An anti-frost agent and a method for preventing efflorescence of clay bricks

Abstract

The present invention provides an anti-frost agent and a method for preventing efflorescence of clay bricks, which relates to the technical field of building material anti-frost. The anti-frost agent provided by the present invention includes separately packaged aluminum salts, water-based epoxy resin AB glue, and silane impregnating agent; the aluminum salts are inorganic aluminum salts. The aluminum salts can convert the highly soluble sodium sulfate in the clay bricks into sodium salts with lower solubility, making it impossible for them to migrate outwards, thereby preventing the efflorescence of clay bricks. Moreover, compared with organic protection materials, the inorganic aluminum salts have good durability and antioxidant properties, thereby endowing the anti-frost agent with good weather resistance; the water-based epoxy resin AB glue and the silane impregnating agent play a role in physical plugging, reducing the outward migration of salts and moisture, thereby preventing the efflorescence of clay bricks.

Description

Technical Field

[0001] The present invention relates to the technical field of building material frost prevention, and particularly relates to an antifrost agent and a method for preventing efflorescence of clay bricks. Background Art

[0002] In brick structures, soluble salts in clay bricks migrate outward and crystallize, forming a white frost-like substance on the surface of clay bricks. This phenomenon is called efflorescence. During the efflorescence process, under the action of the crystallization pressure of salts, bulging and peeling will occur on the wall surface. Therefore, efflorescence not only affects the appearance of the building but also is not conducive to the service performance of the building.

[0003] In the prior art, organic protective materials are mainly used to brush the surface of clay bricks to prevent efflorescence, mainly including silicone resins, acrylic resins, organofluorine resins, etc. Although these organic protective materials can weaken the occurrence of efflorescence to a certain extent, the antifrost effect still needs to be improved, and the weather resistance is insufficient. Summary of the Invention

[0004] The purpose of the present invention is to provide an antifrost agent and a method for preventing efflorescence of clay bricks. The antifrost agent of the present invention has a good antifrost effect on clay bricks and good weather resistance.

[0005] In order to achieve the above invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides an antifrost agent, which includes separately packaged aluminum salts, water-based epoxy resin AB glue, and silane impregnating agent; the aluminum salts are inorganic aluminum salts.

[0007] Preferably, the aluminum salts include aluminum chloride or aluminum nitrate.

[0008] Preferably, the silane impregnating agent contains isobutyltriethoxysilane.

[0009] Preferably, the mass content of isobutyltriethoxysilane in the silane impregnating agent is above 98%.

[0010] The present invention provides a method for preventing efflorescence of clay bricks, which uses the antifrost agent described in the above solution to treat clay bricks, including the following steps:

[0011] Dissolve the aluminum salts in water to obtain an aluminum salt aqueous solution;

[0012] Mix the A emulsion and B colloid in the water-based epoxy resin AB glue, and dissolve the obtained mixture in water to obtain a water-based epoxy resin AB glue aqueous solution;

[0013] Soak the clay bricks in the aluminum salt aqueous solution, the water-based epoxy resin AB glue aqueous solution, and the silane impregnating agent in sequence;

[0014] Alternatively, coat the surface of the clay brick with the aluminum salt aqueous solution, the waterborne epoxy resin AB glue solution, and the silane impregnating agent in sequence.

[0015] Preferably, when the treatment method for the clay brick is immersion, the mass concentration of the aluminum salt aqueous solution is 15-20%; when the treatment method for the clay brick is coating, the mass concentration of the aluminum salt aqueous solution is 7-10%.

[0016] Preferably, the mass content of the waterborne epoxy resin AB glue in the waterborne epoxy resin AB glue solution is 10-15%; the mass ratio of the A emulsion to the B colloid in the waterborne epoxy resin AB glue is 2:1.

[0017] Preferably, the immersion time is independently 0.5-1 h.

[0018] Preferably, the coating method includes brushing or spraying.

[0019] Preferably, the coating amount of the aluminum salt aqueous solution is 350 g / m 2 or more; the coating amount of the waterborne epoxy resin AB glue solution is 350 g / m 2 or more; the coating amount of the silane impregnating agent is 300 g / m 2 or more.

