Inorganic waterproof plugging cement material and preparation method thereof

Abstract

The invention discloses an inorganic waterproof leaking stoppage cement material and a preparation method thereof, the inorganic waterproof leaking stoppage cement material comprises the following components in parts by weight: 19-58 parts of heavy magnesium oxide, 36 parts of monopotassium phosphate, 6-45 parts of calcium silicate and 30 parts of water, and the sum of the parts by weight of the heavy magnesium oxide and the parts by weight of the calcium silicate is 64. Therefore, the calcium silicate is added on the basis of the heavy magnesium oxide and the monopotassium phosphate, the volume expansion reaction of the calcium silicate and the monopotassium phosphate can be utilized to counteract the volume shrinkage of the magnesium potassium phosphate cement, and meanwhile, the volume expansion during the generation of the calcium potassium hydrogen phosphate is limited by utilizing the volume shrinkage of the magnesium potassium phosphate cement; the aperture size is prevented from being increased, so that the cement impermeability is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of engineering waterproofing and plugging, and particularly to inorganic waterproofing and plugging materials. Background Art

[0002] In construction engineering, water conservancy projects, municipal engineering, and tunnel engineering, leakage of buildings and structures often occurs due to poor structural design, improper selection of waterproof materials, poor construction quality, uneven settlement of the foundation, etc. Especially in the case of a large increase in high-rise buildings at present, basements, elevator shafts, roof water tanks, etc. have also increased accordingly. If these structures are not properly treated, leakage will occur, affecting the normal use and service life of the structures, and plugging and anti-seepage treatment must be carried out.

[0003] Repair materials generally include two categories: inorganic and organic. Among them, organic materials are usually modified by polymers to produce better repair effects, but this often comes at the cost of affecting cement hydration and reducing the early strength of the repair mortar. Moreover, in engineering waterproofing and plugging, repair materials often require early strength more. Therefore, in the inorganic material system, magnesium phosphate cement has a unique gelling system as an inorganic repair material. Compared with PC, MKP cement has the advantages of quick setting, high early strength, low shrinkage rate, firm bonding with the PC matrix, and low pH value. However, magnesium phosphate cement itself has poor water resistance and certain shrinkage, so it cannot meet the engineering waterproofing requirements in engineering. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides an inorganic waterproof and plugging cement material.

[0005] An inorganic waterproof and plugging cement material according to the first aspect of the embodiments of the present invention includes: 20 parts to 58 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 6 parts to 45 parts of calcium silicate, and 30 parts of water by weight. Among them, the sum of the weight parts of the heavy magnesium oxide and the calcium silicate is 64. The fineness of the heavy magnesium oxide is 1200 mesh, and the fineness of the calcium silicate is 1200 mesh.

[0006] Preferably, the weight part of the heavy magnesium oxide is 32 parts, and the weight part of the calcium silicate is 32 parts. At this time, the initial and final setting times of the waterproof material formed are relatively moderate, the strength is the highest, the pore distribution is reasonable, the anti-seepage performance is slightly reduced, and the volume is basically non-shrinking.

[0007] Specifically, calcium silicate itself is a chain silicate mineral. It has micro-fibrous particles, which can not only effectively improve the flexural strength and fracture toughness of magnesium potassium phosphate cement, but also fill the pores of magnesium potassium phosphate cement, improve the water resistance of magnesium potassium phosphate cement, and reduce the shrinkage of magnesium potassium phosphate cement.

[0008] More specifically, heavy magnesium oxide and potassium dihydrogen phosphate can undergo an acid-base reaction to obtain magnesium phosphate cement. This reaction releases a large amount of heat, which accelerates the hydration of the cement, resulting in too rapid setting of the cement and making it difficult to use the cement in large quantities. Usually, a relatively large amount of retarder is required to slow down the setting rate. However, excessive use of the retarder will cause a decrease in strength, resulting in more harm than good.

[0009] Therefore, by adding calcium silicate to partially replace heavy magnesium oxide and utilizing the endothermic reaction between calcium silicate and potassium dihydrogen phosphate, a retarding effect can be achieved, such that the final setting time of the magnesium phosphate cement is about 10 minutes, providing more ample and operable time for engineering construction. At the same time, the generation amount of K-struvite is also increased, thereby increasing the strength of the cement itself.

