Resin mortar

Abstract

To provide resin mortar which prevents material separation, and has high strength development property while being lightweight.SOLUTION: Resin mortar contains a thermosetting resin, a curing agent, a lightweight aggregate having a particle diameter of 0.5 mm or less, and at least two kinds of inorganic powders, wherein the lightweight aggregate having the particle diameter of 0.5 mm or less is 10 to 380 pts.mass with respect to 100 pts.mass of the thermosetting resin, and the content of the total of the inorganic powders is 50 to 480 pts.mass with respect to 100 pts.mass of the thermosetting resin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin mortar. [Background technology]

[0002] Resin mortars using epoxy resins and the like have traditionally been used for repairing and reinforcing defects in flooring materials, concrete structures, etc. Technologies have also been developed to reduce the weight of resin mortars by using artificial lightweight aggregates or natural lightweight aggregates, thereby reducing the load on structures (see, for example, Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 6-219806 [Patent Document 2] Japanese Patent Application Publication No. 10-194811 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-179134 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, as structures are expected to have longer lifespans, there has been a growing demand for higher strength repair and reinforcement materials. However, when attempts are made to reduce weight (density) by increasing the amount of lightweight aggregate mixed in order to reduce the load on the structure, there is a risk that the compressive strength will decrease and the required performance will not be met. Another issue is that lightweight aggregate has a low specific gravity, making it prone to material separation.

[0005] Therefore, an object of the present invention is to provide a resin mortar that does not separate and is lightweight yet has high strength development. [Means for solving the problem]

[0006] As a result of extensive research into the above-mentioned problems, the present inventors have found that by combining a specific lightweight aggregate with an inorganic powder, a resin mortar that is excellent in resistance to material separation and exhibits high strength development can be obtained.

[0007] That is, the present invention is as follows. [1] A resin mortar containing a thermosetting resin, a curing agent, lightweight aggregate having a particle size of 0.5 mm or less, and at least two types of inorganic powder, wherein the amount of the lightweight aggregate having a particle size of 0.5 mm or less is 10 to 380 parts by mass per 100 parts by mass of the thermosetting resin, and the total content of the inorganic powders is 50 to 480 parts by mass per 100 parts by mass of the thermosetting resin. [2] The resin mortar according to [1], wherein the inorganic powder is at least two inorganic powders selected from fly ash, calcium carbonate powder, silica powder, blast furnace slab powder, silica fume, amorphous aluminosilicate, cements, and gypsums. [3] The resin mortar according to [1] or [2], which has a density of 0.8 to 1.53 kg / L when hardened. [4] When hardened, the compressive strength at 28 days is 50 N / mm, measured at 20°C in accordance with JIS A 1108:2018 "Test method for compressive strength of concrete." 2 The resin mortar according to [1] or [2] above. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin mortar that does not segregate and that is lightweight yet has high strength development properties. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, one embodiment of the present invention will be described in detail.

[0010] The resin mortar of this embodiment contains a thermosetting resin, a curing agent, lightweight aggregate with a particle size of 0.5 mm or less, and at least two types of inorganic powders.

[0011] The thermosetting resin is not particularly limited as long as it is cured by the application of heat. Examples of the thermosetting resin include epoxy resin, phenol resin, urethane resin, urea resin, melamine resin, and unsaturated polyester resin. One type of thermosetting resin may be used alone, or two or more types may be used in combination. The thermosetting resin is preferably an epoxy resin from the viewpoint of being more excellent in strength development.

[0012] The epoxy resin is preferably, for example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a phenol novolac type epoxy resin, or a cresol novolac type epoxy resin. From the viewpoint of being more excellent in strength development, the epoxy resin is preferably a bisphenol A type epoxy resin.

[0013] The curing agent is not particularly limited as long as it accelerates the curing of the thermosetting resin, and can be selected depending on the thermosetting resin used. Examples of curing agents for epoxy resins include amine-based curing agents, imidazole-based curing agents, and acid anhydride-based curing agents. Examples of amine-based curing agents include aliphatic amines, aromatic amines, and polyamidoamines. As curing agents for epoxy resins, amine-based curing agents are preferred from the viewpoint of superior reactivity, and polyamidoamines are particularly preferred. One type of curing agent may be used alone, or two or more types may be used in combination.

[0014] The lightweight aggregate is not particularly limited as long as it satisfies the particle size described below, and examples thereof include perlite, which is an inorganic expandable aggregate obtained by firing and foaming obsidian, perlite, etc., fly ash balloons generated in thermal power plants, foamed glass particles (glass balloons), foamed resins formed from resin compositions and having air bubbles, etc. One type of lightweight aggregate may be used alone, or two or more types may be used in combination.

