An environmentally friendly fly ash and mineral powder double mixed concrete

Abstract

The present application relates to the technical field of concrete, and discloses an environmentally friendly fly ash and mineral powder double-mixed concrete, comprising the following raw materials by weight: 90-120 parts of cement, 40-70 parts of fly ash, 30-50 parts of mineral powder, 180-260 parts of machine-made sand, 100-150 parts of river sand, 350-500 parts of gravel, 85-100 parts of water, 3-15 parts of ethyl palmitate, and 2-8 parts of tea polyphenols. The environmentally friendly fly ash and mineral powder double-mixed concrete prepared by the present application using components with specific contents has excellent comprehensive performance, high early strength and stable performance.

Description

Technical Field

[0001] The present application relates to the technical field of concrete, and in particular to an environmentally friendly concrete mixed with fly ash and mineral powder. Background Art

[0002] Concrete is a general term for an engineering composite material that is made of aggregates bonded together by a cementitious material. Usually, concrete refers to cement as a cementitious material, sand and stone as aggregates, mixed with water in a certain proportion, and then mixed to obtain cement concrete, also known as ordinary concrete. It is a commonly used building material and is widely used in the construction of various buildings, bridges, tunnels, roads and other infrastructure.

[0003] With the development of concrete technology, admixtures have gradually become an important component of concrete, which can improve various working properties of concrete, including fluidity, filling, water retention, etc., making concrete easier to construct; it can improve the later strength of concrete, and can reduce the degree of water evaporation and chemical erosion, increase the durability of concrete, and extend its service life; and it can replace part of the cement, reduce the porosity and water absorption of the concrete, thereby reducing the amount of cement used, saving resources and energy; and reducing carbon dioxide emissions in the production process of cement, which has a certain contribution to reducing greenhouse gas emissions and alleviating global warming.

[0004] At present, there is concrete mixed with fly ash and mineral powder. Although the concrete prepared with fly ash and mineral powder has the advantages of environmental protection, increased strength and durability, improved working performance, reduced thermal cracks and reduced costs, etc.

[0005] However, concrete mixed with fly ash and mineral powder has the disadvantages of low early strength and unstable performance. This is mainly because the content of active substances in fly ash and mineral powder is lower than that of cement. Active substances are the main components of hydration reaction. When the content of active substances is low, the hydration reaction rate of concrete will decrease, resulting in a decrease in early strength. In addition, there are more amorphous substances in fly ash and mineral powder, and their structure is relatively loose, making it difficult to form a solid hydration product.

[0006] Therefore, there is an urgent need to provide a dual-mixed concrete with high early strength, stable performance and environmental protection. Summary of the invention

[0007] In order to solve at least one of the above technical problems and develop a double-mixed concrete with high early strength, stable performance and environmental protection, the present application provides an environmentally friendly fly ash and mineral powder double-mixed concrete.

[0008] On the one hand, the present application provides an environmentally friendly fly ash and mineral powder co-mixed concrete, comprising the following raw materials in parts by weight: 90-120 parts of cement, 40-70 parts of fly ash, 30-50 parts of mineral powder, 180-260 parts of machine-made sand, 100-150 parts of river sand, 350-500 parts of gravel, 85-100 parts of water, 3-15 parts of ethyl palmitate, and 2-8 parts of tea polyphenols.

[0009] By adopting the above technical scheme, the environmentally friendly fly ash and mineral powder double-mixed concrete prepared by the application using specific content components has excellent comprehensive performance, high early strength and stable performance; using specific content of fly ash and mineral powder, the porosity and water absorption of concrete are reduced, so that the fluidity, filling and water retention are improved;

[0010] The specific content of ethyl palmitate used in the present application can not only interact with substances such as Ca(OH)2 in concrete to form a more stable interface layer, refine the aggregate in the concrete, improve its compactness, promote hydration reaction, and make the concrete more compact, thereby reducing the porosity and water absorption inside the concrete and improving its strength and stability, but also has good compatibility with fly ash, mineral powder and other components in concrete, and improves the dispersion performance of fly ash and mineral powder in concrete, improves the uniformity and stability of concrete, thereby improving the working performance and mechanical properties of concrete;

[0011] The present application adopts a specific content of tea polyphenols with multiple biological activities, which can effectively improve the durability and stability of concrete, improve the dispersion performance of fly ash and mineral powder in concrete, and promote the hardening speed of concrete, improve the early strength and improve the anti-segregation ability of concrete, so that it can maintain uniformity and stability during pouring and curing, thereby further improving the early strength of concrete.

