KR20220145109A - Mortar composition and concrete composition using organic-inorganic hybrid water-repellent - Google Patents

Abstract

Disclosed are a mortar composition and a concrete composition using an organic-inorganic complex water repellent. The mortar composition of the present invention is a repair mortar composition used for repair work on deteriorated concrete structures, and includes cement, fine aggregate, an inorganic metal salt-based powder water repellent, and an organic silicon-based liquid water repellent. The concrete composition of the present invention is a concrete composition for expressing water repellency inside concrete, and includes cement, fine aggregate, coarse aggregate, an inorganic metal salt-based powder water repellent, and an organic silicon-based liquid water repellent. According to the present invention, the mortar composition and the concrete composition may prevent deterioration factors such as moisture from penetrating into concrete.

Description

Mortar composition and concrete composition using organic-inorganic composite water repellent {MORTAR COMPOSITION AND CONCRETE COMPOSITION USING ORGANIC-INORGANIC HYBRID WATER-REPELLENT}

The present invention relates to a mortar composition and a concrete composition using an organic-inorganic composite water repellent agent, and more particularly, to a mortar/concrete composition, while securing water repellency to prevent a deterioration factor such as moisture from penetrating into the concrete while securing the compression It relates to an organic-inorganic composite water repellent that can overcome the limit of the decrease in strength.

Reinforced concrete is the most widely used construction material for buildings and civil structures. However, since concrete has a porous structure with many voids inside, various deterioration factors such as CO ₂ , Cl ^- easily penetrate from the outside. Since the concentration of chlorine ions is higher than the limit state, it has a serious durability degradation problem, in which the proof strength is lowered due to the occurrence of cracks in concrete due to corrosion of reinforcing bars. In particular, when a deterioration factor such as Cl ⁻ penetrates into the concrete, the penetration rate of diffusion into the interior is relatively slow, but when dissolved and moved by moisture, the penetration rate rapidly increases.

Therefore, in order to protect porous concrete, a method of applying a surface impregnation agent or a water repellent to the concrete surface is widely used, and this surface application and impregnation method has fewer problems in that the film peels off or peels off unlike the coating method. is expanding However, if the concrete itself deteriorates due to cracking or peeling, the impregnated surface layer is damaged, and the expected durability cannot be secured.

In consideration of this aspect, recently, various water repellent materials are mixed into concrete or mortar to show water repellency even inside cracks even when the concrete itself is peeled or cracked, and studies to improve the durability of concrete are being conducted. In this regard, when the silicone-based liquid water repellent, which is an organic material, is mixed, a very high water repellency performance can be secured and workability is improved, but there is a disadvantage in that a lot of air is entrained and the compressive strength is greatly reduced. On the other hand, when an inorganic metal salt-based powder-type water repellent is mixed, the amount of air is reduced and, although it is a hydrophobic material, the decrease in compressive strength due to the fine powder is relatively small compared to the water-based water repellent, but the workability is lowered and the water repellent performance is lowered. The downside is that it's not that big. Among these, the decrease in compressive strength is the biggest problem. When an organic silicone-based water repellent is actually mixed, the water repellency performance is excellent and the workability is increased, but the compressive strength is decreased by about 30-40%, and the amount of air is Although this decreased and showed the expression of water repellency, it was confirmed that the compressive strength was also decreased by about 10-20% as a result of the experiment.

So far, research is in progress to overcome the limitations of compressive strength reduction while securing water repellency by using the advantages and disadvantages of each material by using both an organic silicone-based liquid (water-based) water repellent and an inorganic metal salt-based water repellent at the same time. not.

Accordingly, the present invention provides a silicone-based liquid water repellent that is an organic material and an inorganic metal salt-based powder-type water repellent that is an organic material in order to solve the problems such as an increase in the amount of air and a decrease in compressive strength while securing the water repellency required for the mortar/concrete composition. We would like to propose an organic-inorganic composite water repellent that complements the strengths and weaknesses of each other.

Related prior art documents include Japanese Patent No. 4555066 (Title of the Invention: Repair Method of Concrete Structure, Announcement Date: September 29, 2010) and the like.

