A curing agent for concrete pipes and a method for preparing and applying the same

Abstract

The present application relates to the technical field of concrete curing agent, more particularly, to a curing agent for concrete pipeline and a preparation and construction method thereof.The present application aims to solve the problems of poor adhesion, low water retention rate and insufficient physical strength of the existing curing agent.The first object of the present application is to provide a curing agent for concrete pipeline, which comprises the following components by weight:100-160 parts of single-component polyurea;30-50 parts of diluent;10-20 parts of Portland cement;6-10 parts of slag powder.The second object of the present application is to provide a preparation method of the curing agent for concrete pipeline.The third object of the present application is to provide a construction method of the curing agent for concrete pipeline.

Description

A curing agent for concrete pipes, its preparation and application method Technical Field

[0001] This invention relates to the field of concrete curing agents, and more specifically, to a curing agent for concrete pipes and its preparation and application methods. Background Technology

[0002] If concrete pipes are not properly cured, a large amount of moisture will evaporate from the concrete. This not only leads to flaking or powdering on the surface of the concrete pipe, forming surface defects such as honeycomb and pitting, but also causes significant shrinkage deformation, resulting in drying shrinkage cracks and even affecting the early strength development of the concrete, thus impacting the durability of the concrete pipe. During the construction of concrete pipes, methods such as water spraying, covering with a thin film, or steam curing are often used to prevent moisture evaporation. These methods are time-consuming and labor-intensive, and they often fail to achieve the desired results.

[0003] Concrete curing agent, also known as concrete protective agent or concrete curing liquid, is applied by spraying to form a curing film on the concrete surface. This film isolates the concrete surface from the air, reduces or even prevents moisture evaporation, minimizes concrete shrinkage and cracking, and maximizes hydration by utilizing the moisture contained within the concrete, thus achieving the purpose of curing.

[0004] Most concrete curing agents on the market are silicate-based, paraffin-based, and polymer resin-based. While paraffin-based agents have a high water retention rate, their strength is too poor, making them easy to scratch and wear. Polymer resin-based agents can meet basic water retention requirements, but their bonding strength with the concrete surface is poor, making them easily washed away and broken by rainwater. While silicate-based agents are inexpensive, have strong surface bonding, good hardness, and high wear resistance, their water retention rate is relatively poor.

[0005] To address the aforementioned issues, there is an urgent need to develop a concrete curing agent that has high water retention, good impact resistance, good wear resistance, and strong adhesion to the concrete surface. Summary of the Invention

[0006] The present invention aims to overcome at least one of the defects of the prior art and provides a curing agent for concrete pipes and its preparation and construction method, which solves the problems of poor bonding force between existing curing agents and concrete, low water retention rate and insufficient physical strength.

[0007] The first objective of this invention is to provide a curing agent for concrete pipes, comprising the following components in parts by weight:

[0008] 100-160 parts of single-component polyurea;

[0009] 30-50 parts diluent;

[0010] 10-20 parts of silicate cement;

[0011] 6-10 parts of slag powder.

[0012] The concrete pipe curing agent of the present invention uses the above-mentioned proportions of silicate cement and slag powder as filler materials for a single-component polyurea. During construction, it can undergo a hydration reaction with the moisture inside the polyurea coating, forming more steric hindrance. Water vapor molecules are subject to greater diffusion resistance inside the coating, further preventing the evaporation of moisture inside the concrete. In addition, the viscosity of the single-component polyurea is made suitable for spraying by using the above-mentioned proportions of diluent, which allows the curing agent to be more efficiently dispersed on the surface of the concrete pipe to be constructed, thereby providing high-performance curing for the concrete pipe. The high-performance curing agent of this invention, when sprayed onto the outer surface of concrete pipes, not only functions as a curing agent to reduce cracking caused by moisture evaporation, but also leverages the strong impact resistance of the polyurea coating to improve the impact resistance of the concrete pipes. Simultaneously, it enhances surface smoothness and reduces frictional resistance during jacking construction. Compared to existing curing agents such as silicate-based, paraffin-based, and polymer resin-based agents, the high-performance curing agent of this invention exhibits superior impact resistance, abrasion resistance, and water retention capacity, and can form a high-strength bond with the concrete surface, demonstrating excellent curing performance and significantly improving the durability of concrete pipes.

[0013] Furthermore, the concrete pipe curing agent comprises the following components in parts by weight:

[0014] 115-145 parts of single-component polyurea;

[0015] 35-45 parts diluent;

[0016] 12.5-17.5 parts of silicate cement;

[0017] 7-9 parts of slag powder.

