Concrete tackifier as well as preparation method and application thereof

Abstract

The invention discloses a concrete tackifier and a preparation method and application thereof, and belongs to the technical field of concrete admixtures, the concrete tackifier comprises a nanometer material, a high-viscosity polymer, a water reducing agent and / or an organic matter additive, the high-viscosity polymer is a mixture of hydroxypropyl methyl cellulose and polyacrylamide, and the water reducing agent is a mixture of hydroxypropyl methyl cellulose and polyacrylamide. According to the concrete tackifier disclosed by the invention, a three-dimensional network structure is formed among molecular chains through synergistic cooperation of the nano material and the high-viscosity polymer, so that the cohesiveness is remarkably improved, and meanwhile, micropores are filled with the nano particles, and the compactness is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete admixtures, and particularly to a concrete thickener and its preparation method and application. Background Art

[0002] A concrete thickener is a chemical additive used to improve the working performance of concrete and is widely used in construction projects. Its main function is to increase the viscosity of concrete, improve its fluidity and pumpability, and at the same time reduce segregation and bleeding phenomena. With the continuous improvement of the requirements for concrete performance in the construction industry, the research and application of thickeners have attracted increasing attention.

[0003] Currently, common concrete thickeners on the market mainly include: mostly high-viscosity cellulose ethers (such as HPMC) or organic polymer materials. These thickeners have the following problems: the viscosity increase is limited, and fluidity loss is likely to occur at high dosages; some thickeners have poor compatibility with water reducers, affecting the pumping performance of concrete; the cost is relatively high, and some raw materials lack environmental friendliness. Summary of the Invention

[0004] The purpose of the present invention is to provide a concrete thickener for the technical defects existing in the prior art.

[0005] Another purpose of the present invention is to provide a preparation method of the concrete thickener.

[0006] Another purpose of the present invention is to provide the application of the concrete thickener in building materials.

[0007] The technical solution adopted to achieve the purpose of the present invention is as follows:

[0008] A concrete thickener includes a nanomaterial, a highly viscous polymer, a water reducer, and / or an organic additive. Among them, by mass parts, the ratio of the nanomaterial, water-soluble polymer, and water reducer is (55 - 80):(10 - 20):(5 - 15);

[0009] The highly viscous polymer is a mixture of hydroxypropyl methylcellulose and polyacrylamide, and the mass ratio of hydroxypropyl methylcellulose to polyacrylamide is 1:2;

[0010] The organic additive is a retarder, an early strength agent, or an antifoaming agent.

[0011] In the above technical solution, when the organic additive is a retarder, the mass ratio of the nanomaterial, water-soluble polymer, water reducer, and retarder is (55 - 80):(10 - 20):(5 - 15):(0 - 5);

[0012] When the organic additive is an early strength agent, the mass ratio of the nano material, the water-soluble polymer, the water reducing agent and the early strength agent is (55-80):(10-20):(5-15):(0-10);

[0013] When the organic additive is an air entraining agent, the mass ratio of the nano material, the water-soluble polymer, the water reducing agent and the air entraining agent is (55-80):(10-20):(5-15):(0-0.05).

[0014] In the above technical solution, the particle size of the nano material is 10-50 nm.

[0015] In the above technical solution, the nano material is nano silica or modified nano clay.

[0016] In the above technical solution, the early strength agent is calcium formate, the setting retarder is sodium gluconate, the air entraining agent is silicone air entraining agent, and the water reducing agent is polycarboxylate water reducing agent.

[0017] Another aspect of the present invention also includes a preparation method of the concrete thickening agent, wherein hydroxypropyl methylcellulose and polyacrylamide are uniformly mixed, and then the nano material and / or the organic additive are added and stirred evenly to obtain the concrete thickening agent.

[0018] Another aspect of the present invention also includes the application of the concrete thickening agent in building materials.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. The concrete thickening agent of the present invention forms a three-dimensional network structure between molecular chains through the synergistic cooperation of the nano material and the highly viscous polymer, significantly improving the cohesiveness. At the same time, the nano particles fill the micro pores, enhancing the density.

