High-strength concrete and preparation method thereof

Abstract

The invention relates to the technical field of concrete, and discloses high-strength concrete and a preparation method thereof. The concrete comprises the following components: 800 to 850 parts of cement, 150 to 160 parts of glass beads, 100 to 120 parts of mineral powder, 80 to 100 parts of silica fume, 900 to 950 parts of fine aggregate, 8 to 10 parts of a water reducing agent, 10 to 15 parts of chitosan, 20 to 25 parts of acrylamide, 1 to 2 parts of an initiator, 5 to 6 parts of a coupling agent, 1 to 2 parts of a cross-linking agent, 1 to 2 parts of nano silver oxide, 200 to 210 parts of water and 50 to 60 parts of an acetic acid solution. Chitosan and acrylamide are copolymerized to obtain a polyhydroxy copolymer with a three-dimensional network structure, so that the strength of the concrete is improved; the nano silver oxide is loaded on the three-dimensional network copolymer, the nano silver oxide has excellent antibacterial performance, polyhydroxy on the copolymer structure has good oxidability and reducibility, and the antibacterial ability of the silver oxide is synergistically promoted. The concrete prepared by the preparation method disclosed by the invention keeps high strength while having excellent antibacterial ability.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete, and in particular to a high-strength concrete and a preparation method thereof. Background Art

[0002] Concrete is a common building material, mainly composed of a mixture of cement, sand, gravel and water. However, in some special applications, such as sewer systems, marine engineering, hospitals, food processing plants, etc., the surface of concrete is susceptible to invasion by microorganisms such as bacteria and mold, causing a series of problems, including rising maintenance costs, damaged structural integrity, and potential safety hazards. At present, the common way to improve the antibacterial ability of concrete is to add antibacterial agents to concrete, but some antibacterial agents or their addition methods will affect the structure and performance of concrete, weaken the strength of concrete, and limit its wide application. Chinese patent CN115093185A discloses an antibacterial and corrosion-resistant concrete for deep sewage discharge and a preparation method thereof. The antibacterial agent used is a mixture of copper carbonate and SiO2 micropowder in a mass ratio of 1: (8-12). The method of adding the antibacterial agent is to add the antibacterial agent and dispersant, admixture, etc. into water and disperse them evenly, and then mix and stir them with cement-based raw materials. Chinese patent CN112624709A discloses an antibacterial cement concrete and its preparation method, in which titanium dioxide, zirconium dioxide and graphite phase carbon nitride are added to cement concrete. The above methods simply introduce the antibacterial agent in the form of an admixture and then stir and disperse it, which affects the overall structure of the concrete and makes it difficult to ensure the strength and durability of the concrete. In addition, the dissolution and erosion of water in a humid environment also easily causes the antibacterial components in the antibacterial concrete to be lost, affecting the antibacterial effect. Summary of the invention

[0003] In order to overcome the shortcomings and deficiencies of the prior art, the present invention aims to provide a high-strength concrete and a preparation method thereof, wherein the prepared concrete has excellent antibacterial ability while maintaining high strength.

[0004] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0005] A high-strength concrete comprises, by weight, 800-850 parts of cement, 150-160 parts of glass microspheres, 100-120 parts of mineral powder, 80-100 parts of silica fume, 900-950 parts of fine aggregate, 8-10 parts of water reducer, 10-15 parts of chitosan, 20-25 parts of acrylamide, 1-2 parts of initiator, 5-6 parts of coupling agent, 1-2 parts of cross-linking agent, 1-2 parts of nano silver oxide, 200-210 parts of water and 50-60 parts of acetic acid solution.

[0006] Preferably, the mineral powder is S95 grade mineral powder.

[0007] Preferably, the fine aggregate is quartz sand.

[0008] Preferably, the quartz sand comprises 50% coarse sand, 15% medium sand and 35% fine sand.

[0009] Preferably, the water reducer is a polycarboxylate water reducer.

[0010] Preferably, the initiator is azobisisobutylamidine dihydrochloride.

[0011] Preferably, the coupling agent is a silane coupling agent.

[0012] Preferably, the cross-linking agent is DCP.

[0013] The method for preparing high-strength concrete comprises the following steps:

[0014] (1) adding chitosan and acrylamide to an acetic acid solution and stirring and mixing, then heating, adding an initiator, a coupling agent, a crosslinking agent, and nano silver oxide, stirring and reacting, filtering after the reaction is completed, washing with deionized water, drying and grinding into powder to obtain a chitosan acrylamide copolymer;

[0015] (2) mixing cement, glass beads, mineral powder, silica fume and fine aggregate, and then adding chitosan acrylamide copolymer, mixing and stirring to obtain a powder mixture;

[0016] (3) The water reducer is dissolved in an equal weight of water, and then added to the powder mixture and stirred evenly to obtain a solid-liquid mixture. Finally, the remaining water is added under stirring to obtain a high-strength concrete.