[0018] Furthermore, the concrete pipe curing agent comprises the following components in parts by weight:

[0019] 130 parts of single-component polyurea;

[0020] 40 parts of diluent;

[0021] 15 parts of silicate cement;

[0022] 8 parts of slag powder.

[0023] Furthermore, the silicate cement has a particle size of 800-1000 mesh; and / or, the slag powder has a particle size of 800-1200 mesh.

[0024] Furthermore, the diluent is any one or a mixture of two or more of butyl acetate, xylene, dimethyl acetate, and propylene carbonate.

[0025] A second objective of this invention is to provide a method for preparing a curing agent for concrete pipes, comprising the following steps:

[0026] S1. Weigh the silicate cement and the slag powder according to the proportion, stir and mix them evenly to obtain the first mixed material;

[0027] S2. Weigh the single-component polyurea and the diluent according to the proportion, stir and mix them to obtain a second mixed material, and then add the first mixed material obtained in step S1 to the second mixed material and mix them to obtain a curing agent for concrete pipes.

[0028] Further, in step S2, the single-component polyurea and the diluent are stirred and mixed for 2-3 minutes to obtain the second mixed material;

[0029] Further, in step S2, the first mixed material is added to the second mixed material and stirred for 3-4 minutes to obtain the curing agent for concrete pipes.

[0030] Further, in step S2, the viscosity of the prepared concrete pipe curing agent is 600-1500 MPa·s.

[0031] A third objective of this invention is to provide a method for applying the above-mentioned curing agent for concrete pipes or the curing agent for concrete pipes prepared by the above-mentioned method: the high-performance curing agent is sprayed onto the surface of the concrete pipe and then cured.

[0032] Furthermore, the ambient temperature during construction is not lower than 10℃; and / or, within 30 minutes after the high-performance curing agent is prepared, the high-performance curing agent is sprayed onto the surface of the concrete pipe; during construction, the thickness of the high-performance curing agent sprayed onto the surface of the concrete pipe is 0.5-1mm; and / or, the high-performance curing agent is cured 5-10 minutes after being sprayed onto the surface of the concrete pipe.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The curing agent for concrete pipes involved in the present invention can improve the curing effect of concrete pipes, improve the mechanical properties and durability of the pipes, thereby improving the service life of concrete pipes. (2) The curing agent for concrete pipes involved in the present invention has the characteristics of high water retention, strong adhesion, good impact resistance, good wear resistance and good durability. Attached Figure Description

[0034] Figure 1 is a process flow diagram of the preparation method of the curing agent for concrete pipes of the present invention. Detailed Implementation

[0035] This invention first provides a curing agent for concrete pipes, comprising the following components in parts by weight:

[0036] 100-160 parts of single-component polyurea;

[0037] 30-50 parts diluent;

[0038] 10-20 parts of silicate cement;

[0039] 6-10 parts of slag powder.

[0040] The high-performance curing agent of this invention, when sprayed onto the outer surface of concrete pipes, not only functions as a curing agent to reduce cracking caused by moisture evaporation, but also leverages the strong impact resistance of the polyurea coating to improve the impact resistance of the concrete pipes. Simultaneously, it enhances surface smoothness and reduces frictional resistance during jacking construction. Compared to existing curing agents such as silicate-based, paraffin-based, and polymer resin-based agents, the high-performance curing agent of this invention exhibits superior impact resistance, abrasion resistance, and water retention capacity, and can form a high-strength bond with the concrete surface, demonstrating excellent curing performance and significantly improving the durability of concrete pipes.

[0041] To further improve the performance of the curing agent after application to the surface of concrete pipes, in a preferred embodiment, the curing agent for concrete pipes comprises the following components in parts by weight:

[0042] 115-145 parts of single-component polyurea;

[0043] 35-45 parts diluent;

[0044] 12.5-17.5 parts of silicate cement;

[0045] 7-9 parts of slag powder.

[0046] Test results show that by using the above-mentioned weight ratio, the prepared concrete pipe curing agent can be applied to the surface of concrete pipes, further improving compressive strength and adhesion performance, and maintaining good performance in terms of impact resistance, water penetration resistance, aging resistance, temperature resistance and water resistance.