An object of the present invention is a mortar composition using an organic-inorganic composite water repellent that can solve problems such as an increase in the amount of air and a decrease in compressive strength while securing water repellency to prevent a deterioration factor such as moisture from penetrating into the concrete. and to provide a concrete composition.

The above object is, according to the present invention, in the repair mortar composition used for repair work for a concrete structure in which deterioration has occurred, cement, fine aggregate, inorganic metal salt-based powder-type water repellent, and organic silicon-based liquid water repellent. It is achieved by a mortar composition using the group composite water repellent.

In addition, the above object is, according to the present invention, in the concrete composition for expressing water-repellent performance in concrete, cement, fine aggregate, coarse aggregate, inorganic metal salt-based powder-type water-repellent agent, and organic silicone-based liquid water-repellent agent, characterized in that it contains It is achieved by a concrete composition using an organic-inorganic composite water repellent.

Here, the inorganic metal salt-based powder-type water repellent is preferably provided as a stearate powder-type water repellent, and the organic silicon-based liquid water repellent is preferably provided as a silane-siloxane aqueous water repellent.

Preferably, the sterarate powder water repellent includes calcium stearate and zinc stearate, and the calcium stearate and the zinc stearate may be mixed in a weight ratio of 9.5 to 8.5: 0.5 to 1.5 by weight.

Preferably, the solid content of the silane-siloxane aqueous water repellent agent may be 40 to 60% by weight.

Preferably, the inorganic metal salt-based powder-type water repellent and the organic silicon-based liquid water repellent agent (based on solid content) may be mixed in a weight ratio of 3 to 6:1.

Preferably, the organic-inorganic composite water repellent including the inorganic metal salt-based powder water repellent and the organic silicon-based liquid water repellent (based on solid content) may be blended in an amount of 1 to 3% by weight based on 100% by weight of the cement.

Preferably, the inorganic metal salt-based powder-type water repellent is mixed with the cement and dry bibim, and the organic silicon-based liquid water repellent may be mixed together with the fine aggregate after the cement paste is manufactured.

In the present invention, in the mortar / concrete composition, an organic silicone-based liquid water repellent agent and an inorganic metal salt-based powder-type water repellent are mixed and used. By presenting this, it is possible to solve problems such as an increase in the amount of air and a decrease in compressive strength generated by the existing water repellents while securing the water repellency to prevent the deterioration factors from penetrating into the concrete.

1 is a graph showing the compressive strength test results for the test specimens according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention.
Figure 2 shows the SEM image of the water repellent-free mortar test body and the test body mixed with the organic silicone-based liquid water repellent agent, Figure 3 shows the SEM & EDS analysis results of the test body mixed with the organic silicone-based liquid water repellent agent.
4 is a graph showing the amount of water absorption per unit area over time of the test specimens according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention.
5 shows a 500-fold magnified SEM image of the surface of the water repellent-free mortar test body and the inorganic metal salt-based powder-type water repellent mixed, and FIG. The SEM image of the surface of the magnified 10,000 times is shown.
7 is a graph showing the amount of passing charge for the test specimens according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing preferred embodiments of the present invention with reference to the accompanying drawings. However, in describing the present invention, a description of a function or configuration already known will be omitted in order to clarify the gist of the present invention.

The mortar composition using the organic-inorganic composite water repellent of the present invention is a repair mortar composition used for repair work on a concrete structure in which deterioration has occurred, and includes cement, fine aggregate, and an organic/inorganic composite water repellent, wherein the organic/inorganic composite water repellent is an inorganic metal salt. It is provided as a powder-based water repellent and an organic silicone-based liquid water repellent.

In addition, the concrete composition using the organic-inorganic composite water repellent of the present invention is a concrete composition for expressing water-repellent performance inside concrete, and includes cement, fine aggregate, coarse aggregate, and organic-inorganic composite water repellent, wherein the organic/inorganic composite water repellent is It is provided as an inorganic metal salt-based powder-type water repellent and an organic silicone-based liquid water repellent.

