Resin mortar

Abstract

To provide resin mortar which is excellent in flowability and 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 A having a particle diameter of 0.5 mm or less, a lightweight aggregate B having a particle diameter of more than 0.5 mm and 5 mm or less, and inorganic powder, wherein the content of the inorganic powder is 25 to 450 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. In addition, lightweight aggregate has a low specific gravity and is prone to water absorption, which poses the issue of material separation and a decrease in fluidity.

[0005] Therefore, an object of the present invention is to provide a resin mortar that has excellent fluidity, does not cause material segregation, is lightweight, and yet has sufficient strength development. [Means for solving the problem]

[0006] As a result of intensive research into the above-mentioned problems, the present inventors have found that by combining specific lightweight aggregates and adjusting the content of inorganic powder, a resin mortar can be obtained that has excellent fluidity and resistance to material separation and exhibits sufficient strength development.

[0007] That is, the present invention is as follows. [1] A resin mortar containing a thermosetting resin, a curing agent, lightweight aggregate A having a particle size of 0.5 mm or less, lightweight aggregate B having a particle size of more than 0.5 mm and 5 mm or less, and inorganic powder, wherein the content of the inorganic powder is 25 to 450 parts by mass per 100 parts by mass of the thermosetting resin. [2] The resin mortar according to [1], wherein the content of lightweight aggregate A is 20 to 280 parts by mass and the content of lightweight aggregate B is 1 to 45 parts by mass per 100 parts by mass of the thermosetting resin. [3] The resin mortar according to [1] or [2], wherein the inorganic powder is at least one inorganic powder selected from fly ash, calcium carbonate powder, silica powder, blast furnace slab powder, silica fume, amorphous aluminosilicate, cements, and gypsums. [4] The resin mortar according to [1] or [2], which has a density of 0.8 to 1.3 kg / L when hardened. [5] When hardened, the compressive strength at 28 days is 20 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 has excellent fluidity, does not cause material segregation, and is lightweight yet has sufficient strength development. 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 A having a particle size of 0.5 mm or less, lightweight aggregate B having a particle size of more than 0.5 mm and 5 mm or less, and inorganic powder.

[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 conditions 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 includes lightweight aggregate A with a particle size of 0.5 mm or less and lightweight aggregate B with a particle size of more than 0.5 mm and less than 5 mm. By using such lightweight aggregates in combination, it is possible to reduce weight, while also achieving good strength development and fluidity. In this specification, lightweight aggregate with a particle size of more than 0.5 mm and less than 5 mm refers to aggregate that passes through a 5 mm sieve and remains on a 0.5 mm sieve, and lightweight aggregate with a particle size of 0.5 mm or less refers to aggregate that passes through a 0.5 mm sieve.

[0016] The average particle size of lightweight aggregate A is preferably 0.1 to 0.45 mm, more preferably 0.15 to 0.4 mm, and even more preferably 0.2 to 0.35 mm. The average particle size of lightweight aggregate B is preferably 0.5 to 3 mm, more preferably 0.6 to 2 mm, and even more preferably 0.7 to 1.5 mm. When the average particle sizes of lightweight aggregates A and B are within the above ranges, it is easy to achieve both lightweight construction and good strength development while ensuring flowability. In this specification, the average particle size refers to the particle size (d50, median diameter) at which the cumulative frequency is 50% by mass.

[0017] The unit volume mass of lightweight aggregate A 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. The unit volume mass of lightweight aggregate B is preferably 0.05 to 0.4 kg / L, more preferably 0.1 to 0.35 kg / L, and even more preferably 0.15 to 0.3 kg / L. If the unit volume masses of lightweight aggregates A and B are within the above ranges, it is easy to achieve both light weight and strength development.