[0020] The present invention provides an anti-frost agent, which includes separately packaged aluminum salt, waterborne epoxy resin AB glue, and silane impregnating agent; the aluminum salt is an inorganic aluminum salt. In the present invention, the aluminum salt first forms hydrated ions in the aqueous solution, with H2O molecules as ligands, and generates complex ions through hydrolysis, and undergoes a complex reaction with the main component sodium sulfate causing efflorescence, making it unable to migrate out of the clay brick, thereby preventing the efflorescence of the clay brick. Moreover, the inorganic aluminum salt has good durability and antioxidant properties compared with organic protective materials, thereby endowing the anti-frost agent with good weather resistance; the waterborne epoxy resin AB glue can form a dense and firm polymer film, and the silane impregnating agent can form a waterproof film with the moisture on the surface of the clay brick to prevent moisture intrusion. The waterborne epoxy resin AB glue and the silane impregnating agent together play a role of physical plugging, which can reduce the outward migration of salts and moisture, thereby preventing the efflorescence of the clay brick.

[0021] The present invention provides a method for preventing the efflorescence of clay bricks. Treat the clay bricks with the anti-frost agent described in the above solution, including the following steps: dissolve the aluminum salt in water to obtain an aluminum salt aqueous solution; mix the A emulsion and the B colloid in the waterborne epoxy resin AB glue, and dissolve the obtained mixture in water to obtain a waterborne epoxy resin AB glue solution; immerse the clay bricks in the aluminum salt aqueous solution, the waterborne epoxy resin AB glue solution, and the silane impregnating agent in sequence; or coat the surface of the clay brick with the aluminum salt aqueous solution, the epoxy resin AB glue solution, and the silane impregnating agent in sequence.

[0022] In the present invention, the clay brick is first treated with an aluminum salt aqueous solution to convert the highly soluble sodium sulfate in the clay brick into a sodium salt with a lower solubility, so that it cannot migrate outwards, thereby preventing the efflorescence of the clay brick. Then, it is treated with an aqueous epoxy resin AB glue solution and a silane impregnating agent. The aqueous epoxy resin AB glue and the silane impregnating agent not only have the effect of physical blocking, which can reduce the outward migration of salts and moisture, but also can protect the inorganic aluminum salt. Even if the epoxy resin and the silane impregnating agent fail, the aluminum salt can still prevent the efflorescence of the clay brick.

[0023] In addition, in the present invention, the clay brick is first treated with an aqueous epoxy resin AB glue solution and then with a silane impregnating agent, which can prevent the formation of a waterproof layer after the treatment with the silane impregnating agent, resulting in the inability of the aqueous epoxy resin AB glue to penetrate into the clay brick. Description of the Drawings

[0024] Figure 1 Photograph of the efflorescence degree of the clay brick without using the anti-efflorescence agent;

[0025] Figure 2 Photograph of the efflorescence degree of the clay brick after being soaked in anti-efflorescence agent 1;

[0026] Figure 3 Photograph of the efflorescence degree of the clay brick after being soaked in anti-efflorescence agent 2;

[0027] Figure 4 Photograph of the efflorescence degree of the clay brick after being soaked in anti-efflorescence agent 3;

[0028] Figure 5 Photograph of the efflorescence degree of the clay brick after being soaked in anti-efflorescence agents 1, 2, and 3 in Example 1;

[0029] Figure 6 Photograph of the efflorescence degree of the clay brick after being soaked in anti-efflorescence agents 1, 2, and 3 in Example 2;

[0030] Figure 7 Photograph of the efflorescence degree of the clay brick after being soaked in anti-efflorescence agents 1, 2, and 3 in Example 3;

[0031] Figure 8 Photograph of the efflorescence degree of the clay brick after being painted with anti-efflorescence agent 1';

[0032] Figure 9 Photograph of the efflorescence degree of the clay brick after being painted with anti-efflorescence agent 2;

[0033] Figure 10 Photograph of the efflorescence degree of the clay brick after being painted with anti-efflorescence agent 3;

[0034] Figure 11 Photograph of the efflorescence degree of the clay brick after being painted with anti-efflorescence agents 1', 2, and 3 in Example 4;

[0035] Figure 12Photos of the efflorescence degree of clay bricks after applying anti-frost agents 1', 2, and 3 in Example 5;

[0036] Figure 13 Photos of the efflorescence degree of clay bricks after applying anti-frost agents 1', 2, and 3 in Example 6. Detailed implementation manners

[0037] The present invention provides an anti-frost agent, which includes separately packaged aluminum salts, water-based epoxy resin AB glue, and silane impregnating agent; the aluminum salts are inorganic aluminum salts.