[0010] In addition, the formed potassium magnesium phosphate cement itself has poor crack resistance, and the potassium magnesium phosphate cement itself also has a certain degree of shrinkage. In the prior art, an expansive agent is generally used as the expansion source for compensating shrinkage. However, once the expansive agent is not properly controlled, adverse reactions will occur, affecting the durability of the building.

[0011] After adding calcium silicate in this way, calcium silicate and potassium dihydrogen phosphate can undergo an endothermic reaction to generate calcium potassium hydrogen phosphate, and its reaction equation is as follows: CaSiO3 + 3KH2PO4 + H2O → CaK3H(PO4)2 + 2H2O + H2SiO3. During this process, volume expansion will occur, increasing the large pore diameter of its structure and decreasing the small pore diameter. However, the increase in the large pore diameter will affect the impermeability of the cement.

[0012] Thus, the volume expansion reaction between calcium silicate and potassium dihydrogen phosphate is used to offset the volume shrinkage of the potassium magnesium phosphate cement. At the same time, it is also equivalent to using the volume shrinkage of the potassium magnesium phosphate cement to limit the volume expansion during the formation of calcium potassium hydrogen phosphate, avoiding the increase in pore size, thereby ensuring the impermeability of the cement.

[0013] In some embodiments of the present invention, the heavy magnesium oxide is the heavy magnesium oxide calcined at 1500°C, or a retarder is added. Among them, the reaction between potassium dihydrogen phosphate and heavy magnesium oxide is an acid-base reaction, and it is easy to have a situation where the reaction rate is too fast. Using high temperature can remove part of the activity of the potassium magnesium phosphate cement, or boric acid is added as a retarder to extend the reaction time, so that it can have workability.

[0014] Preferably, the retarder is 1.6 parts by weight, and the retarder used is boric acid.

[0015] In some embodiments of the present invention, polyester fiber is further included, and the weight range of the polyester fiber is 0.7 to 1. Adding polyester fiber to potassium magnesium phosphate cement can reduce the brittleness of potassium magnesium phosphate cement, and polyester fiber usually chemically reacts with ordinary Portland cement and is destroyed, but will not be destroyed in magnesium phosphate cement.

[0016] When in use, potassium magnesium phosphate cement itself is relatively brittle. The present invention adds polyester fibers so that the flake monomers can be easily dispersed into fiber monofilaments under the action of water immersion and the friction of the mixer, thereby achieving an anti-cracking effect and further effectively improving the mechanical properties, freeze-thaw resistance and impermeability of the concrete.

[0017] Moreover, polyester fibers usually undergo chemical reactions with ordinary Portland cement and are destroyed, but this does not occur in potassium magnesium phosphate cement, thereby effectively improving the coupling effect between polyester fibers and potassium magnesium phosphate cement.

[0018] According to a second aspect of an embodiment of the present invention, a method for preparing an inorganic waterproof and leak-proof cement material comprises the following steps: S1. Dissolve the weighed potassium dihydrogen phosphate in the weighed water, put it into a stirring pot and stir it quickly, then put the weighed calcium silicate, heavy magnesium oxide powder and polyester fiber into it and mix them thoroughly.

[0019] S2. After adding boric acid, the mixed powder is sent into a stirring pot for thorough stirring.

[0020] Specifically, the inorganic waterproof plugging cement material prepared by the preparation method has the advantages of high rapid setting and early strength, and can be widely used in various plugging and water stopping, emergency repair and other projects. In addition, the product has strong adhesion to various interfaces, has the performance of penetrating crystallization and permanent waterproofing, and is non-toxic, odorless, pollution-free, non-flammable, and resistant to chemical corrosion.

[0021] Beneficial Effects

[0022] The present invention adds calcium silicate on the basis of heavy magnesium oxide and potassium dihydrogen phosphate, and can use the volume expansion reaction of calcium silicate and potassium dihydrogen phosphate to offset the volume shrinkage of potassium magnesium phosphate cement. At the same time, it is equivalent to using the volume shrinkage of potassium magnesium phosphate cement to limit the volume expansion when generating potassium calcium hydrogen phosphate, avoiding the increase of pore size, thereby ensuring the cement impermeability.

