JP3190277B2 - Cement composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement composition, and more particularly to a cement composition that can be suitably used as a coating for preventing deterioration or preventing rusting of concrete, mortar, slate, steel frame and the like.

[0002]

2. Description of the Related Art In recent years, especially after the problem of acid rain has risen, it has reached a wide range of areas, such as dams and seawalls, bridges, tunnels, and other general building facilities, sewage pipes, tetrapots, telephone poles, and the like. Up to now, the problems of deterioration and corrosion of concrete and its secondary products used for various civil engineering and building structures, and metal building materials, etc., have been highlighted, and concrete in the concrete that weakens the building structures following this Various coating materials have been tried to prevent rusting or deterioration or to prevent rust.

The first of the functions required of such a coating material is
Blocks water and outside air from entering the concrete, thereby neutralizing or degrading concrete due to the effects of airborne salts or carbon dioxide, or acid rain or acid soil, or corroding reinforcing steel or steel frames in structures. The purpose is to form a strong and dense protective film that can prevent the formation of a protective film.

[0004] The second function required for such a coating material is that it is possible to manage and adjust the fluidity and the like so that ordinary on-site construction such as spraying and brushing can be easily performed.

Conventionally, one of the earliest methods used for such a measure is a paint, especially an organic solvent-based paint which is said to have a higher coating strength than a water-soluble or water-dispersed one. is there. However, although the cured film made of paint is excellent in blocking water and air, dew condensation is likely to occur due to the temperature difference between the inside and outside of the building, and since most of the film is made of synthetic polymer, it is decomposed by light, Deterioration is inevitable. Furthermore, there is a problem regarding the inhalation toxicity of the organic solvent.

In order to cope with this, a coating material mainly composed of an inorganic component substantially free of an organic solvent or a synthetic resin has been developed. Many proposals have been made on cement-based compositions capable of forming a cured product having a higher density and strength than those of a cement-based composition.

In the first place, a so-called blast furnace cement in which granulated blast furnace slag is blended with hydraulic cement typified by Portland cement is used to produce a high-strength concrete hardened material having a long-term corrosion resistance due to the potential alkali hydraulicity of the slag. Giving is well known in the art. In recent developments, the mainstream is to improve the quality by further blending various kinds of admixtures with this blast furnace cement. For example, Japanese Patent Application Laid-Open No. 7-61852 discloses Portland cement and granulated blast furnace slag. A cement composition containing fine powder, blast furnace slowly cooled slag, and lithium nitrite is disclosed. According to such a composition, the lithium ions derived from lithium nitrite during the hydration reaction react with the surface portion of the blast furnace slowly cooled slag of the crystalline powder to form a concrete material structure having a strong bonding force. It is said that it can be obtained.

On the other hand, as disclosed in JP-A-8-34644, the composition is almost the same as lime, aluminum oxide, iron oxide, silica, etc. The material was heated and melted at 1250 ° C. or higher, and then rapidly cooled to obtain a melt vitrified to a specific crystal structure.
In some cases, acid-resistant and high-strength concrete can be obtained by adding 0% by weight.

Further, a method has been attempted in which a so-called polymer cement obtained by mixing an emulsion of a synthetic high molecular polymer having excellent adhesion to a substrate and flexibility is coated as a coating material on the surface of a building material.

As described above, taking effective measures to protect building facilities and civil engineering structures generally made of concrete, mortar, slate, steel frame, etc. from environmental changes over a long period of time is currently required in the industry. It is one of the urgent tasks in the field.

[0011]

However, the conventionally proposed cement compositions for coating materials, admixtures for modifying concrete, or polymer cements have the following problems during the coagulation and hardening reactions of cement. Since it does not solve the problems, it is considered that improvement of the strength, chemical resistance, and the like of the obtained concrete cannot be so expected.

That is, when water is added to Portland cement or the like to form a paste, a hydration reaction starts immediately and coagulation occurs. After loss of fluidity, a calcium silicate hydrate gel or the like is formed and hardened. In that case, the hydrate gel generated by this hydration reaction with water, that is, ettringite, is adsorbed and absorbed by other aggregates, slag, silica sand, admixture, etc., including cement components such as lime and silica stone. However, if the particle size of ettringite is large and coarse, these various components do not disperse finely, and as a result, the physical structure of the concrete or mortar after curing is not so large. While not becoming dense, the amount of calcium hydroxide and calcium carbonate generated over time from inside the ettringite increases and the chemical stability inside the concrete is impaired, and as a result, it also causes the weakness of concrete etc. It becomes. And, among the techniques proposed in the related art, there is no technique that focuses on this point and aims at improvement.

