Method for preparing airport super high performance concrete by using waste ceramic tile aggregate

Abstract

The application discloses a method for preparing airport super high performance concrete by using waste ceramic tile aggregate, and comprises the following steps: (1) soaking the waste ceramic tile fine aggregate in a saturated sodium carbonate solution, adding excess Ca 2+ source after completion, separating the fine aggregate after standing, and then drying to obtain pretreated fine aggregate; (2) spraying a sodium alginate solution on the pretreated fine aggregate and stirring uniformly, spraying a Ca 2+ containing solution after standing, and spraying a mixture of citric acid and ethanol. After standing, the fine aggregate is dried to obtain modified waste ceramic tile fine aggregate; and (3) uniformly mixing cement, river sand fine aggregate, modified waste ceramic tile fine aggregate, fly ash, silica fume, fiber, water reducing agent and mixing water to obtain super high performance concrete. The application not only reduces the adverse effect on the fluidity of the concrete, but also improves the dispersion degree of the retarder and the stability of the prepared super high performance concrete, so that the application is more suitable for the construction requirements of the airport runway.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of airport concrete preparation, and particularly relates to a method for preparing airport super high performance concrete by using waste ceramic tile aggregate. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of increasing an understanding of the general context of the present application and does not necessarily constitute an acknowledgement or any form of suggestion that this information forms part of the prior art already known to a person of ordinary skill in the art.

[0003] At present, airport runways are generally paved with concrete. Compared with other building materials, the concrete airport runway has the advantages of high strength, compression resistance, low cost, relatively easy construction, and is more suitable for bearing the friction and impact of the runway caused by the aircraft during the process of taking off, landing and taxiing. Due to the above-mentioned special use environment of the aircraft runway, the concrete runway is more prone to cracking, peeling, spalling and wear and tear during service. Therefore, the airport concrete has higher requirements for various mechanical performance indicators. The super high performance concrete is an innovative new building material designed by using the maximum packing density theory, that is, the gaps between the millimeter-sized particles (fine aggregate) are filled with micrometer-sized particles (cement, fly ash, and mineral powder), and the gaps between the micrometer-sized particles are filled with sub-micrometer-sized particles (silica fume), so that the pore structure is more compact, and the strength and durability are more excellent. The super high performance concrete is commonly used in bridge, tunnel, water port wharf, airport runway and other engineering construction.

[0004] China produces hundreds of millions of tons of waste ceramic tiles every year, which are difficult to be recycled by ceramic tile manufacturing enterprises, and most of them are simply treated as construction waste, such as landfill, used as roadbed materials, etc. In addition, some researchers try to use waste ceramic tiles as concrete aggregate, which not only promotes the resource utilization of such construction waste, but also reduces the use of non-renewable resources such as natural sandstone. At the same time, the waste ceramic tile aggregate also has the characteristics of lighter concrete quality and better impermeability. However, the present inventors found that when the waste ceramic tile aggregate is added to the super high performance concrete to replace the natural sand fine aggregate therein, the fluidity of the concrete becomes poor, which further leads to an increase in the internal pore defects of the concrete and a decrease in the mechanical properties. The reason is that the super high performance concrete controls the water-cement ratio at a relatively low level in order to ensure higher compactness, and the water absorption rate of the waste ceramic tile aggregate is higher than that of the natural sandstone aggregate, which is more likely to absorb the mixing water, thereby reducing the mixing water in the concrete, reducing the fluidity, and increasing the difficulty of vibration compaction. SUMMARY

[0005] In view of the above problems, the application discloses a method for preparing airport super high performance concrete by using waste ceramic tile aggregate.

[0006] The method for preparing airport super high performance concrete by using waste ceramic tile aggregate comprises the following steps:

[0007] (1) soaking the waste ceramic tile fine aggregate in a sodium carbonate saturated solution, adding an excess of Ca 2+ source after completion, separating the fine aggregate after standing, and then drying to obtain pretreated fine aggregate.

[0008] (2) spraying a sodium alginate solution on the pretreated fine aggregate and stirring uniformly, spraying a Ca 2+ containing solution after standing, and then spraying a mixture of citric acid and ethanol. After completion, standing, and then drying the fine aggregate, the modified waste ceramic tile fine aggregate is obtained.