[0021] 2. The concrete thickening agent of the present invention uses industrial by-product nano silica, which is beneficial to environmental protection.

[0022] 3. The present invention optimizes the ratio of the polycarboxylate water reducing agent, the nano silica and the highly viscous polymer to ensure good fluidity at high viscosity. Description of the Drawings

[0023] Figure 1 It is a comparison chart of the 28-day chloride ion penetration depth of the concrete thickening agent of Example 1 of the present invention incorporated into concrete (test group) and the reference group (blank group) without incorporation.

[0024] Figure 2 It is a comparison chart of the 28-day carbonation depth of the concrete thickening agent of Example 1 of the present invention incorporated into concrete (test group) and the reference group (blank group) without incorporation. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] Example 1

[0027] A method for preparing a concrete viscosity enhancer comprises the following steps: evenly mixing 50g of hydroxypropyl methylcellulose and 100g of polyacrylamide, and then adding 800g of nano silicon dioxide and 50g of a water reducing agent and stirring the mixture evenly to obtain the concrete viscosity enhancer.

[0028] Concrete with different strength grades is prepared as shown in Table 1.

[0029] Table 1 Concrete mix ratio / kg / m 3

[0030] Strength grade Cement Fly ash Aggregate Sand Water reducing agent Water C30 280 70 1080 800 3.5 160 C30 fine aggregate 400 50 845 845 4.5 180 C60 400 120 1140 640 5.2 156

[0031] The properties of the concrete with strength grade C30 fine aggregate in Table 1 and the concrete with strength grade C30 fine aggregate mixed with the concrete viscosity enhancer of Example 1 were tested. The test results are shown in Table 2.

[0032] Table 2

[0033]

[0034] From Table 2 and Figure 1 - Figure 2 It can be seen that after the addition of concrete viscosity enhancer, the fine particles in the viscosity enhancer filled the pores, making the concrete denser, so that the viscosity and impermeability of the concrete in the test group were improved. The chloride ion permeability coefficient of the concrete was reduced by 68.9%, the carbonization depth was reduced by 38.7%, and the viscosity ratio was 165%.

[0035] Example 2

[0036] 50 g of hydroxypropyl methylcellulose and 100 g of polyacrylamide were mixed evenly, and then 700 g of nano silicon dioxide, 50 g of water reducer and 100 g of calcium formate were added and stirred evenly to obtain a concrete viscosity enhancer.

[0037] Example 3

[0038] 50 g of hydroxypropyl methylcellulose and 100 g of polyacrylamide were mixed evenly, and then 750 g of nano silicon dioxide, 50 g of water reducer and 50 g of sodium gluconate were added and stirred evenly to obtain a concrete viscosity enhancer.

[0039] Example 4

[0040] Mix 50 g of hydroxypropyl methylcellulose and 100 g of polyacrylamide evenly, then add 799.5 g of nano-silica, 50 g of water reducing agent and 0.5 g of silicone defoamer and stir evenly to obtain a concrete thickening agent.

[0041] Example 5

[0042] Mix 50 g of hydroxypropyl methylcellulose and 100 g of polyacrylamide evenly, then add 700 g of nano-silica and 150 g of water reducing agent and stir evenly to obtain a concrete thickening agent.

[0043] Comparative Example 1

[0044] A preparation method of a concrete admixture, mix 800 g of nano-silica, 50 g of hydroxypropyl methylcellulose and 50 g of water reducing agent evenly to obtain a concrete admixture.

[0045] Comparative Example 2

[0046] A preparation method of a concrete admixture, mix 800 g of nano-silica, 100 g of polyacrylamide and 50 g of water reducing agent evenly to obtain a concrete admixture.

[0047] Comparative Example 3

[0048] A preparation method of a concrete admixture, mix 800 g of nano-silica and 50 g of water reducing agent evenly to obtain a concrete admixture.

