JP2010155740A - High-fluidity mortar - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-fluidity mortar which is one having a higher fluidity suitable for placement at a temperature as low as about 5°C and suitable for application as e.g., a levelling material and can be applied without encountering troubles of placement workability and the properties of placed mortar because its viscosity does not excessively lower even in a high-temperature environment. <P>SOLUTION: A high-fluidity mortar is provided which comprises calcium carbonate (α) having a particle size constitution in which particles with particle diameters larger than 0.6 mm are not present, the content of particles with particle diameters of 0.3-0.6 mm is 0.1-0.5 mass%, the content of particles with particle diameters of 0.15-0.3 mm is 8-15 mass%, the content of particles with particle diameters of 0.09-0.15 mm is 12-25 mass%, and the particles with particle diameters smaller than 0.09 mm constitute the balance, a fine aggregate (β) other than calcium carbonate, an expanding material, a water-retaining and thickening substance, a water-reducing agent, and a portland cement, wherein (α)/(β) is 0.8-3 in terms of a mass ratio. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a high-flowing mortar that can be used as, for example, a leveling adjusting material, a flooring material, etc., and is particularly suitable for a leveler material for a building structure and can be applied at a low temperature.

High-fluid mortar containing hydraulic components such as cement can form a horizontal surface simply by pouring into a floor slab, for example, and is used as a leveling material for construction. When using high-flowing mortar, it is important to set fluidity suitable for construction. When fluidity is manipulated, it is important to adjust the properties that are affected by the fluidity. In order to obtain a mortar with a high fluidity, since it generally contains a large amount of kneaded water, material separation, dry cracking, etc. are likely to occur, and although horizontality can be obtained, it is difficult to obtain a construction with a good surface condition. . In order to deal with such a problem, for example, a composition suitable for obtaining a horizontal plane by blending various admixture components as follows into cement has been proposed. That is, sand (aggregate), lime-based expansion agent, dispersant, fly ash and cellulose-based water retention agent (refer to Patent Document 1), aggregate, dispersant, shrinkage reducing agent, setting like gypsum A blend of an accelerator, a thickener and an antifoaming agent (see Patent Document 2), an aggregate, a water reducing agent, an antifoaming agent, a coagulation regulator, and a water-soluble cellulose ether (see Patent Document 3). ) Etc. are known. Even in mortars for which such measures are taken, the viscosity generally increases greatly with a decrease in temperature. Therefore, when it is intended to be used at a low temperature, the viscosity becomes high and the fluidity is lowered, and the workability of the work is remarkably lowered. The tendency to increase the viscosity due to a decrease in temperature is more remarkable for mortar containing a thickening component. Self-leveling cement-based mortar suitable for low-temperature construction is also known, but most of them use fast-hardening components. (For example, refer to Patent Documents 4 to 6.) Since these are mainly intended to improve the setting / curability at low temperatures, it is difficult to construct at higher temperatures, and those that are not so are highly viscous at low temperatures. Condensation progresses quickly in the state. The highly viscous mortar is difficult to remove fine bubbles entrained at the time of kneading, and this tends to float on the surface of the work or leave a trace of bubble breakage, resulting in a rough surface. As a measure for obtaining a low-viscosity mortar at a low temperature, it is known that a high fluidity suitable for a self-leveling material can be obtained at a low temperature when a dispersant containing a specific vinyl copolymer as an active ingredient is used. (For example, see Patent Document 7)
JP-A-56-84358 JP 7-267704 A JP 2006-56763 A JP-A-7-69704 JP 2000-211961 A JP 2006-16223 A JP-A-8-290955

  When general cement-based high-fluidity mortar is applied at a low temperature, the above-described construction work and defects on the surface of the work occur due to an increase in viscosity at a low temperature. In addition, mortar that exhibits high fluidity at low temperatures by using a special dispersant or the like is not suitable for construction use because its viscosity decreases excessively when the temperature increases. On the other hand, in particular, leveling regulators such as levelers for building structures need to have high-accuracy self-smoothness, so that higher fluidity is required to meet such applications. The present invention is a high-flowing mortar having higher fluidity that is suitable for construction use at a low temperature of about 5 ° C. and suitable for use in a leveler material, etc. The objective is to provide a high-flowing mortar that can be used without affecting the workability and the properties of the work.