[0009] (3) uniformly mixing cement, river sand fine aggregate, modified waste ceramic tile fine aggregate, fly ash, silica fume, fiber, water reducing agent and mixing water to obtain super high performance concrete.

[0010] Further, in step (1), the molar ratio of Ca 2+ to sodium carbonate is 1.1-1.3:1. Alternatively, the Ca 2+ source comprises at least one of calcium chloride, calcium nitrate and calcium acetate.

[0011] Further, in step (1), the standing time is 15-30 min, so that the precipitation reaction of carbonate and calcium ions in the fine aggregate is fully carried out.

[0012] Further, in step (1), the drying temperature is 70-90 DEG C, and the drying time is 1-1.5 hours, so as to reduce the moisture in the pores of the fine aggregate and facilitate the entry of the sodium alginate solution.

[0013] Further, in step (2), the ratio of the pretreated fine aggregate to the sodium alginate solution is 1g:2-3.5ml. Alternatively, the mass fraction of the sodium alginate solution in the mixture is 30-40%.

[0014] Further, in step (2), the ratio of the pretreated fine aggregate to the Ca 2+ containing solution is 1g:1.2-1.8ml. Alternatively, the Ca 2+ containing solution comprises at least one of calcium chloride, calcium nitrate and calcium acetate.2+ The concentration of the Ca 2+ The solution includes at least one of a calcium chloride solution, a calcium nitrate solution, a calcium acetate solution, etc.

[0015] Further, in step (2), the ratio of the pretreated fine aggregate to the mixed solution is 1g:0.5-1.0ml. Optionally, the mass fraction of citric acid in the mixed solution is 5-8%.

[0016] Further, in step (2), the standing time is 20-30min.

[0017] Further, in step (2), the drying temperature is 40-50℃, and the drying time is 40-60min.

[0018] Further, in step (3), the ratio of the cement, the river sand fine aggregate, the modified waste ceramic tile fine aggregate, the fly ash, the silica ash, the fiber, the water reducing agent, and the mixing water is: 30-45 parts by weight: 50-60 parts by weight: 20-27 parts by weight: 5-9 parts by weight: 8-15 parts by weight: 5-7 parts by weight: 0.6-1.0 parts by weight: 8.5-14 parts by weight.

[0019] Further, in step (3), the fiber includes at least one of a polyethylene fiber, a polypropylene fiber, a carbon fiber, etc. Optionally, the length of the fiber is 10-30mm. It should be noted that a steel fiber is not suitable to be selected, because it is easy to be exposed after the abrasion of the concrete matrix, which causes damage to the tires of the airplane or other vehicles on the runway.

[0020] Further, in step (3), the water reducing agent includes any one of a polycarboxylic acid water reducing agent, a naphthalene series water reducing agent, an aliphatic water reducing agent, etc. Optionally, the water reducing rate of the water reducing agent is 20-30%.

[0021] Compared with the prior art, the present application has at least the following beneficial technical effects:

[0022] The present application first soaks the waste ceramic tile fine aggregate in a saturated sodium carbonate solution, then adds an excess of Ca 2+ After the source, the carbonate ions in the pores of the fine aggregate can react with the calcium ions to form calcium carbonate, thereby filling and compacting the pores of the fine aggregate to form a pretreated fine aggregate. Then the present application further applies a sodium alginate solution to the pretreated fine aggregate, so that the sodium alginate is adsorbed in the pores and on the surface of the pretreated fine aggregate. When spraying the Ca 2+The sodium alginate after the solution is cross-linked under the action of calcium ions. On the one hand, the sodium alginate in the pores of the pretreated fine aggregate is cross-linked to form waterproof gel, which is filled in the pores to further compact the pores, reduce the water absorption rate, and prevent the decrease of the mechanical properties caused by the decrease of the fluidity of the concrete by the waste ceramic tile aggregate. On the other hand, the sodium alginate on the surface of the pretreated fine aggregate is cross-linked to form a coating film, and the citric acid sprayed thereon is chelated with the calcium ions on the coating film. After drying and removing the ethanol, the modified waste ceramic tile fine aggregate loaded with citric acid is obtained. This kind of fine aggregate can more uniformly distribute the retarding agent citric acid in the concrete, and improve the stability of the mechanical properties of the concrete. This is because the usual way of adding a retarding agent is to directly add the retarding agent to the concrete raw materials for mixing. However, since the amount of the retarding agent added is usually small, it is difficult to achieve uniform dispersion, especially in the concrete with a lower water-cement ratio in the present application. This will cause large differences in the mechanical properties of the concrete prepared in different batches, i.e., the problem of unstable performance, which easily leads to large differences in the structural performance of the concrete in different construction sections, which is not conducive to the control of the engineering quality. The present application utilizes the process of reducing the water absorption rate of the waste ceramic tile fine aggregate, and utilizes the special relationship between calcium ions and sodium alginate and citric acid. The coating film formed by the cross-linking of the sodium alginate is used as a carrier, and the calcium ions thereon are used as binding sites, so that the citric acid retarding agent is more stably loaded on the surface of the fine aggregate, and then uniformly dispersed in the concrete with these fine aggregates, effectively improving the quality stability of the concrete prepared in different batches. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings, which form a part of the present description, are used to provide a further understanding of the present application and are incorporated in and constitute a part of the application. Embodiments of the present application and its description are used to explain the present application and do not constitute an improper limitation of the present application. Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0024] Figure 1 The compressive strength distribution diagram of the concrete test piece prepared in the following examples.

[0025] Figure 2 The effect diagram for the flow test of the following examples. DETAILED DESCRIPTION

[0026] The present application will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application and do not limit the scope of the present application. The experimental methods not specified in the following examples are usually carried out according to the conventional conditions or according to the conditions recommended by the manufacturers.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The reagents or materials used in the present application can be purchased through conventional routes. Unless otherwise specified, the reagents or materials used in the present application are used in accordance with conventional methods in the art or in accordance with the product instructions. In addition, any method and material similar or equivalent to those described can be used in the present application. The preferred methods and materials described herein are only for demonstration.

[0028] Example 1

[0029] A method for preparing airport ultra-high performance concrete using waste ceramic tile aggregate, comprising the following steps:

[0030] (1) The waste ceramic tile is crushed and passed through a 20-mesh sieve to obtain waste ceramic tile fine aggregate. The fine aggregate is soaked in a saturated sodium carbonate solution for 30 min. After completion, the fine aggregate is dried in an oven at 85°C for 1 hour according to the Ca 2+ Calcium chloride is added in a molar ratio of 1.2:1 with sodium carbonate, and then left to stand for 20 min. The fine aggregate is filtered out and placed in an oven to dry at 85°C for 1 hour, obtaining the pretreated fine aggregate.

[0031] (2) The pretreated fine aggregate is first sprayed with a 30% sodium alginate solution in a ratio of 1g:3ml, stirred uniformly, and left to stand for 20 min. Then, 1 mol / L calcium chloride solution is sprayed onto the pretreated fine aggregate in a ratio of 1g:1.5ml, stirred uniformly. Then, a mixture of citric acid and ethanol (with a mass fraction of citric acid of 6%) is sprayed onto the pretreated fine aggregate in a ratio of 1g:0.8ml, stirred uniformly, and left to stand for 30 min. Then, the obtained fine aggregate is placed in an oven to dry at 40°C for 60 min, obtaining the modified waste ceramic tile fine aggregate.

[0032] (3) 42.5 ordinary portland cement, river sand fine aggregate, the modified waste ceramic tile fine aggregate prepared in this embodiment, fly ash, silica fume, and polyethylene fibers with a length of 20mm are placed in a mixer in a ratio of 40 parts by weight:55 parts by weight:24 parts by weight:7 parts by weight:12 parts by weight:6 parts by weight, dry mixed for 3 min, then 0.8 parts by weight of polycarboxylic acid water reducer (water reducing rate 30%) and 11.5 parts by weight of mixing water are added and stirred for 5 min, obtaining the ultra-high performance concrete slurry.