[0038] In the present invention, unless otherwise specified, the raw materials used are all well-known commercially available products in the art.

[0039] In the present invention, the aluminum salts preferably include aluminum chloride or aluminum nitrate. In the present invention, the aluminum salts first form hydrated ions in an aqueous solution, with H2O molecules as ligands, and generate complex ions through hydrolysis. A complexation reaction occurs with sodium sulfate, the main component causing efflorescence, making it unable to migrate out of the clay bricks, thereby preventing the efflorescence of clay bricks. Moreover, inorganic aluminum salts have good durability and antioxidant properties compared with organic protection materials, thus imparting good weather resistance to the anti-frost agent.

[0040] In the present invention, the silane impregnating agent preferably contains isobutyltriethoxysilane; the mass content of isobutyltriethoxysilane in the silane impregnating agent is preferably above 98%. In the present invention, the silane impregnating agent is preferably purchased from Taobao, with the model JC-100 and the product name silane impregnating agent. In the present invention, isobutyltriethoxysilane has a small molecule structure and can chemically react with the moisture on the surface of the clay bricks to generate hydroxyl groups, forming a water-repellent treatment layer, thereby achieving the effect of waterproofing.

[0041] In the present invention, the water-based epoxy resin AB glue can form a dense and strong polymer film, and the silane impregnating agent can form a waterproof film with the moisture on the surface of the clay bricks to prevent moisture intrusion. The water-based epoxy resin AB glue and the silane impregnating agent jointly play a role of physical plugging, which can reduce the outward migration of salts and moisture, thereby preventing the efflorescence of clay bricks.

[0042] The present invention provides a method for preventing the efflorescence of clay bricks. The clay bricks are treated with the anti-frost agent described in the above solution, including the following steps:

[0043] Dissolve the aluminum salts in water to obtain an aluminum salt aqueous solution;

[0044] Mix the A emulsion and B colloid in the water-based epoxy resin AB glue, and dissolve the obtained mixture in water to obtain a water-based epoxy resin AB glue aqueous solution;

[0045] Soak the clay bricks successively in the aluminum salt aqueous solution, the water-based epoxy resin AB glue aqueous solution, and the silane impregnating agent.

[0046] The present invention dissolves an aluminum salt in water to obtain an aluminum salt aqueous solution. In the present invention, the water is preferably deionized water. Using deionized water in the present invention can avoid introducing other ions and prevent efflorescence of clay bricks.

[0047] In the present invention, the mass concentration of the aluminum salt aqueous solution is preferably 15-20%, more preferably 16-19%, and further preferably 17-18%.

[0048] The present invention mixes the A emulsion and the B colloid in the water-based epoxy resin AB glue, and dissolves the obtained mixture in water to obtain a water-based epoxy resin AB glue aqueous solution.

[0049] In the present invention, the mass content of the water-based epoxy resin AB glue in the water-based epoxy resin AB glue aqueous solution is preferably 10-15%, more preferably 11-14%, and further preferably 12-13%; the mass ratio of the A emulsion to the B colloid in the water-based epoxy resin AB glue is preferably 2:1.

[0050] After obtaining the aluminum salt aqueous solution, the water-based epoxy resin AB glue aqueous solution, and the silane impregnating agent, the present invention immerses the clay bricks in the aluminum salt aqueous solution, the water-based epoxy resin AB glue aqueous solution, and the silane impregnating agent in sequence.

[0051] The present invention has no special requirements for the clay bricks, and any clay bricks well-known in the art can be used.

[0052] Before immersing the clay bricks in the aluminum salt aqueous solution, the present invention preferably pre-treats the clay bricks first; the pre-treatment preferably includes: using a brush to remove the floating dust on the surface of the clay bricks, then rinsing with water, and then drying in a natural environment for 2-3 h. In the present invention, the rinsing water is preferably tap water. The present invention pre-treats the clay bricks to facilitate the subsequent rapid penetration of the anti-frost agent into the clay bricks.

[0053] The present invention has no special requirements for the dosages of the aluminum salt aqueous solution, the water-based epoxy resin AB glue aqueous solution, and the silane impregnating agent, as long as the clay bricks can be completely immersed.

