonite, a homogeneous, high-strength cellular composite material of practical size has not yet been realized. Even if the water / solids ratio reduction restriction described in Patent Document 3 is relaxed and the viscosity is reduced by applying the method described in Patent Document 4, as the height of the expanded body increases (e.g., 700 mm) during the expansion and pre-curing process, the expanded body may collapse due to its own weight, or the bubbles may coalesce and float after expansion, resulting in a deterioration in density distribution, which reduces productivity, especially when reinforced with reinforcing bars.

[0010] The following Non-Patent Document 1 (Dongming Yang et al.) discloses aerated concrete that uses waste materials containing blast furnace slag as raw materials in order to reduce CFP. ２ Although the aerated concrete has a high absorption capacity and a predetermined compressive strength, the void ratio of water and air combined is only 44.4% to 46.1% (see Fig. 9(f)). From the void ratio shown in Fig. 9 of Non-Patent Document 1, the bulk density is 1.10 g / cm ３ The compressive strength shown in Fig. 10 is calculated to be 3.5 N / mm ２ Therefore, ECS0.5 in Non-Patent Document 1 = 3.5 * 0.5 ２ / 1.1 ２ = 0.72 N / mm ２ Therefore, the cellular composite material described in Non-Patent Document 1 has a lower density equivalent compressive strength (ECS) of 0.5 compared to that of the present invention. ０．５ ) is considerably inferior.

[0011] As described above, in the development of conventional carbonated calcium silicate compositions, multiple voids, and cellular composite materials (carbonation-cured ALC) formed by carbonating these compositions, the CFP has been reduced compared to AAC, while the mechanical properties have been improved. However, it has been difficult to produce large, homogeneous cellular composites with high mechanical properties that can be used for various applications with high productivity, similar to AAC. Therefore, there is still a need to provide homogeneous cellular composites with low CFP, high mechanical properties, and large, practical sizes that can replace AAC.

[0012] Japanese Patent No. 6522036 Japanese Patent No. 6479805 Japanese Patent No. 6837996 International Publication No. 2018 / 175769

[0013] ACS Sustainable Chem. Eng. 2021, 9, 3363-3375

[0014] In view of the state of the art, the problem to be solved by the present invention is to provide a cellular composite material having a large, homogeneous, and multiple voids, which is made by carbonated calcium silicate composition, and which can reduce CFP and has high mechanical properties.

[0015] Conventional techniques for improving mechanical properties have been associated with difficulties in handling the slurry due to its high viscosity and instability of bubbles during scale-up production. One of the reasons for this is the limited amount of water, which is limited to a water / solid ratio of 0.45 or less. To address this issue, for example, increasing the amount of water to a water / solid ratio of 0.5 suppresses the increase in slurry viscosity, stabilizes bubbles, and improves the rheological properties of the expanded body during the expansion and pre-curing processes, for example, by adding a water-reducing agent. This is expected to lead to the production of large composites with good density uniformity and high productivity. However, increasing the water / solid ratio may result in the loss of mechanical properties. Under these circumstances, the inventors focused on the difference in the main components of the carbonated precursor. Specifically, the main components of AAC are tobermorite and C-S-H: calcium silicate hydrate (e.g., 5CaO·6SiO ２ ・5H ２ O), whereas the main component of the conventional cellular composite materials (carbonate-hardened ALC) described in Patent Documents 1 to 4 is anhydrous calcium silicate (e.g., CaO.SiO ２The inventors of the present application have conducted extensive research and experiments into improving both the rheological properties and the mechanical properties by blending a hitherto unknown latent hydraulic raw material and generating hydrates (for example, amorphous hydrates such as calcium-aluminate-silicate-hydrate, hereinafter also referred to as C-A-S-H) or hydrate crystals such as hydrotalcite) in the expansion process. In other words, in the process of forming a cellular composite material, they have discovered that a calcium silicate hydrate (C-A-S-H) is formed by hydration together with anhydrous calcium silicate as a precursor for carbonation. It was thought that by using raw materials to realize a preliminary skeletal structure before carbonation and then carbonating it, it would be possible to reduce the coarse pores in the bonding matrix, homogenize the material, and improve strength. As a result of extensive research and experimentation into raw materials that can form this C-A-S-H, the inventors unexpectedly discovered that by blending a specific amount of a specific latent hydraulic fine powder with calcium silicate fine powder, the rheological properties of the slurry during foaming and pre-hardening can be improved, solving the above-mentioned problem of scaling up during production, and also reducing the coarse pores in the pre-hardened material and homogenizing it, which led to the completion of the present invention.

[0016] That is, the present invention is as follows: [1] A cellular composite material comprising: a binding matrix in which a silica / calcium silicate continuous phase, in which a silica continuous phase is formed around a plurality of calcium silicate particles, and a calcium carbonate continuous phase coexist, and in which the calcium silicate particles are substantially uniformly dispersed within the binding matrix; and a plurality of voids, which are pores within the binding matrix and are in the form of bubbles or interconnected channels formed between the binding matrix; wherein the porosity of the cellular composite material is 50% by volume or more and 90% by volume or less; the cellular composite material is in the form of a rectangular parallelepiped, and the sum of the three external dimensions of length, width, and height is 700 mm or more; the coefficient of variation of the partial bulk density of the cellular composite material = standard deviation / mean value × 100 is 10% or less; and the cellular composite material satisfies the following formula (1): 0.5 density converted compressive strength (σ0.5 [N / mm ２ ]) = compressive strength (σ [N / mm ２]) × (absolute dry density ρ [g / cm ３ ]) ２ / (0.5 [g / cm ３ ]) ２ The compressive strength converted into a density of 0.5 is 3.00 N / mm ２ [2] The cellular composite material characterized in that the compressive strength converted into a density of 0.5 is 3.50 N / mm ２ [3] The cellular composite material according to [1], wherein the compressive strength converted into a density of 0.5 is 4.50 N / mm ２ [4] The cellular composite material according to any one of [1] to [3], wherein the pore volume of pores with a pore radius of 0.2 μm to 3.0 μm is 0.115 mL / g or less. [5] The cellular composite material according to any one of [1] to [4], wherein the Al / Si ratio of the particulate calcium silicate measured by SEM-EDX is 0.44 or more and 0.76 or less. [6] The cellular composite material according to any one of [1] to [5], wherein the Mg / Si ratio of the particulate calcium silicate measured by SEM-EDX is 0.21 or more and 0.38 or less. [7] The cellular composite material according to any one of [1] to [6], wherein the Al / Si ratio of the silica continuous phase measured by SEM-EDX is 0.10 or more and 0.40 or less. [8] The cellular composite material according to any one of [1] to [7], wherein the carbonation degree of the cellular composite material is 60% to 75%. [9] The cellular composite material according to any one of [1] to [7], wherein the cellular composite material is a cellular composite material having a carbonation degree of 60% to 75%.

[10] The cellular composite material according to any one of [1] to [7], wherein the cellular composite material is a cellular composite material having a carbonation degree of 60% to 75%.

[11] The cellular composite material according to any one of [1] to [7], wherein the cellular composite material is a cellular composite material having a carbonation degree of 60% to 75%.

[12] The cellular composite material according to any one of [1] to [7], wherein the cellular composite material is a cellular composite material having a carbonation degree of 60% to 75%.

[13] The cellular composite material according to any one ２ and Al ２ O ３ and MgO, Portland cement, quicklime, and a foaming agent at a water / solid ratio (W / S) of 1.0 or less to prepare a wet mixture or slurry; pouring the obtained wet mixture or slurry into a mold; generating hydrogen gas using the foaming agent to cause volume expansion of the wet mixture or slurry; pre-hardening the obtained expanded wet mixture until it is hard enough to be removed from the mold and moved; optionally cutting the obtained pre-hardened expanded mixture into a desired product shape; optionally cutting the cut expanded mixture at normal pressure, at a temperature of 30°C to 90°C, at a relative humidity of 1% to 100%, and in a CO２

[10] The method for producing a cellular composite material according to any one of [1] to [3], comprising a step of curing the mixture in an atmosphere having a gas concentration of 5% to 95% for 6 to 72 hours.

[10] The method according to [9], wherein the height of the expanded wet mixture obtained after the step of generating hydrogen gas with the foaming agent to cause volume expansion of the wet mixture or slurry is 350 mm or more and 1,000 mm or less.

[11] The method according to [9], wherein the water / solid ratio (W / S) of the wet mixture or slurry is 0.46 or more and 1.00 or less.

[12] The method according to [9], wherein a magnesium additive is further added and mixed in the step of preparing the wet mixture or slurry.

[13] The calcium silicate fine powder is CaSiO ３ (wollastonite or pseudowollastonite), Ca ３ Si ２ O ３ (rankinite), Ca ２ SiO ４

[14] The method according to [9], wherein the calcium silicate phase comprises one or more selected from the group consisting of CaO and SiO (bellite, larnite, bridgegate), and amorphous calcium silicate phases, each of which optionally comprises one or more metal ions or oxides, or a mixture thereof. ２ and Al ２ O ３

[15] The method according to [9], wherein the latent hydraulic fine powder containing CaO and SiO ２ and Al ２ O ３

[16] The method according to [9], wherein the latent hydraulic fine powder containing CaO and SiO further contains JIS Type II (JIS A 6201) fly ash.

[17] The method according to [9], wherein the ratio of the calcium silicate fine powder in the solid content of the wet mixture or slurry is 25 wt % to 75 wt %.