[0023] At the same time, the endothermic reaction of calcium silicate and potassium dihydrogen phosphate can slow down the acid-base exothermic reaction between heavy magnesium oxide and potassium dihydrogen phosphate, thereby slowing down the rate of cement hydration and avoiding the occurrence of cement coagulation too quickly, thereby providing more ample operating time for engineering construction.

[0024] In addition, the price of heavy magnesium oxide is relatively high, while the wollastonite rich in calcium silicate has a lower cost. Using wollastonite to partially replace heavy magnesium oxide can greatly reduce the material cost. Detailed implementation manners

[0025] The following will describe clearly and completely the technical solutions in the embodiments of the present invention in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] In the following embodiments, the effects of raw materials and components in different weight parts on the performance of the waterproof and leak-proof material are tested. Among them, the following steps are included: S1. First, weigh potassium dihydrogen phosphate and water, dissolve potassium dihydrogen phosphate in the weighed water, put it into a stirring pot, with a rotation speed of 125 rad / min, stir for 60 s, and then fully mix wollastonite, heavy magnesium oxide powder and polyester fiber.

[0027] S2. After adding boric acid to the stirring pot, then send the mixed powder into the stirring pot, with a rotation speed of 125 rad / min, and stir fully for 2 min.

[0028] S3. Apply the material prepared above to the place where leakage needs to be plugged and conduct detection.

[0029] Comparative example 1 In this embodiment, the components of the waterproof and leak-proof cement material include: heavy magnesium oxide, potassium dihydrogen phosphate, boric acid. Among them, the following raw materials in weight parts are included: 64 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 3.2 parts of retarder, 30 parts of water, and boric acid is 5% of heavy magnesium oxide.

[0030] Comparative example 2 In this embodiment, the components of the waterproof and leak-proof cement material include: heavy magnesium oxide, potassium dihydrogen phosphate, wollastonite. Among them, the following raw materials in weight parts are included: 32 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 32 parts of wollastonite, and 30 parts of water.

[0031] Example 1

[0032] In this embodiment, the waterproof and leak-proof cement material is composed of heavy magnesium oxide, potassium dihydrogen phosphate, boric acid, wollastonite. Among them, the following raw materials in weight parts are included: 58 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 2.87 parts of retarder, 6 parts of wollastonite, 30 parts of water, and the boric acid is 5% of heavy magnesium oxide.

[0033] At this time, compared with the parameters of Comparative Example 1, the proportion of calcium silicate replacing heavy magnesium oxide is 10%.

[0034] Example 2

[0035] In this example, the components of the waterproof and leak-stopping cement material include the following raw materials in parts by weight: 32 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 1.6 parts of retarder, 32 parts of calcium silicate, 30 parts of water, and the boric acid is 5% of the heavy magnesium oxide.

[0036] At this time, compared with the parameters of Comparative Example 1, the proportion of calcium silicate replacing heavy magnesium oxide is 50%.

[0037] Example 3

[0038] In this example, the components of the waterproof and leak-stopping cement material include the following raw materials in parts by weight: 19 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 0.96 parts of retarder, 45 parts of calcium silicate, 30 parts of water, and the boric acid is 5% of the heavy magnesium oxide.

[0039] At this time, compared with the parameters of Comparative Example 1, the proportion of calcium silicate replacing heavy magnesium oxide is 70%.

[0040] The component ratios of the above examples and comparative examples are summarized as shown in Table 1: Table 1. Mixing ratios of each component in Examples 1 to 3 ; Table 2. Compressive strength and setting time of different specimens ; Combining the data in Tables 1, 2 and 5, it can be seen that: the final setting time of the material formed by Comparative Example 1 as the traditional potassium magnesium phosphate cement is very short, the early compressive strength is relatively high, but the early volume shrinkage is also relatively high.

[0041] After comparing the parameters of Comparative Example 1 and Comparative Example 2, it can be found that: without adding the boric acid retarder, the final setting time of the material prepared by the combination of calcium silicate, heavy magnesium oxide and potassium dihydrogen phosphate is similar to that of the traditional potassium magnesium phosphate cement, indicating that this combination can indeed play a role in slowing down the final setting time.