[0054] In the present invention, the soaking time is independently preferably 0.5-1 h, more preferably 40-50 min. Before the next soaking, the present invention preferably dries the clay bricks soaked last time in natural conditions for 1-2 h. The present invention dries the clay bricks soaked last time in natural conditions before the next soaking, which is beneficial for the anti-frost agent to be more stable in the clay bricks.

[0055] After the soaking of the clay bricks in the silane impregnating agent is completed, the present invention preferably takes out the clay bricks and places them in a natural drying environment for drying for more than 24 hours.

[0056] The above method for preventing efflorescence of clay bricks is denoted as Method 1.

[0057] The present invention also provides another method for preventing efflorescence of clay bricks, denoted as Method 2, which includes the following steps: successively coating an aluminum salt aqueous solution, an aqueous epoxy resin AB glue solution, and a silane impregnating agent on the surface of the clay bricks.

[0058] Before coating the aluminum salt aqueous solution onto the surface of the clay bricks, the present invention preferably pre-treats the clay bricks first. The pre-treatment method is the same as that in Method 1 and will not be elaborated here.

[0059] In the present invention, when Method 2 is adopted, the mass concentration of the aluminum salt aqueous solution is preferably 7-10%, more preferably 7.5-9.5%, and further preferably 8-9%.

[0060] In the present invention, the coating method preferably includes brushing or spraying, and more preferably brushing.

[0061] In the present invention, the coating amount of the aluminum salt aqueous solution is preferably 350 g / m 2 or more; the coating amount of the aqueous epoxy resin AB glue solution is preferably 350 g / m 2 or more; the coating amount of the silane impregnating agent is preferably 300 g / m 2 or more.

[0062] In the present invention, the coatings of the aluminum salt aqueous solution, the aqueous epoxy resin AB glue solution, and the silane impregnating agent are all preferably repeatedly coated, and the number of repetitions is preferably 2-3 times. Taking 3 repetitions as an example, when performing 3 repeated coatings, successively coating the aluminum salt aqueous solution, the aqueous epoxy resin AB glue solution, and the silane impregnating agent on the surface of the clay bricks means first repeatedly coating the aluminum salt aqueous solution on the surface of the clay bricks 3 times, then repeatedly coating the aqueous epoxy resin AB glue solution on the surface of the clay bricks 3 times, and finally repeatedly coating the silane impregnating agent on the surface of the clay bricks 3 times.

[0063] In the present invention, the coating amount of the aluminum salt aqueous solution each time is independently preferably 350-400 g / m 2 , more preferably 360-390 g / m 2 , and further preferably 370-380 g / m 2 ; the coating amount of the aqueous epoxy resin AB glue solution each time is independently preferably 350-400 g / m 2 , more preferably 360-390 g / m 2 , and further preferably 370-380 g / m 2 ; the coating amount of the silane impregnating agent each time is independently 300-350 g / m 2, more preferably 310 - 340 g / m 2 , further preferably 320 - 330 g / m 2 .

[0064] Before the next coating, the present invention preferably places the clay bricks coated last time in a natural environment for drying to ensure that there is no free water on the surface of the clay bricks. In the present invention, specifically, the interval time between two adjacent coatings is controlled to be 3 - 20 min to ensure that there is no free water on the surface of the clay bricks.

[0065] In the present invention, the coating is preferably carried out in the order from left to right and from top to bottom on a single brick surface.

[0066] After the last coating is completed, the present invention preferably places the clay bricks in a natural drying environment for drying for more than 24 hours.

[0067] In the present invention, when the clay bricks exist in the form of bricks, the present invention preferably uses Method 1 to treat the clay bricks. At this time, the frost prevention effect after treatment by Method 1 is better than that of Method 2.

[0068] When the clay bricks exist in a brick structure, such as building an ancient building with clay bricks, the present invention preferably uses Method 2 to treat the clay bricks for convenient construction.

[0069] Whether it is Method 1 or Method 2, the present invention first uses an aluminum salt aqueous solution to treat the clay bricks, and then uses an aqueous epoxy resin AB glue solution and a silane impregnating agent to treat the clay bricks.

[0070] The present invention first uses an aluminum salt aqueous solution to treat the clay bricks, converting the highly soluble sodium sulfate in the clay bricks into a sodium salt with lower solubility, making it unable to migrate outwards, thereby preventing the efflorescence of the clay bricks; then uses an aqueous epoxy resin AB glue solution and a silane impregnating agent to treat. The aqueous epoxy resin AB glue and the silane impregnating agent not only have the function of physical blockage, reducing the outward migration of salts and moisture, but also can protect the inorganic aluminum salt. Even if the epoxy resin and the silane impregnating agent fail, the aluminum salt can still prevent the efflorescence of the clay bricks.