[0015] The lightweight aggregate is mainly composed of lightweight aggregate with a particle size of 0.5 mm or less. In this specification, lightweight aggregate with a particle size of 0.5 mm or less refers to aggregate that passes through a 0.5 mm sieve. Lightweight aggregate with a particle size of 0.5 mm or less preferably has an average particle size of 0.1 to 0.45 mm, more preferably 0.15 to 0.4 mm, and even more preferably 0.2 to 0.35 mm. If the average particle size is within the above range, it is easy to achieve both lightweight and good strength development while ensuring fluidity. In this specification, the average particle size refers to the particle size (d50, median diameter) at which the cumulative frequency is 50% by mass.

[0016] The unit volume mass of the lightweight aggregate having a particle size of 0.5 mm or less is preferably 0.4 to 0.8 kg / L, more preferably 0.45 to 0.75 kg / L, and even more preferably 0.5 to 0.7 kg / L, from the viewpoint of facilitating weight reduction.

[0017] The content of the lightweight aggregate having a particle size of 0.5 mm or less is 10 to 380 parts by mass relative to 100 parts by mass of the thermosetting resin. If the content of the lightweight aggregate having a particle size of 0.5 mm or less is outside the above range, the kneadability of the resin mortar may decrease, material separation may occur, and the density and strength development upon hardening may decrease. From the viewpoint of being less prone to material separation, being lightweight, and having even better strength development, the content of the lightweight aggregate having a particle size of 0.5 mm or less is preferably 50 to 300 parts by mass, more preferably 80 to 250 parts by mass, and even more preferably 100 to 200 parts by mass relative to 100 parts by mass of the thermosetting resin.

[0018] The lightweight aggregate may contain lightweight aggregate of over 0.5 mm, but from the viewpoint of achieving a better balance between density and strength development upon hardening, the content is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total mass of the lightweight aggregate, and may be substantially free of lightweight aggregate. In this specification, lightweight aggregate of over 0.5 mm refers to aggregate that remains on a 0.5 mm sieve.

[0019] The resin mortar of this embodiment contains at least two types of inorganic powders. The inorganic powders are not particularly limited as long as they are inorganic powders other than metal powders. Examples of inorganic powders include fly ash, calcium carbonate powder, silica powder, blast furnace slab powder, silica fume, amorphous aluminosilicates, cements, and gypsum. Among these, fly ash, calcium carbonate powder, and silica fume are preferred as inorganic powders, as they exhibit superior strength development. In this specification, inorganic powder refers to powders that pass through a 0.075 mm sieve.

[0020] The total content of the inorganic powders is 50 to 480 parts by mass relative to 100 parts by mass of the thermosetting resin. If the total content of the inorganic powders is outside this range, the kneadability of the resin mortar may decrease, material separation may occur, and the density and strength development upon hardening may decrease. From the viewpoint of being less prone to material separation, being lightweight, and having even better strength development, the total content of the inorganic powders is preferably 100 to 400 parts by mass, more preferably 120 to 300 parts by mass, and even more preferably 150 to 250 parts by mass relative to 100 parts by mass of the thermosetting resin.

[0021] When fly ash is used as the inorganic powder, the fineness is set to a Blaine specific surface area of ​​1500 to 8000 cm from the viewpoint of achieving better strength development. 2 / g is preferred, and 2000 to 6000 cm 2 From the viewpoint of achieving even better strength development, the content of fly ash is preferably 25 to 250 parts by mass, more preferably 50 to 200 parts by mass, and even more preferably 70 to 150 parts by mass relative to 100 parts by mass of the thermosetting resin. The mass proportion of fly ash in the inorganic powder (mass%, [mass of fly ash] / [mass of inorganic powder]×100) is preferably 35 to 65 mass%, more preferably 40 to 60 mass%, and even more preferably 45 to 55 mass%, from the viewpoint of achieving even better strength development.

[0022] When calcium carbonate powder is used as the inorganic powder, the content of the calcium carbonate powder is preferably 25 to 250 parts by mass, more preferably 50 to 200 parts by mass, and even more preferably 70 to 150 parts by mass relative to 100 parts by mass of the thermosetting resin, from the viewpoint of achieving even better strength development. The mass ratio of calcium carbonate powder to inorganic powder (mass %, [mass of calcium carbonate powder] / [mass of inorganic powder]×100) is preferably 35 to 65 mass %, more preferably 40 to 60 mass %, and even more preferably 45 to 55 mass %, from the viewpoint of achieving even better strength development.

[0023] The resin mortar of this embodiment may contain other components than those described above as long as the effects of the present invention are not impaired. Examples of such components include expanding agents, foaming agents, antifoaming agents, waterproofing agents, rust inhibitors, shrinkage reducing agents, thickeners, water retention agents, pigments, water repellents, efflorescence inhibitors, fibers, and various aggregates (crushed sand, river sand, sea sand, etc.).