  As a result of investigations for solving the above problems, the present inventors have found that in high flow mortar containing Portland cement as a binder phase forming component, when calcium carbonate having a specific particle size configuration is used as a component for forming a non-binding phase, slipperiness is achieved. As a result, it has been found that higher fluidity can be imparted, and that temperature dependence of fluidity is reduced, and a fine aggregate made of a material other than calcium carbonate and calcium carbonate is specified. It has also been found that, by setting the content ratio, an increase in viscosity of the mortar at a low temperature is suppressed and stable fluidity can be obtained, and the present invention has been completed.

  That is, the present invention does not contain particles having a particle size configuration exceeding 0.6 mm, the particle content is 0.1 to 0.5% by mass with a particle size of 0.3 to 0.6 mm, and the particle size is 0.15. Calcium carbonate (α) composed of particles having a particle content of 8 to 15% by mass of ~ 0.3 mm, a particle content of 12 to 25% by mass of 0.09 to 0.15 mm and a particle size of less than 0.09 mm. It contains fine aggregate (β) other than calcium carbonate, expansion material, water retention and thickening substance, water reducing agent and Portland cement, and (α) / (β) is 0.8 to 3 in mass ratio. It is a high-flowing mortar characterized by this. Moreover, this invention is the said high fluid mortar which contains an antifoamer further. Moreover, this invention is the leveler material for construction formed by containing one of the said high fluid mortars.

  The high-fluidity mortar according to the present invention has higher fluidity suitable for construction applications that require high-accuracy self-smoothness such as building leveler materials, for example, from a low temperature of about 5 ° C. to room temperature. In addition, a construction with substantially no material separation, shrinkage cracks, or bubble marks on the surface can be obtained after construction.

  The high flow mortar of the present invention uses Portland cement as a binder phase forming component. The type of Portland cement is not particularly limited. For example, in addition to various Portland cements such as normal, early strength, super early strength, moderate heat, and low heat, blast furnace cement and fly ash can be used as long as they are based on Portland cement. Mixed cement such as cement may be used. Two or more types of Portland cement may be used. Preferably, normal portland cement and early strength or very early strength portland cement are preferably used in combination, since the simminess during construction becomes good. When used in combination, it is appropriate to use an amount corresponding to 5 to 30% by mass of ordinary Portland cement used as early or very early Portland cement.

  Moreover, the high fluidity mortar of this invention contains an expansion | swelling material. The expansion material is not particularly limited as long as it can be used for mortar and concrete. Preferably, an expansion material capable of causing volume expansion by a hydration reaction such as lime or ettringite is used. Examples of the lime-based expansion material include a clinker pulverized product in which free quick lime is co-generated, and a limestone calcined pulverized product as an active ingredient. The ettringite-based expansion material is not limited as long as it reacts with water to produce an ettringite phase, and examples thereof include those containing calcium sulfoaluminate as an active ingredient. Lime-based and ettringite-based expansion materials may be used in combination. The use of the expansion material suppresses a relatively large shrinkage from curing to drying, and can prevent the occurrence of initial cracks. The blending amount of the expansion material is preferably 2 to 15 parts by mass with respect to 100 parts by mass of the cement content. If it is less than 2 parts by mass, shrinkage during curing cannot be sufficiently suppressed, and if it exceeds 15 parts by mass, there is a risk of expansion cracking due to overexpansion, which is not appropriate.