[0017] Preferably, the heating temperature in step (1) is 50-70° C. and the reaction time is 4-6 h.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The concrete prepared by the present invention has excellent antibacterial ability and maintains high strength. The present invention copolymerizes chitosan and acrylamide to obtain a polyhydroxy copolymer with a three-dimensional network structure, which improves the water retention capacity of the concrete and alleviates the excessive evaporation of water, thereby helping to improve the homogeneity and crack resistance of the concrete, and ultimately enhancing the strength of the concrete. In addition, nano silver oxide is loaded on the three-dimensional network copolymer, and the silver oxide has excellent antibacterial properties. When the silver oxide contacts water, silver ions are released from its surface, which has a strong bactericidal effect on various bacteria and microorganisms, and the polyhydroxyl groups on the copolymer structure have good oxidizability and reducibility, which play a synergistic role in promoting the antibacterial ability of the silver oxide. DETAILED DESCRIPTION

[0020] The modified epoxy resin conductive adhesive and its preparation method of the present invention are further described below in conjunction with the embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention.

[0021] Embodiment 1:

[0022] A high-strength concrete comprises, by weight, 800 parts of cement, 150 parts of glass microspheres, 100 parts of S95 grade mineral powder, 80 parts of silica fume, 900 parts of quartz sand, 8 parts of polycarboxylic acid water reducer, 10 parts of chitosan, 20 parts of acrylamide, 1 part of azobisisobutylamidine dihydrochloride, 5 parts of silane coupling agent, 1 part of DCP, 1 part of nano silver oxide, 200 parts of water and 50 parts of acetic acid solution.

[0023] In parts by weight, the preparation method of the high-strength concrete described in this embodiment is:

[0024] (1) adding chitosan and acrylamide to an acetic acid solution and stirring and mixing, then heating to 50° C., adding azobisisobutylamidine dihydrochloride, a silane coupling agent, DCP, and nano silver oxide, stirring and reacting for 5 hours, filtering after the reaction is completed, washing with deionized water, drying and grinding into powder to obtain a chitosan acrylamide copolymer;

[0025] (2) mixing cement, glass beads, S95 mineral powder, silica fume and quartz sand, and then adding chitosan acrylamide copolymer, mixing and stirring to obtain a powder mixture;

[0026] (3) The polycarboxylate water reducer is dissolved in an equal weight of water, and then added to the powder mixture and stirred evenly to obtain a solid-liquid mixture. Finally, the remaining water is added under stirring to obtain a high-strength concrete.

[0027] Embodiment 2:

[0028] A high-strength concrete comprises, by weight, 825 parts of cement, 155 parts of glass microspheres, 110 parts of S95 grade mineral powder, 90 parts of silica fume, 925 parts of quartz sand, 9 parts of polycarboxylic acid water reducer, 12 parts of chitosan, 22 parts of acrylamide, 1 part of azobisisobutylamidine dihydrochloride, 6 parts of silane coupling agent, 2 parts of DCP, 2 parts of nano silver oxide, 205 parts of water and 55 parts of acetic acid solution.

[0029] In parts by weight, the preparation method of the high-strength concrete described in this embodiment is:

[0030] (1) adding chitosan and acrylamide to an acetic acid solution and stirring and mixing, then heating to 70° C., adding azobisisobutylamidine dihydrochloride, a silane coupling agent, DCP, and nano silver oxide, stirring and reacting for 6 hours, filtering after the reaction is completed, washing with deionized water, drying and grinding into powder to obtain a chitosan acrylamide copolymer;

[0031] (2) mixing cement, glass beads, S95 mineral powder, silica fume and quartz sand, and then adding chitosan acrylamide copolymer, mixing and stirring to obtain a powder mixture;

[0032] (3) The polycarboxylate water reducer is dissolved in an equal weight of water, and then added to the powder mixture and stirred evenly to obtain a solid-liquid mixture. Finally, the remaining water is added under stirring to obtain a high-strength concrete.

[0033] Embodiment 3:

[0034] A high-strength concrete comprises, by weight, 850 parts of cement, 160 parts of glass microspheres, 120 parts of S95 grade mineral powder, 100 parts of silica fume, 950 parts of quartz sand, 10 parts of polycarboxylic acid water reducer, 15 parts of chitosan, 25 parts of acrylamide, 2 parts of azobisisobutylamidine dihydrochloride, 6 parts of silane coupling agent, 1 part of DCP, 2 parts of nano silver oxide, 210 parts of water and 60 parts of acetic acid solution.

[0035] In parts by weight, the preparation method of the high-strength concrete described in this embodiment is:

[0036] (1) adding chitosan and acrylamide to an acetic acid solution and stirring and mixing, then heating to 60° C., adding azobisisobutylamidine dihydrochloride, a silane coupling agent, DCP, and nano silver oxide, stirring and reacting for 6 hours, filtering after the reaction is completed, washing with deionized water, drying and grinding into powder to obtain a chitosan acrylamide copolymer;

[0037] (2) mixing cement, glass beads, S95 mineral powder, silica fume and quartz sand, and then adding chitosan acrylamide copolymer, mixing and stirring to obtain a powder mixture;

[0038] (3) The polycarboxylate water reducer is dissolved in an equal weight of water, and then added to the powder mixture and stirred evenly to obtain a solid-liquid mixture. Finally, the remaining water is added under stirring to obtain a high-strength concrete.

