JP2006321685A - Microencapsulated concrete-mixing type cement crystal forming and proliferating accelerator, and method of forming and proliferating cement crystal using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mixing type high performance cement crystal forming/proliferating accelerator capable of making freshly placed concrete surely and permanently water-impermeable and extent in service life, and to provide its utilization method. <P>SOLUTION: The concrete is made water-impermeable and highly durable by mixing microcapsules, formed by encapsulating a catalytic compound for accelerating or assisting the formation/proliferation of cement crystals of the concrete and a co-catalytic compound or a crystal constitutive element compound as core materials included in a coating film material, with ready-mixed concrete and releasing the core material at a time or slowly with desired timing corresponding to the characteristics of the respective core materials by using core material releasing control function which is a basic characteristic of a microcapsule while stably protecting and keeping the encapsulated core materials until the timing of effectively exhibiting the performance to form and proliferate the required cement crystals in a required place at an effective time after the early time hardening of the concrete. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a microencapsulated concrete-mixed cement crystal formation and growth accelerator having a time difference effect, and a cement crystal formation and growth promotion method using the same.

  The biggest problem common to new concrete structures is water leakage mainly at the discontinuous surface of concrete, such as cracks and various seams, which occurs after the initial hardening process of the placed concrete.

  In fact, the conventional admixture cannot be expected to have a reliable water-stopping effect against such problems. The reason for this is that conventional admixtures have already finished the reaction immediately after the concrete is placed before the occurrence of deformation such as cracking or water leakage, or the excess water or the watering of the cast concrete itself. The admixture or its components are washed away by the spilled water at the installation site, and the effect is diminished.

  For this reason, as a physical water stop method as a follow-up countermeasure, it is common to apply and fill with a surface coating material such as a resin-based material or a filler. However, it is difficult to maintain the effect over a long period due to the nature of these materials and construction methods. Thus, the basic and biggest problem described above remains unresolved.

Japanese Patent Publication No. 05-027595 JP 2005-060165 A

  In view of the above-described problems, the present invention is intended to cope with various deformations of a concrete structure to be newly installed, including water leakage including a concrete discontinuity surface that occurs mainly after the initial hardening process of the placed concrete. An object of the present invention is to provide a reliable and effective admixture-type high-performance cement crystal formation / growth promoter and its utilization method.

  Among the admixture-type high-performance cement crystal formation / growth promoters according to the present invention, the one according to claim 1 is a catalytic compound that promotes or supports the formation / growth of concrete cement crystals, and a co-catalytic compound, or crystal It is characterized by being a microcapsule in which a constituent element compound is contained in a coating substance as a core substance.

  According to the second aspect of the present invention, there is provided the admixture-type high-performance cement crystal production / growth promoting agent according to the first aspect, wherein the microcapsules release the core material temporarily or slowly at a timing according to the characteristics of the core material. It is possible.

  According to the third aspect of the present invention, the microcapsule has a diameter of about 1 mm in the admixture type high performance cement crystal production / growth promoter of the first or second aspect.

  The invention according to claim 4 is characterized in that, in the admixing type high performance cement crystal production / growth promoter of claim 1 or 2, the diameter of the microcapsules is 1 mm or less.

  In the admixture-type high-performance cement crystal production / growth promoter according to any one of claims 1 to 4, the coating substance is a component of cement crystal such as silica, calcium carbonate, or the like. It is a synthetic polymer material, silicone or the like.

  Among the cement crystal formation / growth promoting methods according to the present invention, the method according to claim 6 is characterized in that the mixing type high performance cement crystal production / growth promoting agent according to any one of claims 1 to 5 is mixed with fresh concrete, and the microcapsules The core material is temporarily released or slowly released from the base, and the effective time after the initial hardening of the concrete is generated, and the necessary cement crystals are generated and propagated in the necessary parts to make the concrete impervious and highly durable. It is characterized by.

  According to claim 7, the admixture-type high-performance cement crystal formation / growth promoter according to any one of claims 1 to 5 is mixed with ready-mixed concrete, and the encapsulated catalytic compound or other core substance is added to the required timing. Until the core material is temporarily released or slowly released from the microcapsules at a necessary timing according to the characteristics of the core material according to the core material release control function. In addition, it is characterized in that the concrete is made impermeable and highly durable by generating and multiplying the necessary cement crystals at the required site after the initial hardening of the concrete.

  That is, the time-efficiency concrete admixture type cement crystal formation / growth promoter according to the present invention includes a catalytic compound that promotes cement crystal generation / growth, a co-catalytic compound that promotes the action, or a cement crystal constituent element. It is characterized by being microencapsulated with a compound or the like as a core substance.