  The high flow mortar of the present invention contains water retention and thickening substances. Here, the water retention and thickening substance refers to a substance capable of imparting water retention and thickening to cement-based mortar, and is a single component substance (for example, a single compound) having both performances. Alternatively, a combination of both a water-retaining substance and a thickening substance (a mixture of a water-retaining substance and a thickening substance) may be used. Any of these can be used as long as it can be used for mortar and concrete. Examples of the former include water-soluble cellulose ether, and more specifically, methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose and the like are exemplified. Water-soluble cellulose ether suppresses material separation by thickening action. In addition, due to the water retention effect, for example, when applied to floors with unevenness, the drying period of the part where the construction thickness becomes thin and the part where the thickness becomes thick are matched, and cracks caused by the difference in the drying shrinkage time of the construction are suppressed. Contributes to reducing the difference in moisture content between the surface layer and the lower layer during the drying process. The compounding amount of the water-soluble cellulose ether is preferably 0.08 to 0.5 parts by mass with respect to 100 parts by mass of cement. If it is less than 0.08 parts by mass, material separation and cracking cannot be sufficiently suppressed, and if it exceeds 0.5 parts by mass, the viscosity may increase excessively and desired fluidity may not be obtained, which may reduce workability. Because there is, it is not appropriate.

  The high flow mortar of the present invention contains a water reducing agent. The water reducing agent can be used for mortar and concrete, and if it has a water reducing action, any of the so-called dispersant, high performance water reducing agent, AE water reducing agent, high performance AE water reducing agent or fluidizing agent can be used. Good and the ingredients are not limited. Among these, polycarboxylic acid-based water reducing agents are preferable because good fluidity can be exhibited even at low temperatures. What is necessary is just to determine the compounding quantity of a water reducing agent suitably for every active ingredient, for example, when using a polycarboxylic acid type high performance water reducing agent, 0.4-1 mass part is preferable with respect to 100 mass parts of cement contents. In this case, if it is less than 0.4 parts by mass, it will be difficult to ensure fluidity suitable for construction at low temperature without reducing the strength, and if it exceeds 1 part by mass, the viscosity will be excessively reduced and material separation will occur. It is not appropriate because it is easy to wake up.

  The high flow mortar of the present invention preferably contains an antifoaming agent. Any antifoaming agent can be used as long as it can be used for mortar and concrete. The use of antifoaming agent prevents the appearance of air bubbles that can easily be seen on the surface of the work due to the air entrained after water injection of high-flowing mortar, making it easier to obtain a smooth surface. Is preferred. As for the compounding quantity of an antifoamer, 0.05-1 mass part is preferable in conversion of solid content with respect to 100 mass parts of cement contents. If the amount is less than 0.05 parts by mass, it is difficult to remove the bubbles, and even if an amount of the antifoaming agent exceeding 1 part by mass is used, the blending effect is not improved and only the cost is increased, which is not appropriate.

  Moreover, the high fluidity mortar of this invention contains the calcium carbonate which consists of the following particle size structure. That is, there is no inclusion of particles exceeding a particle size of 0.6 mm, a particle content of 0.1 to 0.5% by mass with a particle size of 0.3 to 0.6 mm, and a particle content of 0.15 to 0.3 mm. The calcium carbonate has a particle size composition of 8 to 15% by mass, a particle content of 12 to 25% by mass with a particle size of 0.09 to 0.15 mm, and the remainder consisting of particles with a particle size of less than 0.09 mm. By using calcium carbonate, slipperiness can be imparted to the binder phase non-forming component, and by using the particle size constitution, particularly high slipperiness is seen, resulting in higher fluidity. Furthermore, since the fluidity obtained in this manner has little temperature dependence, not only high fluidity can be obtained at low temperatures, but also high fluidity can be exhibited at room temperature or higher. Moreover, it becomes easy to obtain the suppression effect | action of material separation by setting it as this particle size structure. Use of calcium carbonate having a particle size deviating from the particle size constitution is not preferable because it is difficult to obtain higher fluidity at a low temperature. In particular, the inclusion of particles having a particle size exceeding 0.6 mm results in a decrease in strength, and if the content of fine particles is excessively greater than that determined by the particle size configuration, the slipping property of calcium carbonate is remarkably reduced or material separation is reduced. Since it becomes easy to produce, it is not preferable.