[18] The method according to

[16] , wherein the ratio of the calcium silicate fine powder in the solid content of the wet mixture or slurry is 25 wt % to 75 wt %. ２ and Al ２ O ３

[18] A composite material comprising: a binder matrix in which a silica / calcium silicate continuous phase, in which a silica continuous phase is formed around a plurality of calcium silicate particles, and a calcium carbonate continuous phase coexist, and in which the calcium silicate particles are substantially uniformly dispersed therein; and a plurality of voids, which are pores within the binder matrix and are in the form of bubbles or interconnected channels formed between the binder matrices; wherein the cellular composite material is characterized by a compressive strength (σ0.5 [N / mm 2 ]) of the cellular composite material as expressed by the following formula (1): ２ ]) = compressive strength (σ [N / mm ２ ]) × (absolute dry density ρ [g / cm ３ ]) ２ / (0.5 [g / cm ３ ]) ２ The compressive strength converted into a density of 0.5 is 3.00 N / mm ２ A composite material characterized by:

[0017] The cellular composite material of the present invention can reduce CFP, and by using a specific latent hydraulic fine powder as a raw material, this hydrates to generate C-A-S-H, which as a result improves the rheological properties of the slurry during foaming and pre-curing, making it possible to produce cellular composite materials of large, practical sizes. At the same time, the number of coarse pores in the binding matrix is ​​reduced and the binding matrix is ​​homogenized, achieving high mechanical properties. This makes it possible to replace AAC, and it is a building material that can be suitably used for various applications such as exterior walls, interior materials, ceiling materials, roofing materials, flooring materials, insulation materials, humidity control materials, sound-absorbing materials, corner panels, etc.

[0018] (a) A backscattered electron image (magnification: 3000x) of the cross section of the bond matrix of the cellular composite material of Example 1, showing typical observed phases, and the EDX map acquisition area. (b) An EDX spectrum of the entire EDX map acquisition area of ​​Example 1. Note that K, L, and M attached to the element symbols represent the K line, L line, and M line, respectively. (a) A backscattered electron image (magnification: 3000x) of the cross section of the bond matrix of the cellular composite material of Comparative Example 1, showing typical observed phases, and the EDX map acquisition area. (b) An EDX spectrum of the entire EDX map acquisition area of ​​Comparative Example 2. Note that K, L, and M attached to the element symbols represent the K line, L line, and M line, respectively. (a) EDX elemental analysis areas of the cross section of the bond matrix of the cellular composite material of Example 1 are indicated by symbols 1 to 4. Symbol 1 is estimated to be calcium silicate, symbol 2 is estimated to be a silica phase surrounding the calcium silicate, symbol 3 is estimated to be a silica phase, and symbol 4 is estimated to be a calcium carbonate phase. (b) EDX elemental analysis regions in the cross section of the bonding matrix of the cellular composite material of Comparative Example 1 are indicated by symbols 1 to 3. Symbol 1 is estimated to be a silica phase, and symbols 2 and 3 are estimated to be calcium carbonate phases. (a) is an Al / Si elemental ratio map in the EDX map acquisition region of Example 1, (b) is a graph showing the change in Al / Si elemental ratio along the arrow line in (a), (c) is an Al / Si elemental ratio map similar to (a), and (d) is a graph showing the change in Al / Si elemental ratio along the arrow line in (c). (a) is an Al / Si elemental ratio map in the EDX map acquisition region of Comparative Example 1, and (b) is a graph showing the change in Al / Si elemental ratio along the arrow line in (a). (a) An elemental map of the percentages of C, Si, Ca, Al, and Mg obtained from the EDX spectrum in the EDX map acquisition region of the cross section of Example 1, and (b) is a map of the elemental ratios Al / Si and Mg / Al using the elemental map of (a). (a) An elemental map of the percentages of C, Si, Ca, Al, and Mg obtained from the EDX spectrum in the EDX map acquisition region of the cross section of Comparative Example 1, and (b) is a map of the elemental ratios Al / Si and Mg / Al using the elemental map of (a).1A and 1B are distribution diagrams of calcium silicate, silica, and calcium carbonate phases identified from EDX elemental maps in (a) Example 1 and (b) Comparative Example 1, respectively. (a) A three-dimensional conceptual diagram of the bonding matrix of the present invention is shown, compared with (b) the prior art. (a) An X-ray CT image (field angle: φ35 mm) of the cellular composite material of Example 1, and (b) a high-resolution X-ray CT overhead view (field angle: 500 μm × 500 μm × 300 μm) of the bonding matrix of Example 1, showing the field angle (50 μm × 40 μm) corresponding to the EDX map acquisition range. (b) Pore distributions of the cellular composite materials of Example 1, Comparative Example 1, and Comparative Example 2 are shown. (c) Graphs showing the pore distributions of the cellular composite materials of (a) Example 1 and (b) Comparative Example 2, respectively, before and after the carbonation process. 1 is a graph showing the relationship between the pore volume (mL / g) in the pore radius range of 0.2 to 3 μm and the compressive strength converted to a density of 0.5 in Examples, Comparative Examples 1 and 2.

[0019]

[0023] Hereinafter, embodiments of the present invention will be described in detail. One embodiment of the present invention is a cellular composite material comprising: a binding matrix in which a silica / calcium silicate continuous phase, in which a silica continuous phase is formed around a plurality of calcium silicate particles, and a calcium carbonate continuous phase coexist, and in which the calcium silicate particles are substantially uniformly dispersed within the binding matrix; and a plurality of voids, which are pores within the binding matrix and are in the form of bubbles or interconnected channels formed between the binding matrix; wherein the porosity of the cellular composite material is 50% by volume or more and 90% by volume or less; the cellular composite material is in the form of a rectangular parallelepiped, and the sum of the three external dimensions of length, width, and height is 700 mm or more; the coefficient of variation of the partial bulk density of the cellular composite material = standard deviation / average value x 100 is 10% or less; and the cellular composite material has a compressive strength (σ0.5 [N / mm ]) of 0.5 density converted into σ0.5 [N / mm ] as expressed by the following formula (1): ２ ]) = compressive strength (σ [N / mm ２ ]) × (absolute dry density ρ [g / cm ３ ]) ２ / (0.5 [g / cm ３ ]) ２ The compressive strength converted into a density of 0.5 is 3.00 N / mm ２The cellular composite material is characterized by the above.

[0020] <Binding element> In the prior art cellular composite material (carbonate cured ALC) described in Patent Document 3, calcium silicate fine powder is mainly used as raw material, and the raw material of calcium silicate and CO are mixed by the LPTS method (for example, gas-assisted HLPS process). ２ By contacting the ３ (s) + CO ２ (g) → CaCO ３ (s)+SiO ２ (s) generates the binding element, i.e., the raw material and the externally added CO ２ Thus, calcium silicate is consumed by the reaction, leaving a core containing the remaining calcium silicate phase, surrounded by SiO ２ A first layer rich in CaCO3 and surrounding the first layer ３ The carbonation reaction generally proceeds sufficiently to eliminate the calcium silicate phase-containing core, allowing the first layer of silica to take its place. The resulting multiple binding elements then integrate with the calcium carbonate continuous phase to form a substantially uniformly dispersed binding matrix therein. Figure 8(b) shows a conceptual diagram of the microphase structure of the prior art. ２ The calcium silicate raw material to be contacted with (g) can be a fine calcium silicate powder, for example, CaSiO ３ (wollastonite or pseudowollastonite), Ca ３ Si ２ O ３ (rankinite), Ca ２ SiO ４The calcium silicate (CS) particles contain one or more calcium silicate phases selected from the group consisting of belite, larnite, bridge guide, and amorphous calcium silicate phases, each of which may optionally contain one or more metal ions or oxides, or a mixture thereof. That is, calcium carbonate (CC) is generated around the calcium silicate (CS) particles by the carbonation reaction to fill the pore space, and the reaction proceeds while calcium is released from the calcium silicate (CS) particles. As a result, silica (S) remains in the form of layers around the calcium silicate (CS) particles, or is completely reacted to become silica particles, and both remain in the form of particles. Calcium carbonate (CC) is generated around the silica (S), and CO ２ The silica-calcium silicate (S-CS) fills the pore space, which was continuous before contact with the calcium silicate, and is further connected to calcium carbonate and / or silica and / or fillers formed from other particles of calcium silicate. Thus, silica-calcium silicate (S-CS) is usually in the form of particles, and exists fragmented and discretely in the matrix of continuously formed calcium carbonate (CC). Therefore, the bonding matrix of the prior art cellular composite material is "a calcium silicate core and SiO2 surrounding the core." ２ A first layer rich in CaCO3 surrounding the first layer ３ and a second layer rich in calcium carbonate, and / or a plurality of particulate silica are substantially uniformly dispersed therein and integrally formed with a calcium carbonate continuous phase.

[0021] On the other hand, as illustrated in Figures 8(a) and 9(a), the cellular composite material of the present invention comprises a silica / calcium silicate continuous phase, in which a silica continuous phase is formed around a plurality of calcium silicate particles, and a calcium carbonate continuous phase, with the calcium silicate particles being substantially uniformly dispersed within the continuous phase to form a bonding matrix. As used herein, the terms "continuous," "continuously," and "continuous phase" refer to a state or phase in which similar phases are connected or connected to each other in three dimensions and intertwined with other phases. In SEM-EDX images of two-dimensional cross sections, when observing a large area containing a large number of raw material particles (at least 10 or more), the continuous phase can be confirmed as a broad phase (a sea of ​​silica) containing two or more multiples of other phases (e.g., islands of calcium silicate particles), or as a phase with a shape independent of the shape of the raw material particles. When the raw material particles are large, e.g., approximately 10 μm or larger, this can also be confirmed by optical microscopy of a polished cross section.

