JP2018154511A - Rapid curing polymer cement composition and rapid curing polymer cement mortar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rapid curing polymer cement composition and a rapid curing polymer cement mortar which are excellent in flowability, and excellent in initial strength development and strength development after an initial stage.SOLUTION: The rapid curing polymer cement composition contains rapid curing cement, gypsums, quick lime, a polymer for cement, and fine aggregate including fine aggregate A of a particle diameter of 0.6 mm or more and fine aggregate B of a particle diameter of 0.09 mm or more and less than 0.3 mm. In the composition, a mass ratio of the gypsums and the quicklime([mass of gypsums]/[mass of quicklime]) is 1.1 or more, a total content of the fine aggregate A and the fine aggregate B is 50 parts by mass or more with respect to the total mass of the fine aggregate as 100 parts by mass, and a mass ratio of the fine aggregate A and the fine aggregate B ([mass of fine aggregate A]/[mass of fine aggregate B]) is 1.5 to 5.SELECTED DRAWING: None

Description

  The present invention relates to a fast setting polymer cement composition and a fast setting polymer cement mortar.

  In order to solve problems such as cracking and peeling of concrete structures, such as drying shrinkage, chemical resistance, and strength caused by cement hydrate, polymer cement mortar containing various polymers in mortar has been developed. Widely used as a construction material. However, in conventional polymer cement mortar, it takes a long time for the cement to harden, and this tendency is more prominent especially at low temperatures. Therefore, the conventional polymer cement mortar has not always been sufficient for construction on site.

  In recent years, a polymer cement mortar using a rapid setting cement having a high setting speed has been proposed in order to accelerate the setting of the cement (for example, Patent Document 1).

JP 2013-234489 A

  By the way, since the polymer cement mortar is used as a repair / reinforcement material, it is required to satisfy not only the curing rate but also good fluidity and compressive strength. In order to further increase the compressive strength of the polymer cement, the cement hardened body is densified by reducing the water cement ratio. However, when the water cement ratio is reduced, the fluidity tends to deteriorate, and it is difficult to achieve both good fluidity and compressive strength.

  An object of the present invention is to provide a fast-curing polymer cement composition and a fast-curing polymer cement mortar that are excellent in fluidity and excellent in initial strength development and initial strength development.

As a result of intensive studies on the above problems, the present inventors combined fast-hardening cement, gypsum, and quicklime, and further blended a specific amount of fine aggregate having a specific particle size to achieve good fluidity and strength development. It was found that both can be achieved. That is, the present invention is, for example, the following fast-curing polymer cement composition and fast-curing polymer cement mortar [1] to [6].
[1] Fast-hardening cement, gypsum, quicklime, polymer for cement, fine aggregate A having a particle size of 0.6 mm or more and fine aggregate B having a particle size of 0.09 mm or more and less than 0.3 mm A quick-hardening polymer cement composition containing a fine aggregate, wherein the mass ratio of gypsum and quicklime ([mass of gypsum] / [mass of quicklime]) is 1.1 or more; The total content of A and fine aggregate B is 50 parts by mass or more, where the total mass of fine aggregate is 100 parts by mass, and the mass ratio of fine aggregate A and fine aggregate B ([fine aggregate A [Mass] / [Mass of fine aggregate B]) is 1.5-5.
[2] The composition according to [1], wherein the total content of gypsum and quicklime is 2.5 to 20 parts by mass, where the total mass of quick-setting cement, gypsum and quicklime is 100 parts by mass. .
[3] The composition according to [1] or [2], wherein the mass ratio of gypsum and quicklime is 1.8 to 4.
[4] The total mass of fast-curing cement, gypsum and quicklime is 100 parts by mass, 10 to 50 parts by mass of cement polymer, and 200 to 350 parts by mass of fine aggregate are included. A composition according to any one of the above.
[5] The composition according to any one of [1] to [4], further comprising a water reducing agent.
[6] The composition according to any one of [1] to [5] and water, and 20 to 45 mass of water, with the total mass of fast-setting cement, gypsum and quicklime being 100 parts by mass. Quick-hardening polymer cement mortar.

  ADVANTAGE OF THE INVENTION According to this invention, the quick-hardening polymer cement composition and quick-hardening polymer cement mortar which are excellent in fluidity | liquidity and are excellent also in the initial stage strength expression property and the strength expression property after the initial stage can be provided.