[0012] Optionally, the weight ratio of the ethyl palmitate to the tea polyphenols is (0.8-1.6):1.

[0013] By adopting the above technical solution, the present application uses a more optimal ratio of ethyl palmitate and tea polyphenols, and the comprehensive performance of the prepared concrete is more excellent.

[0014] Optionally, the tea polyphenols are tea polyphenol-porous calcium carbonate microspheres, which are prepared from tea polyphenols and calcium carbonate in a weight ratio of 1:(1.5-3.5).

[0015] By adopting the above technical scheme, the present application adopts tea polyphenol-porous calcium carbonate microspheres added to concrete, which not only improves the dispersion uniformity of tea polyphenols in concrete, thereby improving the strength and stability of concrete, but also the porous calcium carbonate forms a three-dimensional spatial network structure in the cement paste, thereby improving the workability and strength of the concrete. At the same time, calcium carbonate can also promote the evaporation rate of water in the concrete, increase the hardening speed and density of the concrete, thereby reducing the porosity and water absorption rate of the concrete, and improving its durability and stability.

[0016] Optionally, the specific surface area of ​​the calcium carbonate is 360-580m 2 / g.

[0017] Optionally, the average particle size of the calcium carbonate is not greater than 300 nm.

[0018] By adopting the above technical solution, the present application uses calcium carbonate of specific specifications, which has a higher specific surface area and interacts more strongly with water molecules and cement particles, making it easier to disperse in concrete and form a three-dimensional spatial network structure. At the same time, it is easier to form a tight stacking, thereby improving the density and strength of the concrete.

[0019] Optionally, β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles are also included, and the content of the β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 0.2-1.5wt% of the cement content.

[0020] By adopting the above technical scheme, the β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles also added in the present application have good stability, can improve the anti-segregation ability of concrete, and maintain uniformity and stability during pouring and curing. The addition of β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles can improve the mechanical properties and durability of concrete. Through the adsorption effect of nanoparticles, the dispersibility and stability of concrete admixtures can be improved, thereby improving the working performance and mechanical properties of concrete, and promoting the hardening speed of concrete, thereby improving the early strength of concrete.

[0021] Optionally, the content of the β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 0.8-1wt% of the amount of cement.

[0022] By adopting the above technical solution, the present application selects a better range of β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles, and the comprehensive performance of the prepared concrete is more excellent.

[0023] Optionally, the cement is Portland cement.

[0024] Optionally, the fineness modulus of the machine-made sand is 2.3-2.8.

[0025] Optionally, the fineness modulus of the river sand is 1.2-1.5.

[0026] In summary, the present invention includes at least one of the following beneficial technical effects:

[0027] 1. The environmentally friendly fly ash and mineral powder co-mixed concrete prepared by the application with specific content of components has excellent comprehensive performance, high early strength and stable performance;

[0028] 2. The specific content of ethyl palmitate used in the present application can not only interact with substances such as Ca(OH)2 in concrete to form a more stable interface layer, refine the aggregate in the concrete, improve its compactness, promote hydration reaction, and make the concrete more compact, thereby reducing the porosity and water absorption inside the concrete and improving its strength and stability, but also has good compatibility with fly ash, mineral powder and other components in concrete, and improves the dispersion performance of fly ash and mineral powder in concrete, improves the uniformity and stability of concrete, thereby improving the working performance and mechanical properties of concrete;

[0029] 3. The tea polyphenols with a specific content in the present application have multiple biological activities that can effectively improve the durability and stability of concrete, improve the dispersion performance of fly ash and mineral powder in concrete, and promote the hardening speed of concrete, improve the early strength and improve the anti-segregation ability of concrete, so that it maintains uniformity and stability during pouring and curing, thereby further improving the early strength of concrete. DETAILED DESCRIPTION

[0030] The present application is further described in detail below with reference to the embodiments.

[0031] The present application designs an environmentally friendly fly ash and mineral powder double-mixed concrete, which includes the following raw materials in parts by weight: 90-120 parts of cement, 40-70 parts of fly ash, 30-50 parts of mineral powder, 180-260 parts of machine-made sand, 100-150 parts of river sand, 350-500 parts of gravel, 85-100 parts of water, 3-15 parts of ethyl palmitate, and 2-8 parts of tea polyphenols.

[0032] The preparation method of the environmentally friendly fly ash and mineral powder co-mixed concrete in this application: refer to "GB / T50080-2016".