[0071] The present invention first uses an aqueous epoxy resin AB glue solution to treat, and then uses a silane impregnating agent to treat, which can prevent the formation of a waterproof layer after the treatment with the silane impregnating agent, resulting in the inability of the aqueous epoxy resin AB glue to penetrate into the clay bricks.

[0072] The following examples are used to illustrate in detail the anti - frosting agent and the method for preventing the efflorescence of clay bricks provided by the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0073] The experimental clay bricks used in Comparative Examples 1 - 4 and Examples 1 - 4:

[0074] To quickly evaluate the efflorescence characteristics of clay bricks before and after using anti-frost agents, a rapid efflorescence experiment was designed, that is, the clay bricks were pre-soaked in a salt solution to accelerate the occurrence of efflorescence. The salt solution used was a mixed solution with a mass fraction of 1% Na2SO4 and 0.2% CaSO4·2H2O. The clay bricks were soaked with the strip side down in the mixed solution for 6 h, during which the top surface of the clay bricks was 60 cm higher than the liquid level of the solution. The clay bricks were taken out and air-dried naturally for 1 h, then dried in a constant temperature drying oven at 60 °C for 8 h, and finally cooled naturally to room temperature. The surface of the dried clay bricks was rinsed first with tap water and then with deionized water to remove the precipitated frost layer, and then dried in the natural environment for 2 h to obtain the clay bricks required for the experiment.

[0075] For the convenience of discussion, in the following examples and comparative examples, the aluminum chloride aqueous solution is denoted as anti-frost agent 1; the aluminum nitrate aqueous solution is denoted as anti-frost agent 1'; the water-based epoxy resin AB glue aqueous solution is denoted as anti-frost agent 2; the silane impregnating agent is purchased from Taobao and is denoted as anti-frost agent 3.

[0076] Example 1

[0077] (1) Weigh, mix, and stir aluminum chloride and deionized water according to a mass ratio of 15:85 to prepare anti-frost agent 1, and the volume of the prepared anti-frost agent 1 is 20 L.

[0078] (2) Pre-mix and stir the A emulsion and B colloid of the water-based epoxy resin according to a mass ratio of 2:1. Subsequently, weigh, mix, and stir the mixture of water-based epoxy resin A and B glue and deionized water according to a mass ratio of 1:9 to obtain anti-frost agent 2, and the volume of the prepared anti-frost agent 2 is 20 L.

[0079] (3) Anti-frost agent 3 is a silane impregnating agent. Measure 20 L for standby.

[0080] (4) Place the anti-frost agent solutions in 3 plastic boxes of 30 L respectively. Then soak the experimental clay bricks first in anti-frost agent 1, then in anti-frost agent 2, and finally in anti-frost agent 3. The soaking time for each time is 0.5 h. Before the next soaking, the clay bricks need to be dried in natural conditions for 1 h. After the soaking operation in anti-frost agent 3 is completed, the clay bricks are placed in a natural drying environment and dried for 24 hours.

[0081] Example 2

[0082] The difference from Example 1 is only that the mass ratio of aluminum chloride to deionized water in anti-frost agent 1 is 17:83, and the mass ratio of the mixture of epoxy resin A and B glue to deionized water in anti-frost agent 2 is 13:87.

[0083] Example 3

[0084] It is only different from Example 1 in that the mass ratio of aluminum chloride to deionized water in Frost Preventive 1 is 20:80, and the mass ratio of the mixture of epoxy resins A and B to deionized water in Frost Preventive 2 is 15:85.

[0085] Comparative Examples 1-7

[0086] The compositions of Frost Preventives 1, 2, and 3 used in Comparative Examples 1-7 are the same as those in Example 1.

[0087] Taking the clay brick that was not treated with a frost preventive and soaked in deionized water as the blank sample, the clay bricks soaked only in Frost Preventives 1, 2, and 3 were marked as Comparative Example 1, Comparative Example 2, and Comparative Example 3 respectively;

[0088] Changing the soaking order of the frost preventive, the clay brick soaked successively in Frost Preventives 2, 3, and 1 was marked as Comparative Example 4;

[0089] The clay brick soaked successively in Frost Preventives 1 and 2 was marked as Comparative Example 5;

[0090] The clay brick soaked successively in Frost Preventives 1 and 3 was marked as Comparative Example 6;

[0091] The clay brick soaked successively in Frost Preventives 2 and 3 was marked as Comparative Example 7.