  Hereinafter, although an embodiment of the present invention is described in detail, the present invention is not limited to this.

  The fast-curing polymer cement composition of the present embodiment includes a fast-curing cement, gypsum, quicklime, a cement polymer, fine aggregate A having a particle size of 0.6 mm or more, and a particle size of 0.09 mm or more and 0.0. And a fine aggregate including a fine aggregate B that is less than 3 mm.

The fast-curing cement preferably contains calcium aluminate as an active ingredient, and includes 11CaO · 7Al ₂ O ₃ · CaX ₂ (X represents a halogen atom) or 3CaO · 3Al ₂ O ₃ · CaSO ₄ (auin). What contains as an active ingredient is more preferable. 11CaO · 7Al ₂ O ₃ · CaX ₂ is a so-called calcium aluminate halide cement. The halogen atom is preferably a fluorine atom. Auin is also called calcium sulfoaluminate cement (auin cement). These are called super fast cements and are marketed under the trade name jet cement or super jet cement. Auin-based cement is most preferable as the fast-curing cement.
As calcium aluminate, in addition to this, when CaO is represented by C, Al ₂ O ₃ by A, and Fe ₂ O ₃ by F, C ₃ A, C ₂ A, C ₁₂ A ₇ , C ₅ A ₃ , Calcium aluminate having a mineral composition denoted as CA, C ₃ A ₅ or CA _2, calcium aluminoferrite denoted as C ₂ AF, C ₄ AF, etc., alumina cement, and SiO ₂ , K ₂ O, Fe ₂ O ₃ , TiO _2, or the like in which they are dissolved or combined are included. Calcium aluminates may be crystalline or amorphous. As the quick-hardening cement, a material obtained by adding a quick-hardening admixture prepared by blending these calcium aluminates and inorganic salts such as gypsum to Portland cement can also be used. A quick-hardening cement may be used individually by 1 type, and may use 2 or more types together.

  The fast-curing cement may be obtained by replacing part of the fast-curing cement with Portland cement. As Portland cement, normal Portland cement, early-strength Portland cement, ultra-early strong Portland cement, moderately hot Portland cement, low heat Portland cement, etc. can be used. The content of Portland cement is preferably 20 parts by mass or less, preferably 10 parts by mass or less, with respect to 100 parts by mass of the fast-curing cement, from the viewpoint of securing a better pot life, early strength development, and durability against repeated loading. Is more preferable.

The gypsum is not particularly limited, and examples thereof include anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum. The gypsum is not particularly limited in its raw material history, and may be various types of chemical gypsum, for example. As the gypsum, type II anhydrous gypsum may be used from the viewpoint that the medium-to-long-term strength development is more likely to be promoted. One type of gypsum may be used alone, or two or more types may be used in combination. The particle size of the gypsum is not particularly limited, but is preferably 3000 to 10,000 cm ² / g in terms of the specific surface area of the brane from the viewpoint of obtaining a reaction activity that is easier to control.

The quicklime is not particularly limited as long as it has hydration reaction activity, and any quicklime may be used. The quick lime according to the present embodiment may be a calcium oxide simple substance or a calcined lime burned with free calcium oxide as a main component. Examples of the quick lime include quick lime such as soft calcined quick lime, medium calcined quick lime, hard calcined quick lime, and extremely hard calcined quick lime. A quicklime may be used individually by 1 type, and may use 2 or more types together. Although the particle size of quicklime is not specifically limited, 2000-6000 cm < ² > / g is preferable at a Blaine specific surface area from a viewpoint of obtaining the reaction activity which is easier to control.

  The total content of gypsum and quicklime is 2.5 to 20 parts by mass, with the total mass of fast-setting cement, gypsum and quicklime being 100 parts by mass, from the viewpoint that better initial strength development is obtained. Is preferable, 5-15 mass parts is more preferable, and 5-10 mass parts is still more preferable.

  The mass ratio of gypsum and quicklime ([mass of gypsum] / [mass of quicklime]) is 1.1 or more, and preferably 20 or less. The mass ratio of gypsum and quicklime is preferably, for example, 1.1 to 15, more preferably 1.5 to 5, still more preferably 1.8 to 4, and particularly preferably 1.8 to 3.5. If the mass ratio of gypsum and quicklime is in the above range, good fluidity can be easily ensured, and the strength development from the beginning can be further improved.