  Moreover, the high flow mortar of this invention contains fine aggregates other than calcium carbonate. The fine aggregate other than calcium carbonate is not particularly limited as long as it can be used for mortar and concrete. Specific examples include natural fine aggregates such as mountain sand, river sand, sea sand, crushed sand, and artificial fine aggregates obtained by firing raw materials mainly composed of mineral powder. A new aggregate is desirable for obtaining higher strength. The maximum particle diameter of the fine aggregate is preferably 2.5 mm or less, and more preferably a fine aggregate having a maximum particle diameter of 1.2 mm or less is used, but in any case, a specific particle size configuration is not used. The content of fine aggregates other than calcium carbonate in the mortar of the present invention is preferably 1.3 to 2.5 parts by mass with respect to 100 parts by mass of cement. If the amount is less than 1.3 parts by mass, the shrinkage increases and cracks are likely to occur, which is not suitable. Moreover, since the intensity | strength of a construction material may fall when it exceeds 2.5 mass parts, it is not suitable.

  The high flow mortar of the present invention has a mass ratio of the calcium carbonate (α) and fine aggregate (β) other than calcium carbonate of 0.8 to 3.0 in terms of (α) / (β). To do. By setting it as the said mass ratio, the viscosity rise of a mortar can be suppressed and the stable fluidity | liquidity can be expressed even at low temperature. If the mass ratio (α) / (β) is less than 0.8, the effect of blending fine aggregates cannot be obtained substantially, and it becomes difficult to stably obtain fluidity with good workability. On the other hand, if the mass ratio (α) / (β) exceeds 3, the viscosity of the mortar becomes too large particularly at low temperatures, and it becomes difficult to obtain fluidity.

  Moreover, the high flow mortar of this invention may contain a component other than the above in the range which does not lose the effect of this invention substantially. Examples of such components include shrinkage reducing materials that can be used in mortar and concrete, anti-whitening agents, fibers, setting modifiers, water repellents, pozzolanic reactive substances, gypsum, clay minerals, pigments, and the like. Moreover, the compounding quantity of the kneading | mixing water of the high fluid mortar of this invention is not restrict | limited in particular. As a suitable example in the case of construction at 20 ° C., the amount of kneading water is generally 23 to 28 parts by mass with respect to 100 parts by mass of the high flow mortar. In this case, if it is less than about 23 parts by mass, fluidity suitable for good workability may not be obtained, and if it exceeds about 28 parts by mass, it will be difficult to improve the surface layer strength of the construction.

  Moreover, this invention is the leveler material for construction formed by containing the said high fluid mortar. The content of components other than the high flow mortar is not particularly limited as long as the effect of the present invention is not substantially lost, but when using a high flow mortar that does not contain an antifoaming agent, it is more preferable to use an antifoaming agent in combination. Since favorable surface smoothness is obtained, it is preferable. Further, it may be one that does not contain components other than the high fluidity mortar except for the kneaded water.

Hereinafter, the present invention will be described in detail by way of examples.
Next, using materials selected from A1 to G shown below, kneading water is first put into a kneading container so that the blending amount shown in Table 1 is reached, then other materials are put together and kneaded for about 90 seconds. A fluid mortar was made. This mortar was prepared in the same manner in both environments of a temperature of 20 ° C. and a temperature of 5 ° C. However, only the amount of the kneaded water was changed depending on the temperature. The particle size of calcium carbonate (F1 to F3) was adjusted by pulverizing and sieving commercially available calcium carbonate.
A1: Normal Portland cement (manufactured by Taiheiyo Cement Co., Ltd.)
A2: Early strong Portland cement (manufactured by Taiheiyo Cement Co., Ltd.)
B: Lime-based expansion material (trade name: Taiheiyo Expan, manufactured by Taiheiyo Materials Co., Ltd.)
C: Water-soluble methylcellulose thickener (trade name; Metroles 90SH-4000, manufactured by Shin-Etsu Chemical Co., Ltd.)
D: Polycarboxylic acid-based high-performance water reducing agent (trade name; Mighty 21P, manufactured by Kao Corporation)
E: Fine aggregate (Yamagata Silica Sand No. 6-7)
F1: Calcium carbonate (particle content exceeding 0.6 mm 0%, particle content 0.3 to 0.6 mm particle size 0.3 mass%, particle content 0.15 to 0.3 mm particle content 13. 2% by mass, particle content of 0.09 to 0.15 mm, particle content 19.5% by mass, particle content of less than 0.09 mm particle size 67% by mass)
F2: Calcium carbonate (particle content exceeding 0.6 mm 0%, particle content 0.3 to 0.6 mm, 0.3% by mass, particle content 0.15 to 0.3 mm) 3% by mass, particle content of 0.09 to 0.15 mm, 8.1% by mass, particle content of less than 0.09 mm, 86.3% by mass)
F3; calcium carbonate (particle content exceeding 0.6 mm 1%, particle content 0.3 to 0.6 mm, particle content 5.9% by mass, particle size 0.15 to 0.3 mm, particle content 28. 1 mass%, particle content 27.6 mass% with a particle size of 0.09 to 0.15 mm, particle content 37.4 mass% with a particle size of less than 0.09 mm)
G: Antifoaming agent (trade name; SN deformer AHP, manufactured by San Nopco)