[0092] Using a digital camera to record the efflorescence results on the surface of the clay brick, the efflorescence photos of the blank sample, Comparative Examples 1-3, and Examples 1-3 are respectively as Figures 1 - 7 shown, Figures 1 to 7 in which, (a) is the strip surface of the clay brick, and (b) is the large surface of the clay brick.

[0093] The image analysis method was used to calculate the proportion of the efflorescence area in the total surface area of the clay brick, and combined with the efflorescence mass swept down and weighed by a brush, as the quantitative evaluation basis for efflorescence.

[0094] The efflorescence results of the blank sample, Examples 1-3, and Comparative Examples 1-7 are shown in Table 1.

[0095] Table 1 Efflorescence effects of clay bricks treated with different frost preventives

[0096]

[0097]

[0098] It can be seen from Table 1 that Examples 1-3 have obvious effects on preventing the efflorescence of clay bricks, the relative efflorescence area and efflorescence amount are significantly reduced, and the precipitation of frost in the clay bricks is effectively prevented.

[0099] The clay bricks treated with the anti-frost agent in Examples 1 to 3 were placed outdoors under natural conditions for weathering experiments for 180 days. It was found that the clay bricks basically no longer showed the phenomenon of efflorescence, indicating that the anti-frost agent has good durability and antioxidant properties.

[0100] In addition, it can also be seen from the results of Comparative Example 4 in Table 1 that when the soaking order of the anti-frost agent was changed, compared with the blank group, the relative efflorescence area and the amount of efflorescence decreased, but the clay bricks still showed slight efflorescence and could not effectively prevent the efflorescence of clay bricks.

[0101] When two anti-frost agents were used, compared with the blank group, the relative efflorescence area and the amount of efflorescence decreased, but the clay bricks still showed slight efflorescence and could not effectively prevent the efflorescence of clay bricks.

[0102] Example 4

[0103] (1) Aluminum nitrate and deionized water were made into a solution in a ratio of 7:93, and after stirring evenly, anti-frost agent 1' was obtained.

[0104] (2) Anti-frost agent 2: The A emulsion and B colloid of waterborne epoxy resin were pre-mixed and stirred in a mass ratio of 2:1. Subsequently, the mixture of waterborne epoxy resin A and B colloid was weighed, mixed, and stirred with deionized water in a ratio of 1:9 to obtain anti-frost agent 2.

[0105] (3) Anti-frost agent 3 is a silane impregnating agent, and 20 L was measured and set aside for use.

[0106] (4) On the outer surface of the clay brick, anti-frost agent 1' was evenly brushed 3 times first, and then anti-frost agent 2 was brushed 3 times. The interval time between each brushing was 15 min. Before repeating the brushing, the clay brick must be dry to the touch. The brushing amount of anti-frost agents 1' and 2 was both 350 g / m 2 , and the operation was carried out in the order of the large surface, the strip surface, and the top surface, from left to right and from top to bottom.

[0107] (6) Anti-frost agent 3 was evenly brushed on the coating surface. The brushing amount of anti-frost agent 3 was 300 g / m 2 , and the operation was carried out in the order of the large surface, the strip surface, and the top surface, from left to right and from top to bottom. Each clay brick was brushed 2 times. After the first brushing was completed, the second brushing was carried out immediately. The interval time was 3 min. After the brushing was completed, the clay brick was naturally dried for 24 hours.

[0108] Example 5

[0109] (1) To quickly evaluate the efflorescence characteristics of clay bricks before and after using anti-efflorescence agents, an efflorescence experiment of brick masonry was simulated, that is, the clay bricks were pre-soaked in a salt solution to accelerate the appearance of efflorescence. The salt solution used was a mixed solution with a mass fraction of 1% of Na2SO4 and 0.2% of CaSO4·2H2O. The clay bricks were immersed in the mixed solution with the strip surface facing down for 6 h, during which the top surface of the clay bricks was 60 cm higher than the liquid level of the solution. The clay bricks were taken out and air-dried naturally for 1 h, then dried in a constant temperature drying oven at 60 °C for 8 h, and finally cooled naturally to room temperature. The surface of the dried clay bricks was rinsed with tap water to remove the precipitated frost layer, and then dried in the natural environment for 2.5 h.