That is, the mortar composition of the present invention and the concrete composition of the present invention are characterized by mixing an inorganic metal salt-based powder-type water repellent agent and an organic-inorganic composite water repellent agent provided as an organic silicon-based liquid water repellent agent when mixing mortar or concrete. At this time, the inorganic metal salt-based powder-type water repellent is mixed with cement and dry bibim, and the organic silicon-based liquid water repellent is preferably mixed together with the fine aggregate or with the fine and coarse aggregate after the cement paste is manufactured.

In the present invention, the inorganic metal salt-based powder water repellent is provided as a stearate powder water repellent, and the organic silicon-based liquid water repellent is provided as a silane-siloxane aqueous water repellent. In particular, in the present invention, the stearate powder-type water repellent includes calcium stearate and zinc stearate, but calcium stearate and zinc stearate are 9.5-8.5: 0.5-1.5 weight ratio (more preferably Preferably, it is mixed in a ratio of 9: 1 by weight), and the solid content of the silane-siloxane aqueous water repellent is preferably 40 to 60% by weight (most preferably 50% by weight).

The inorganic metal salt-based powder-type water repellent (stearate powder-type water repellent) and the organic silicon-based liquid water repellent (silane-siloxane water-based water repellent) having the above components increase the amount of air generated by the existing water repellents while ensuring sufficient water repellency required, In order to solve problems such as lowering of compressive strength, it is preferable to mix in a 3-6: 1 weight ratio (more preferably 5: 1 weight ratio), and a detailed description thereof is provided in Examples of the present invention and its experiments The results will be described later. At this time, the weight ratio of the organic silicone-based liquid water repellent (silane-siloxane water repellent) is based on the weight of the solid content, excluding the mixing water.

In addition, the organic-inorganic composite water repellent including the inorganic metal salt-based powder water repellent and the organic silicon liquid water repellent (solid content) as described above showed a relatively large decrease in compressive strength and a change in water repellency performance according to the experimental results. Cement 100 weight It is preferable to mix|blend in 1-3 weight% (more preferably 2 weight%) with respect to %.

On the other hand, in the present invention, the cement is preferably provided as a type of ordinary Portland cement having a fineness of 2,800 cm ² /g or more. For reference, fine aggregates and coarse aggregates can be used in accordance with general specifications for mortar or concrete.

Hereinafter, the configuration and effect of the present invention will be described in more detail by describing preferred embodiments of the present invention and the experimental results thereof. However, this is presented as a preferred example of the present invention, and the present invention is not limited or limited by the examples disclosed below.

1. Experiment Overview

<Material used>

In this experiment, cement type 1 ordinary Portland cement was used, and for fine aggregate, standard yarn conforming to KS L ISO 679 was used.

[Table 1] and [Table 2] show the characteristics of the organic silicon-based liquid water repellent, silane-siloxane modified water repellent, and the inorganic metal salt-based powder water repellent, calcium stearate and zinc stearate, used in this experiment, respectively. Silicone-based silane-silonic acid has a milky white color, has alkalinity, and has a solid content of 50%, so it is a material that needs correction for the mixing water. Stearate is a fine powder having a lower density than that of cement, and has neutral or weak alkalinity.

<Experiment plan>

[Table 3] shows the mortar formulation table according to Comparative Examples 1 to 3 and Examples 1 to 4 used in this experiment.

In this experiment, Examples 1 to 4 were cement mortars using both the organic-inorganic composite water repellent according to the present invention, that is, an inorganic metal salt-based powder water repellent (stearate powder type water repellent) and an organic silicone-based liquid water repellent agent (silane-siloxane water repellent). As test specimens made of the composition, wherein the inorganic metal salt-based powder-type water repellent agent and the organic silicone-based liquid water repellent agent were in Example 1 (P3L1) 3 : 1 weight ratio, Example 2 (P4L1) 4 : 1 weight ratio, Example 3 (P5L1) has a 5 : 1 weight ratio and Example 4 (P6L1) has a 6 : 1 weight ratio.