The polymer for cement is preferably a polymer specified in JIS A 6203: 2015 “Cement-mixing polymer dispersion and re-emulsifying powder resin”. Examples of such cement polymers include polymer dispersions and re-emulsifying powder resins. Examples of the polymer dispersion include synthetic rubbers such as styrene butadiene rubber; natural rubbers; rubber asphalts; ethylene vinyl acetates; acrylate esters; resin asphalts. Among them, the polymer dispersion is preferably a synthetic rubber system, an ethylene vinyl acetate system, and an acrylate system, and specifically, synthetic rubber latex, polyacrylic acid ester, and ethylene vinyl acetate are more preferable. Examples of the re-emulsifying powder resin include synthetic rubbers such as styrene butadiene rubber; acrylate esters; ethylene vinyl acetates; vinyl acetate / versaic acid vinyl esters; vinyl acetate / vinyl versatate / acrylates. As the polymer for cement, a polymer dispersion may be used, a re-emulsified powder resin may be used, or a polymer dispersion and a re-emulsified powder resin may be used in combination.
Among the above polymers for cement, a polymer dispersion of styrene butadiene rubber and / or a re-emulsified powder resin is preferable from the viewpoint that the adhesion to concrete is further improved. Styrene butadiene rubber is a kind of synthetic rubber obtained by copolymerization of styrene and butadiene, and the quality can be appropriately adjusted depending on the styrene content and the vulcanization amount. For mixing with cement, the amount of bound styrene is often 50 to 70% by mass, and is used with improved stability and adhesiveness. As the cement polymer, one kind may be used alone, or two or more kinds may be used in combination.

  The content of the polymer for cement is preferably 10 to 50 parts by mass, more preferably 10 to 40 parts by mass, more preferably 10 to 35 parts by mass in terms of solid content, with the total mass of fast-setting cement, gypsum and quicklime being 100 parts by mass. Part by mass is more preferred, 12.5 to 30 parts by mass is even more preferred, and 15 to 25 parts by mass is particularly preferred. If the content of the polymer for cement is within the above range, it is easy to ensure sufficient adhesion strength with concrete and the strength development tends to be difficult to decrease.

  Examples of the fine aggregate include river sand, quartz sand, crushed sand, cryolite, limestone sand, and slag aggregate. Among these fine aggregates, it is preferable to use fine aggregates such as silica sand and limestone sand whose particle size is adjusted without containing fine powder or coarse aggregate. The fine aggregate has a particle diameter of less than 5 mm that is normally used (5 mm sieve passage). One type of fine aggregate may be used alone, or two or more types may be used in combination.

  The fast-setting polymer cement composition of the present embodiment includes a fine aggregate A having a particle size of 0.6 mm or more and a fine aggregate B having a particle size of 0.09 mm or more and less than 0.3 mm. The particle size of the fine aggregate A is preferably less than 5 mm. Fine aggregate A passes through a sieve having an opening of 5 mm and remains on the sieve having an opening of 0.6 mm, and fine aggregate B passes through a sieve having an opening of 0.3 mm and has an opening of 0.09 mm. It stays on the sieve.

  The total content of fine aggregate A and fine aggregate B is 50 parts by mass or more, preferably 75 parts by mass or more, and more preferably 80 parts by mass or more, with the total mass of the fine aggregate being 100 parts by mass. The upper limit of the total content of the fine aggregate A and the fine aggregate B may be 100 parts by mass, or 90 parts by mass or less, where the total mass of the fine aggregate is 100 parts by mass. If the total content of the fine aggregate A and the fine aggregate B is within the above range, it is easy to ensure better fluidity.

  The mass ratio of fine aggregate A and fine aggregate B ([mass of fine aggregate A] / [mass of fine aggregate B]) is 1.5 to 5, preferably 1.5 to 3. .8 to 2.5 is more preferable. If the mass ratio of the fine aggregate A and the fine aggregate B is within the above range, it is easy to ensure better fluidity and long-term strength development.