[0047] In some embodiments, to improve the filling effect on the polyurea coating, the particle size of silicate cement is 800-1000 mesh; and / or the particle size of slag powder is 800-1200 mesh. Based on the above dimensions, silicate cement and slag powder can act as micron-sized filler materials for the polyurea coating, enhancing its ability to undergo hydration reaction with moisture, thereby further improving the water retention capacity of the curing agent.

[0048] In some implementations, to optimize the dilution effect on polyurea, the diluent is any one or a mixture of two or more of butyl acetate, xylene, dimethyl ester, and propylene carbonate.

[0049] Secondly, as shown in Figure 1, the present invention provides a method for preparing the above-mentioned curing agent for concrete pipes, comprising the following steps:

[0050] S1. Weigh out silicate cement and slag powder according to the proportion, stir and mix them evenly to obtain the first mixed material;

[0051] S2. Weigh out the single-component polyurea and diluent according to the proportion, stir and mix them to obtain the second mixture. Then add the first mixture obtained in step S1 to the second mixture and mix well to obtain the curing agent for concrete pipes.

[0052] In some implementations, in step S2, the single-component polyurea and diluent are stirred and mixed for 2-3 minutes to obtain the second mixed material. Test results show that when the mixing time is less than 2 minutes, the polyurea is not sufficiently dispersed in the diluent, which affects the physical properties of the final curing agent and results in uneven protective effect of the curing agent on the surface of the concrete pipe after construction. When the mixing time is 3 minutes, sufficient mixing effect has been achieved. Continuing to mix will only prolong the preparation time of the curing agent and generate unnecessary additional costs.

[0053] In some implementations, in step S2, the first mixture is added to the second mixture and stirred for 3-4 minutes to obtain a curing agent for concrete pipes.

[0054] In a preferred embodiment, to facilitate spraying, the viscosity of the prepared concrete pipe curing agent is 600-1500 MPa·s, which helps the curing agent to be evenly dispersed in the concrete pipe and to achieve uniform and high-strength protection on the surface of the concrete pipe.

[0055] Furthermore, the present invention also provides a method for applying the above-mentioned curing agent for concrete pipes: the high-performance curing agent is sprayed onto the surface of the concrete pipe and then cured.

[0056] In some implementation methods, the ambient temperature during construction is not lower than 10°C.

[0057] In some implementations, the high-performance curing agent is sprayed onto the surface of the concrete pipe within 30 minutes of its preparation.

[0058] In some implementations, the high-performance curing agent is sprayed onto the surface of the concrete pipe to a thickness of 0.5-1 mm.

[0059] In some implementations, the high-performance curing agent is sprayed onto the concrete pipe surface and cures in 5-10 minutes.

[0060] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0061] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0062] Example 1

[0063] This embodiment provides a curing agent for concrete pipes, comprising the following raw materials in parts by weight:

[0064] 100 parts of one-component polyurea;

[0065] 30 parts of pure butyl ester diluent;

[0066] 10 parts of 800-1000 mesh silicate cement;

[0067] 6 parts of 800-1200 mesh slag powder.

[0068] The method for preparing a curing agent for concrete pipes provided in this embodiment includes the following steps:

[0069] Step S1: Weigh out silicate cement and slag powder according to the proportion, put them into a mixer and mix evenly, then set aside.

[0070] Step S2: Weigh out the single-component polyurea and diluent according to the proportion and put them into the mixing device. Mix 2-3 parts until uniform. Then, put the cement and slag powder mixture prepared in step S1 into the mixing device and stir for 3-4 minutes to obtain a concrete pipe curing agent with a viscosity of 600-1500 mPa.s that is ready for spraying.

[0071] The construction method for the curing agent for concrete pipes provided in this embodiment is as follows:

[0072] In an environment not lower than 10℃, use a spraying device to spray a 0.5-1mm thick high-performance curing agent onto the surface of the freshly demolded concrete pipe within 30 minutes. Allow the surface of the curing agent to cure for 2-3 minutes and fully cure for 5-10 minutes to prevent the curing agent from flowing, thereby improving the curing effect.

[0073] Example 2

[0074] Except for the different formulation of the curing agent for concrete pipes, the other conditions are the same as in Example 1.

[0075] The concrete pipe curing agent provided in this embodiment comprises the following raw materials in parts by weight:

[0076] 160 parts of single-component polyurea;

[0077] 50 parts of pure butyl ester diluent;

[0078] 20 parts of 800-1000 mesh silicate cement;

[0079] 10 parts of 800-1200 mesh slag powder.

[0080] The preparation method of the curing agent for concrete pipes in this embodiment is the same as that in Embodiment 1.