[0110] (2) Aluminum nitrate and deionized water were made into a solution in a ratio of 8:92, and after stirring evenly, anti-efflorescence agent 1’ was obtained.

[0111] (3) The A emulsion and B colloid of waterborne epoxy resin were pre-mixed and stirred in a mass ratio of 2:1. Subsequently, the mixture of waterborne epoxy resin A and B colloid and deionized water were weighed and mixed in a mass ratio of 13:87, and after stirring evenly, anti-efflorescence agent 2 was obtained.

[0112] (4) Anti-efflorescence agent 3 was a silane impregnating agent, and 20 L was measured for standby.

[0113] (5) On the outer surface of the clay bricks in step (1), anti-efflorescence agent 1’ was evenly brushed 3 times first, and then anti-efflorescence agent 2 was brushed 3 times. The interval time between each brushing was 18 min. Before repeating the brushing, the clay bricks had to be dry to the touch. The brushing amounts of anti-efflorescence agent 1’ and 2 were both 375 g / m 2 , and the operation was carried out in the order of the large surface, strip surface, and top surface, from left to right and from top to bottom.

[0114] (6) Anti-efflorescence agent 3 was evenly brushed on the coating surface. The brushing amount of anti-efflorescence agent 3 was 325 g / m 2 , and the operation was carried out in the order of the large surface, strip surface, and top surface, from left to right and from top to bottom. Each clay brick was brushed 2 times. After the first brushing was completed, the second brushing was carried out immediately. The interval time was 3 min. After the brushing was completed, the clay bricks should be naturally dried for 24 hours.

[0115] Example 6

[0116] (1) To quickly evaluate the efflorescence characteristics of clay bricks before and after using anti-efflorescence agents, an efflorescence experiment of brick masonry was simulated, that is, the clay bricks were pre-soaked in a salt solution to accelerate the appearance of efflorescence. The salt solution used was a mixed solution with a mass fraction of 1% Na2SO4 and 0.2% CaSO4·2H2O. The clay bricks were immersed in the mixed solution with the strip surface facing down for 6 hours, during which the top surface of the clay bricks was 60 cm higher than the liquid level of the solution. The clay bricks were taken out and air-dried naturally for 1 hour, then placed in a constant temperature drying oven at 60 °C and dried for 8 hours, and finally cooled naturally to room temperature. The surface of the dried clay bricks was rinsed with tap water to remove the precipitated frost layer, and then dried in the natural environment for 3 hours.

[0117] (2) Aluminum nitrate and deionized water were made into a solution in a ratio of 10:90, and anti-efflorescence agent 1' was obtained after stirring evenly.

[0118] (3) The A emulsion and B colloid of waterborne epoxy resin were pre-mixed and stirred in a mass ratio of 2:1. Subsequently, the mixture of waterborne epoxy resin A and B colloid was weighed and mixed with deionized water in a mass ratio of 15:85, and anti-efflorescence agent 2 was obtained after stirring evenly.

[0119] (4) Anti-efflorescence agent 3 is a silane impregnating agent, and 20 L was measured for standby.

[0120] (5) First, apply anti-efflorescence agent 1' evenly on the outer surface of the clay bricks for 3 times, and then apply anti-efflorescence agent 2 for 3 times. The interval time between each application is 20 minutes. Before repeating the application, the clay bricks must be dry to the touch. The application amount of both anti-efflorescence agent 1' and 2 is 400 g / m 2 , and the operation should be carried out in the order of the large surface, strip surface, and top surface, from left to right and from top to bottom.

[0121] (6) Apply anti-efflorescence agent 3 evenly on the coating surface. The application amount of anti-efflorescence agent 3 is 350 g / m 2 , and the operation should be carried out in the order of the large surface, strip surface, and top surface, from left to right and from top to bottom. Each clay brick is applied 2 times. After the first application is completed, the second application is carried out immediately. The interval time is 3 minutes. After the application is completed, the clay bricks should be dried naturally for 24 hours.

[0122] Comparative Example 8

[0123] The difference from Example 5 is only that the clay bricks are only coated with anti-efflorescence agent 1' for 3 times, and anti-efflorescence agents 2 and 3 are not coated.