[0022] The cellular composite material of this embodiment differs from the conventional carbonate-hardened ALC in that it contains calcium silicate fine powder as well as CaO and SiO as raw materials. ２ and Al ２ O ３The present invention is characterized in that the core of the binding element contains a latent hydraulic fine powder, such as that derived from granulated blast furnace slag powder, by further using a latent hydraulic fine powder containing MgO. By using such a specific latent hydraulic fine powder as a raw material, the latent hydraulic fine powder in the calcium silicate hydrates in a stage prior to the carbonation reaction, temporarily filling the continuous pore space around the fine powder (particles) to form C-A-S-H. In this process, hydrates such as ettringite (AFt), monosulfate (AFm), and calcium aluminate hydrate (C4AH13) are also formed, but hereinafter, C-A-S-H will be abbreviated as C-A-S-H. The subsequent carbonation reaction carbonates the calcium silicate and C-A-S-H, further filling the pores and promoting densification. While calcium silicate forms a continuous calcium carbonate phase, as in the prior art, the C-A-S-H formed within the interconnected pore space prior to carbonation also forms a continuous silica phase in addition to calcium carbonate. This (i) enables large foaming with adequate thickening, (ii) reduces interparticle voids where calcium carbonate does not form, and thereby increases strength. Furthermore, (iii) the coexistence of a calcium carbonate continuous phase and a silica / calcium silicate continuous phase through the hydration-carbonation mechanism also increases strength. Figure 9 shows a conceptual diagram (a) of the microphase structure of the cellular composite material of the present invention and a conceptual diagram (b) of the prior art. In the microphase structure of the present invention, a calcium carbonate continuous phase and a silica / calcium silicate continuous phase coexist, whereas in the microphase structure of the prior art, silica / calcium silicate is a discontinuous phase, and the calcium carbonate continuous phase and the silica / calcium silicate continuous phase do not coexist.

[0023] For example, as described in Wiedmann, et al., PNAS, 112(20) 6271-6276, September 3, 2013, there has been a demand in recent years for a reduction in material footprint (MFP). In AAC and the cellular composite materials (carbonate-cured ALC) described in Patent Documents 1 to 4, natural resources and industrial products produced using natural resources are used as the majority of raw materials. That is, AAC primarily uses Portland cement, quicklime, and silica stone, while the cellular composite materials use fillers such as calcium silicate, including wollastonite, lime, and silica stone as their primary raw materials. Because these materials are produced from natural resources or by burning them, the amount of natural resources mined is large, which increases the MFP. Portland cement and calcium silicate (when synthesized) can be produced using by-products such as industrial waste as part of their raw materials, but because the calcium source requires lime, a natural resource, for the majority of the calcium, and the high-temperature firing process requires a large amount of fuel resources, their MFP remains relatively high, and quicklime faces similar challenges. Therefore, if industrial by-products generated in large quantities in other industries, which have traditionally been downcycled for landfill or roadbed materials, can be mixed into the raw materials, reducing the amount of raw materials derived from natural resources, this will lead to a reduction in MFP. Examples of industrial by-products that can reduce the MFP of cellular composite materials include blast furnace slag and fly ash, as shown below.

[0024] <CaO and SiO ２ and Al ２ O ３ Latent hydraulic fine powder containing CaO and MgO> The following can be used as the latent hydraulic fine powder. Generally, slag is a by-product generated during metal refining, and there are various types. It can be classified into iron and steel slag and non-ferrous metal slag. Iron and steel slag can be divided into blast furnace slag and steelmaking slag. Steelmaking slag can be divided into converter slag and electric furnace slag. Non-ferrous metal slag can be divided into copper slag and ferro-nickel slag. Although the various slags differ depending on the various processes, they all contain mainly CaO, SiO ２ , MgO as the main component, Al ２ O ３There are granulated slag that has been made amorphous by the cooling method, and slowly cooled slag that has been crystallized. For example, blast furnace slag contains silica (SiO ２ Examples of suitable latent hydraulic fine powders include granulated blast furnace slag, which is a slag in which non-iron components such as iron (Fe) and iron oxide (CaO) are melted and bonded with lime (CaO), and then rapidly cooled to form an amorphous form, or slowly cooled blast furnace slag, which is slowly cooled to form a crystal. In the production of the cellular composite material of the present invention, ground blast furnace slag is more preferably used as the latent hydraulic fine powder because it contains large amounts of carbonateable calcium and magnesium, is relatively stable in quality as an industrial waste product, and has moderate hydraulic properties. Generally, so-called combustion ash, including fly ash, is ash produced as a by-product during combustion or incineration in thermal power generation, boilers, and waste treatment processes. While the composition and properties vary depending on the combustion method, for example, large amounts of bottom ash and fly ash, which are the ash from the combustion of heavy oil fuel, coal fuel, and biomass fuel in thermal power generation, are produced as by-products. Combustion ash such as fly ash does not have sufficient hydraulic properties on its own, so there is no problem in using it in combination with slags, but it is difficult to use it alone as a latent hydraulic fine powder, and it is preferable to treat it as a filler, as described below.

[0025] For reference, the compositions of blast furnace slag described in general literature (see http: / / www.jstage.jst.go.jp / article / mukimate1953 / 1977 / 147 / 1977_147_80 / _pdf), the ground blast furnace slag used in Example 1 and Comparative Examples 1 and 2 (Esment 4000 manufactured by Nippon Steel Blast Furnace Cement Co., Ltd.), and Pecs Cement (Solidia cement, calcium silicate manufactured by Solidia Technologies) were analyzed by XRF elemental analysis, and the weight ratios were converted to molar ratios. These compositions are shown in Table 1 below.

[0026]

[0027] <Portland cement, quicklime> Hydraulicity is generally the property of reacting simply by mixing with water to produce insoluble hydrates, which thicken and harden. Portland cement, a typical example of a hydraulic material, is a fine powder whose main components are hydraulic substances such as alite and belite, and in water it gradually produces an amorphous gel hydrate called calcium silicate hydrate: C-S-H (also known as C-A-S-H when focusing on aluminum), which thickens and hardens. In Japan, there are various types of Portland cement, such as high-early-strength, normal, and low-heat, depending on the speed at which the hydraulic properties of the cement appear (early-strength). There are similar types outside Japan, and they are widely used. Examples of hydraulic materials other than Portland cement include quicklime (CaO), calcined gypsum (CaSO ４ ・1 / 2H ２ Crystalline hydrates (e.g., Ca(OH) O) ２ , CaSO ４ ・2H ２ O), but compared to Portland cement which forms amorphous gel hydrate, the rate of thickening and hardening is relatively steep, and its applications are limited.

[0028] Portland cement is also used in the production of AAC, which contains a large amount of air voids, and its hydraulic development rate plays an important role in the volume expansion and pre-hardening processes. ２ and Al ２ O ３ The latent hydraulic property of "latent hydraulic fine powder containing CaO and MgO" is a property that is not hydraulic on its own, but can be given hydraulic properties in the presence of a suitable activator (stimulant) such as an alkaline substance or gypsum, which will be described later. Known latent hydraulic materials include the above-mentioned slag, combustion ash, burned kaolin, and pozzolan, and it is said that ions derived from the corresponding activator act on the latent hydraulic material in water to form gels such as C-A-S-H and N-A-S-H, thereby exhibiting hydraulic properties similar to the hydration of Portland cement. In the mechanism of forming such gels, from the viewpoint of reactivity, "CaO and SiO ２ and Al ２ O ３The "latent hydraulic fine powder containing MgO" is preferably in the form of a fine powder having a particle size of 0.1 μm to 1 mm.

[0029] <Activator (Stimulator)> "CaO and SiO ２ and Al ２ O ３ Examples of activators for the "latent hydraulic fine powder containing calcium hydroxide and MgO" include alkaline substances such as portland cement, alumina cement, sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, calcium oxide (quicklime), calcium hydroxide (slaked lime), sodium nitrite, calcium nitrite, monoethanolamine, diethanolamine, triethanolamine, and ethanoldiisopropanolamine (for example, those with a pH of 8 to 14 in the aqueous dispersion), and neutral substances such as calcium sulfate (gypsum), sodium sulfate, sodium nitrate, and calcium nitrate, and these can be selected individually or in combination. The portland cement, alumina cement, and quicklime mentioned above are preferably used because they act as activators and also have hydraulic properties of their own.

[0030] CaO and SiO used in other embodiments of the present invention described below ２ and Al ２ O ３ The latent hydraulic fine powder containing MgO and the activator are preferably a combination of ground granulated blast furnace slag and Portland cement, and more preferably a combination of ground granulated blast furnace slag, Portland cement, and quicklime.

[0031] <Filler> A filler may be added during the production of the cellular composite material of this embodiment. The filler is not particularly limited as long as it is generated by a chemical reaction other than the reaction that produces calcium carbonate within the process or is inactive in the reaction that produces calcium carbonate, and is a fine particle of approximately 0.01 mm to 1000 μm that is substantially uniformly incorporated into the binding matrix. The filler may be included to the extent that it affects the irritation, hydraulic properties, and carbonation reactivity of the latent hydraulic fine powder but does not impair these effects. Examples of fillers include the aforementioned activators, mineral fillers (limestone, feldspar, silica stone, clay), and by-products (slag, fly ash, incineration ash, silica fume, waste concrete, ready-mix concrete sludge, etc.). Therefore, the cellular composite material of this embodiment may contain silica particles derived from the filler used as a raw material.