Further, in the polymer cement, since a cationic resin emulsion is exclusively used, it is difficult to control the reaction between the strongly alkaline cement hydrate and the cationic emulsion, and the hydration reaction causes the fluid to flow more quickly. The property is lost, and as a result, it is not suitable for general repair and topcoating.

Accordingly, the present invention provides a method for producing a hydrate gel in which various constituents are finely dispersed during a hydration reaction at the time of setting and hardening of cement. The concrete or its coating is radically denatured and denatured to a strong one, and as a result, it can be suitably used as a coating for deterioration prevention or rust prevention of concrete, mortar, slate, steel frame, etc., and An object of the present invention is to provide a cement composition which can maintain a fluidity even after addition of a resin emulsion and can produce a coating material which is easy to apply and has good adhesion and stiffness.

[0015]

Means for Solving the Problems A cement composition according to the present invention for solving the above problems comprises 30 to 40 parts by weight of Portland cement, 10 parts by weight of granulated blast furnace slag, 5 to 15 parts by weight. Resin emulsion and ammonium chloride
, Calcium chloride, potassium carbonate, iron sulfate, and
0.3 to 0.5 parts by weight of an aqueous solution of magnesium chloride (hereinafter referred to as "catalyst solution").

As described above, in the cement composition of the present invention, an ion-rich catalyst solution adjusted to contain various cationic metal ions by adding various inorganic compounds can be used for portland cement and blast furnace water granulation. It is blended with blast furnace cement made of slag, resin emulsion and the like. The present inventors mixed and cured the above catalyst solution together with blast furnace cement, polymer cement, etc., to obtain concrete or mortar modified into a dense and strong structure with a high bonding force, which was effective in blocking water and air. It has been found that it is excellent and has good adhesion or flexibility due to the presence of the resin emulsion, hardly causes hair cracks and the like, and can be suitably used as a coating material having good fluidity or workability after a hydration reaction. Was.

Although the theory is not necessarily clear, the high electron concentration of the catalyst solution acts to finely disperse the anionic ettringite and other compounds produced by the hydration reaction, and as a result, the ettringite or blast furnace It is considered that the particle size of the granulated slag and the like becomes minute and a dense and strong structure can be obtained.

On the other hand, on the other hand, the self-hardening reactivity in the alkali which the granulated blast furnace slag has potentially contributes to the synergistic effect, thereby further increasing the denseness or strength of the obtained concrete structure. It is also considered to be.

At this time, the granulated blast furnace slag includes 6,
It is preferable to use a powder finely divided to about 000 to 8,000 branes. The surface area for self-reaction, which is alkaline hydraulic, increases, and the resulting coated film becomes denser and stronger, and disperses other aggregates, silica sand, resin emulsion, or ettringite, etc. This is because it becomes easy to enter between the adsorbed substances, filling these gaps, and further promoting the densification of the obtained coated coating film.

On the other hand, the cationic resin emulsion is also stabilized by the high concentration of cations in the catalyst solution, so that the reactivity with the anionic cement hydrate gel is suppressed, and It is considered that the properties of the resin emulsion and the cement hydrate, which have been difficult in the past, can be easily managed, and the workability is excellent.

At this time, the resin emulsion is preferably a cationic one such as an epoxy-based or acrylic-based resin which can be electrostatically absorbed with the cement component, but an anionic or nonionic resin emulsion can also be used. . Also, as the solid content concentration of the resin emulsion,
For example, those having 45 to 50% can be suitably used.

[0022]

[0023]

[0024]

[0025]

[0026]

An example of a method for preparing this catalyst solution will be described. First, 1 to 3 parts by weight of ammonium chloride and 1 to 4 parts by weight of potassium carbonate are added to 100 parts by weight of water from which calcium (chlorine) has been removed. Are added to water at the same time, for example, by mixing them in advance. Simultaneous addition promotes ionization of these components,
This is because solution adjustment becomes easy.

After the addition, the mixture is stirred for about 12 to 18 minutes and the water temperature is kept at 3 to 10 ° C. By keeping the water temperature in this temperature range, the action of the obtained solution can always be stably obtained.

Then, 3 to 10 parts by weight of iron sulfate is added thereto, and the mixture is stirred for about 12 to 18 minutes. When this iron sulfate is added to water, the water temperature is set to 3 to 3 for the same reason as described above.
Keep at 10 ° C.

Next, 70 to 150 parts by weight of calcium chloride
And mix for about 25-35 minutes.

