TW201720781A - Permeable crystalline type self-healing cement-based waterproof coating achieving the waterproof effect of self-healing and permanent recycling - Google Patents

Abstract

This invention relates to a permeable crystalline type self-healing cement-based waterproof coating comprising 76wt% of cement, 10wt% of quartz sand and 14wt% of a crystallizing agent, wherein the crystallizing agent comprises 1.85wt% to 4.53wt% of an inorganic chelating agent, 2.47wt% to 7.82wt% of a crystallization precipitant, 3.09wt% to 8.44wt% of a complexing aid, and 1.24wt% to 6.59wt% of an additive. The waterproof coating of this invention can be crystallized to plug a crack as water permeates into the crack whenever a cement base generates the crack, so as to achieve the waterproofeffect of self-healing and permanent recycling .

Description

Penetrating crystalline self-healing cement-based waterproof coating

The present invention relates to a waterproof coating; more specifically, a permeable crystalline self-healing cement-based waterproof coating which, when a crack occurs in a cement base, forms crystals as water penetrates into the crack. Sealing cracks to achieve self-healing permanent circulation waterproofing effect.

Taiwan is surrounded by the sea and is located in the seismic zone. Concrete or brick walls are subject to vibrations, which can cause cracks of different sizes, so that external harmful ions and moisture can easily penetrate into the concrete along the pores or micro-infiltration, resulting in wall cancer and water leakage. Neutralization and deterioration of mold growth, in order to find effective and can solve the problem of water leakage in buildings, in the prior art, the common methods to solve water leakage are nothing more than: (1) destroying the hole: destroying the source of water leakage and making up New concrete; (2) Water-stopping needle: Epoxy resin (EPOXY) or Polyurethane (PU) foaming agent is injected into the crack.

However, the above two methods belong to the method of reinforcing and stopping the leak afterwards, and the effect of stopping leakage and subsequent prevention of moisture penetration is limited. Therefore, in order to improve the waterproof ability of the concrete itself, it is usually added with pozzolanic materials to increase the compactness, or further apply a waterproof coating on the concrete surface in advance, and common waterproof coating materials such as polyurethane (Polyurethane) , PU) and epoxy resin (EPOXY) chemical resin, rubberized asphalt, etc., which do not react with concrete. However, such a treatment method requires a long construction time and requires professionals and professional equipment. The waterproof effect is easily affected by the external environment, and the waterproof effect is lost even if the surface of the waterproof coating is scratched or worn.

In order to solve the above problems, the patent document (Taiwan Patent Publication No. 201100606 "Concrete seamless surface layering method and structure thereof") describes the use of a permeable hardener to solve the problem of waterproofing of concrete, mainly in the concrete surface layer. The osmotic hardener is coated on the crack, and the osmotic hardener penetrates into the crack and is combined with calcium hydroxide (Ca(OH) ₂ ) (slaked lime) in the concrete via the osmotic hardener (ie, the Possolan reaction). Calcium Silicate Hydrate Gel (CSH), which is used to heal the cracks in the concrete surface layer and strengthen the structural strength of the surface of the concrete surface layer. However, this document is effective in solving the problem of waterproofing of concrete by using osmotic hardener, but the total amount of such osmotic hardener is limited, and as the corsolan reaction proceeds, the active ions in the osmotic hardener gradually When the consumption is exhausted, the concentration is less and less, and the reaction is exhausted. If the concrete has micro-cracks, micropores and other defects, the active substance can no longer react with Ca ²⁺ ions and form insoluble crystals. Loss of its waterproof effect. On the other hand, Ca ²⁺ ions easily react with cement, so that a large amount of active ions in the cement are inefficiently consumed, which inevitably affects the effect of reactive ions infiltrating into the interior of the concrete.

In view of the above, it is necessary to provide a self-healing cement-based waterproof coating of osmotic crystallization type, and when the cement base is cracked, the active material will penetrate into the crack by water to form crystals to block the crack by water. And the active substance is not consumed as the crystalline substance is formed, and the self-healing permanent circulation waterproofing is achieved. Efficacy, to solve the above problems.

The main object of the present invention is to provide a permeable crystalline self-healing cement-based waterproof coating. When a crack occurs in a cement base, the active material permeates through the water and penetrates into the crack with a crystallization agent to form crystals to block the crack. And the active material is not consumed as the crystalline material is formed, and the self-healing permanent circulation waterproofing effect is achieved.