  The content of the fine aggregate is preferably 200 to 350 parts by mass, more preferably 225 to 325 parts by mass, and even more preferably 250 to 310 parts by mass, with the total mass of the quick setting cement, gypsum and quicklime being 100 parts by mass. preferable. If the content of the fine aggregate is within the above range, the pot life can be easily secured, and better strength development can be easily obtained.

  The quick-setting polymer cement composition of the present embodiment may contain a water reducing agent. The water reducing agent includes a high performance water reducing agent, a high performance AE water reducing agent, an AE water reducing agent, and a fluidizing agent. Examples of such a water reducing agent include water reducing agents defined in JIS A 6204: 2011 “Chemical admixture for concrete”. Examples of the water reducing agent include polycarboxylic acid water reducing agents, naphthalene sulfonic acid water reducing agents, lignin sulfonic acid water reducing agents, melamine water reducing agents, and acrylic water reducing agents. Of these, naphthalenesulfonic acid-based water reducing agents are preferred. A water reducing agent may be used individually by 1 type, and may use 2 or more types together.

  The content of the water reducing agent is from 0.5 to 5 parts by mass, with 100 parts by mass as the total mass of the quick-hardening cement, gypsum and quick lime, from the viewpoint that fluidity is easily secured and the initial strength development is further excellent. 1 to 3.5 parts by mass is more preferable.

  The fast-curing polymer cement composition of the present embodiment may contain a setting retarder. By including a setting retarder, it is easy to ensure pot life even when the kneading temperature of the polymer cement mortar becomes high, such as in summer. Examples of the setting retarder include organic acids such as citric acid, gluconic acid, malic acid and tartaric acid or salts thereof; boric acid such as boric acid and sodium borate; phosphate; alkali metal carbonate; Inorganic salts such as carbonates; saccharides. Among these, citric acid, citrate, tartaric acid, tartrate, and alkali metal carbonate are preferable. The setting retarder may be a powder or a liquid (for example, in the form of an aqueous solution, an emulsion, or a suspension). A set retarder may be used individually by 1 type, and may use 2 or more types together.

  The content of the setting retarder is 0.5 to 5 parts by mass in terms of the active ingredient (solid component) in the setting retarder, where the total mass of the quick-hardening cement, gypsum and quicklime is 100 parts by mass. Is preferable, and it is more preferable that it is 1-3 mass parts. When the content of the setting retarder is within the above range, the pot life can be easily secured, and the initial strength development is unlikely to decrease.

  The quick-setting polymer cement composition of the present embodiment may use various admixtures as long as the effects of the present invention are not impaired. Examples of the admixture include antifoaming agents, waterproofing agents, rust preventives, shrinkage reducing agents, thickeners, water retention agents, pigments, water repellency, whitening prevention agents, and fibers.

  The quick-hardening polymer cement composition of this embodiment can also be made into a concrete composition using coarse aggregate. Examples of the coarse aggregate include river gravel, land gravel, crushed stone, artificial coarse aggregate, slag coarse aggregate, recycled coarse aggregate, and the like. The coarse aggregate has a particle size of 5 mm or more (5 mm sieve residue), preferably 25 mm or less. The content of the coarse aggregate can be appropriately set within the range of the amount usually used for preparing concrete.

  The fast-curing polymer cement composition of the present embodiment can be prepared by mixing with a commonly used kneading tool, and the tool is not particularly limited. Examples of the kneading instrument include a Hobart mixer, a hand mixer, a tilting cylinder mixer, and a biaxial mixer.

  The fast-curing polymer cement composition of the present embodiment can be mixed with water and prepared as mortar or concrete, and the water content may be appropriately adjusted according to the application. The content of water is preferably 20 to 50 parts by mass, more preferably 22.5 to 40 parts by mass, and even more preferably 25 to 40 parts by mass, with the total mass of fast-setting cement, gypsum and quicklime being 100 parts by mass. preferable. If the water content is within the above range, it is easier to secure fluidity, and it is easy to suppress the occurrence of material separation, the increase in shrinkage of the cured body, and the decrease in initial strength development.

  Preparation of the quick-hardening polymer cement mortar of this embodiment can use the same kneading tool as a normal polymer cement mortar, and is not specifically limited. As a kneading instrument, for example, the above-described one can be used.