On the other hand, Comparative Example 1 (OPC) is a test specimen prepared with a cement mortar composition using only one type of ordinary Portland cement without mixing any water repellent agent, and Comparative Example 2 (Powder) is an inorganic metal salt-based powder water repellent (stearate powder) as a water repellent. A test specimen made of a cement mortar composition using only a water repellent type), and Comparative Example 3 (Liquid) is a test specimen made of a cement mortar composition using only an organic silicone-based liquid water repellent (silane-siloxane water repellent) as a water repellent.

Flow, air volume, and compressive strength tests were performed to evaluate the physical performance of the mortar mixed with organic/inorganic composite water repellent, and water absorption and chloride penetration resistance tests were performed to evaluate the water repellency performance. The organic/inorganic composite water repellent used in the experiment was added at 2 wt% compared to 100 wt% of cement, which showed relatively large changes in compressive strength and water repellency as a result of existing literature and preliminary experiments. Calcium stearate (Ca): zinc stearate (Zn) = 9: 1 weight ratio, which has excellent water repellency and showed the lowest decrease in compressive strength, was applied. In addition, considering that the solid content of the organic silicone-based liquid water repellent is 50%, the amount of mixing water was adjusted. The mixing ratio of the organic/inorganic composite water repellent was adjusted by considering the decrease in compressive strength, and the amount of the organic silicone-based liquid water repellent (silane-siloxane water repellent) that greatly reduces the compressive strength.

2. Experimental method

<Evaluation of construction performance of non-solidified mortar>

The air quantity test was conducted in accordance with KS F 2421. Flow experiment was conducted based on KS L 5105, and flow and air volume measurement were performed by setting 200±5mm and 7±% as target performance ranges based on water-binding material ratio (W/C) 50% and water repellent-free mortar. carried out.

<Compressive strength>

After demolding the specimen manufactured according to KS L ISO 679, dry curing was performed. Compressive strength was measured using 30Ton UTM at the age of 3, 7, 14, and 28 days. After measuring the compressive strength of three specimens by level, the average value was calculated as the compressive strength. Compressive strength test was performed by fabricating a 50x50x50 cubic mold.

<Absorbency>

After air-drying for 28 days, epoxy was coated on the side of the cured specimen and dried in the air for 24 hours. After measuring the weight of the specimen after drying, the specimen was immersed in water to a depth of about 10 mm, and the weight of the specimen was measured over time for 10, 30, 60, and 360 minutes to derive the water absorption rate and water absorption coefficient per area. The experiment was conducted based on KS F 2609, and since the absorption coefficient calculated through four or more measured values has a linear relationship, the experiment was terminated at 360 minutes.

<Chloride Penetration Resistance (RCPT)>

Chloride permeation resistance test (RCPT = Rapid Chloride Permeability Test) procedure is as follows. First, after cutting to a thickness of 50 mm from the center of a Ø100×200 round specimen cured for 28 days in dry conditions to the pouring surface and the bottom, respectively, in order to proceed with the experiment in one direction, epoxy coating was performed on the side of the cut specimen, 24 Time was cured at room temperature. The epoxy cured test specimen was placed in a desiccator, and the vacuum was maintained at a pressure of 133 Pa or less for 3 hours. After immersion, put the specimen in a chloride penetration resistant cell and assemble it, then put 3.0% sodium chloride and 0.3N sodium hydroxide into the assembled cell. The cell was connected to a constant voltage power supply, and 60v was supplied for 6 hours, and the current value was recorded every 30 minutes from the beginning to derive the amount of through-charge through [Equation 1] below.

In [Equation 1] above, Q is the amount of passing charge (C), and I ₀ is the current (A) immediately after the voltage is applied. I _t represents the current (A) after t minutes have elapsed after voltage is applied. Chloride penetration resistance test was conducted based on KS F 2711.