[0032] Crystalline fillers contained in the cellular composite material of this embodiment can be detected by powder X-ray diffraction analysis, and cristobalite (SiO ２ ), quartz (SiO ２ ), melilite group [akermanite (Ca ２ MgSi ２ O ７ ), gehlenite (Ca ２ Al ２ SiO ７ ), soda dammelite (NaCaAlSi ２ O ７ )], or hydrotalcite (Mg ６ Al ２ CO ３ (OH) １６ ・4 (H ２ It can be confirmed that the compound further contains

[0033] Another embodiment of the present invention is a method for producing a granular ... ２ and Al ２ O ３and MgO, Portland cement, quicklime, and a foaming agent at a water / solid ratio (W / S) of 1.0 or less to prepare a wet mixture or slurry; pouring the obtained wet mixture or slurry into a mold; generating hydrogen gas using the foaming agent to cause a volume expansion of the wet mixture or slurry, and pre-hardening the obtained expanded wet mixture until it is hard enough to be removed from the mold and moved; optionally cutting the obtained pre-hardened expanded mixture into a desired product shape; optionally cutting the cut expanded mixture into a desired product shape; and subjecting the cut expanded mixture to a process of heating at normal pressure, a temperature of 30°C to 90°C, a relative humidity of 1% to 100%, and CO ２ and curing the mixture in an atmosphere having a gas concentration of 5% to 95% for 6 to 72 hours.

[0034] <Step of preparing a slurry> First, a calcium silicate fine powder, a filler if necessary, CaO and SiO ２ and Al ２ O ３ A wet mixture or slurry (wet slurry) is prepared by kneading latent hydraulic fine powder containing MgO, Portland cement, quicklime, a foaming agent, and water. The weight ratio of calcium silicate in the slurry solids can be 5% to 85%, preferably 25% to 75%.

[0035] The weight ratio of filler in the slurry solids can be 5% to 30%, 0% to 10% quicklime, and 5% to 20% portland cement, preferably 0% to 7% quicklime and 5% to 15% portland cement.

[0036] CaO and SiO in the slurry solids ２ and Al ２ O ３ The weight ratio of the latent hydraulic fine powder containing MgO can be 10% to 80%, preferably 15% to 65%, and more preferably 30% to 60%.

[0037] The weight ratio of the foaming agent to the solid content of the slurry can be 0.01% to 1% of the mass of the metallic aluminum powder (aluminum powder). The appropriate amount of foaming agent, i.e., the amount of bubbles generated in the process of obtaining an expanded body, varies depending on the density of the cellular composite material to be obtained. To obtain a cellular composite material with a bulk density of 0.5 to 0.6, the amount is adjusted to approximately 0.08% to 0.15%.

[0038] As described in Patent Document 4, small amounts of other additives may be added when forming the slurry. Magnesium additives, such as one or more inorganic magnesium salts including magnesium, magnesium salts, and / or magnesium oxide, may be added, including, for example, metallic magnesium powder, magnesium carboxylates such as magnesium acetate, magnesium hydroxide, magnesium oxide, magnesium nitrate, and magnesium sulfate. The amount of magnesium additive added is preferably 0.01% to 10%, more preferably 0.1% to 5%, and even more preferably 0.5% to 3%, based on the mass of the solid raw materials. If the amount is too small, the effect of increasing the strength of the cellular composite material will not be achieved, and if the amount is too large, the effect will be limited.

[0039] Rheological property improvers, surfactants, shrinkage reducers, and water repellents can also be suitably used, and the amount of each added is adjusted appropriately depending on the desired effect, but is usually 5% or less by mass of the solid content. Examples of rheological property improvers that can be used include commercially available water reducing agents, lignin sulfonic acid-based, and polycarboxylic acid-based water reducing agents. Examples of surfactants that can be used include alkali soaps (fatty acid alkali salts, e.g., potassium oleate), potassium alkylene sulfosuccinate, polyoxyethylene alkyl ethers, alkyl betaines, and fatty acid alkanolamides. Examples of shrinkage reducers that can be used include polyether-based shrinkage reducers. Examples of water repellents that can be used include silicone-based water repellents and fluorine-based water repellents.

[0040] The water / solids ratio (W / S), which is the mass ratio of water to solid raw materials other than water in the wet slurry, can be 1.0 or less, preferably 0.46 to 1.0, more preferably 0.50 to 0.75.

[0041] <Step of Pouring into Mold> The wet slurry prepared as described above is poured into a mold. If necessary, reinforcing bars can be placed in the mold beforehand.

[0042] <Reinforcing Bars, Reinforcing Materials> In the production of the cellular composite of this embodiment, in order to increase bending strength, shear strength, and toughness, a small amount of reinforcing material made of steel bars, synthetic fibers, or natural fibers can be embedded for reinforcement. Reinforcement may be in the form of rods, nets, cages, or ribs, or randomly with short fibers. Examples include rod-shaped steel bars organized into cages or ribs and embedded after rust prevention treatment. Those embedded with rust-proofed rod-shaped steel bars or lath mesh are suitable for panel composites, and lintels reinforced with rod-shaped steel bars or nets are preferred. Metal fittings, bolts, nuts, etc. can also be embedded to facilitate attachment to architectural structures.

[0043] <Size> As with AAC, the size of the final cellular composite material is preferably large for ease of application, efficiency, and manufacturing efficiency, but any dimensions can be used. However, when the cellular composite material of this embodiment is in the form of a rectangular parallelepiped, the sum of the external dimensions (length, width, and height) must be 700 mm or more. Blocks and lintels have lengths of 200 mm to 3000 mm, widths of 100 mm to 450 mm, and thicknesses of 50 mm to 600 mm, examples of which include blocks of 600 mm x 300 mm x 200 mm and lintels of 1800 mm x 300 mm x 250 mm. Panels have lengths of 600 mm to 6000 mm, widths of 300 mm to 900 mm, and thicknesses of 35 mm to 300 mm, examples of which include panels of 3000 mm x 600 mm x 100 mm and 1800 mm x 600 mm x 100 mm.

[0044] <A process of generating hydrogen gas using a foaming agent, causing the volumetric expansion of the wet mixture or slurry, and pre-hardening the resulting expanded wet mixture until it is hard enough to be removed from the mold and moved.> In this process, the wet mixture or slurry (hereinafter also referred to as wet slurry) undergoes macroscopic changes such as expansion and hardening, but roughly the following two chemical reactions occur. 1. The foaming agent added to the slurry reacts to generate multiple hydrogen gas bubbles, achieving volume expansion. The reaction is, for example, due to the action of hydroxide ions in the alkaline slurry, according to the following formula: 4Al + 6OH － → 2Al ２ O ３ + 3H ２2. The latent hydraulic fine powder or Portland cement in the wet slurry changes its rheological properties through a hydration reaction with water, i.e., increases in viscosity. The viscosity then increases further, the fluidity disappears, and the product is pre-hardened until it becomes movable as an expanded body. This allows it to be easily removed from the mold and subsequent processes, such as moving or cutting, can be carried out. To efficiently produce the desired large-sized, uniform cellular composite of this embodiment, it is preferable that the changes in reactions 1 and 2 above occur simultaneously and gradually during the volume expansion stage. Incompatible timing and speed of the two reactions can lead to defects such as uneven height of the expanded body, non-uniform density due to coalescence and flow of bubbles inside the expanded body, and / or internal defects due to partial expansion. This is demonstrated in the model experiments of Example 1 and Comparative Example 1 described below. For example, if the first and second reactions occur in a stepwise fashion, such that most of the expansion in the first reaction is completed before the thickening of the slurry in the second reaction, the coalescence and flow of bubbles within the expanded body can lead to density non-uniformity. Furthermore, this non-uniformity manifests itself as localized variations in bulk density, which can undesirably lead to localized deterioration of mechanical properties in large-sized products. Furthermore, these bubble instabilities can undesirably cause unexpected shortfalls in the height of the expanded body, defects within the expanded body, or collapses of the expanded body. Conversely, if the thickening in the second reaction occurs before the foaming in the first reaction, the already thickened slurry will be difficult to expand in volume, resulting in failure to obtain a cellular composite material with the desired density, or internal defects due to partial internal expansion. Alternatively, for example, if reactions 1 and 2 occur simultaneously or separately and rapidly, both are exothermic chemical reactions, and heating further accelerates each reaction, leading to instability of the expanded body, which is thought to be due to local runaway reactions inside the large-sized expanded body, and therefore to failure to obtain the desired large-sized bubble composite.

[0045] In this process, both Reactions 1 and 2 are solid / liquid reactions (with some gas generation) and are affected by diffusion. Therefore, the process time can be shortened by increasing the slurry temperature or the ambient temperature of this process. This process can be completed within a desired time period without impairing the desired effect. For example, 1 to 48 hours, preferably 2 to 24 hours, and more preferably 2 to 12 hours. The temperature is not particularly limited, but a temperature of 10 to 80°C, preferably 15 to 50°C, is used to facilitate temperature control with low energy consumption. When the expanded mixture is cut into the desired product shape in the subsequent process, it is desirable for the size of the expanded mixture to be large. This is because the larger the size of the original expanded mixture, the more efficiently multiple products can be produced by cutting with fewer excess scraps. In particular, the taller the expanded mixture, the more space-efficiently multiple large-sized products can be produced. In this process, large-sized expanded mixtures exceeding 600 mm in height can be easily obtained.