  The fast-curing polymer cement composition of the present embodiment and the fast-curing polymer cement mortar using the composition have good fluidity, excellent initial strength development, and stable strength after the initial stage. Since the expression can be exhibited, it is excellent in workability and durability. Moreover, since the quick-hardening polymer cement composition of this embodiment and the quick-hardening polymer cement mortar using the same use the fast-hardening cement, the hardening speed is high and the working time can be shortened. Therefore, such a fast-curing polymer cement composition and a fast-curing polymer cement mortar using the composition can also be used as a repair / reinforcing material for concrete structures, roads, and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to this.

  Table 1 shows materials used, and Table 2 shows fine aggregates adjusted in particle size. The fine aggregates were adjusted to those of each particle size distribution by sieving with various sieves.

[Formulation design]
The total mass of fast-curing cement, gypsum and quicklime is 100 parts by mass, and quicklime, gypsum, and fine aggregate are blended and designed as shown in Table 3, and one part by weight of water reducing agent and setting retarder are added. Prepared. Various types of polymer cement mortars were prepared by putting the above powder into a cement polymer (solid content conversion) prepared with water in the amount shown in Table 3 and kneading with a hand mixer for 90 seconds.

[Evaluation method]
-Consistency The fluidity of the polymer cement mortar was evaluated by measuring the consistency. The consistency is JIS R 5201: 2015 [“Cement physical testing method” 12. According to the flow test], it was measured in a 20 ° C. environment. Consistency was evaluated as good (◯) when the flow of 15 strokes / drawing flow was 1.35 or more, and evaluated as poor (×) when the flow was less than 1.35.

-Compressive strength The strength development property of the polymer cement mortar was evaluated by measuring the compressive strength of the cured product. The compressive strength was measured according to JSCE-G 505-2010 “Method for testing compressive strength of mortar or cement paste using a cylindrical specimen (draft)” at 2 hours and 28 days of age. . The dimensions of the specimen were 50 mm in diameter and 100 mm in height. Curing was first carried out in a constant temperature bath at 20 ° C., and after demolding the next day, it was cured in air at 20 ° C. until the age of age. If the material age was 10 N / mm ² or more at 2 hours of age and 45 N / mm ² or more at 28 days of material age, it was judged that strength development was good.

[result]
Table 4 shows the test results. It was shown that the polymer cement mortars of the examples were excellent in fluidity and excellent in initial strength development and initial and subsequent strength development, and these properties could be compatible. On the other hand, the polymer cement mortar in which the ratio of gypsum and quicklime and the particle size or content of fine aggregate are not appropriate cannot achieve both fluidity and strength development. In addition, the polymer cement mortar using the early strong cement was not cured at the age of 2 hours.

Claims (6)

Fine bones including fast-setting cement, gypsum, quicklime, polymer for cement, fine aggregate A having a particle size of 0.6 mm or more and fine aggregate B having a particle size of 0.09 mm or more and less than 0.3 mm A fast-curing polymer cement composition comprising:
The mass ratio of the gypsum and the quick lime ([mass of gypsum] / [mass of quick lime]) is 1.1 or more,
The total content of the fine aggregate A and the fine aggregate B is 50 parts by mass or more when the total mass of the fine aggregate is 100 parts by mass,
The composition whose mass ratio ([mass of fine aggregate A] / [mass of fine aggregate B]) of the said fine aggregate A and the said fine aggregate B is 1.5-5.   2. The total content of the gypsum and the quicklime is 2.5 to 20 parts by mass, where the total mass of the quick-hardening cement, the gypsum, and the quicklime is 100 parts by mass. Composition.   The composition according to claim 1 or 2, wherein a mass ratio of pre-gypsum and said quicklime is 1.8-4. The total mass of the quick-setting cement, the gypsum and the quicklime is 100 parts by mass,
The composition according to any one of claims 1 to 3, comprising 10 to 50 parts by mass of the cement polymer and 200 to 350 parts by mass of the fine aggregate.   Furthermore, the composition as described in any one of Claims 1-4 containing a water reducing agent. Including the composition according to any one of claims 1 to 5 and water,
A fast-hardening polymer cement mortar containing 20 to 45 parts by weight of the water, where the total weight of the quick-hardening cement, the gypsum and the quicklime is 100 parts by weight.