[0081] Example 3

[0082] Except for the different formulation of the curing agent for concrete pipes, the other conditions are the same as in Example 1.

[0083] The concrete pipe curing agent provided in this embodiment comprises the following raw materials in parts by weight:

[0084] 115 parts of single-component polyurea;

[0085] 35 parts of pure xylene diluent;

[0086] 12.5 parts of 800-1000 mesh silicate cement;

[0087] 7 parts of 800-1200 mesh slag powder.

[0088] The preparation method of the curing agent for concrete pipes in this embodiment is the same as that in Embodiment 1.

[0089] Example 4

[0090] Except for the different formulation of the curing agent for concrete pipes, the other conditions are the same as in Example 1.

[0091] The concrete pipe curing agent provided in this embodiment comprises the following raw materials in parts by weight:

[0092] 145 parts of single-component polyurea;

[0093] 45 parts of pure dimethyl ester diluent;

[0094] 17.5 parts of 800-1000 mesh silicate cement;

[0095] Nine parts of 800-1200 mesh slag powder.

[0096] The preparation method of the curing agent for concrete pipes in this embodiment is the same as that in Embodiment 1.

[0097] Example 5

[0098] Except for the different formulation of the curing agent for concrete pipes, the other conditions are the same as in Example 1.

[0099] The concrete pipe curing agent provided in this embodiment comprises the following raw materials in parts by weight:

[0100] 130 parts of single-component polyurea;

[0101] 40 parts of propylene carbonate diluent;

[0102] 15 parts of 800-1000 mesh silicate cement;

[0103] 8 parts of 800-1200 mesh slag powder.

[0104] The preparation method of the curing agent for concrete pipes in this embodiment is the same as that in Embodiment 1.

[0105] Comparative Example 1

[0106] This comparative example provides a formula for a curing agent for concrete pipes, except that the other conditions are the same as in Example 1, except that there are 5 parts of silicate cement.

[0107] Comparative Example 2

[0108] This comparative example provides a formula for a curing agent for concrete pipes, except that the other conditions are the same as in Example 1, except that there are 30 parts of silicate cement.

[0109] Comparative Example 3

[0110] This comparative example provides a formula for a curing agent for concrete pipes, except that the conditions are the same as in Example 1, except that there are 60 parts of pure butyl ester diluent.

[0111] Comparative Example 4

[0112] This comparative example provides a formula for a curing agent for concrete pipes, except that the other conditions are the same as in Example 1, except that there are 10 parts of pure butyl ester diluent.

[0113] Comparative Example 5

[0114] This comparative example provides a curing agent formulation for concrete pipes, except that the conditions are the same as in Example 1, except that there are 0 parts of silicate cement and 0 parts of slag powder.

[0115] Comparative Example 6

[0116] The difference between this comparative example and the embodiment is that, when curing the concrete pipe, the curing agent for concrete pipes provided in the embodiment is not sprayed, but water spraying is used for moisturizing curing.

[0117] Test case

[0118] The curing agents used for concrete pipes in Implementation Cases 1-5 and Comparative Cases 1-5 were sprayed onto the surfaces of identical, freshly demolded concrete pipes using the same construction method, as well as the concrete pipe in Comparative Case 6 without curing agent application. After standard curing for 28 days, all samples were cut into standard specimens. The compressive strength of the different specimens was tested, and the adhesion, impact resistance, water penetration resistance, water resistance, and temperature resistance of the curing agent layer on the surface of the specimens with different curing agents were also tested. The experimental data are shown in Table 1.

[0119] Table 1. Test data of curing agents for concrete pipes

[0120]

[0121]

[0122]

[0123] According to the test data in Table 1, compared with Example 1, the curing agent formula of Comparative Example 1 reduced the amount of silicate cement to 5 parts. Compared with the Example, the concrete specimens cured in Comparative Example 1 showed a significant decrease in adhesion, impact resistance, temperature resistance, 28-day compressive strength, water permeability, aging resistance and water resistance.

[0124] Compared to Example 1, the curing agent formulation of Comparative Example 2 increased the amount of silicate cement to 30 parts. Compared with the Example, the 28-day compressive strength, adhesion, impact resistance, water permeability resistance, water resistance, aging resistance and temperature resistance of the concrete specimens cured in Comparative Example 2 all decreased significantly.