[0049] Comparative Example 4

[0050] A preparation method of a concrete admixture, mix 50 g of hydroxypropyl methylcellulose, 100 g of polyacrylamide and 50 g of water reducing agent evenly to obtain a concrete admixture.

[0051] Incorporate the concrete thickening agents of Examples 1 - 5 into the prepared concrete in Table 1 at different dosages, and compare with the blank group without adding the concrete thickening agent to test the performance of the concrete, as shown in Tables 3 - 5 specifically.

[0052] Table 3 Concrete application performance of different samples (C30)

[0053]

[0054] Table 4 Concrete application performance of different samples (C30 fine aggregate)

[0055]

[0056] Table 5 Concrete application performance of different samples (C60)

[0057]

[0058]

[0059] As can be seen from Table 3 to Table 5, compared with the blank group (concretes of different strength grades without adding concrete thickening agent), the slump / spread and compressive strength of concretes of different strength grades added with concrete thickening agent have been significantly improved.

[0060] The concrete thickening agent of Example 1 and the concrete admixtures of Comparative Examples 1-4 were incorporated into the concrete with a grade strength of C30 fine aggregate prepared in Table 1 at the same dosage, and the viscosities were respectively tested. By testing the viscosity of the concrete with a grade strength of C30 fine aggregate, the viscosity ratio was calculated, and the results are shown in Table 6.

[0061] Table 6

[0062]

[0063] According to the requirements of the Railway Concrete Standard TB / T 3275-2018 of the People's Republic of China, the viscosity ratio of the thickening agent is ≥150%. Viscosity ratio = viscosity of concrete with thickening agent / viscosity of concrete without thickening agent. As can be seen from Table 6, the viscosity ratios in Comparative Documents 1-4 do not meet the requirements. It can be seen that the four substances of hydroxypropyl methylcellulose, polyacrylamide, nano-silica and water reducing agent in the concrete thickening agent of the present invention are all indispensable and cooperate synergistically to finally meet the industry requirements.

[0064] 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 refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A concrete viscosity enhancer, characterized in that: The invention comprises nanomaterials, high viscosity polymers, water reducing agents and / or organic additives, wherein the ratio of the nanomaterials, water-soluble polymers and water reducing agents is (55-80): (10-20): (5-15) by weight. The high viscosity polymer is a mixture of hydroxypropyl methylcellulose and polyacrylamide, and the mass ratio of the hydroxypropyl methylcellulose to the polyacrylamide is 1:2; The organic additive is a retarder, an early strength agent or a defoamer.

2. The concrete viscosity enhancer according to claim 1, characterized in that: When the organic additive is a retarder, the mass ratio of the nano material, the water-soluble polymer, the water reducer and the retarder is (55-80): (10-20): (5-15): (0-5); When the organic additive is an early strength agent, the mass ratio of the nano material, the water-soluble polymer, the water reducing agent and the early strength agent is (55-80): (10-20): (5-15): (0-10); When the organic additive is a defoaming agent, the mass ratio of the nano material, the water-soluble polymer, the water reducing agent and the defoaming agent is (55-80): (10-20): (5-15): (0-0.05).

3. The concrete viscosity enhancer according to claim 1, characterized in that: The particle size of the nano material is 10 to 50 nm.

4. The concrete viscosity enhancer according to claim 1, characterized in that: The nano material is nano silicon dioxide.

5. The concrete viscosity enhancer according to claim 1, characterized in that: The nano material is modified nano clay.

6. The concrete viscosity enhancer according to claim 1, characterized in that: The early strength agent is calcium formate, the retarder is sodium gluconate, the defoamer is an organosilicon defoamer, and the water reducer is a polycarboxylic acid water reducer.

7. The method for preparing a concrete viscosity enhancer according to any one of claims 1 to 6, characterized in that: The hydroxypropyl methylcellulose and polyacrylamide are mixed evenly, and then the nanometer material and / or organic additive are added and stirred evenly to obtain the concrete viscosity enhancer.

8. Use of the concrete viscosity enhancer according to any one of claims 1 to 6 in building materials.

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