In order to achieve the above object, the present invention provides a permeable crystalline self-healing cement-based waterproof coating comprising 76% by weight of cement, 10% by weight of quartz sand and 14% by weight of a crystallization agent, and 14% by weight of the crystallization agent comprises an inorganic chelating agent. 1.85~4.53wt%, the crystal precipitation agent is 2.47~7.82wt%, the complexing aid is 3.09~8.44wt%, and the auxiliary agent is 1.24~6.59wt%.

Wherein the inorganic chelating agent is an active substance selected from at least one of sodium tripolyphosphate, citric acid, aluminum stearate, ethylenediaminetetraacetic acid (EDTA), tartaric acid, sodium citrate, triethanolamine and sodium gluconate. combination. The crystal precipitation agent is selected from the group consisting of magnesium ruthenate, sodium aluminate, potassium aluminate, calcium citrate, potassium citrate, lithium niobate, sodium citrate and cerium oxide. The complexing agent is selected from at least one combination of sodium carbonate, calcium carbonate, potassium carbonate, lithium carbonate, aluminum sulfate, sodium hydrogencarbonate, and magnesium carbonate. The adjuvant is selected from the group consisting of potassium hydroxide, sodium hydroxide, hydrazine hydroxide, potassium oxide, sodium oxide, calcium oxide, and magnesium oxide.

The invention is characterized in that the waterproof coating can be applied to the cement base surface as a waterproof layer, and when the cement base is cracked, the inorganic chelating agent penetrates into the cement base by the crystallization agent through water and It reacts with the cement-based product to form a water-impermeable crystalline material, thereby sealing the crack and waterproofing. In addition, the waterproof coating The inorganic chelating agent does not deplete with the reaction, so even if a new crack occurs, the inorganic chelating agent that is not consumed by the reaction will bring the crystallizing agent into the new crack and the cement-based product. The reaction is carried out to form a water-impermeable crystalline material, thereby blocking new cracks.

Therefore, in the waterproof coating of the present invention, the inorganic chelating agent penetrates into the crack by water to form crystals to block cracks when the cement base is cracked, and the inorganic chelating agent does not crystallize. It is consumed by the formation of substances, so as to achieve the effect of self-healing permanent circulation waterproofing.

1a is a crystal diagram of a concrete sample to which the waterproof coating of the present invention is not applied; FIG. 1b is a crystal diagram of a concrete sample coated with the waterproof coating of the present invention at a depth of 1 cm; and FIG. 2 is a water-repellent coating to which the present invention is applied. The crystal specimen of the concrete specimen at a depth of 2 cm; FIG. 3 is a crystal diagram of the concrete specimen having the waterproof coating of the present invention at a depth of 3 cm; and FIG. 4 is a concrete specimen having the waterproof coating of the invention applied to the depth a crystallographic view at 4 cm; Fig. 5 is a crystallographic view of a concrete sample coated with the waterproof coating of the present invention at a depth of 5 cm; and Fig. 6 is an EDS diagram of the waterproof coating of the present invention at a crystallization point; and Fig. 7 is a view of the present invention The EDS diagram of the waterproof coating at the non-crystalline surface.

The osmotic crystalline self-healing cement-based waterproof coating of the present invention comprises 76% by weight of cement, 10% by weight of quartz sand and 14% by weight of a crystallization agent, and 14% by weight of the crystallization agent comprises an inorganic chelating agent (ie, an active substance). It is 1.85~4.53wt%, the crystal precipitation agent is 2.47~7.82wt%, the complexing aid is 3.09~8.44wt%, and the auxiliary agent is 1.24~6.59wt%. Wherein the inorganic chelating agent is an active substance selected from at least one of sodium tripolyphosphate, citric acid, aluminum stearate, ethylenediaminetetraacetic acid (EDTA), tartaric acid, sodium citrate, triethanolamine and sodium gluconate. In combination, the crystal precipitation agent is selected from the group consisting of magnesium citrate, sodium aluminate, potassium aluminate, calcium citrate, potassium citrate, lithium niobate, sodium citrate and cerium oxide. The agent is selected from the group consisting of sodium carbonate, calcium carbonate, potassium carbonate, lithium carbonate, aluminum sulfate, sodium hydrogencarbonate and magnesium carbonate. The auxiliary agent is selected from the group consisting of potassium hydroxide, sodium hydroxide, hydrogen peroxide, and oxidation. At least one of potassium, sodium oxide, calcium oxide and magnesium oxide is combined.

The film-forming substance of the waterproof material is mainly cement. The quartz sand is mainly considering the drying and shrinking of the coating and is beneficial to the coating and spraying of the coating. The active material is mainly used to penetrate into the interior of the cement base with a crystallization agent to form a crystallized core. The crystal precipitation agent is mainly used to help crystal precipitation. The complexing aid is mainly used to effectively combine the active material with the crystalline precipitating agent. The additive is mainly used to subsidize the lack of crystal precipitation agent for the waterproof coating.