  Carbonate which reacts easily with calcium hydroxide or the like to produce calcium carbonate and exhibits water-stopping property can also be added.

  A catalytic compound to be encapsulated in a microcapsule as a core substance, a co-catalytic compound that assists the action, or a compound containing a cement crystal constituent element is disclosed in Patent Document 1 (Japanese Patent Publication No. 05-027595: Patent). No. 1815985) is applicable to organic acids having a plurality of carboxyl groups or salts thereof, or acids having the same or similar performance and salts thereof. Further, a calcium salt of an organic acid having a plurality of carboxyl groups or an inorganic phosphate-based calcium complex compound disclosed in Patent Document 2 (Japanese Patent Laid-Open No. 2005-060165) described above, and performance equivalent to or similar to these The calcium salt possessed is also applicable.

  In addition, examples of the core material include calcium hydroxide, calcium carbonate, calcium sulfate, etc., which are the main elements constituting the cement crystal, fine particle silica, fly ash silica, or fine powder of blast furnace slag. Can do.

When the above core material is released from the microcapsule according to the set timing of its release control function, it generates a cement crystal by a mechanism or a generation reaction according to the basic cement crystal formation reaction by the catalytic compound shown below. Promote the growth of the produced cement crystals.
In the formula, L is a catalytic compound.

  In addition, the microcapsules may have an appropriate size of about 1 mm in diameter or less, and the film (wall) material may be an inorganic material, a synthetic polymer material, a material produced in nature, or the like. In addition, a wide range of materials can be applied except those that are particularly harmful to the physical properties of concrete.

  The atmosphere in which such microcapsules are used is alkaline, and the temperature is within the temperature of the cast concrete. In such a concrete atmosphere, the core material is set to be released from the inside of the microcapsule once or slowly at the timing when the above-mentioned core material is required after the initial hardening of the concrete. . This is an adjustment within the basic functions and basic characteristics inherent to the microcapsule, and can be achieved without any particular problem by selecting the film (wall) material and setting the film (wall) thickness.

  As a general and familiar film material, silica, calcium carbonate or the like, which is a component of cement crystal, or a synthetic polymer material having a wide versatility, silicone, or the like can be used.

  The present invention is an admixture-type high-performance cement crystal formation / proliferation promoter intended for reliable permanent impermeability and long life of newly placed concrete in a new structure. Catalytic compounds that promote or support growth are encapsulated in microcapsules as a core material and mixed with ready-mixed concrete, thereby exhibiting color development characteristics compared to conventional agents. In other words, in the case of breathing water after concrete placement, or in underground or underground structures, the function related to crystal formation / growth has been lost or expired before the core substance is activated by the outflow water. It is possible to solve the problem, while holding each core material stably, and the catalytic compound released from the microcapsule at the site where crack formation, water leakage and other crystals need to be generated and proliferated after the initial hardening of the cast concrete. A certain water impermeability effect is obtained by the effect of the cement crystal formation / growth promoter.

  Examples of experiments and figures conducted by the inventors of the present invention on the best mode of a cement admixture-type cement crystal formation / growth promoting agent having a time difference effect according to the present invention and a cement crystal generation / growth promoting method using the same are shown below. The description will be given with reference.

First, in the ready-mixed concrete (design standard strength 24N / mm ² ),
(A) A fumaric acid which is a divalent carboxylic acid so as to have a concentration of 200 ppm is microencapsulated using silica as a film (average particle diameter 200 micrometers, average film thickness 10 micrometers), and mixed,
(B) A mixture of fumaric acid so as to be 200 ppm,
Two columnar specimens (diameter 30 cm, height 20 cm) are made of two types of blended concrete, and air-cured under normal environmental conditions in the mold, after 5 days of material age, by splitting method Penetration and cracks (width of about 0.1 mm) were generated.

  FIG. 1 conceptually shows a compressive strength measuring device 2 used to make a crack 3 in each cylindrical specimen 1. FIG. 2 is a conceptual diagram showing a state in which the crack 3 is adjusted using the hose band 4 in order to secure the crack 3 with an appropriate width for use in the test. The tightening strength of the hose band 4 was adjusted, and the width of the crack 3 was adjusted by measuring both the upper and lower surfaces of the cylindrical specimen 1 using an image analyzer.

  Subsequently, it set to the water-stop test apparatus 5 as shown in FIG. In setting, in order to prevent water intrusion and leakage into the cylindrical specimen 1 from other than cracks, sealing was performed as described below. In FIG. 3, 6 is a water supply tank, which can keep the water level constant by supplying water from the water supply. In the figure, 7 is a pump, 8 is a water bottle for pressurization, 9 is a water supply pipe, 10 is a sample holder, 11 is a water leak receiver, and 12 is a return pipe to the water supply tank 6. For example, a sealing material in which paraffin and rosin are mixed at a ratio of 1: 1 is applied to the outer periphery of the sample 1 to be inserted into the sample holder 10 to maintain watertightness.