[0033] Five groups of concrete test pieces are prepared using the ultra-high performance concrete slurry prepared in this embodiment, and then the compressive strength of the concrete test pieces is tested according to the "Ultra-high Performance Concrete Test Method Standard" (T / CECS 864-2021) when the curing period is 28 days. The compressive strength distribution of each concrete test piece is as follows: Figure 1The average value of the compressive strength of the above five groups of test pieces is calculated as the compressive strength of the ultra-high performance concrete of the present embodiment. In addition, the fluidity of the ultra-high performance concrete slurry prepared in the present embodiment is tested according to the “Cement Mortar Fluidity Test Method” (GB / T 2419-2005) (reference Figure 2 ). The test results of the above two performance indicators are: compressive strength = 112.85 MPa, fluidity = 213 mm.

[0034] Example 2

[0035] A method for preparing airport ultra-high performance concrete using waste ceramic tile aggregate, comprising the following steps:

[0036] (1) The waste ceramic tile is crushed and passed through a 30-mesh sieve to obtain waste ceramic tile fine aggregate. The fine aggregate is soaked in a saturated sodium carbonate solution for 20 min. After completion, calcium nitrate is added in a molar ratio of 1.1:1 with respect to sodium carbonate, and then left to stand for 15 min. The fine aggregate is filtered out and placed in an oven to dry at 70°C for 1.5 hours to obtain pretreated fine aggregate. 2+ (1) The waste ceramic tile is crushed and passed through a 30-mesh sieve to obtain waste ceramic tile fine aggregate. The fine aggregate is soaked in a saturated sodium carbonate solution for 20 min. After completion, calcium nitrate is added in a molar ratio of 1.1:1 with respect to sodium carbonate, and then left to stand for 15 min. The fine aggregate is filtered out and placed in an oven to dry at 70°C for 1.5 hours to obtain pretreated fine aggregate.

[0037] (2) The pretreated fine aggregate is first sprayed with a 35% sodium alginate solution in a ratio of 1g:3.5ml, stirred uniformly, and left to stand for 20 min. Then, 0.9 mol / L calcium nitrate solution is sprayed onto the pretreated fine aggregate in a ratio of 1g:1.8ml, and stirred uniformly. Then, a mixture of citric acid and ethanol (with a mass fraction of citric acid of 5%) is sprayed onto the pretreated fine aggregate in a ratio of 1g:1.0ml, stirred uniformly, and left to stand for 20 min. Then, the obtained fine aggregate is placed in an oven to dry at 50°C for 40 min to obtain modified waste ceramic tile fine aggregate.

[0038] (3) 42.5 ordinary Portland cement, river sand fine aggregate, the modified waste ceramic tile fine aggregate prepared in the present embodiment, fly ash, silica fume, and polypropylene fibers with a length of 10 mm are placed in a mixer in a ratio of 45 parts by weight:60 parts by weight:27 parts by weight:9 parts by weight:15 parts by weight:7 parts by weight, dry mixed for 3 min, then 1.0 part by weight of polycarboxylic acid water reducer (water reducing rate 20%) and 14 parts by weight of mixing water are added and stirred for 5 min to obtain an ultra-high performance concrete slurry.

[0039] Five groups of concrete test pieces are prepared using the ultra-high performance concrete slurry prepared in the present embodiment, and then the compressive strength of the concrete test pieces after curing for 28 days is tested according to the “Ultra-High Performance Concrete Test Method Standard” (T / CECS 864-2021). The compressive strength distribution of each concrete test piece is as follows: Figure 1The average value of the compressive strength of the above five groups of test pieces is calculated as the compressive strength of the ultra-high performance concrete of the present embodiment. In addition, the fluidity of the ultra-high performance concrete slurry prepared in the present embodiment is tested according to the "Cement Mortar Fluidity Test Method" (GB / T 2419-2005). The test results of the above two performance indicators are: compressive strength = 109.11 MPa, fluidity = 209 mm.