The osmotic crystalline self-healing cement-based waterproof coating of the present invention is mainly applied to a cement base surface as a waterproof layer, and when the cement base is cracked, the active material of the waterproof coating (ie, an inorganic chelating agent) The crystallizing agent is infiltrated into the interior of the cement base by water and reacts with the product in the cement matrix to form an impervious crystalline material, thereby sealing the crack waterproof.

When the crystallizing agent reacts with the cement-based product to form a water-impermeable crystalline material, the active material does not be depleted with the reaction, so even if a new crack occurs, the active material carries the active substance. The crystallization agent penetrates into the new crack, causing the crystallization agent to react with the cement-based internal product to form a water-impermeable crystalline material, thereby blocking new cracks.

It can be seen from the above that the waterproof coating of the present invention can penetrate the crack into the crack along with water to form a crystal to block the crack with the water when the cement base is cracked, and the active material does not follow It is consumed by the formation of crystals, thereby achieving the effect of self-healing permanent circulation waterproofing.

The invention performs a setting time test, a compressive strength test, a water permeability depth test, an impermeability level test and a microscopic test on a test piece of a permeable crystalline self-healing cement-based waterproof paint.

Before the tests were carried out, the condensation time test was carried out using the CNS 786 hydraulic cement setting time test method (Fei's needle method). During the experiment, the experiment was carried out under normal temperature conditions and kept without wind. The test method of time, it is expected that the condensation time can be up to 600min. The compressive strength test refers to the sixth section of the compressive strength of the penetrating waterproof coating of the cement machine GB18445 cement machine in 28 days and can not be less than 15MPa as a test index. The permeable depth test is conducted by the German standard DIN1048 concrete and reinforced concrete structure water permeability test, the maximum penetration depth of the test water mark (test group / control group 28 days) 85%, both qualified. The impermeability grade test refers to the concrete impermeability of section 7.3.6 of the cement-based permeable crystalline waterproof material of the continental standard GB18445. The test pressure increases from 0.1 MPa to 0.1 MPa every eight hours, up to 1.2 MPa, and the impermeability pressure ratio (There is paint concrete ÷ no paint concrete × 100%) ≧ 250%.

In the setting time test, the test ratio and test results of the test body are shown in Table 1 below. According to the test results of the test ratio (T1~T12), the setting time is within 600 min.

In the compressive strength test, the compressive strength test is carried out using a universal testing machine as follows:

(1) The mixing environment test temperature is 20±2°C, and the relative humidity cannot be lower than 50%.

(2) Refer to the mechanical mixing method of CNS3655 hydraulic cement and viscous cement and concrete, the test body is 40X40X160mm.

(3) Carrying out the pressure test after curing to the specified number of days.

The test ratio and test results of the test body are shown in Table 2 below. Test results of the test ratio, the compressive strength is consistent with the test index of compressive strength greater than 15 MPa.

In the permeable depth test, the current permeable water is tested by two tests, namely the water permeable test of positive water pressure and negative water pressure. The permeable test of the present invention is positive water pressure, that is, test from the paint surface, using permeable water. The test can show the waterproof performance of the coating. The smaller the permeable depth, the better the waterproof performance. It is expected that the permeable depth ratio (the permeable depth of the paint concrete ÷ the depth of the permeable concrete without paint concrete × 100%) is 75%.

The method of the permeable depth test is as follows:

(1) The ambient temperature is 23 ± 2 °C.

(2) Refer to the specification CNS1230 laboratory concrete sample preparation and maintenance method, the sample size is ψ15×12cm.

(3) Soaking water for one day after demolding the specimen.

(4) After taking out, the test body is dried to saturation in the surface.

(5) Apply the paint at a dosage of 0.8 kg/m ³ , and let it stand for one day after application.

(6) The test body is cured, and the surface of the paint is not exposed to water. Therefore, the test body is immersed in water at a depth of about 2/3, and the upper paint surface is covered with a damp cloth for curing.

(7) After the age is reached, the test body is taken out and air-dried.

(8) Scrap the surface coating of the test piece clean.

(9) Apply epoxy resin to the side of the test piece until the epoxy resin is dried.

(10) Place the test piece on the top of the water permeable instrument, clamp the test piece, adjust the water pressure to 5 Bar water pressure, take it out after three days, and split the test piece to measure the water penetration depth.