  About the produced high fluidity mortar, the flow was measured according to the flow test method of the Architectural Institute of Japan standard JASS 15M-103 as fluidity | liquidity evaluation. As for the flow, the mortar prepared at a temperature of 20 ° C. is 20 ° C., and the mortar prepared at a temperature of 5 ° C. is 5 ° C. with respect to the high-flowing mortar immediately after the end of the kneading (when about 2 minutes have passed since water injection) Each was measured below. Moreover, the mortar produced at 5 ° C. was 5 ° C. so that the produced high-flowing mortar had a thickness of about 1 cm in a plastic container having an inner dimension of 13 cm, a width of 8.5 cm, and a height of 1.8 cm. The mortar produced at 20 ° C. was poured at a temperature of 20 ° C., respectively. As evaluation of material separability, the presence or absence of bleeding water generation on the surface of the construction left for 30 minutes was visually observed. Furthermore, as an evaluation of the surface condition of each construction after 1 day at 5 ° C. and 20 ° C. from the construction, it is visually confirmed whether or not there are bubbles bulging, pinholes or floating film formation on the surface. In the case where no occurrence of odor was observed, the surface condition was judged as “good”, and other cases were judged as “bad”. Further, about 3.6 liters of the high-flow mortar thus prepared was poured from one side of the container so as to have a thickness of 1 cm into a wooden container having an internal size horizontally installed and having a length of 180 × width of 20 × depth of 2 cm. . A level was applied evenly to the surface of the mortar that had passed one day after pouring, and it was examined whether or not a horizontal surface was obtained, and it was evaluated whether the mortar had smoothness as an architectural leveler. When the horizontal surface was obtained on the entire surface, the self-smoothness was “present”, and the others were judged as “no”. In this evaluation, the mortar produced at a temperature of 5 ° C. was cast at 5 ° C., and the mortar produced at a temperature of 20 ° C. was evaluated as self-smoothness by casting at 20 ° C. The above measurement and evaluation results are shown in Table 2.

  From Table 2, the high fluidity mortar according to the present invention stably exhibits very high fluidity suitable for construction even at low temperature (5 ° C) or at ordinary temperature (20 ° C), and the surface condition is good after construction and material separation. It can be seen that there is no substantial occurrence. Furthermore, it turns out that the self-smoothness suitable for the leveler material for construction is also provided.

Claims (3)

Particles whose particle size composition does not contain particles with a particle size exceeding 0.6 mm, particles with a particle size of 0.3 to 0.6 mm, 0.1 to 0.5% by mass, particles with a particle size of 0.15 to 0.3 mm Calcium carbonate (α) composed of particles having a content of 8 to 15% by mass, a particle content of 12 to 25% by mass and a remaining particle size of less than 0.09 mm, and fine bones other than calcium carbonate It contains a material (β), an expansion material, a water retention and thickening substance, a water reducing agent and Portland cement, and (α) / (β) is 0.8 to 3 in mass ratio. Flowing mortar. Furthermore, the high fluid mortar of Claim 1 containing an antifoamer. An architectural leveler material comprising the high fluidity mortar according to claim 1.