[0040] Example 3

[0041] A method for preparing airport ultra-high performance concrete using waste ceramic tile aggregate, comprising the following steps:

[0042] (1) The waste ceramic tile is crushed and passed through a 10-mesh sieve to obtain waste ceramic tile fine aggregate. The fine aggregate is soaked in a saturated sodium carbonate solution for 30 min. After completion, the Ca 2+ Calcium chloride is added in a molar ratio of 1.3:1 with sodium carbonate, and then left to stand for 20 min. The fine aggregate is filtered out and placed in an oven to dry at 90℃ for 1 hour to obtain the pretreated fine aggregate.

[0043] (2) The pretreated fine aggregate is first sprayed with a 40% sodium alginate solution in a ratio of 1g:2ml, stirred uniformly, and left to stand for 20 min. Then, the pretreated fine aggregate is sprayed with a 1.5 mol / L calcium chloride solution in a ratio of 1g:1.2ml, stirred uniformly. Then, the pretreated fine aggregate is sprayed with a mixture of citric acid and ethanol (wherein the mass fraction of citric acid is 8%) in a ratio of 1g:0.5ml, stirred uniformly, and left to stand for 25 min. Then, the obtained fine aggregate is placed in an oven to dry at 45℃ for 50 min to obtain the modified waste ceramic tile fine aggregate.

[0044] (3) 42.5 ordinary Portland cement, river sand fine aggregate, the modified waste ceramic tile fine aggregate prepared in the present embodiment, fly ash, silica fume, and polyethylene fibers with a length of 30mm are placed in a mixer in a ratio of 30 parts by weight:50 parts by weight:20 parts by weight:5 parts by weight:8 parts by weight:5 parts by weight, dry mixed for 3 min, then 0.6 parts by weight of polycarboxylic acid water reducer (water reducing rate 30%) and 8.5 parts by weight of mixing water are added and stirred for 5 min to obtain an ultra-high performance concrete slurry.

[0045] Five groups of concrete test pieces are prepared using the ultra-high performance concrete slurry prepared in the present embodiment, and then the compressive strength of the concrete test pieces after curing for 28 days is tested according to the "Ultra-High Performance Concrete Test Method Standard" (T / CECS 864-2021). The compressive strength distribution of each concrete test piece is as follows: Figure 1The average value of the compressive strength of the above five groups of test pieces is calculated as the compressive strength of the ultra-high performance concrete of the present embodiment. In addition, the fluidity of the ultra-high performance concrete slurry prepared in the present embodiment is tested according to the “Cement Mortar Fluidity Test Method” (GB / T 2419-2005). The test results of the above two performance indicators are: compressive strength = 113.29 MPa, fluidity = 217 mm.

[0046] Example 4

[0047] A method for preparing airport ultra-high performance concrete using waste ceramic tile aggregate, comprising the following steps:

[0048] Five groups of concrete test pieces are prepared using the ultra-high performance concrete slurry prepared in the present embodiment, and then the compressive strength of the concrete test pieces after curing for 28 days is tested according to the “Ultra-High Performance Concrete Test Method Standard” (T / CECS 864-2021). The compressive strength distribution of each concrete test piece is shown in Figure 1 The average value of the compressive strength of the above five groups of test pieces is calculated as the compressive strength of the ultra-high performance concrete of the present embodiment. In addition, the fluidity of the ultra-high performance concrete slurry prepared in the present embodiment is tested according to the “Cement Mortar Fluidity Test Method” (GB / T 2419-2005). The test results of the above two performance indicators are: compressive strength = 113.29 MPa, fluidity = 217 mm.

[0049] Example 5

[0050] A method for preparing airport ultra-high performance concrete using waste ceramic tile aggregate, comprising the following steps:

[0051] (1) The waste ceramic tile is crushed and passed through a 20-mesh sieve to obtain waste ceramic tile fine aggregate. The fine aggregate is soaked in a saturated sodium carbonate solution for 30 min. After completion, calcium chloride is added in a molar ratio of 1.2:1 with respect to sodium carbonate, and then left to stand for 20 min. The fine aggregate is filtered out and placed in an oven to dry at 85°C for 1 hour, obtaining a pretreated fine aggregate. 2+ Calcium chloride is added in a molar ratio of 1.2:1 with respect to sodium carbonate, and then left to stand for 20 min. The fine aggregate is filtered out and placed in an oven to dry at 85°C for 1 hour, obtaining a pretreated fine aggregate.