[0031]

Then, the obtained solution is further added to 10 to 15
While standing time, the water temperature 15 to 20 ° C., preferably cooled to 17-18 ° C., and thereafter, 3 to 7 parts by weight of Ma chloride
The addition of gnesium will ultimately result in the catalyst solution used in the composition of the present invention.

The cement composition of the present invention further contains 6 as an aggregate within a range where the object of the present invention is achieved.
No. 8 to 8 or fine powder of silica sand, or water reducing agents and rust inhibitors as various admixtures, or AE agents, pigments, chelating agents,
Other additives such as bentonite as a viscosity modifier and methylcellulose as a leveling agent can be blended.

The cement composition of the present invention is mainly composed of a powder mixture comprising Portland cement, granulated granulated blast furnace slag, and other powder components such as aggregate and fine silica sand powder. By mixing the catalyst solution with a liquid material having a solid content of about 50% to which an AE agent or a pigment is added, a hydration reaction starts and the concrete solution or the mortar hardens.

The cured film can be used as a covering material for floors, roofs, walls, repairs, and the like, and can be applied in a general construction method such as a spraying method, a plastering method, a roller method, a brushing method, or the like. Can be used.

Each mixing ratio of the cement composition of the present invention is as follows:
Various changes can be made within the above range according to the use and the strength to be obtained. For example, in the case of a floor covering material, Portland cement 40 parts by weight, granulated blast furnace slag 10 parts by weight, resin emulsion 5 parts by weight, aggregate 40
It is preferable to use parts by weight, 5 parts by weight of fine silica sand, 0.3 parts by weight of the catalyst solution, and the like.

On the other hand, when it is desired to further increase the strength, the content of the aggregate is increased, and when it is desired to further improve the flexibility, the mixing ratio of the resin emulsion is increased. Can be changed.

[0038]

Hereinafter, the present invention will be described in more detail by way of examples. Preparation of Catalyst Solution To 123 kg of industrial water, 12 g of sodium thiosulfate was added and stirred for 10 minutes to fix and remove calcium in the water. Next, while maintaining the water temperature at about 7 ° C., 1.7 kg of ammonium chloride and 2.9 kg of potassium carbonate were simultaneously added, and the mixture was stirred for 15 minutes. After adding 0.6 kg, the mixture was further stirred for 15 minutes. Further, 130 kg of calcium chloride is added to this solution.
And stirred for 30 minutes, then left at room temperature for 12 hours,
When the water temperature is about 17-18 ° C, 6.1k
g of magnesium chloride was added to obtain about 270 kg of a catalyst solution. Preparation of concrete specimen A and concrete comparison product B
A powder mixture consisting of 40 parts by weight of Portland cement and 10 parts by weight of granulated blast furnace slag (particle size: 6,000 branes) was mixed with 5 parts by weight of a modified acrylic ester copolymer emulsion (total solid content: 45%, A liquid material obtained by mixing a commercially available product having a pH of about 8.5 and a specific gravity of about 1.0) with 0.3 parts by weight of the above catalyst solution was added, and the mixture was cured in the air at 20 ° C. for 28 days.
A concrete specimen A of 4 cm × 4 cm × 16 cm was prepared. On the other hand, Portland cement was air-cured at 20 ° C. for 28 days under the same W / C conditions as described above using only ordinary water to prepare a 4 cm × 4 cm × 16 cm ordinary concrete comparative product B. Each of the specimen A and the comparative product B was subjected to a strain test. As a result, as shown in FIG.
While the specimen was broken at a stress of kgf / cm ² and a strain rate of 200 × 10 ⁻⁶ , in the concrete specimen A obtained from the composition according to the present invention, even when a stress of 110 kgf / cm ² was applied, The strain rate was about 3,800 × 10 ⁻⁶ , which did not cause breakage. It was found that the resin emulsion was excellent in flexibility when blended. Preparation of mortar comparative product C and water absorption test In addition to the above concrete comparative product B, 4 cm x 4 cm x 1 using ordinary water, Portland cement and No. 6 silica sand
A 6 cm 1: 3 mortar comparative product C was prepared by curing in air at 20 ° C. for 28 days under the same W / C conditions as described above. The mortar comparative product C, the concrete comparative product B, and the concrete specimen A are each JIS-A-620.
A water absorption test was performed in accordance with No. 3. As a result, as shown in FIG. 2, the concrete comparative product B and the mortar comparative product C
Shows that the water absorption was large from an early stage, and showed high water absorption of 13% by volume and 26% by volume after 72 hours. On the other hand, the concrete sample A showed a water absorption of 3% even after 72 hours. It was found that a dense structure was obtained by mixing the catalyst solution or the pulverized granulated blast furnace slag as low as 0.6% by volume. Water vapor permeation inhibition test A water vapor permeation inhibition test was carried out on each of the mortar comparative product C and the concrete specimen A in accordance with JIS-Z-0208. As a result, as shown in FIG.
The mortar comparative product C has a water vapor permeation amount per day of 120.
While was as large as 130 g / m ^2, the concrete specimen A, as small as 25 g / m ² before and after, this also, by also blended with the catalyst solution or finely divided blast furnace slag, structure Was found to be dense. Mortar specimen D, normal mortar comparative product E and polymer
Preparation of Mortar Comparative Product F and Compressive Strength Test Based on the composition of the concrete specimen A prepared above, using No. 6 silica sand and curing in the air at 20 ° C. for 28 days, 4 cm × 4 cm × 16 cm: A 3 mortar specimen D was prepared. On the other hand, a normal 1: 3 mortar comparative product E of the same dimensions was prepared under the same conditions as above using ordinary water, Portland cement and No. 6 silica sand. Further, based on the composition of the mortar comparative product E, an SBR (styrene-butadiene rubber) latex as a resin emulsion was further added, and under the same conditions as above, the same size of 1: 3
Comparative polymer mortar F was prepared. Next, each of the molded articles D, E, and F was immersed in kerosene or a mixed solvent of toluene and ethyl acetate for 28 days, and a compression strength test was performed on each of the specimen D and the comparative articles E and F. As a result, as shown in FIG. 4, the mortar specimen D obtained from the composition according to the present invention, even after immersion,
In addition, even in the case of untreated products, the compressive strength is higher than those of the comparative products E and F, and the addition of the catalyst solution or the finely ground granulated blast furnace slag has excellent chemical resistance, and the components are firmly combined. It turned out to be binding.