[0033] The preparation method of tea polyphenol-porous calcium carbonate microspheres is as follows: tea polyphenol is dissolved in ethanol to prepare a tea polyphenol solution for later use; calcium carbonate is dissolved in water, and the tea polyphenol solution is added dropwise, mixed and stirred to coat the tea polyphenol on the surface of the calcium carbonate, and then washed with water and dried at low temperature to prepare tea polyphenol-porous calcium carbonate microspheres, wherein the amount of ethanol used is twice the amount of tea polyphenol.

[0034] The raw material models of this application are as follows. Unless otherwise specified, the raw materials of this application are all commercially available:

[0035] The chemical composition of the mineral powder includes: SiO2 is 85-95%;

[0036] The chemical composition of fly ash includes: SiO2 is 40-60%, Al2O3 is 20-30%, Fe2O3 is 5-15%, and CaO is 2-6%;

[0037] Water: selected from tap water;

[0038] Ethyl palmitate: purity 98%, Shanghai Yuanye Biotechnology Co., Ltd.;

[0039] Tea polyphenols: purity 98%, Shanghai Yuanye Biotechnology Co., Ltd.

[0040] β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles: product number, 364363, Xi'an Qiyue Biotechnology Co., Ltd.;

[0041] Calcium carbonate: purity 99%;

[0042] Portland cement: Product No., BD9158, Hubei Baidu Chemical Co., Ltd.;

[0043] Stone: 5-25mm crushed stone, good gradation, mud content 0.4%, mud block content 0.2%, needle-like particles 6%, apparent density 2675kg / m 3 , bulk density 1560kg / m 3 .

[0044] Test items and methods:

[0045] Compressive strength and flexural strength (MPa): Tested in accordance with "GB / T50081-2019 Standard for Test Methods for Physical and Mechanical Properties of Concrete". Specific embodiments

[0047] Examples 1-3

[0048] The raw material dosage of the environmentally friendly fly ash and mineral powder co-mixed concrete in Example 1-3 is shown in Table 1.

[0049] Table 1

[0050] Dosage / kg Example 1 Example 2 Example 3 cement 90 105 120 Fly ash 40 55 70 Mineral powder 30 40 50 Machine-made sand 180 210 260 river sand 100 130 150 Stone 350 420 500 water 85 92 100 Ethyl palmitate 3 10 15 Tea polyphenols 5 8 2

[0051] Among them, cement is silicate cement, and the fineness modulus of machine-made sand and mineral sand is shown in Table 2.

[0052] Table 2

[0053] Fineness modulus Example 1 Example 2 Example 3 Machine-made sand 2.3 2.5 2.8 river sand 1.2 1.4 1.5

[0054] Embodiment 4-6

[0055] Based on Example 2, except for the different weight ratio of ethyl palmitate and tea polyphenols, the other components and preparation methods are consistent with Example 2, wherein the total weight of ethyl palmitate and tea polyphenols remains unchanged, which is 18 kg.

[0056] Example 4

[0057] The weight ratio of ethyl palmitate to tea polyphenols is 0.8:1.

[0058] Example 5

[0059] The weight ratio of ethyl palmitate to tea polyphenols is 1:1.

[0060] Example 6

[0061] The weight ratio of ethyl palmitate to tea polyphenols is 1.6:1.

[0062] Comparative Example 1

[0063] Based on Example 2, except that an equal amount of tea polyphenols was used to replace ethyl palmitate, the other components and preparation method were the same as those in Example 2.

[0064] Comparative Example 2

[0065] Based on Example 2, except that an equal amount of ethyl palmitate was used to replace tea polyphenols, the other components and preparation methods were the same as those in Example 2.

[0066] The concrete prepared in Examples 1-3 and Comparative Examples 1-2 was subjected to performance testing, and the test results are shown in Table 3.

[0067] Table 3

[0068]

[0069]

[0070] It can be seen from Examples 1-3 and Table 3 that the environmentally friendly fly ash and mineral powder co-mixed concrete prepared by the present application using the components with specific contents has excellent comprehensive performance, high early strength and stable performance;

[0071] It can be seen from Examples 2, 4-6 and Table 3 that the present application selects a better ratio of ethyl palmitate and tea polyphenols, and the comprehensive performance of the prepared concrete is more excellent;

[0072] It can be seen from Comparative Examples 1-2, Example 2 and Table 3 that the early strength of concrete prepared by the ethyl palmitate and tea polyphenol system in the present application is higher than the early strength of concrete prepared by using only ethyl palmitate or tea polyphenols, and the comprehensive performance is better. The inventor speculates that the addition of ethyl palmitate can form a more stable interface layer in the concrete, refine the aggregate in the concrete, improve its compactness, and promote hydration reaction, while the various biological activities of tea polyphenols at a specific content can effectively improve the durability and stability of the concrete, improve the dispersion performance of fly ash and mineral powder in the concrete, and thus improve the early strength of the concrete.