[0039] Comparative Example 1: The only difference between this comparative example and Example 1 is that no nano silver oxide is added to all the raw materials, and the other raw materials and steps are the same as those in Example 1.

[0040] Comparative Example 2: The difference between this comparative example and Example 1 is that chitosan and acrylamide are not added to all the raw materials, and the other raw materials and steps are the same as those in Example 1.

[0041] Comparative Example 3: The difference between this comparative example and Example 1 is that chitosan, acrylamide and nano silver oxide are not added to all the raw materials, and the other raw materials and steps are the same as those in Example 1.

[0042] Performance Test:

[0043] 1.28d compressive strength: Tested in accordance with GB / T50081-2019 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete".

[0044] 2. Antibacterial performance test:

[0045] Prepare a culture solution containing 10 g / L of peptone, 5 g / L of yeast extract and 10 g / L of sodium chloride, adjust the pH of the culture solution to 7.0, add the concrete prepared in each embodiment and comparative example to the corresponding culture solution, sterilize at high temperature, and then inject the initial bacterial solution, the initial bacterial solution is an Escherichia coli solution, and the bacterial concentration of the Escherichia coli solution is 1.5×10 8 coli solution was 5 mL, and then each sample was placed in an incubator at 37°C and cultured for 48 hours, and then the bacterial concentration in the culture solution was tested.

[0046] Table 1: Concrete performance test

[0047] 28d compressive strength (MPa) <![CDATA[48h bacterial concentration (×10 6 cells / mL)]]> Example 1 86.9 3.12 Example 2 90.4 3.05 Example 3 92.5 3.24 Comparative Example 1 87.3 176.48 Comparative Example 2 63.6 12.51 Comparative Example 3 69.7 194.75

[0048] As can be seen from the above table, the bacterial concentration of Comparative Example 1 is much higher than that of Example 1, because no nano silver oxide is added in Comparative Example 1, while the nano silver oxide in Example 1 releases silver ions, which has a strong bactericidal effect on a variety of bacteria and microorganisms, and has a very good antibacterial effect. The 28d compressive strength of Comparative Example 2 is lower than that of Example 1, because there is no copolymer of chitosan and acrylamide in Comparative Example 2, while there is a chitosan acrylamide copolymer in Example 1, and the polyhydroxy three-dimensional network structure thereof improves the water retention capacity of concrete, alleviates the excessive evaporation of water, thereby helping to improve the homogeneity and crack resistance of concrete, and finally enhances the strength of concrete. It can be seen from the combination of Comparative Examples 1-3 and Example 1 that the bacterial concentration of Example 1 is lower than that of Comparative Examples 1-3, because nano silver oxide is loaded on the three-dimensional network chitosan acrylamide copolymer, which will produce a synergistic effect, and the antibacterial effect is better than the single effect of the two.

[0049] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A high-strength concrete, characterized in that: The raw materials include, by weight, 800-850 parts of cement, 150-160 parts of glass beads, 100-120 parts of mineral powder, 80-100 parts of silica fume, 900-950 parts of fine aggregate, 8-10 parts of water reducer, 10-15 parts of chitosan, 20-25 parts of acrylamide, 1-2 parts of initiator, 5-6 parts of coupling agent, 1-2 parts of cross-linking agent, 1-2 parts of nano silver oxide, 200-210 parts of water and 50-60 parts of acetic acid solution.

2. A high-strength concrete according to claim 1, characterized in that: The mineral powder is S95 grade mineral powder.

3. The high-strength concrete according to claim 1, characterized in that: The fine aggregate is quartz sand.

4. A high-strength concrete according to claim 3, characterized in that: The quartz sand comprises 50% coarse sand, 15% medium sand and 35% fine sand.

5. The high-strength concrete according to claim 1, characterized in that: The water reducer is a polycarboxylate water reducer.

6. The high-strength concrete according to claim 1, characterized in that: The initiator is azobisisobutylamidine dihydrochloride.

7. The high-strength concrete according to claim 1, characterized in that: The coupling agent is a silane coupling agent.

8. The high-strength concrete according to claim 1, characterized in that: The cross-linking agent is DCP.

9. A method for preparing high-strength concrete according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: (1) adding chitosan and acrylamide to an acetic acid solution and stirring and mixing, then heating, adding an initiator, a coupling agent, a crosslinking agent, and nano silver oxide, stirring and reacting, filtering after the reaction is completed, washing with deionized water, drying and grinding into powder to obtain a chitosan acrylamide copolymer; (2) mixing cement, glass beads, mineral powder, silica fume and fine aggregate, and then adding chitosan acrylamide copolymer, mixing and stirring to obtain a powder mixture; (3) The water reducer is dissolved in an equal weight of water, and then added to the powder mixture and stirred evenly to obtain a solid-liquid mixture. Finally, the remaining water is added under stirring to obtain a high-strength concrete.

10. The method for preparing high-strength concrete according to claim 9, characterized in that: The heating temperature in step (1) is 50-70° C. and the reaction time is 4-6 hours.