[0046] <Step of Cutting the Resulting Pre-cured Expanded Mix into the Desired Product Shape> In this step, the resultant pre-cured expanded mix can be cut into the desired shape and size, such as a panel, block, or lintel, in the same way as AAC. For cutting, a single or multiple steel wire-mounted tools or devices can be used, as with AAC. This allows a single expanded mix to be cut into one or multiple expanded mixes, and cellular composites of the desired product shape and uniform size can be easily and quickly obtained. In the manufacturing method of this embodiment, the expanded body is stable during volume expansion. For example, an expanded body with a height of 667 mm can be obtained. From one expanded body, multiple panel products measuring 600 mm x 600 mm x 75 mm can be obtained. Furthermore, by using a horizontally larger mold, it is possible to produce multiple larger products, such as 600 mm x 3000 mm x 75 mm, from an expanded body of the same height.

[0047] <Step of Hardening the Cut Expanded Mixture> The cut expanded mixture is cured in a CO atmosphere of 5% to 95% (e.g., 20% to 95%, 30% to 95%, 40% to 95%, 50% to 95%, 5% to 85%, 5% to 75%, 5% to 60%, 5% to 50%, 5% to 30%) at atmospheric pressure, a temperature of 30°C or higher, and a relative humidity of 1% to 100% (e.g., about 5% to 100%, about 10% to 100%, about 20% to 100%, about 30% to 100%, about 50% to 100%, about 60% to 100%, about 1% to 80%, about 1% to 70%, about 1% to 60%, about 1% to 50%, about 1% to 40%, or about 1% to 30%). ２ The foam composite can be cured by conventional processes, including curing in an atmosphere of a gas concentration for 6 to 72 hours (e.g., 12 to 72 hours, 24 to 72 hours, 36 to 72 hours, 6 to 48 hours, 6 to 36 hours, 6 to 24 hours, 6 to about 12 hours).

[0048] The present invention will be specifically described below with reference to examples and comparative examples. First, the methods for measuring the various physical properties used in the examples and comparative examples will be described.

[0049] (1) Porosity (%) The porosity of the cellular composite material was determined as follows. (a) Calculation of porosity (vol%) by X-ray CT <Apparatus> Shimadzu Corporation (inspexio SMX-225CT), tungsten target (tungsten), tube voltage / tube current (160 kV / 40 μA) <Photographing conditions> SID 1000 mm, SOD 118.9 mm, 1200 images taken by offset scanning, 3D imaging equivalent to a spatial resolution of 35 μm / pix (S sample, I imager, O object, D distance) <Analysis conditions> The obtained 3D image was binarized, and the porosity in the measurement space was calculated by treating the dark areas as bubbles and the bright areas as a composite matrix. Figure 10(a) is an example of a 2D tomographic image from the 3D image of the material of Example 1. (b) Specific volume (cm) of the composite material ３ / g) was calculated from the reciprocal of the absolute dry density calculated by the method described in (3) below. The calculated specific volume was multiplied by the foam ratio calculated in (a) to obtain the foam volume (cm ３ / g), and the part excluding air bubbles is the volume of the bonding matrix including the pores (cm３ (c) The pore volume (cm) of 0.004 to 10 μm particles obtained by the method described in (7) below. ３ / g) from the volume of the bonding matrix including the pores determined in (b). ３ (d) The specific volume of the material obtained in each of (a) to (c) above is taken as 100%, and the volume of the bubbles, pores, and solid matter (cm ３ The sum of the ratios of air bubbles and pore volume among the respective ratios (g / g) was defined as the porosity (%). In Figures 10(a) and (b), points with higher X-ray absorption are shown brighter, with the brighter reticulated areas representing the bonding matrix and the darker areas representing air bubbles. As illustrated in Figure 10(b), three-dimensional analysis revealed that the air bubble ratio in Example 1 was 60%. Figure 10(b) also shows, in order from brightest to darkest, calcium silicate, calcium carbonate, silica, and multiple voids. Air bubbles are identified as dark, coarse spheres. Calcium silicate (blast furnace slag) is identified as bright particles. Calcium carbonate is identified as a fine, continuous structure that is the next brightest after calcium silicate. Silica is identified as a fine, continuous structure that is the next brightest after calcium carbonate, surrounding the calcium silicate and penetrating the calcium carbonate.

[0050] (2) Compression strength (σ [N / mm ２ ]) A core sample of 50 mm diameter x 60 mm height was taken from a portion of the cellular composite material perpendicular to the foaming direction. This sample was dried in a convection dryer at 45°C for 3 days, and then left to stand at 20°C and 60% RH for at least 7 days until there was no change in weight, to adjust the moisture content. Furthermore, the diameter D (mm), height H (mm), and weight W1 (g) of the sample after moisture content adjustment were measured. Next, a compression test was performed using a universal tester at a loading rate of 0.3 mm / min, and the breaking strength A (N) was measured. The compressive strength at this time (σ [N / mm ２ ]) was calculated by the following formula: σ [N / mm ２ ]=A / ((D / 2) ２ ×π)

[0051] (3) Absolute dry density (ρ [g / cm ３ ]) Absolute dry density (ρ [g / cm ３]) was calculated based on the following formula: ρ = W3 × (W1 / W2) / ((D / 2) ２ ×π×H / 1000) {where W3 (g) is the weight of the sample after measuring the compressive strength in (2) above when it is dried in a convection dryer at 110°C for at least 4 days until the weight remains constant, W1 (g) is the weight of the sample after adjusting for moisture content, W2 (g) is the weight of the sample after measuring the compressive strength, D (mm) is the diameter of the sample after adjusting for moisture content, and H (mm) is the height of the sample after adjusting for moisture content.}

[0052] (4) Density 0.5 equivalent compressive strength (ECS ０．５ )(σ0.5[N / mm ２ ]) Density 0.5 converted compressive strength (σ0.5 [N / mm ２ ]) was calculated by the following formula: ２ ]) = compressive strength (σ [N / mm ２ ]) × (absolute dry density ρ [g / cm ３ ]) ２ / (0.5 [g / cm ３ ]) ２ was calculated by

[0053] (5) Measurement of Partial Density and Coefficient of Variation (CV) At points where the foam composite is divided into five or more equal parts in the foaming direction, cores (e.g., φ50 mm x 60 mm) or rectangular parallelepipeds (e.g., 40 mm x 40 mm x 40 mm) whose dimensions can be measured are cut out, and the partial bulk density at each position (i.e., four or more measurement points) is calculated from the bulk volume calculated from each dimension and the weight after bone drying at 100 to 110°C. Using each of the obtained partial densities, the coefficient of variation of the partial density was calculated using the following formula: Coefficient of variation (CV) of partial density = standard deviation / average value of partial density.

[0054] (6) SEM-EDX Measurements. Multiple rectangular parallelepipeds (10 mm x 5 mm x 5 mm) were cut from the interior of the cellular composite material. The analysis surface was polished using abrasive paper, and then the polished cross section was finished using an ion beam processing device (SM-09010 manufactured by JEOL Ltd.) to prepare a cross section for SEM-EDX measurement of the cellular composite material. For SEM-EDX measurements, an SEM (Helios 650 manufactured by FEI) equipped with an EDX device (ELECT PLUS manufactured by AMETEK EDAX) was used. An electron beam acceleration voltage of 7 kV was used for the measurements, and EDX spectra were acquired from any position or region of the sample cross section. Spectral analysis was performed using the software (TEAM Ver. 4.5) provided with the EDX device to obtain quantitative values ​​(at%) for each detected element. For quantitative value analysis, K-line spectra were used for each element.

[0055] (7) Pore volume (cm ３ / g). A portion of the cellular composite material was crushed to obtain 2-4 mm pieces. These were then dried at 105±5°C until a certain weight was reached, and then completely dried for use as a measurement sample. The pore size distribution of this measurement sample was measured by mercury intrusion porosimetry using a Micrometrics Autopore 9500. Mercury intrusion porosimetry measures the pore size distribution based on the relationship between the intrusion pressure and the amount of intrusion when forcing mercury into a porous material such as lightweight aerated concrete. The pore size distribution is calculated assuming cylindrical pores. The measurable pore size range is approximately 0.004 μm to 100 μm. While this measurement does not represent the actual pore radius, it is used as an index of the size of the gaps between the constituent materials and is an extremely effective analytical tool for characterizing the pore structure of porous materials such as lightweight aerated concrete. The contact angle between mercury and the sample was 130°, and the surface tension of mercury was calculated to be 484 dyn / cm. Here, the pore volume from the obtained pore distribution was obtained as the volume of pores with pore diameters in the range of 0.004 μm to 10.0 μm per unit mass (1 g) (total pore volume) of the solid content of the measurement sample. The pore volume of pores in the range of pore diameters of 0.004 μm to 10.0 μm present in the bonding matrix was classified into the following pore regions A to C: Pore A region: A region having a pore radius of 0.004 μm to 0.2 μm, i.e., the pores in this region increase in size compared to before carbonation as a result of the binding element precursors being converted into binding elements by carbonation, dividing the larger pores in region B. Pore B region: A region having a pore radius of 0.2 μm to 3.0 μm, i.e., the pores in this region existed even before the carbonation step and were filled with binding elements by carbonation. Pore ​​C region: A region having a pore radius of 3.0 μm to 10.0 μm, i.e., the pores in this region existed before the carbonation process, are not sealed with water, and are filled with binding elements due to carbonation only within the adsorbed water layer. Bubble region: A region having a pore radius of more than 10.0 μm, i.e., the pores in this region existed before the carbonation process, are not sealed with water, and are filled with binding elements due to carbonation only within the water layer adsorbed on the inner surface of the bubbles, and is a region of bubbles whose generation can be controlled by a bubble agent such as aluminum powder.As shown in Figure 11, the pore volume in the 0.2-3 μm radius region of the cellular composite material of Example 1 was smaller than the pore volumes of the conventional Comparative Examples 1 and 2. Furthermore, as shown in Figure 12, the pore volume in the 0.2-3 μm radius region of the cellular composite material of Example 1 (a) was already smaller than that of Comparative Example 2 (b) before the carbonation process, and the pore volume in the same range after the carbonation process was reduced.