[0052] (2) Spray a 30% sodium alginate solution onto the pretreated fine aggregate at a ratio of 1g:3ml, stir well, and let stand for 20 minutes. Then spray a 1mol / L calcium chloride solution onto the pretreated fine aggregate at a ratio of 1g:1.5ml, stir well, and let stand for 30 minutes. Then place the obtained fine aggregate in an oven and dry at 40℃ for 60 minutes to obtain modified waste ceramic tile fine aggregate.

[0053] (3) 42.5 ordinary silicate cement, river sand fine aggregate, the modified waste ceramic tile fine aggregate prepared in this embodiment, fly ash, silica fume, and polyethylene fiber with a length of 20 mm are placed in a mixer and dry-mixed for 3 minutes in a ratio of 40 parts by weight: 55 parts by weight: 24 parts by weight: 7 parts by weight: 12 parts by weight: 6 parts by weight. Then, 0.8 parts by weight of polycarboxylate superplasticizer (water reduction rate of 30%), 0.05 parts by weight of citric acid and 11.5 parts by weight of mixing water are added and mixed for 5 minutes to obtain ultra-high performance concrete slurry.

[0054] Five groups of concrete specimens were prepared using the ultra-high performance concrete slurry prepared in this embodiment. The compressive strength of the concrete specimens after curing for 28 days was then tested according to the "Standard for Test Methods of Ultra-High Performance Concrete" (T / CECS 864-2021). The distribution of compressive strength of each concrete specimen is shown below. Figure 1 As shown, the average compressive strength of the five groups of specimens was calculated as the compressive strength of the ultra-high performance concrete in this embodiment. In addition, the flowability of the ultra-high performance concrete slurry prepared in this embodiment was tested according to the "Method for Determination of Flowability of Cement Mortar" (GB / T 2419-2005). The test results for the above two performance indicators are: compressive strength = 106.06 MPa, flowability = 201 mm.

[0055] Example 6

[0056] A method for preparing ultra-high performance concrete for airports using waste ceramic tile aggregate is the same as in Example 2 above, except that the modified waste ceramic tile fine aggregate in this example is prepared using the following method:

[0057] (1) After crushing the waste ceramic tiles, pass them through a 30-mesh sieve to obtain fine aggregate from the waste ceramic tiles. Soak the fine aggregate in a saturated sodium carbonate solution for 20 minutes. After completion, follow the Ca... 2+ Calcium nitrate was added to sodium carbonate at a molar ratio of 1.1:1, and then allowed to stand for 15 minutes. The fine aggregate was filtered out and dried in an oven at 70°C for 1.5 hours to obtain the pretreated fine aggregate.

[0058] (2) Spray a mixture of citric acid and ethanol (with a mass fraction of 5% citric acid) onto the pretreated fine aggregate at a ratio of 1g:1.0ml. After stirring evenly, let it stand for 20 minutes. Then place the obtained fine aggregate in an oven and dry it at 50℃ for 40 minutes to obtain modified waste ceramic tile fine aggregate.

[0059] Five groups of concrete specimens were prepared using the ultra-high performance concrete slurry prepared in this embodiment. The compressive strength of the concrete specimens after curing for 28 days was then tested according to the "Standard for Test Methods of Ultra-High Performance Concrete" (T / CECS 864-2021). The distribution of compressive strength of each concrete specimen is shown below. Figure 1 As shown, the average compressive strength of the five groups of specimens was calculated as the compressive strength of the ultra-high performance concrete in this embodiment. In addition, the flowability of the ultra-high performance concrete slurry prepared in this embodiment was tested according to the "Method for Determination of Flowability of Cement Mortar" (GB / T 2419-2005). The test results for the above two performance indicators are: compressive strength = 102.95 MPa, flowability = 193 mm.