3. Experimental Results and Analysis

<Change in flow and air volume according to the amount of water repellent mixed>

[Table 4] below shows the flow and air amount test results for the mortars according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention. All specimens (Comparative Examples 1 and 2 and Examples 1 to 4) except for the specimen of Comparative Example 3 (Liquid) in which the organic silicone-based liquid water repellent (silane-siloxane aqueous water repellent) was mixed was set as the target performance range in this study. 200±15mm and air volume of 7±1% were satisfied. In the case of organic silicone-based liquid water repellent, it is judged to have excellent workability by entraining a lot of air inside when mixed. However, the test specimen of Comparative Example 2 (Powder), in which the inorganic metal salt-based powder-type water repellent (stearate powder-type water repellent) was mixed, confirmed a decrease in the amount of air when the amount of metal salt was increased, which closed the pores inside the mortar when the metal salt-based stearate was added. considered to be charging.

<Relationship between mixing amount of water repellent and compressive strength>

1 is a graph showing the compressive strength test results for the test specimens according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention.

Compressive strength was improved over time in all specimens, and the compressive strength of the specimen without water repellent agent (Comparative Example 1) was 30 and 36 MPa, respectively, at the early age of 3 days and 7 days, indicating a characteristic of expressing high compressive strength. In the case of the test specimens containing the water repellent agent (Comparative Examples 2 and 3 and Examples 1 to 4), overall strength enhancement was significantly increased after 14 days of age.

In the case of the inorganic metal salt-based powder-type water repellent (Comparative Example 2), the compressive strength was low until 14 days of age, but after 28 days of age, it was 39.5 MPa, showing a high compressive strength of 97.5% compared to the non-mixed mortar. The organic silicone-based liquid water repellent (Comparative Example 3) had a compressive strength of 24 MPa at the age of 28 days, confirming a 42% decrease in compressive strength compared to an unmixed mortar.

The test body containing the organic-inorganic composite water repellent agent (Examples 1 to 4) showed a higher compressive strength than the test body containing the organic silicone liquid water repellent agent (Comparative Example 3) regardless of age, and at 28 days of age, it was about 38 MPa. Compared to the test specimen of Comparative Example 3, it exhibited higher compressive strength. Specifically, Example 1 (P5L1) showed a decrease in compressive strength of about 2.5% compared to Comparative Example 2 (Powder), a test body containing an inorganic metal salt-based powder-type water repellent at 38.5 MPa, and in Example 4 (P6L1) , the compressive strength was 39.5 MPa, confirming the same compressive strength as in Comparative Example 2 (Powder), which decreased the amount of silicone-based liquid water repellent mixed therein, and increased the amount of metal salt-based stearate, resulting in a decrease in air volume and mortar It is judged that the stearate is filled inside as a filler, and in the case of Example 4 (P6L1), it is considered that it does not affect the decrease in compressive strength because the mixed silicone-based liquid water repellent is very small.

Figure 2 shows the SEM image of the water repellent-free mortar test body and the test body mixed with the organic silicone-based liquid water repellent agent, Figure 3 shows the SEM & EDS analysis results of the test body mixed with the organic silicone-based liquid water repellent agent.

As shown in FIGS. 2 and 3, microcracks were confirmed on the surface of the test specimen containing the organic silicon-based liquid water repellent compared to the water repellent-free mortar specimen, and the bonding surface of fine aggregate and cement paste, which was judged to be the cause of the decrease in compressive strength. As a result of (ITZ) analysis, it was measured that the Si content in the ITZ (The Interfacial Transition Zone) part was about 6 times higher than that of the water repellent-free mortar test specimen. It is judged that the compressive strength is greatly reduced due to these two causes.

<Change in water absorption per unit area due to mixing of water repellent>

4 is a graph showing the amount of water absorption per unit area over time of the test specimens according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention.

Referring to FIG. 4 , it was found that the water repellency performance of all the specimens except for Comparative Example 1 (OPC), which was a mortar-free mortar test body, was excellent. Specifically, in the case of Comparative Example 1 (OPC), the water absorption per area continuously increased over time, and after 6 hours, the water absorption per area was 1.394 kg/m ² . In the case of Comparative Example 2 (Powder), which is a test body containing an inorganic metal salt-based water repellent, it is 0.12 kg/m ² , which is 92% less than Comparative Example 1 (OPC). was not found to be absorbed.