[0124] Comparative Example 9

[0125] The difference from Example 5 is only that the clay bricks are only coated with anti-efflorescence agent 2 for 3 times, and anti-efflorescence agents 1' and 3 are not coated.

[0126] Comparative Example 10

[0127] The difference from Example 5 is only that the clay brick is only coated with the frost-proof agent 3 twice, and the frost-proof agents 1' and 2 are not coated.

[0128] Comparative Example 11

[0129] The difference from Example 5 is only that the frost-proof agent 1' is coated three times first, and then the frost-proof agent 2 is coated three times, and the frost-proof agent 3 is not coated.

[0130] Comparative Example 12

[0131] The difference from Example 5 is only that the frost-proof agent 1' is coated three times first, and then the frost-proof agent 3 is coated twice, and the frost-proof agent 2 is not coated.

[0132] Comparative Example 13

[0133] The difference from Example 5 is only that the frost-proof agent 2 is coated three times first, and then the frost-proof agent 3 is coated twice, and the frost-proof agent 1' is not coated.

[0134] The digital camera was used to record the efflorescence results on the surface of the clay brick. The efflorescence photos of Comparative Examples 8-10 and Examples 4-6 are respectively as Figures 8 - 13 shown. Figures 8 to 13 Among them, (a) is the strip surface of the clay brick, and (b) is the large surface of the clay brick.

[0135] The efflorescence results of the blank sample, Comparative Examples 8-13 and Examples 4-6 are shown in Table 2.

[0136] Table 2 Efflorescence effects of clay bricks treated with different frost-proof agents

[0137]

[0138] It can be seen from Table 2 that Examples 4-6 have obvious effects on preventing the efflorescence of clay bricks. Compared with before brushing, the relative efflorescence area of the clay bricks after brushing is significantly reduced, effectively preventing the precipitation of frost in the clay bricks. The clay bricks after brushing the frost-proof agents in Examples 4-6 were placed outdoors under natural conditions for weathering experiments, and it was found that the clay bricks basically no longer showed efflorescence phenomena, indicating that the frost-proof agent has good durability and antioxidant properties.

[0139] In addition, it can also be seen from Table 2 that when one or two frost-proof agents are used, although the frost-proof effect is improved compared with the blank sample, the clay bricks still show slight or medium efflorescence and cannot effectively prevent the efflorescence of the clay bricks.

[0140] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and retouches can still be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.

Claims

1. A method for preventing efflorescence of clay bricks, characterized in that, It includes the following steps: Dissolve the aluminum salt in water to obtain an aluminum salt aqueous solution; Mix the A emulsion and B colloid in the water-based epoxy resin AB glue, and dissolve the obtained mixture in water to obtain a water-based epoxy resin AB glue aqueous solution; Soak the clay brick successively in the aluminum salt aqueous solution, the water-based epoxy resin AB glue aqueous solution and the silane impregnating agent; Alternatively, coat the aluminum salt aqueous solution, the water-based epoxy resin AB glue aqueous solution and the silane impregnating agent successively on the surface of the clay brick.

2. The method according to claim 1, wherein When the treatment method for the clay brick is soaking, the mass concentration of the aluminum salt aqueous solution is 15-20%; when the treatment method for the clay brick is coating, the mass concentration of the aluminum salt aqueous solution is 7-10%.

3. The method according to claim 1, characterized in that, The mass content of the water-based epoxy resin AB glue in the water-based epoxy resin AB glue aqueous solution is 10-15%; the mass ratio of the A emulsion to the B colloid in the water-based epoxy resin AB glue is 2:

1.

4. The method according to any one of claims 1 to 3, characterized in that The soaking time is independently 0.5-1 h.

5. The method according to claim 1, characterized in that, The coating method includes brushing or spraying.

6. The method according to claim 1 or 5, characterized in that, The coating amount of the aluminum salt aqueous solution is 350 g / m 2 or more; the coating amount of the water-based epoxy resin AB glue aqueous solution is 350 g / m 2 or more; the coating amount of the silane impregnating agent is 300 g / m 2 or more.

7. The method according to claim 1, characterized in that, The aluminum salt includes aluminum chloride or aluminum nitrate.

8. The method according to claim 1, wherein The silane impregnating agent contains isobutyltriethoxysilane.

9. The method according to claim 8, wherein The mass content of isobutyltriethoxysilane in the silane impregnating agent is above 98%.

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