[0024] The method for producing the resin mortar of this embodiment is not particularly limited, and the resin mortar can be produced by mixing using a mixer such as a hand mixer, a pan mixer, a twin-shaft mixer, a line mixer, a dicross mixer, or any other commercially available general-purpose mortar mixer.

[0025] The resin mortar of this embodiment preferably has a density of 0.8 to 1.53 kg / L, more preferably 0.9 to 1.4 kg / L, and even more preferably 1.0 to 1.3 kg / L, when hardened. If the density of the resin mortar is within the above range, the load on the structure can be easily reduced.

[0026] The resin mortar of this embodiment has a compressive strength of 50 N / mm2 at 28 days of age, measured at 20°C in accordance with JIS A 1108:2018 "Test method for compressive strength of concrete" when hardened. 2 It is preferable that the resistance is 55N / mm or more. 2 More preferably, it is 60N / mm 2More preferably, it is 62 N / mm or more. 2 It is particularly preferable that the compressive strength of the resin mortar when hardened is 100 N / mm or more. 2 If the compressive strength of the resin mortar is within the above range, sufficient strength can be obtained, and therefore the resin mortar can be suitably used for repairing and reinforcing structures.

[0027] The resin mortar can be hardened by treatment such as heating or adding a hardener. The resin mortar of this embodiment does not separate and exhibits high strength while being lightweight. Therefore, it can reduce the load on structures and extend their lifespan, and can be suitably used for repairing and reinforcing structures. [Example]

[0028] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these. All examples were carried out in an environment of 20°C.

[0029] [material] Thermosetting resin: Bisphenol A epoxy resin (manufactured by Nisshin Seiki Co., Ltd.) Hardener: Polyamidoamine hardener (manufactured by Nisshin Seiki Co., Ltd.) Lightweight aggregate A: Perlite A (average particle size 0.3 mm (grain size 0.5 mm or less), unit volume mass 0.6 kg / L) Lightweight aggregate B: Perlite B (average particle size 1.0 mm (particle size 0.5 mm to 5 mm), unit volume mass 0.2 kg / L) Inorganic fine powder A: Fly ash (blaine specific surface area 2500 cm 2 / g) Inorganic fine powder B: calcium carbonate powder (commercially available)

[0030] [Preparation of resin mortar] The mixture was designed with the proportions shown in Table 1 relative to 100 parts by mass of thermosetting resin. The thermosetting resin and curing agent were mixed using a hand mixer in a 20°C environment, and then the remaining ingredients were added and mixed to prepare approximately 1 L of resin mortar.

[0031] [Table 1]

[0032] [Evaluation method] Each item was evaluated by the following method. The evaluation results are shown in Table 2. Nos. 6 and 9 could not be kneaded, so various evaluation tests were not carried out. ·Material separation resistance The mixed resin mortar was filled into a φ50 x 100 mm formwork and sealed and cured in a 20°C environment for 28 days. After that, when the formwork was removed, the specimens were visually inspected to see if any separation had occurred. If the individual material components formed layers, it was judged that separation had occurred. Density (unit mass) The density (kg / L) was measured by measuring the volume and mass of a compressive strength test specimen (φ50 × 100 mm). Compression strength The compressive strength at 28 days of age was measured in accordance with JIS A 1108:2018 "Testing Method for Compressive Strength of Concrete." The specimens were 50 mm in diameter and 100 mm in height. The specimens were sealed and cured until 28 days of age, always cured in a constant temperature bath at 20°C.

[0033] [Table 2] TIFF2025136214000002.tif83121

[0034] The resin mortar of the example did not separate, was lightweight with a density of less than 1.55 kg / L, and had a strength of 50 N / mm 2 On the other hand, the resin mortars of the comparative examples were unable to be kneaded in the first place, suffered from material separation, had high density, and did not have excellent compressive strength.

Claims

1. The composition comprises a thermosetting resin, a curing agent, lightweight aggregate having a particle size of 0.5 mm or less, and at least two types of inorganic powders; The lightweight aggregate having a particle size of 0.5 mm or less is 10 to 380 parts by mass relative to 100 parts by mass of the thermosetting resin, The resin mortar has a total content of the inorganic powder of 50 to 480 parts by mass relative to 100 parts by mass of the thermosetting resin.

2. The resin mortar according to claim 1, wherein the inorganic powder is at least two inorganic powders selected from fly ash, calcium carbonate powder, silica powder, blast furnace slab powder, silica fume, amorphous aluminosilicate, cements, and gypsums.

3. The resin mortar according to claim 1 or 2, having a density of 0.8 to 1.53 kg / L when hardened.

4. When hardened, the compressive strength at 28 days is 50 N / mm, measured at 20°C in accordance with JIS A 1108:2018 "Test method for compressive strength of concrete". ２ The resin mortar according to claim 1 or 2.

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