Table 3 below is an experimental comparison of the water permeability of waterproof coatings. The main purpose is to evaluate the ability of the surface of the concrete to seal the waterproof crystalline coating to resist the entry of external water molecules into the sample. It can be found that the concrete sample (control group) to which the waterproof coating of the present invention is not applied has an average water permeation depth of 4 cm, and the concrete (test group) of the self-penetrating cement-based waterproof coating of the permeated crystalline type of the present invention has an average water permeability depth. It is only 1.0-3.0cm, which is consistent with the permeable depth ratio (the permeable depth of paint concrete, the permeable depth of paint concrete × 100%) is 75%.

In the impermeability class test, the method is as follows:

(1) The ambient temperature is 23 ± 2 °C.

(2) Refer to the CNS1230 laboratory test room preparation and maintenance method. The sample size is 17.5cm in diameter, 18.5cm in diameter and 14.5cm in height.

(3) Soaking water for one day after demolding the specimen.

(4) After taking out, the test body is dried to saturation in the surface.

(5) Apply the paint at a dosage of 0.8 kg/m ³ , and let it stand for one day after application.

(6) The test body is cured, and the surface of the paint is not exposed to water. Therefore, the test body is immersed in water at a depth of about 2/3, and the upper paint surface is covered with a damp cloth for curing.

(7) After the age is reached, the test body is taken out and air-dried.

(8) Scrap the surface coating of the test piece clean.

(9) Apply rosin and paraffin (mass ratio 1:3) to the side of the test piece and insert it into the test phantom.

(10) Place the test piece on the negative pressure gauge and lock the bolt. The water pressure starts from 0.1 MPa and increases by 0.1 MPa every eight hours until a third test piece of the six test pieces reveals water. Data, the data minus 0.1 MPa is both the impermeability rating of the test group.

The test ratio and test results of the test body are shown in Table 4 below. According to the test results of the test ratio (T01~T06), all of them meet the impermeability pressure ratio (with paint concrete ÷ no paint concrete × 100%). Test indicators.

In the microscopic test, the water-repellent coating sample was prepared by using the ratio of the impermeability pressure of the self-healing cement-based waterproof coating of the osmotic crystalline type of Table 4 to 300%, and the waterproof coating sample was applied thereto. On the concrete specimen. The concrete test system is prepared by mixing cement 250 (kg/m ³ ), coarse aggregate 1110 (kg/m ³ ), 832.5 fine aggregate (kg/m ³ ) and water 187.5 (kg/m ³ ). The cement is a brand cement produced by Taiwan Cement Co., Ltd. It is a first type cement with a fineness of 368.8m ² /kg and a specific gravity of 3.05. Its chemical composition is mainly composed of cerium oxide (SiO ₂ ) and calcium oxide (CaO). And oxides such as alumina (Al ₂ O ₃ ) and iron oxide (Fe ₂ O ₃ ), the proportion of which accounts for more than 95% of the total composition, of which CaO accounts for about 60% to 70%, SiO ₂ About 18% to 25%, Al ₂ O ₃ accounts for 4% to 6%, and Fe ₂ O ₃ accounts for 3% to 5%. The remaining components include about 1 to 5% of metal oxides such as magnesium oxide (MgO), potassium oxide (K ₂ O), and sodium oxide (Na ₂ O). The coarse aggregate is a general gravel having a specific gravity of 2.63 and an FM of 1.73. The fine aggregate is natural river sand with a specific gravity of 2.66 and a fineness modulus (FM) of 2.92. The water is generally tap water.

The manufacturing conditions and microscopic test methods of the concrete specimen are as follows:

(1) The ambient temperature is 23 ± 2 °C.

(2) Refer to the CNS1230 laboratory test room preparation and maintenance method, the concrete sample size is ψ 5 × 10cm.

(3) Soaking water for one day after the concrete specimen is demolded.

(4) After taking out, the concrete sample is dried to saturation in the surface.

(5) Apply the paint at a dosage of 0.8 kg/m ³ , and let it stand for one day after application.

(6) The concrete specimen is cured, and the surface of the paint is not exposed to water. Therefore, the concrete specimen is immersed in water at a depth of about 2/3, and the upper coating surface is covered with a damp cloth for curing.

(7) After the arrival of the age, a 1 cm thick sheet was cut with a concrete cutter to a depth of 1 to 5 cm.

After cutting the sheet, the scanning electron microscope additional energy dispersive spectrometer is used for microscopic analysis, and the magnification is adjusted to about x1000, x3000, and x5000.

Fig. 1a is a crystallographic view of a concrete test body to which the waterproof paint of the present invention is not applied, and Fig. 1b is a crystal view of a concrete test body to which the waterproof paint of the present invention is applied at a depth of 1 cm.