FIG. 5 summarizes the results of other coating film performance tests. In any item, a coating film as a coating material obtained from the cement composition according to the present invention,
It turns out that it is excellent in adhesion to a base material, denseness, and weather resistance.

[0040]

As described above, the cement composition of the present invention has excellent adhesion and flexibility, good chemical resistance,
In addition to providing a dense and strong structure, general construction methods can be used to protect building facilities and civil engineering structures, such as concrete, mortar, slate, and steel frames, from environmental changes over a long period of time. It can be suitably used as a coating material for preventing neutralization or deterioration, corrosion, or rust which causes these weaknesses.

[Brief description of the drawings]

FIG. 1 is a graph showing the difference in flexibility between a concrete specimen obtained from the cement composition of the present invention and conventional ordinary concrete.

FIG. 2 is a graph showing the difference in structural densities between a concrete specimen obtained from the cement composition of the present invention and conventional ordinary concrete and ordinary mortar.

FIG. 3 is a graph showing the difference in the compactness of the structure between a concrete specimen obtained from the cement composition of the present invention and a conventional ordinary mortar.

FIG. 4 is a list showing differences in chemical resistance and strength between a mortar specimen obtained from the cement composition of the present invention and a conventional mortar and polymer mortar.

FIG. 5 is a list showing adhesion, denseness, weather resistance, and the like of a coating film as a coating material obtained from the cement composition of the present invention to a substrate.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI C04B 22:14 22:10) 103: 60 103: 61 111: 23 111: 26 (58) Fields surveyed (Int. Cl. ⁷ , DB name) C04B 28/04 C04B 18/14 C04B 24/26 C04B 22/12 C04B 22/14 C04B 22/10 C04B 18:14 C04B 24:26 C04B 22:12 C04B 22:14 C04B 22:10 C04B 103 : 60 C04B 103: 61 C04B 111: 23 C04B 111: 26

Claims (3)

(57) [Claims] 1 to 30 parts by weight of Portland cement, 10 parts by weight of granulated blast furnace slag, 5 to 15 parts by weight of a resin emulsion, ammonium chloride and calcium chloride
A cement composition comprising 0.3 to 0.5 parts by weight of an aqueous solution of sodium, potassium carbonate, iron sulfate, and magnesium chloride . 2. The cement composition according to claim 1, wherein the granulated blast furnace slag is pulverized to 6,000 to 8,000 branes. 3. An aqueous solution is prepared by adding 100 parts by weight of water to
1-3 parts by weight of ammonium, a salt of calcium 70-1
50 parts by weight, 1-4 parts by weight of potassium carbonate , 3 parts of iron sulfate
The cement composition according to claim 1 or 2, further comprising 10 to 10 parts by weight and 3 to 7 parts by weight of magnesium chloride .