The water-stopping test method was adjusted such that the water pressure was 2 kgf / cm ^2, and the amount of water leakage per hour from the side opposite to the crack was measured over time.

The test results are shown in FIG. As can be seen from the figure, immediately after the start of the test, (a) two microencapsulated catalytic compound blends,
(B) The leakage amount of the four specimens of the two catalytic compound blends without microencapsulation was a value similar to about 70 ml / min, but shows a remarkable difference after 2 hours. The two bodies with microcapsules in (a) showed complete water stoppage in 100 to 120 hours immediately after the start of the test, as compared with the two bodies in (b) showing a gradual decreasing tendency.

  After the water-stopping test for 144 hours, each specimen 1 was completely split, and the central part of the crack was axially (height direction) (1) inlet, (2) center (10 cm), (3) three outlets The material was collected at a depth of 1 Cm from the cracked surface, and the residual concentration of the catalytic compound in each specimen was analyzed. The results are shown in the table of FIG. The analysis method was quantitative analysis by ion chromatography using a UV detector.

  From these test results and analysis results, the catalytic compound that promotes or supports the formation and growth of cement crystals, and the microencapsulation of the co-catalytic compound can be mixed, that is, the growth effect of the cement crystals of the cast concrete, that is, It can be said that this is a very effective technique for the water-stop effect.

  In other words, a catalytic compound that promotes or supports cement crystal formation / growth is encapsulated in a microcapsule as a core material and mixed with freshly placed ready-mixed concrete. In the case of underground structures etc., the core material is not lost or expired until the core material is activated by the outflow water, etc., and each core material is stably held and placed. Certain parts of the concrete that need to be crystallized and proliferated, such as cracks and water leaks after the initial hardening, and cement crystal generation and growth accelerators, including catalytic compounds released from the microcapsules at certain times, ensured A water-impervious effect can be obtained.

It is a side view which shows a compressive strength measuring apparatus. It is a perspective view which shows adjustment of the division rack width of a sample. It is sectional drawing which shows a water-stop test apparatus. It is a figure which shows the result of a water-stop test. It is a figure which shows the catalytic compound residual density | concentration after a water-stop test.

Explanation of symbols

1: Sample 2: Compressive strength measuring device 3: Crack 4: Hose band 5: Water leakage tester 6: Water supply tank 7: Pump 8: Water bottle 9 for pressurization 9: Water supply pipe 10: Sample holder 11: Water leakage receiver 12: Return piping

Claims (7)

Mixing-type high, characterized in that it becomes a microcapsule containing a catalytic compound that promotes or supports the formation and growth of cement crystals of concrete, and a co-catalytic compound or a crystal constituent element compound as a core substance in a coating material Performance cement crystal formation and growth promoter. 2. The admixture type high-performance cement crystal formation / growth promoter according to claim 1, wherein the microcapsules can release or slowly release the core material at a timing according to the characteristics of the core material. Type high-performance cement crystal formation and growth promoter. 3. The admixture-type high-performance cement crystal formation / growth promoter according to claim 1 or 2, wherein the diameter of the microcapsule is about 1 mm. 3. The admixture-type high-performance cement crystal formation / growth promoter according to claim 1 or 2, wherein the microcapsule has a diameter of 1 mm or less. 5. The admixture-type high-performance cement crystal formation / growth promoter according to claim 1, wherein the coating substance is silica, calcium carbonate, or the like, which is a constituent element of cement crystal, or a synthetic polymer material, silicone, or the like. An admixture-type high-performance cement crystal formation / growth promoter. An effect of the concrete after the initial hardening is obtained by mixing the mixing type high performance cement crystal formation / growth promoter according to any one of claims 1 to 5 with the ready-mixed concrete, and releasing the core material from the microcapsules temporarily or slowly. A method for promoting the formation and growth of cement crystals, characterized in that the required cement crystals are generated and propagated at the necessary sites to make the concrete impervious and highly durable. The admixture-type high-performance cement crystal formation / growth promoter according to any one of claims 1 to 5 is mixed with ready-mixed concrete, and the encapsulated catalytic compound and other core materials are stably protected in ready-made concrete until the required timing. The core material is temporarily released or slowly released from the microcapsules at a necessary timing according to the characteristics of the core material according to the core material release control function, and required after the initial hardening of the concrete. A method for promoting the formation and growth of cement crystals, characterized in that the required cement crystals are generated and propagated at necessary sites to make the concrete impervious and highly durable.