Referring to FIG. 1a and FIG. 1b, it can be seen from FIG. 1a that the concrete sample without the waterproof coating of the present invention is not found to have crystals generated inside, and the concrete coated with the waterproof coating of the present invention can be seen from FIG. 1b. For the test piece, the waterproof coating of the present invention was found at 1 cm, and a crystalline substance was found in the pores.

2 is a crystal diagram of a concrete specimen having a waterproof coating of the present invention at a depth of 2 cm, and FIG. 3 is a crystal diagram of a concrete specimen having a waterproof coating of the present invention at a depth of 3 cm, and FIG. 4 is a smear. Invented waterproof coating The concrete sample of the material was crystallized at a depth of 4 cm, and Fig. 5 is a crystal diagram of the concrete sample coated with the waterproof coating of the present invention at a depth of 5 cm.

It can be seen from Fig. 2, Fig. 3, Fig. 4 and Fig. 5 that the concrete sample coated with the waterproof coating of the present invention can still be found at 2 cm, 3 cm, 4 cm or even 5 cm, and with depth, with depth The deeper the crystal is, the finer the crystal is. Therefore, it proves that the waterproof coating of the present invention will crystallize inside the concrete to cause clogging of the pores, so that the crystallizing agent in the coating cannot enter the inside again, thereby generating complete crystals, if new cracks are generated. The crystallization agent of the present invention can again enter the interior of the concrete to produce insoluble water needle crystals inside the concrete.

Figure 6 is an EDS diagram of the water-repellent coating of the present invention at the crystallization point, and Figure 7 is an EDS diagram of the water-repellent coating of the present invention at a non-crystalline point. Since the general concrete is analyzed by the Energy Dispersive Spectrometer (EDS), the active material component of the present invention is not analyzed. Therefore, if the active material of the present invention is found inside the concrete, the outer coating film penetrates and infiltrates. Into the inside, so the crystal composition at the crystallization point can be seen from Fig. 6, and it can be seen from Fig. 7 that the presence of phosphorus (P) can be found in the amorphous portion, which proves that the waterproof coating of the present invention can penetrate into the concrete interior by itself, and concrete. Internal growth of crystals, sealing pores, to achieve waterproof effect.

In the above, it is merely described that the present invention is an embodiment or an embodiment of the technical means for solving the problem, and is not intended to limit the scope of implementation of the present invention. That is, the equivalent changes and modifications made in accordance with the scope of the patent application of the present invention or the scope of the invention are covered by the scope of the invention.

Claims (9)

The invention relates to a self-healing cement-based waterproof coating with osmotic crystallization type, which comprises 76wt% cement, 10wt% quartz sand and 14wt% of crystallization agent, and 14wt% of the crystallization agent comprises 1.85~4.53wt% of inorganic chelating agent, crystal precipitation agent It is 2.47~7.82wt%, the complexing aid is 3.09~8.44wt%, and the auxiliary agent is 1.24~6.59wt%. The osmotic crystalline self-healing cement-based waterproof coating according to claim 1, wherein the inorganic chelating agent is selected from the group consisting of sodium tripolyphosphate, citric acid, aluminum stearate, ethylenediaminetetraacetic acid (EDTA), tartaric acid, At least one of sodium citrate, triethanolamine, and sodium gluconate is combined. The osmotic crystalline self-healing cement-based waterproof coating according to claim 1, wherein the crystal precipitation agent is selected from the group consisting of magnesium citrate, sodium aluminate, potassium aluminate, calcium citrate, potassium citrate, lithium niobate. At least one of sodium citrate and cerium oxide is combined. The osmotic crystalline self-healing cement-based waterproof coating according to claim 1, wherein the complexing agent is selected from the group consisting of sodium carbonate, calcium carbonate, potassium carbonate, lithium carbonate, aluminum sulfate, sodium hydrogencarbonate and magnesium carbonate. At least one combination. The self-healing cement-based waterproof coating according to claim 1, wherein the auxiliary agent is selected from the group consisting of potassium hydroxide, sodium hydroxide, hydrogen peroxide, potassium oxide, sodium oxide, calcium oxide and magnesium oxide. At least one combination. The self-healing cement-based waterproof coating of the osmotic crystalline type according to claim 1 has an impermeability pressure ratio of 250 to 300%. The self-healing cement-based waterproof coating of the osmotic crystalline type according to claim 1 has a compressive strength of 15.79 to 38.49 MPa. The self-healing cement-based waterproof coating of the osmotic crystalline type according to claim 1 has a setting time of 30 to 570 min. The self-healing cement-based waterproof coating of the osmotic crystalline type according to claim 1 has a water permeability depth ratio of 25 to 75%.