[0018] The content of lightweight aggregate A is preferably 20 to 280 parts by mass, more preferably 35 to 200 parts by mass, even more preferably 50 to 180 parts by mass, and particularly preferably 75 to 160 parts by mass, relative to 100 parts by mass of the thermosetting resin. The content of lightweight aggregate A is preferably greater than the content of lightweight aggregate B. If the content of lightweight aggregate A is within the above range, it is easy to ensure weight reduction, good strength development, and flowability. The content of lightweight aggregate B is preferably 1 to 45 parts by mass, more preferably 5 to 35 parts by mass, even more preferably 10 to 30 parts by mass, and particularly preferably 15 to 25 parts by mass, relative to 100 parts by mass of the thermosetting resin. If the content of lightweight aggregate B is within the above range, it is easy to ensure weight reduction, good strength development, and flowability. The total content of the lightweight aggregates A and B is preferably 50 to 250 parts by mass, more preferably 70 to 230 parts by mass, and even more preferably 100 to 200 parts by mass, from the viewpoint of making it easier to ensure lightweight construction and good strength development and fluidity.

[0019] The inorganic powder is not particularly limited as long as it is an inorganic powder other than metal powder. Examples of inorganic powders include fly ash, calcium carbonate powder, silica stone powder, blast furnace slab powder, silica fume, amorphous aluminosilicate, cements, and gypsum. Among these, fly ash, calcium carbonate powder, and silica fume are preferred as inorganic powders from the viewpoint of superior strength development. In this specification, inorganic powder refers to powder that passes through a 0.075 mm sieve.

[0020] The content of the inorganic powder is 25 to 450 parts by mass relative to 100 parts by mass of the thermosetting resin. If the total content of the inorganic powder 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 total content of the inorganic powder is preferably 50 to 400 parts by mass, more preferably 80 to 300 parts by mass, and even more preferably 100 to 250 parts by mass relative to 100 parts by mass of the thermosetting resin.

[0021] 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.).

[0022] 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.

[0023] The resin mortar of this embodiment preferably has a density of 0.8 to 1.3 kg / L when hardened, more preferably 0.85 to 1.2 kg / L, and even more preferably 0.9 to 1.1 kg / L. If the density of the resin mortar is within the above range, the load on the structure can be easily reduced.

[0024] The resin mortar of this embodiment has a compressive strength of 20 N / mm2 at 28 days after hardening, measured in a 20°C environment in accordance with JIS A 1108:2018 "Test method for compressive strength of concrete." 2 It is preferable that the resistance is 22N / mm or more. 2 More preferably, it is 25N / mm 2 The compressive strength of the resin mortar when hardened is 100 N / mm 2If 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.

[0025] 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 sufficient 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]

[0026] 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.

[0027] [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: calcium carbonate powder (commercially available) Inorganic fine powder B: Fly ash (blaine specific surface area 2500 cm 2 / g)

[0028] [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.

[0029] [Table 1]

[0030] [Evaluation method] Each item was evaluated by the following method. The evaluation results are shown in Table 2. No. 10 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. Liquidity (flow value) The flow value of resin mortar was measured in a 20°C environment in accordance with JIS R 5201:2015 "Physical Testing Methods for Cement" 12. Flow Test. Note that the 15-hit drop test was not performed, and fluidity was evaluated from the flow value obtained by pulling out. 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.

[0031] [Table 2]

[0032] The resin mortar of the example has a draw flow value of 180 mm or more, exhibits good fluidity, does not separate, and is lightweight with a density of 1.3 kg / L or less, while all have a flow rate of 20 N / mm 2 On the other hand, the resin mortars in the comparative examples were either unable to be mixed or caused material separation.

Claims

1. The composition includes a thermosetting resin, a curing agent, lightweight aggregate A having a particle size of 0.5 mm or less, lightweight aggregate B having a particle size of more than 0.5 mm and 5 mm or less, and inorganic powder, The resin mortar has a content of the inorganic powder of 25 to 450 parts by mass relative to 100 parts by mass of the thermosetting resin.

2. The content of the lightweight aggregate A is 20 to 280 parts by mass and the content of the lightweight aggregate B is 1 to 45 parts by mass relative to 100 parts by mass of the thermosetting resin. The resin mortar according to claim 1.

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

4. The resin mortar according to claim 1 or 2, having a density of 0.8 to 1.3 kg / L when hardened.

5. When hardened, the compressive strength at 28 days is 20 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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