[0060] Example 7

[0061] A method for preparing ultra-high performance concrete for airports using waste ceramic tile aggregate is similar to Example 3 above, except that the modified waste ceramic tile fine aggregate in this example is prepared as follows: Waste ceramic tiles are crushed and passed through a 10-mesh sieve to obtain waste ceramic tile fine aggregate. A 40% sodium alginate solution is sprayed onto the waste ceramic tile fine aggregate at a ratio of 1g:2ml, stirred evenly, and allowed to stand for 20 minutes. Then, a 1.5mol / L calcium chloride solution is sprayed onto the pretreated fine aggregate at a ratio of 1g:1.2ml, and stirred evenly. Next, a mixture of citric acid and ethanol (with a citric acid mass fraction of 8%) is sprayed onto the pretreated fine aggregate at a ratio of 1g:0.5ml, stirred evenly, and allowed to stand for 25 minutes. Finally, the obtained fine aggregate is placed in an oven and dried at 45℃ for 50 minutes to obtain the modified waste ceramic tile fine aggregate.

[0062] Five groups of concrete specimens were prepared using the ultra-high performance concrete slurry prepared in this embodiment. The compressive strength of the concrete specimens after curing for 28 days was then tested according to the "Standard for Test Methods of Ultra-High Performance Concrete" (T / CECS 864-2021). The distribution of compressive strength of each concrete specimen is shown below. Figure 1The average value of the compressive strength of the above five groups of test pieces is calculated as the compressive strength of the ultra-high performance concrete of the present embodiment. In addition, the fluidity of the ultra-high performance concrete slurry prepared in the present embodiment is tested according to the “Cement Mortar Fluidity Test Method” (GB / T 2419-2005). The test results of the above two performance indicators are: compressive strength = 104.59 MPa, fluidity = 186 mm.

[0063] Example 8

[0064] A method for preparing airport ultra-high performance concrete using waste ceramic tile aggregates, comprising the following steps:

[0065] (1) The waste ceramic tile is crushed and passed through a 30-mesh sieve to obtain waste ceramic tile fine aggregate. The fine aggregate is soaked in a saturated sodium carbonate solution for 20 min. After completion, the Ca 2+ Calcium nitrate is added in a molar ratio of 1.1:1 with sodium carbonate, and then left to stand for 15 min. The fine aggregate is filtered out and placed in an oven to dry at 70°C for 1.5 hours, obtaining the pretreated fine aggregate.

[0066] (2) The pretreated fine aggregate is first sprayed with a 35% sodium alginate solution in a ratio of 1g:3.5ml, stirred evenly, and left to stand for 20 min. Then, the pretreated fine aggregate is sprayed with a mixture of citric acid and ethanol (with a mass fraction of citric acid of 5%) in a ratio of 1g:1.0ml, stirred evenly, and left to stand for 20 min. Then, the obtained fine aggregate is placed in an oven to dry at 50°C for 40 min, obtaining the modified waste ceramic tile fine aggregate.

[0067] Five groups of concrete test pieces are prepared using the ultra-high performance concrete slurry prepared in the present embodiment, and then the compressive strength of the concrete test pieces after curing for 28 days is tested according to the “Ultra-High Performance Concrete Test Method Standard” (T / CECS 864-2021). The compressive strength distribution of each concrete test piece is shown in Figure 1 The average value of the compressive strength of the above five groups of test pieces is calculated as the compressive strength of the ultra-high performance concrete of the present embodiment. In addition, the fluidity of the ultra-high performance concrete slurry prepared in the present embodiment is tested according to the “Cement Mortar Fluidity Test Method” (GB / T 2419-2005). The test results of the above two performance indicators are: compressive strength = 104.59 MPa, fluidity = 186 mm.

[0068] It can be seen from the test results of the above embodiments that the distribution range of the super high performance concrete prepared by the processes of the embodiments 1, 2 and 3 is obviously smaller than that of the other embodiments, and the super high performance concrete has higher compressive strength and better fluidity, which indicates that the processes of the embodiments 1-3 not only reduce the decrease of the mechanical properties caused by the decrease of the fluidity of the concrete due to the waste ceramic tile aggregates, but also improve the dispersion degree of the retarder citric acid, thereby improving the quality stability of the different batches of the prepared super high performance concrete.