[0056] (8) Carbonation Degree (%) After drying the cellular composite material at 105°C for 24 hours, it was ground and 100 to 500 mg of a sample was precisely measured. This was then dissolved in excess hydrochloric acid (5N hydrochloric acid) and the volume of carbon dioxide gas generated was measured using a commercially available mass flow meter. The value was converted to the number of moles of carbon dioxide per 1 g of sample under standard conditions, M, and calculated as v (mol / g). On the other hand, the amount of all calcium components that can react with carbon dioxide was determined by grinding the composite and then calculating the CaO content in the composite by X-ray fluorescence analysis using the glass bead method, and then measuring the corresponding CO ２ The molar amount V (mol / g) was calculated. The carbonation degree (%) was calculated using the following formula: Carbonation degree (%) = (v / V) x 100.

[0057] (9) Carbon dioxide ratio (%) Using the number of moles of carbon dioxide M when calculating the carbonation degree, the carbon dioxide ratio (%) was calculated by converting the formula weight of carbon dioxide, 44 (g / mol), into the mass of carbon dioxide contained in the sample.

[0058] [Example 1: 45.0 parts by mass of ground blast furnace slag, 10.6 parts by mass of high-early-strength cement, and 2.7 parts by mass of quicklime] [Preparation of Slurry] 56.56 kg of water at 35°C was placed in a mixer container and stirred, while adding 3.673 kg of a 26 wt% aqueous magnesium acetate solution, 281.5 g of a 10 wt% dispersion of potassium oleate (FR-14 manufactured by Kao Corporation), 51.03 kg (41.7 parts by mass) of Pecs Cement (Solidia Cement manufactured by Solidia Technologies), and 734.2 g of a polycarboxylic acid-based water-reducing agent (BASF A 50 wt% dispersion of (Glenium 7500), 13.02 kg (10.6 parts by mass) of high-early-strength Portland cement (Ube Mitsubishi Cement Co., Ltd.), 3.255 kg (2.7 parts by mass) of quicklime (Kawai Lime Industry Co., Ltd.), and 55.07 kg (45.0 parts by mass) of ground granulated blast furnace slag (Nippon Steel Blast Furnace Cement Co., Ltd., Esment 4000) as a latent hydraulic material were added to water and mixed for 180 seconds. Furthermore, 1703 g of an aqueous aluminum dispersion containing 140.7 g (0.115 parts by mass) of aluminum powder (Daiwa Metal Powder Co., Ltd.) was added and mixed for 30 seconds to prepare a wet slurry. The resulting slurry contained 61.2 kg of water and 122.4 kg of solid raw materials, resulting in a water / solid ratio of 0.50. The water in the slurry includes the water contained in the dispersion. [Pouring, Pre-curing, and Demolding] The obtained slurry was poured into a 700 mm deep rectangular mold, in which rebar to be embedded had been partially placed, to a height of 253 mm from the bottom plate. The slurry was then pre-cured at an ambient temperature of 23°C for approximately 1 to 4 hours, allowing the slurry to expand in volume and simultaneously. The height of the wet expanded body at this time was a maximum of 672 mm. Next, the pre-cured expanded body, which had become hard enough to be removed from the mold, was removed from the mold. The height of the expanded body at this time was 667 mm. The removed expanded body was then cut using a piano wire cutter and molded into multiple rectangular panels measuring 600 mm along the expansion direction of the expanded body, 600 mm perpendicular to this, and 75 mm thick (600 mm x 600 mm x 75 mm).[Carbonation hardening] The molded expanded body was placed in a carbonation hardening tank and hardened for 18 hours or more at a temperature of 80°C, a relative humidity of 98%, and a carbon dioxide concentration of 95% to obtain a panel-shaped cellular composite (material) with a uniform, visually free defect. [Evaluation of bulk density, homogeneity, and compressive strength] The average partial bulk density μ of the obtained cellular composite was 0.563 g / cm. ３ The partial bulk density was measured at a measurement position of 100 mm (n = 1 to 5) from the bottom plate. The coefficient of variation (CV) was uniform at 2.10%. The compressive strength was 6.03 to 6.68 N / mm ２ The ECS was calculated using the density of each specimen. ０．５ is 4.68 to 5.31 N / mm ２ , average 5.00 N / mm ２ The carbonation degree was 67% and the carbon dioxide ratio was 16%. An example of an SEM image of the cross section of the obtained cellular composite is shown in Figure 1(a).

[0059] [Comparative Example 1] 51.03 kg (41.7 parts by mass) of Pecs Cement (Solidia Cement manufactured by Solidia Technologies), 13.02 kg (10.6 parts by mass) of high-early-strength Portland cement (manufactured by Ube Mitsubishi Cement Co., Ltd.), 3.255 kg (2.7 parts by mass) of quicklime (manufactured by Kawai Lime Industry Co., Ltd.), and 55.07 kg (45.0 parts by mass) of ground granulated blast furnace slag (Nippon Steel Blast Furnace Cement Co., Ltd., Esment 4000) were replaced with 92.5 parts by mass of Pecs Cement and 7.5 parts by mass of quicklime (i.e., high-early-strength Portland cement and ground granulated blast furnace slag, which is a latent hydraulic material, were not used). Except for this, a foam composite was prepared in the same manner as in Example 1. The cellular composite obtained in Comparative Example 1 had visible cracks and was of insufficient quality. This defect was almost horizontal in the middle to upper part of the expanded body where horizontal rebars were present. It was confirmed when the pre-cured expanded body was cut, and was associated with the instability of the expanded body during volume expansion. When no rebars were placed in the mold, a homogeneous cellular composite measuring 600 mm x 600 mm x 75 mm was obtained that was free of visual defects. The maximum height of the expanded body was 660 mm. Next, the pre-cured expanded body, which had reached a hardness sufficient for removal from the mold, was removed from the mold. The height of the expanded body at this time was 607 mm. The average partial bulk density μ of the obtained cellular composite was 0.557 g / cm. ３ The coefficient of variation CV of the partial bulk density at the measurement position from the bottom plate, 100 mm (n = 1 to 5), was uniform at 2.5%. The compressive strength was 2.93 to 4.26 N / mm ２ The ECS0.5 calculated using the density of each test specimen was 2.40 to 3.75 N / mm ２ , average 2.86 N / mm ２The carbonation degree and carbon dioxide ratio were inferior to those of ACC. The results are shown in Table 2 below. [Carbonation degree and carbon dioxide ratio] The carbonation degree was 86% and the carbon dioxide ratio was 21%. Comparative Example 1 corresponds to the composite materials described in Patent Documents 3 and 4, and these values ​​were confirmed to be equivalent to those described in those documents. An example of an SEM image of the cross section of the obtained cellular composite is shown in Figure 2(a). Figure 2(a) (Comparative Example 1) shows that the bonding matrix is ​​coarser than Figure 1(a) (Example 1). This corresponds to the fact that, as shown in Table 2 and Figure 13 below, in Example 1, the pore volume in the bonding matrix for pore radii of 0.2 μm to 3.0 μm was 0.061 (mL / g), while in Comparative Example 1, the pore volume for pore radii of 0.2 μm to 3.0 μm was 0.144 (mL / g). Furthermore, as shown in FIG. 13, it was found that the pore volume of pores with pore radii of 0.2 μm to 3.0 μm in the binding matrix also correlates with ECS 0.5.