And, in the case of the test body incorporating the organic/inorganic composite water repellent agent, it was found that the water absorption per area was large in the order of Example 4 (P6L1) > Example 3 (P5L1) > Example 2 (P4L1) > Example 1 (P3L1). , This is considered to be the result of the decrease in the amount of the organic silicone-based liquid water repellent (silane-siloxane water repellent) with excellent water repellency according to the mixing ratio. Example 4 (P6L1), which had the lowest water-repellent performance among the specimens containing the organic-inorganic composite water repellent, showed 0.072 kg/m ² , 95% less than Comparative Example 1, which is a mortar test without mixing of a water repellent, and showed an inorganic metal salt-based powder-type water repellent. It was confirmed that it was 40% less than that of Comparative Example 2 (Powder), which is a test body in which . All of the specimens containing the organic/inorganic composite water repellent agent (Examples 1 to 4) showed higher water repellency than the specimens containing the inorganic metal salt-based powder-type water repellent agent (Comparative Example 2).

[Table 5] below shows the water absorption coefficients over time of the test specimens according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention.

Referring to [Table 5] above, the water absorption coefficient was also found to converge to 0 regardless of the lapse of time for all specimens except Comparative Example 1 (OPC), which is a water repellent-free mortar test body. Specifically, Comparative Example 2 (Powder), a test body containing an inorganic metal salt-based powder-type water repellent, showed a constant water absorption coefficient of about 0.06, and Comparative Example 3 (Liquid), a test body containing an organic silicone-based liquid water repellent, showed water The absorption coefficient was found to be 0.

And, the water absorption coefficient of the test specimens (Examples 1 to 4) incorporating the organic/inorganic composite water repellent also showed the same tendency as the water absorption per area, and in the case of Example 4 (P6L1), the water absorption coefficient was different from other examples. About 0.03 showed some absorption performance. Therefore, the ratio of Example 3 (P5L1) (mixing ratio of the inorganic metal salt-based powder water repellent and the organic silicon-based liquid water repellent agent) is determined to be the minimum limit of the organic-inorganic composite water repellent agent.

5 shows a 500-fold magnified SEM image of the surface of the water repellent-free mortar test body and the inorganic metal salt-based powder-type water repellent mixed, and FIG. The SEM image of the surface of the magnified 10,000 times is shown.

5 and 6, it was confirmed that the waxy material was coated over the entire surface of the test body containing the inorganic metal salt-based powder-type water repellent differently from the surface of the water repellent-free mortar test body, and it was magnified 10,000 times. , it was confirmed that a waxy material was coated on the surface of the cement hydration product. It is judged that the water repellency effect is exhibited from the inside and the outside by the coating layer formed on the surface of the cement hydrate, and the size of the water repellency is adjusted by the mixing ratio of the organic silicone liquid water repellent (silane-siloxane water repellent) test specimen with strong water repellency. It is considered that the water repellency decreases as the mixing ratio of the powder water repellent increases.

<Result of chloride penetration resistance test>

7 is a graph showing the amount of passing charge for the test specimens according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention.

Referring to FIG. 7 , compared to Comparative Example 1 (OPC), which is a water repellent-free mortar test body, it was found that the amount of passing charge in all specimens decreased according to the incorporation of the water repellent agent. In the case of Comparative Example 2 (Powder), which is an inorganic metal salt-based powder-type water repellent mixing test body, and Comparative Example 3 (Liquid), which is an organic silicon-based liquid water repellent mixing test body, it was about 7007 and 5864 coulomb, which were 48% and 56% lower than Comparative Example 1 (OPC). appear.

And, in the case of Examples 1 to 4, which are organic/inorganic composite water repellent mixing test specimens, it was about 45% lower than Comparative Example 1 (OPC) with an average of about 7300 coulomb. In particular, in the case of Example 1 (P3L1), it was shown to be about 6807 coulomb, which is 3% lower than that of Comparative Example 2 (Powder). However, in the case of Examples 1 to 4, which are organic/inorganic composite water repellent mixing test bodies, the same water absorption coefficient as Comparative Example 3 (Liquid), which is an organic silicon-based liquid water repellent mixing test body, was expected, and a low passing charge was expected, but Example 2 (P4L1) and implementation In the case of the test specimen of Example 3 (P5L1), about 7020 and 7699 coulomb, which were 20% and 30% higher than those of Comparative Example 3 (Liquid), it was confirmed that the amount of passing charge was higher than expected.