[0069] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments or make equivalent replacements to some of the technical features. Any modifications, equivalent replacements or improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing airport ultra-high performance concrete using waste ceramic tile aggregate, characterized by, The method comprises the following steps: (1) the waste ceramic tile fine aggregate is soaked in a saturated sodium carbonate solution, an excess Ca 2+ source is added after completion, the fine aggregate is separated after standing, and then dried to obtain a pretreated fine aggregate; (2) Spraying sodium alginate solution on the pretreated fine aggregate and stirring uniformly, spraying Ca 2+ solution, and then spraying the mixture of citric acid and ethanol; after completion, standing, and then drying the fine aggregate, the modified waste ceramic tile fine aggregate is obtained; (3) uniformly mixing cement 30-45 parts by weight, river sand fine aggregate 50-60 parts by weight, modified waste ceramic tile fine aggregate 20-27 parts by weight, fly ash 5-9 parts by weight, silica ash 8-15 parts by weight, fiber 5-7 parts by weight, water reducing agent 0.6-1.0 parts by weight, and mixing water 8.5-14 parts by weight, to obtain the ultra-high performance concrete; In step (1), the Ca 2+ 1.1 to 1.3: 1 with sodium carbonate; In step (2), the ratio of the pretreated fine aggregate to the sodium alginate solution is 1 g:2-3.5 ml, the ratio of the pretreated fine aggregate to the Ca 2+ solution is 1 g:1.2-1.8 ml, and the ratio of the pretreated fine aggregate to the mixed solution is 1 g:0.5-1 ml, and the mass fraction of citric acid in the mixed solution is 5-8%.

2. The method of claim 1, wherein the waste ceramic aggregate is used to produce the super high performance concrete for airport. In step (1), the Ca 2+ source includes at least one of calcium chloride, calcium nitrate, calcium acetate.

3. The method of claim 1, wherein the waste ceramic aggregate is used to produce the super high performance concrete for airport. In step (1), the standing time is 15-30 min.

4. The method for preparing airport ultra-high performance concrete using waste ceramic aggregate according to claim 1, characterized in that, In step (1), the drying temperature is 70-90℃, and the drying time is 1-1.5 hours.

5. The method of manufacturing airport ultra high performance concrete using waste ceramic aggregate according to claim 1, wherein, In step (2), the mass fraction of the sodium alginate solution is 30-40%.

6. The method of manufacturing airport ultra-high performance concrete using waste ceramic aggregate according to claim 1, wherein, In step (2), the Ca 2+ Ca 2+ concentration is 0.9-1.5 mol / L.

7. The method of manufacturing airport ultra high performance concrete using waste ceramic aggregate according to claim 1, wherein the waste ceramic aggregate is a waste ceramic aggregate produced by crushing a waste ceramic tile. In step (2), the Ca 2+ The solution includes at least one of a calcium chloride solution, a calcium nitrate solution, and a calcium acetate solution.

8. The method for preparing ultra-high performance concrete for airports using waste ceramic tile aggregate according to claim 1, characterized in that, In step (2), the standing time is 20-30 min. 9.The method of claim 1, wherein the waste ceramic aggregate is a waste ceramic aggregate produced by crushing a waste ceramic tile, and the waste ceramic tile is a waste ceramic tile produced by cutting a ceramic tile having a thickness of 10 mm or more. In step (2), the drying temperature is 40-50℃, and the drying time is 40-60 min.

10. The method for preparing airport ultra-high performance concrete using waste ceramic tile aggregates according to any one of claims 1 to 9, characterized in that, In step (3), the fiber comprises at least one of polyethylene fiber, polypropylene fiber and carbon fiber.

11. The method of manufacturing airport ultra-high performance concrete using waste ceramic tile aggregates according to any one of claims 1-9, characterized in that, The length of the fiber is 10-30 mm.

12. The method of manufacturing super high performance concrete for airport using waste ceramic tile aggregates according to any one of claims 1-9, characterized in that, In step (3), the water reducing agent comprises any one of polycarboxylic acid water reducing agent, naphthalene series water reducing agent and aliphatic water reducing agent.

13. The method of manufacturing super high performance concrete for airport using waste ceramic tile aggregates according to any one of claims 1-9, characterized in that, The water reducing rate of the water reducing agent is 20-30%.

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