[0060] [Comparative Example 2] 51.03 kg (41.7 parts by mass) of Pecs Cement (Solidia cement manufactured by Solidia Technologies), 13.02 kg (10.6 parts by mass) of high-early-strength Portland cement (manufactured by Ube Mitsubishi Cement Co., Ltd.), 3.255 kg (2.7 parts by mass) of quicklime (manufactured by Kawai Lime Industry Co., Ltd.), and 55.07 kg (45.0 parts by mass) of ground granulated blast furnace slag (Nippon Steel Blast Furnace Cement Co., Ltd., Esment 4000) were replaced with 86.7 parts by mass of Pecs Cement, 10.6 parts by mass of high-early-strength Portland cement, and 2.7 parts by mass of quicklime (i.e., high-early-strength Portland cement was used, but the latent hydraulic material ground granulated blast furnace slag was not used). A foam composite was prepared in the same manner as in Example 1. In Comparative Example 2, when a reinforcing bar was partially placed in the mold, the resulting cellular composite had no defects at the visual level, but it was confirmed that the bubbles were concentrated at the top of the expanded body and there were clearly fewer bubbles at the bottom of the expanded body. Furthermore, as shown in Figure 12, the pore volume in the pore radius range of 0.2 to 3 μm in Example 1 (see (a)) was already smaller than the pore volume in Comparative Example 2 (see (b)) before the carbonation process, and the pore volume in the same range after the carbonation process was reduced. The average μ of the partial bulk density of the cellular composite at this time was 0.604 g / cm.３ It was. The coefficient of variation CV of the partial bulk density at a measurement position of 100 nm [mm] (n = 1 to 5) from the bottom plate was 14.6%, which was non-uniform, and was associated with the concentration of bubbles in the upper part. Compressive strength is 2.72-7.08N / mm ２ The ECS0.5 calculated using the density of each test specimen was 2.81 to 4.01 N / mm ２ , average 3.49 N / mm ２ and was inferior to AAC. The results are shown in Table 2 below. [Carbonation degree, carbon dioxide ratio] The carbonation degree was 81%, and the carbon dioxide ratio was 19%. As shown in Table 2 below and FIG. 13, in Example 1, the pore volume of pores with pore radii of 0.2 μm to 3.0 μm in the bond matrix was 0.061 (mL / g), while in Comparative Example 2, the pore volume of pores with pore radii of 0.2 μm to 3.0 μm was 0.119 (mL / g). Furthermore, as shown in FIG. 13, it was found that the pore volume of pores with pore radii of 0.2 μm to 3.0 μm in the bond matrix is ​​also correlated with ECS 0.5.

[0061]

[0062] <Effects on the Production of Large, Uniform Foam Composite Materials> The uniformity of the cellular composite materials can be explained by model experiments showing the relationship between volume expansion and viscosity over time during the expansion and pre-curing process. In Comparative Examples 1 and 2, volume expansion (rising of the slurry liquid level) occurred relatively first, followed by an increase in the viscosity of the expanded mixture. That is, volume expansion and viscosity increase occurred in stages. The sudden increase in viscosity after volume expansion caused instability (in-process volume shrinkage) and internal fluctuations in the expanded mass containing many bubbles, leading to undesirable defects such as those observed when rebar was placed in Comparative Example 1. Furthermore, when 10% high-early-strength Portland cement was added as in Comparative Example 2, the viscosity increase was accelerated and the volume stability of the expanded mass was improved compared to Comparative Example 1. However, the coalescence and flow of bubbles within the expanded mass still led to undesirable internal density non-uniformity. In contrast, in Example 1, volume expansion and viscosity increase occurred almost simultaneously and gradually, rather than sequentially and stepwise as in Comparative Examples 1 and 2. It was found that the latent hydraulic ground blast furnace slag thickens while generating CA-S-H, and that the volume expansion and viscosity increase occur almost simultaneously and gradually, which means that it contributes to improving the volume stability of the expanded body, obtaining a composite without defects, and also effectively contributes to improving the density distribution.

[0063] Model experiments on the volume expansion / viscosity increase behavior of the slurry during the volume expansion and pre-curing processes in which the slurry becomes an expanded body can be performed as follows. The raw material water temperature, the ambient temperature during volume expansion / pre-curing, and the jacket water temperature for viscosity increase measurement are all maintained in an isothermal environment of 35°C. Cylindrical containers of the same volume are used as molds with the same pouring height (100 mm) to make the sizes before volume expansion uniform. The volume expansion of the slurry is measured as the liquid level height measured with an optical displacement meter (IL-600, manufactured by Keyence Corporation). The viscosity change of the slurry is measured using a tuning fork viscometer (SV-10, manufactured by A&D Co., Ltd.) to measure the change in viscosity over time. In measuring the viscosity over time, the measured value changes significantly due to the volume expansion caused by aluminum (affected by the density of the slurry). Therefore, to exclude this, the mixture is kneaded for 180 seconds, and a small amount (approximately 15 mL) of the slurry that does not expand in volume before the addition of aluminum powder is taken and measured.

[0064] [SEM-EDX Measurement Results for the Entire Area] SEM-EDX measurements were performed for Example 1 and Comparative Example 1, and the measurement results for the entire field of view are shown in Figure 1(a) and Figure 2(a), respectively. In addition, the element species present in the entire field of view and the ratio (at %) of the number of atoms therein were calculated, and the results are summarized in Table 3 below.

[0065]

[0066] Table 3 shows that the presence of blast furnace slag (Example 1) resulted in less Ca and more Si, Mg, and Al compared to the absence of blast furnace slag (Comparative Example 1). Furthermore, Table 4 below suggests that the presence of blast furnace slag resulted in the presence of a continuous phase rich in silica, i.e., a "silica / calcium silicate continuous phase in which a silica continuous phase is formed around a plurality of calcium silicate particles."

[0067] [SEM-EDX Measurement Results of Each Phase] EDX spectra were analyzed for each phase shown in FIG. 1(a) for Example 1 and FIG. 2(a) for Comparative Example 1. The positions of each phase to be measured are shown in FIGS. 3(a) and 3(b), respectively. Detailed analysis was performed focusing on the squared areas 1, 3, and 4 in FIG. 3(a) and 1 to 3 in FIG. 3(b), and on the boundary area in FIG. 3(a) 2, with the aim of identifying the constituent materials of that area. The elemental species present and their atomic ratios (at %), as well as the atomic ratios of two selected elements necessary to identify the constituent materials, and the estimated constituent materials are shown in Table 4 below.

[0068]

[0069] To identify the main components—calcium silicate, calcium carbonate, and silicon dioxide (silica)—we focused on the Si / Ca and C / Si ratios listed in Table 4. When the Si / Ca ratio exceeded 1, it was assumed to be silicon dioxide, and when it was below 1, it was assumed to be calcium carbonate or calcium silicate. For samples with a Si / Ca ratio below 1, we further focused on the C / Si ratio, and those with a Si / Ca ratio above 1 were assumed to be calcium carbonate, while those below 1 were assumed to be calcium silicate. The coarse particles (region 1) observed in Figure 3(a) of Example 1, in which blast furnace slag was added, were estimated to be calcium silicate based on the Si / Ca ratio in Table 4, and the surrounding region 2 (location) was estimated to contain a silica phase. Similarly, region 3 was estimated to contain silica, and region 4 was estimated to contain calcium carbonate. On the other hand, region 1 in Figure 3(b) of Comparative Example 1, in which blast furnace slag was not added, was estimated to be silica based on the Si / Ca ratio in Table 4, and regions 2 and 3 were estimated to contain calcium carbonate. Next, to identify the origin of calcium silicate, we focused on the Al / Si and Mg / Si ratios. As shown in Table 1, the Al / Si ratio of the raw material blast furnace slag was 0.48, and the Mg / Si ratio was 0.25. Therefore, the coarse particles (area 1) observed in Figure 3(a) were presumed to be particulate calcium silicate derived from the raw material blast furnace slag.

[0070] From Tables 3 and 4, in the case of Example 1 in which blast furnace slag was added, particulate calcium silicate derived from the raw material blast furnace slag (having a high Al / Si ratio similar to the raw material blast furnace slag) and CaCO３ A silica phase was formed around the calcium silicate particles. On the other hand, in Comparative Example 1, where blast furnace slag was not added, calcium carbonate formed a continuous, uniform phase, and silica particles with a low Al / Si ratio were confirmed to be present within the calcium carbonate phase. In other words, Example 1, where blast furnace slag was added, confirmed the presence of a "silica / calcium silicate continuous phase, in which a silica continuous phase was formed around multiple calcium silicate particles," which was not present in Comparative Example 1, where blast furnace slag was not added.

[0071] FIG. 6(a) is a mapping diagram showing the at% distribution of each element, C, Si, Ca, Al, and Mg, determined from K-line analysis based on EDX spectra acquired from the cross section of Example 1. FIG. 6(b) is a mapping diagram showing the element ratios of Al / Si and Mg / Al. Similarly, FIG. 7(a) is a mapping diagram showing the at% distribution of each element, C, Si, Ca, Al, and Mg, based on EDX spectra acquired from the cross section of Comparative Example 1. Similarly, FIG. 7(b) is a mapping diagram showing the element ratios of Al / Si and Mg / Al for Comparative Example 1. In the diagram, higher brightness indicates higher at% or element ratio of the corresponding element. In FIG. 6(a), the C-rich phase is calcium carbonate, which has a continuous and intricate shape. The Si-rich phase is silica, which has a continuous and intricate shape similar to calcium carbonate. The Ca-rich, C-poor, and moderate Si phase is calcium silicate, which has a particulate shape surrounded by continuous silica. Furthermore, in Figure 6(b), the region with the highest Al / Si ratio corresponds well to the particulate calcium silicate phase. The region with the next highest Al / Si ratio corresponds to the silica phase, and the values ​​change continuously. The region with a high Mg / Al ratio is located around the particulate calcium silicate phase, and the region with the next highest Mg / Al ratio corresponds to calcium silicate (blast furnace slag particles) and a continuous silica phase. Since the distributions of Al / Si and Mg / Al and the blast furnace slag particles and their surrounding continuous silica phase are related or similar to each other, it is estimated that the blast furnace slag particles form C-A-S-H through hydration, and that the C-A-S-H then carbonates to form a continuous calcium carbonate phase and a continuous silica phase.