[Table 6] below shows the average of the chloride penetration depth shown by spraying the silver nitrate solution after the chloride penetration resistance test was completed for the test specimens according to Examples 1 to 4 and Comparative Examples 1 to 3 of the present invention.

Referring to [Table 6] above, the chloride penetration depth also showed that the chloride penetration depth was generally low in the specimens containing the water repellent agent. In the case of Comparative Example 3 (Liquid), which is an organic silicon-based liquid water repellent mixing test body, it showed the lowest penetration depth of 21.77 mm, and in Comparative Example 2 (Powder), which is an inorganic metal salt powder type water repellent mixing test body, about 5 mm higher than that of 26.47 showed

And, in the case of Examples 1 to 4, which are organic/inorganic composite water repellent mixing test specimens, Example 2 (P4L1) and Example 3 (P5L1) exhibited relatively high penetration depths of 26.42 and 27.25 mm, respectively, which were caused by the water repellent material. It is judged that it is caused by the micropores inside the specimen and the chemical reaction inside, and it is considered that additional research is needed.

4. Conclusion

In order to solve problems such as an increase in air volume and a decrease in compressive strength when an organic silicone-based liquid water repellent (silane-siloxane water-based water repellent) is mixed with a cementitious material, an organic/inorganic composite water repellent (inorganic metal salt-based powder water repellent and organic silicone liquid water repellent) As a result of evaluating the physical performance and water repellency of the mortar mixed), the following conclusions were obtained.

1) In the case of Comparative Example 3 (Liquid), which is a test body containing an organic silicone liquid water repellent, the compressive strength of the mortar at 28 days of age is 42% compared to Comparative Example 1 (OPC), which is a test body without water repellent agent. It is considered that hydrophobic substances such as silane-siloxane delayed cement hydration reaction in the transition zone (ITZ) of fine aggregates. However, in Comparative Example 2 (Powder), which is an inorganic metal salt-based powder-type water repellent mixing test body, and Example 3 (P5L1) and Example 4 (P6L1) among the organic/inorganic composite water repellent mixing test bodies, the 28-day compressive strength was Comparative Example 1 (OPC) was about 97%, and there was little decrease in compressive strength.

2) Due to the excellent water repellency performance of the organic silicone liquid water repellent (silane-siloxane water repellent), the organic/inorganic composite water repellent test specimens (Examples 1 to 4) containing the organic silicone liquid water repellent agent had a water absorption coefficient and water absorption area of almost 0. In particular, in the range of this experiment, it was confirmed that the water repellency performance of the mortar was very excellent at a mixing ratio of 5:1 or less of the inorganic metal salt-based powder-type water repellent and the organic silicon-based liquid water repellent agent.

3) Comparative Example 3 (Liquid), which is an organic silicon-based liquid water repellent mixing test body, increased air volume and flow with entrained air when mixed inside, but Comparative Example 2 (Powder), an inorganic metal salt-based powder water repellent mixing test body, was stear It is determined that the rate fills the micropores and reduces the amount of air. And Examples 1 to 4 in which the organic/inorganic composite water repellent was mixed had the effect of reducing the flow by about 10% and the amount of air by about 50% compared to Comparative Example 3 (Liquid).

4) The amount of passing charge indicating the chloride penetration resistance of the organic/inorganic composite water repellent mixing test specimens (Examples 1 to 4) was an average of 7300 coulomb, which was about 45% lower than that of 13,432 couloumb of Comparative Example 1 (OPC), which was lower than that of organic matter It is judged by the water-repellent performance of the silicone-based liquid water repellent and the filling effect of the inorganic metal salt-based powder water repellent.