[0125] Compared to Example 1, the curing agent formulation of Comparative Example 3 increased the amount of pure butyl ester diluent to 60 parts. Compared with the example, the 28-day compressive strength of the concrete specimens cured in Comparative Example 3, compared with Example 2, showed a significant decrease in adhesion, impact resistance, water penetration resistance, water resistance, aging resistance, and temperature resistance.

[0126] Compared to Example 1, the curing agent formulation of Comparative Example 4 reduced the amount of pure butyl ester diluent to 10 parts. Compared with the example, the concrete specimens cured in Comparative Example 4 showed a significant decrease in compressive strength, adhesion, impact resistance, water permeability, water resistance, aging resistance, and temperature resistance at 28 days.

[0127] Compared to Example 1, the curing agent formulation of Comparative Example 5 removed two components, silicate cement and slag powder, and only used a single-component polyurea and diluent mixture. Compared with the example, the concrete specimens cured in Comparative Example 5 showed a significant decrease in compressive strength, adhesion, impact resistance, water permeability, water resistance, aging resistance and temperature resistance at 28 days.

[0128] Compared to Example 1, Comparative Example 6 did not apply a curing agent to the concrete pipes but instead used water spraying for moisture retention curing. Compared with Example 1, the compressive strength of the concrete specimens in Comparative Example 6 decreased significantly at 28 days.

[0129] Based on the above tests, it is evident that, with the selected combination of silicate cement, diluent, single-component polyurea, and slag powder, the concrete pipe curing agent of this invention significantly improves the water retention, adhesion, and impact resistance of the concrete curing agent. In particular, the curing effect on concrete pipes is optimal when the curing agent is prepared by combining 130 parts of single-component polyurea, 40 parts of propylene carbonate diluent, 15 parts of 800-1000 mesh silicate cement, and 8 parts of 800-1200 mesh slag powder.

[0130] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A curing agent for concrete pipes, characterized in that, It includes the following components in parts by weight: 100-160 parts of single-component polyurea; 30-50 parts of diluent; 10-20 parts of silicate cement; and 6-10 parts of slag powder.

2. The curing agent for concrete pipes according to claim 1, characterized in that, It includes the following components in parts by weight: 115-145 parts of single-component polyurea; 35-45 parts of diluent; 12.5-17.5 parts of silicate cement; and 7-9 parts of slag powder.

3. The curing agent for concrete pipes according to claim 1, characterized in that, The components include the following parts by weight: 130 parts of single-component polyurea; 40 parts of diluent; 15 parts of silicate cement; and 8 parts of slag powder.

4. The curing agent for concrete pipes according to any one of claims 1-3, characterized in that, The silicate cement has a particle size of 800-1000 mesh; and / or the slag powder has a particle size of 800-1200 mesh.

5. The curing agent for concrete pipes according to any one of claims 1-3, characterized in that, The diluent is any one or a mixture of two or more of butyl acetate, xylene, dimethyl acetate, and propylene carbonate.

6. A method for preparing a curing agent for concrete pipes according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Weigh the silicate cement and the slag powder according to the proportion, stir and mix them evenly to obtain the first mixed material; S2. Weigh the single-component polyurea and the diluent according to the proportion, stir and mix them to obtain a second mixed material, and then add the first mixed material obtained in step S1 to the second mixed material and mix them to obtain a curing agent for concrete pipes.

7. The method for preparing the curing agent for concrete pipes according to claim 6, characterized in that, In step S2, the single-component polyurea and the diluent are stirred and mixed for 2-3 minutes to obtain the second mixed material; and / or, the first mixed material is added to the second mixed material and stirred and mixed for 3-4 minutes to obtain the curing agent for concrete pipes.

8. The method for preparing the curing agent for concrete pipes according to claim 6, characterized in that, In step S2, the viscosity of the prepared concrete pipe curing agent is 600-1500 MPa·s.

9. A method for applying a curing agent to concrete pipes, characterized in that, The curing agent is the curing agent for concrete pipes as described in any one of claims 1-5, or the curing agent is prepared by the preparation method described in any one of claims 6-8; the construction method is: spraying the curing agent onto the surface of the concrete pipe and then curing it.

10. The construction method according to claim 9, characterized in that, The ambient temperature during construction shall not be lower than 10℃; and / or, the curing agent shall be sprayed onto the surface of the concrete pipe within 30 minutes after preparation; and / or, the thickness of the curing agent sprayed onto the surface of the concrete pipe shall be 0.5-1mm; and / or, the curing agent shall be cured 5-10 minutes after being sprayed onto the surface of the concrete pipe.

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