[0072] From the above, it was confirmed that in Example 1 in which blast furnace slag was added, both a calcium carbonate continuous phase and a continuous silica phase containing calcium silicate were formed, and that these first formed C-A-S-H during the expansion process before the blast furnace slag was carbonated, and that the C-A-S-H then formed a continuous phase of calcium carbonate and silica containing the remaining Al and Mg through a carbonation reaction.

[0073] On the other hand, as shown in Figures 7(a) and (b), in Comparative Example 1, in which no blast furnace slag was added, calcium carbonate formed a continuous, uniform phase. Silica generally formed a discontinuous, particulate phase, although some silica particles had calcium carbonate infiltrated into the interior of the particles. Furthermore, in Comparative Example 1, calcium silicate phase was barely detected. This is presumably related to the high carbonation reactivity, which resulted in the consumption of most of the calcium silicate. In other words, in Comparative Example 1, calcium carbonate formed a continuous phase, while silica was a discontinuous phase. Furthermore, in Comparative Example 1, the distribution of Al / Si and Mg / Al was not distributed within the silica, unlike in Example 1. In other words, in Comparative Example 1, the formation of a continuous silica phase due to the formation of blast furnace slag particles and C-A-S-H and the carbonation of C-A-S-H was not confirmed.

[0074] [Consideration of the Al / Si ratio of the "silica / calcium silicate continuous phase in which a silica continuous phase is formed around multiple calcium silicate particles" and construction of a microphase structure model] Figures 4(a) and (c) are Al / Si elemental ratio mapping diagrams for Example 1, in which blast furnace slag was added. On the other hand, Figure 5(a) is a mapping diagram for Comparative Example 1, in which blast furnace slag was not added. In these figures, elemental ratio mapping was performed at designated positions to confirm the changes in the Al / Si elemental ratio at the positions of the line regions indicated by arrows connecting multiple calcium silicate particles. Figures 4(b), (d), and 5(b) show the profiles of Figures 4(a), (c), and 5(a), respectively. In Example 1, in which blast furnace slag was added (Figures 4(b) and (d)), the Al / Si elemental ratio in the silica continuous phase surrounding the calcium silicate was smaller than that in the calcium silicate portion and tended to decrease continuously from the calcium silicate phase. On the other hand, in Comparative Example 1 (Fig. 5(b)), in which no blast furnace slag was added, it was confirmed that Al was not present in the silica phase or was locally and discontinuously dispersed in the calcium carbonate continuous phase. Thus, Figs. 4 and 5 clearly show the difference in microstructure between Example 1 and Comparative Example 1.

[0075] Using the SEM-EDX analysis described above, models of the microphase structure were constructed for the case with blast furnace slag (the present invention) and the case without blast furnace slag (the prior art), as shown in Figures 8 and 9. That is, in the present invention, a continuous silica phase exists around the particulate calcium silicate, and calcium carbonate also forms a continuous phase, forming an intricate structure. On the other hand, in the prior art, particles have a core-shell structure in which a silica phase is formed around the particulate calcium silicate, or as a result of calcium silicate being consumed during the carbonation reaction, particulate silica exists fragmentarily and discretely within the continuous calcium carbonate phase, and no continuous silica phase exists.

[0076] The cellular composite material of the present invention uses calcium silicate and a specific latent hydraulic fine powder as raw materials, thereby reducing CFP and improving the rheology of the slurry during foaming and pre-curing, thereby enabling the production of practically sized cellular composite materials. At the same time, the reduction of coarse pores in the binding matrix and the homogenization of the binding matrix result in a large, homogeneous, multi-porous cellular composite material (carbonation-cured ALC) with high mechanical properties, which is made by carbonated calcium silicate compositions. As a result, this can replace AAC and provide a building material suitable for various applications, such as exterior walls, interior materials, ceilings, roofing materials, flooring materials, insulation materials, humidity control materials, sound-absorbing materials, and corner panels.

Claims

1. A cellular composite material comprising: a binder matrix in which a silica / calcium silicate continuous phase, in which a silica continuous phase is formed around a plurality of calcium silicate particles, and a calcium carbonate continuous phase coexist, and in which the calcium silicate particles are substantially uniformly dispersed within the binder matrix; and a plurality of voids, which are pores within the binder matrix and are voids in the form of bubbles or interconnected channels formed between the binder matrix; wherein the porosity of the cellular composite material is 50% by volume or more and 90% by volume or less; the cellular composite material is in the form of a rectangular parallelepiped, with the sum of the three external dimensions of length, width, and height being 700 mm or more; the coefficient of variation of the partial bulk density of the cellular composite material = standard deviation / average value x 100 is 10% or less; and the cellular composite material satisfies the following formula (1): 0.5 density converted compressive strength (σ0.5 [N / mm ２ ]) = compressive strength (σ [N / mm ２ ]) × (absolute dry density ρ [g / cm ３ ]) ２ / (0.5 [g / cm ３ ]) ２ The compressive strength converted into a density of 0.5 is 3.00 N / mm ２ A cellular composite material characterized by the above.

2. The compressive strength converted into a density of 0.5 is 3.50 N / mm ２ The cellular composite material according to claim 1 .

3. The compressive strength converted into a density of 0.5 is 4.50 N / mm ２ The cellular composite material according to claim 2, wherein 4. A cellular composite material according to any one of claims 1 to 3, in which the pore volume of pores with a pore radius of 0.2 μm to 3.0 μm is 0.115 mL / g or less.

5. A cellular composite material according to any one of claims 1 to 3, wherein the Al / Si ratio of the particulate calcium silicate measured by SEM-EDX is 0.44 or more and 0.76 or less.

6. A cellular composite material according to any one of claims 1 to 3, wherein the Mg / Si ratio of the particulate calcium silicate measured by SEM-EDX is 0.21 or more and 0.38 or less.

7. A cellular composite material according to any one of claims 1 to 3, wherein the Al / Si ratio of the silica continuous phase, as measured by SEM-EDX, is 0.10 or more and 0.40 or less.

8. A cellular composite material according to any one of claims 1 to 3, wherein the carbonation degree of the cellular composite material is between 60% and 75%.

9. The process of: mixing water, calcium silicate fine powder, CaO and SiO ２ and Al ２ O ３ and MgO, Portland cement, quicklime, and a foaming agent at a water / solid ratio (W / S) of 1.0 or less to prepare a wet mixture or slurry; pouring the obtained wet mixture or slurry into a mold; generating hydrogen gas using the foaming agent to cause a volume expansion of the wet mixture or slurry, and pre-hardening the obtained expanded wet mixture until it is hard enough to be removed from the mold and moved; optionally cutting the obtained pre-hardened expanded mixture into a desired product shape; optionally cutting the cut expanded mixture into a desired product shape; and subjecting the cut expanded mixture to a process of heating at normal pressure, a temperature of 30°C to 90°C, a relative humidity of 1% to 100%, and CO ２ A method for producing a cellular composite material according to any one of claims 1 to 3, comprising: a step of curing the cellular composite material in an atmosphere having a gas concentration of 5% to 95% for 6 hours to 72 hours.

10. The method of claim 9, wherein the height of the expanded wet mixture obtained after the step of pre-hardening the expanded wet mixture to a hardness sufficient to allow it to be removed from the mold by generating hydrogen gas with the foaming agent to cause a volume expansion of the wet mixture or slurry is 350 mm or more and 1000 mm or less.

11. The method of claim 9, wherein the water / solids ratio (W / S) of the wet mixture or slurry is 0.46 or more and 1.00 or less.

12. The method of claim 9, wherein a magnesium additive is further added and mixed in the step of preparing the wet mixture or slurry.

13. The calcium silicate fine powder is CaSiO ３ (wollastonite or pseudowollastonite), Ca ３ Si ２ O ３ (rankinite), Ca ２ SiO ４ 10. The method of claim 9, wherein the calcium silicate phase comprises one or more calcium silicate phases selected from the group consisting of: belite, larnite, bridgeguide, and amorphous calcium silicate phases, each of which optionally comprises one or more metal ions or oxides, or mixtures thereof.

14. The CaO and SiO ２ and Al ２ O ３ The method according to claim 9, wherein the latent hydraulic fine powder containing MgO is ground granulated blast furnace slag.

15. The CaO and SiO ２ and Al ２ O ３ The method according to claim 14, wherein the latent hydraulic fine powder containing MgO further contains JIS Type II (JIS A 6201) fly ash.

16. The method according to claim 9, wherein the proportion of the calcium silicate fine powder in the solid content of the wet mixture or slurry is 25 wt % to 75 wt %.

17. The CaO and SiO in the solid content of the wet mixture or slurry ２ and Al ２ O ３ 10. The method according to claim 9, wherein the ratio of the latent hydraulic fine powder containing MgO is 15 wt % to 65 wt % by mass.

18. A composite material comprising: a binder matrix in which a silica / calcium silicate continuous phase, in which a silica continuous phase is formed around a plurality of calcium silicate particles, and a calcium carbonate continuous phase coexist, and the calcium silicate particles are substantially uniformly dispersed therein; and a plurality of voids, which are pores within the binder matrix and are in the form of bubbles or interconnected channels formed between the binder matrices; wherein the cellular composite material has a compressive strength (σ0.5 [N / mm ]) of 0.5 density equivalent (σ0.5 [N / mm ]) as expressed by the following formula (1): ２ ]) = compressive strength (σ [N / mm ２ ]) × (absolute dry density ρ [g / cm ３ ]) ２ / (0.5 [g / cm ３ ]) ２ The compressive strength converted into a density of 0.5 is 3.00 N / mm ２ A composite material characterized by:

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