5) Summarizing the above experiments, the organic-inorganic composite water repellent according to Example 3 (P5L1), in which an inorganic metal salt-based powder water repellent and an organic silicon-based liquid water repellent were mixed in a ratio of 5: 1, prevented a decrease in compressive strength and secured water repellency performance. considered to be the most reasonable and effective for

In conclusion, according to the examples of the present invention and the test results thereof, in the mortar/concrete composition, an organic silicon-based liquid water repellent and an inorganic metal salt-based powder water repellent are mixed and used, but the organic silicone liquid water repellent is a silane-siloxane water repellent agent. So, when the inorganic metal salt-based powder-type water repellent is applied as a stearate powder-type water repellent mixed with calcium stearate and zinc stearate, the inorganic metal salt-based powder-type water repellent and the organic silicon-based liquid water repellent (solid content) are 3 to 6: 1 By mixing in a weight ratio (most preferably 5: 1 weight ratio), the water repellency performance to prevent the deterioration factor from penetrating into the concrete is ensured, while increasing the amount of air generated from the existing water repellent agent, reducing the compressive strength, etc. can solve

The present invention is not limited to the above-described embodiments, and it is apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, it should be said that such modifications or variations shall fall within the scope of the claims of the present invention.

Claims (10)

In the repair mortar composition used for repair work on a concrete structure in which deterioration has occurred,
A mortar composition using an organic-inorganic composite water repellent, comprising cement, fine aggregate, inorganic metal salt-based powder-type water repellent, and organic silicon-based liquid water repellent.
According to claim 1,
The inorganic metal salt-based powder-type water repellent is provided as a stearate powder-type water repellent,
The organic silicone-based liquid water repellent is a silane-siloxane mortar composition using an organic-inorganic composite water repellent, characterized in that provided as an aqueous water repellent.
3. The method of claim 2,
The sterarate powder-type water repellent includes calcium stearate and zinc stearate, wherein the calcium stearate and the zinc stearate are mixed in a weight ratio of 9.5 to 8.5: 0.5 to 1.5 by weight. mortar composition.
3. The method of claim 2,
The silane-siloxane mortar composition using an organic-inorganic composite water repellent, characterized in that the solid content of the aqueous water repellent is 40 to 60% by weight.
5. The method according to any one of claims 1 to 4,
The inorganic metal salt-based powder-type water repellent agent and the organic silicon-based liquid water repellent agent (based on solid content) are 3 to 6: A mortar composition using an organic-inorganic composite water repellent, characterized in that it is mixed in a weight ratio.
6. The method of claim 5,
The organic/inorganic composite water repellent comprising the inorganic metal salt-based powder water repellent and the organic silicon-based liquid water repellent (based on solid content) is blended in an amount of 1 to 3% by weight based on 100% by weight of the cement. Mortar using an organic/inorganic composite water repellent composition.
7. The method of claim 6,
The inorganic metal salt-based powder-type water repellent is mixed with the cement and dry bibim,
The organic silicon-based liquid water repellent is a mortar composition using an organic-inorganic composite water repellent, characterized in that it is mixed with the fine aggregate after the cement paste is manufactured.
In the concrete composition for expressing the water repellency performance inside the concrete,
A concrete composition using an organic-inorganic composite water repellent, comprising cement, fine aggregate, coarse aggregate, inorganic metal salt-based powder-type water repellent, and organic silicon-based liquid water repellent.
9. The method of claim 8,
The inorganic metal salt-based powder-type water repellent is provided as a stearate powder-type water repellent,
The organic silicone-based liquid water repellent is provided as a silane-siloxane water repellent,
The sterarate powder-type water repellent includes calcium stearate and zinc stearate, wherein the calcium stearate and the zinc stearate are mixed in a weight ratio of 9.5 to 8.5: 0.5 to 1.5 by weight. concrete composition.
10. The method according to claim 8 or 9,
The inorganic metal salt-based powder-type water repellent agent and the organic silicone-based liquid water repellent agent (based on solid content) are 3 to 6: Concrete composition using an organic-inorganic composite water repellent, characterized in that it is mixed in a weight ratio of 1.

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