[0042] Combining the data in Tables 1, 2 and 5, comparing the components of Example 2 with those of Example 1 and Example 3, when the proportion of calcium silicate replacing heavy magnesium oxide in Example 2 is 50%, the performance of the waterproof and leak-stopping cement material is relatively the best.

[0043] Example 4

[0044] In this embodiment, the components of the waterproof and leak - plugging cement material include the following raw materials in parts by weight: 32 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 1.6 parts of retarder, 32 parts of calcium silicate, 0.1 part of fiber, and 30 parts of water. The retarder is 5% of the heavy magnesium oxide.

[0045] At this time, compared with the parameters of Example 2, the incorporation amount of polyester fiber is 0.1%.

[0046] Example 5

[0047] In this embodiment, the components of the waterproof and leak - plugging cement material include the following raw materials in parts by weight: 32 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 1.6 parts of retarder, 32 parts of calcium silicate, 0.7 part of fiber, and 30 parts of water. The retarder is 5% of the heavy magnesium oxide.

[0048] At this time, compared with the parameters of Example 2, the incorporation amount of polyester fiber is 0.7%.

[0049] Example 6

[0050] In this embodiment, the components of the waterproof and leak - plugging cement material include the following raw materials in parts by weight: 32 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 1.6 parts of retarder, 32 parts of calcium silicate, 1 part of fiber, and 30 parts of water. The retarder is 5% of the heavy magnesium oxide.

[0051] At this time, compared with the parameters of Example 2, the incorporation amount of polyester fiber is 1%.

[0052] Table 3. Mix ratios of each component from Example 4 to Example 6 ; Table 4. Flexural strength of different specimens ; Table 5. Impermeability strength and shrinkage of different specimens ; It can be seen from the data in Table 3 to Table 5 that the addition of polyester fiber significantly improves the flexural performance and impermeability of the waterproof and leak - plugging cement material.

[0053] Combining the data in Table 3 and Table 5, it can be seen that as the addition amount of calcium silicate increases, the shrinkage rate gradually decreases. Even when the calcium silicate is 70%, there will be a certain degree of volume expansion. Therefore, the volume shrinkage of magnesium potassium phosphate cement can be slowed down.

[0054] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example.

[0055] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. An inorganic waterproof and leak-stopping cement material, characterized in that, include: The following weight parts are used: 19 to 58 parts of heavy magnesium oxide, 36 parts of potassium dihydrogen phosphate, 6 to 45 parts of calcium silicate, and 30 parts of water, wherein the sum of the weight parts of the heavy magnesium oxide and the weight parts of the calcium silicate is 64.

2. The inorganic waterproof and plugging cement material according to claim 1, characterized in that, The weight portion of the heavy magnesium oxide is 32 parts, and the weight portion of the calcium silicate is 32 parts.

3. An inorganic waterproof and plugging cement material according to claim 1 or 2, characterized in that, The heavy magnesium oxide is heavy magnesium oxide sintered at 1500° C. to reduce its partial activity.

4. An inorganic waterproof and plugging cement material according to claim 3, characterized in that, The fineness of the heavy magnesium oxide is 1200 mesh, and the fineness of the calcium silicate is 1200 mesh.

5. An inorganic waterproof and leak - plugging cement material according to claim 1 or 2, characterized in that, Also includes: 1.6 parts of retarder by weight, wherein boric acid is used as the retarder.

6. The inorganic waterproof and plugging cement material according to claim 1, characterized in that, Also includes: Polyester.

7. An inorganic waterproof and plugging cement material according to claim 6, characterized in that, The weight portion of the polyester fiber ranges from 0.7 to 1 part.

8. A preparation method of an inorganic waterproof and leak-stopping cement material, characterized in that, The preparation method comprises the following steps: S1. Dissolve the weighed potassium dihydrogen phosphate in the weighed water, put it into a stirring pot for rapid stirring, then put the weighed calcium silicate, heavy magnesium oxide powder and polyester fiber into it, and mix them thoroughly; S2. After adding boric acid, the mixed powder is sent into a stirring pot for thorough stirring.