[0073] Embodiment 7-9

[0074] Based on Example 2, except that an equal amount of tea polyphenol-porous calcium carbonate microspheres are used to replace tea polyphenol, the other components and preparation methods are consistent with Example 2, wherein the tea polyphenol-porous calcium carbonate microspheres are prepared from tea polyphenol and calcium carbonate, and the specific surface area of ​​calcium carbonate is 360m 2 / g, and the average particle size is 300nm.

[0075] Example 7

[0076] The tea polyphenol-porous calcium carbonate microspheres are prepared by including tea polyphenol and calcium carbonate in a weight ratio of 1:1.5.

[0077] Example 8

[0078] The tea polyphenol-porous calcium carbonate microspheres are prepared by including tea polyphenol and calcium carbonate in a weight ratio of 1:2.2.

[0079] Example 9

[0080] The tea polyphenol-porous calcium carbonate microspheres are prepared by including tea polyphenol and calcium carbonate in a weight ratio of 1:3.5.

[0081] Embodiment 10-11

[0082] Based on Example 8, except for the specific surface area and average particle size of calcium carbonate, the other components and preparation methods are consistent with Example 8.

[0083] Example 10

[0084] The specific surface area of ​​calcium carbonate is 450m 2 / g, and the average particle size is 150nm.

[0085] Embodiment 11

[0086] The specific surface area of ​​calcium carbonate is 580m 2 / g, and the average particle size is 80nm.

[0087] The concrete prepared in Examples 7-11 was subjected to performance testing, and the test results are shown in Table 4.

[0088] Table 4

[0089]

[0090] It can be seen from Examples 2, 7-11 and Table 4 that the concrete prepared by using an equal amount of tea polyphenol-porous calcium carbonate microspheres to replace tea polyphenol in the present application has higher early strength. This is because the addition of tea polyphenol-porous calcium carbonate microspheres not only improves the dispersion uniformity of tea polyphenols in concrete, thereby improving the strength and stability of concrete, but also porous calcium carbonate forms a three-dimensional spatial network structure in cement paste, thereby improving the workability and strength of concrete. At the same time, calcium carbonate microspheres can also promote the evaporation rate of water in concrete, increase the hardening speed and density of concrete, thereby reducing the porosity and water absorption rate of concrete, and improving its durability and stability.

[0091] It can be seen from Examples 7-9 and Table 4 that the early strength of the concrete in the present application is affected by the dosage of tea polyphenols. The early strength first increases and then decreases with the increase in the dosage of tea polyphenols. The inventors speculate that the addition of tea polyphenols can more effectively improve the dispersion properties of admixtures in concrete, but excessive addition may make the concrete more fragile and reduce the strength of the concrete.

[0092] Examples 12-16

[0093] Based on Example 10, except for adding β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles, the other components and preparation methods are the same as those of Example 10.

[0094] Example 12

[0095] The dosage of β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 0.2wt% of the dosage of cement.

[0096] Example 13

[0097] The dosage of β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 0.8wt% of the dosage of cement.

[0098] Embodiment 14

[0099] The dosage of β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 0.9wt% of the dosage of cement.

[0100] Embodiment 15

[0101] The dosage of β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 1wt% of the dosage of cement.

[0102] Example 16

[0103] The dosage of β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 1.5wt% of the dosage of cement.

[0104] The concrete prepared in Examples 12-16 was subjected to performance testing, and the test results are shown in Table 5.

[0105] Table 5

[0106]

[0107] It can be seen from Examples 10, 12-16 and Table 5 that the addition of β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles of the present application can improve the mechanical properties and durability of concrete. Through the adsorption of nanoparticles, the dispersibility and stability of concrete admixtures can be improved, thereby improving the working performance and mechanical properties of concrete, and promoting the hardening speed of concrete, thereby improving the early strength of concrete. The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, all equivalent changes made according to the principles of the present application should be covered within the protection scope of the present application.

Claims

1. An environmentally friendly fly ash and mineral powder double-mixed concrete, characterized in that: The invention comprises the following raw materials in parts by weight: 90-120 parts of cement, 40-70 parts of fly ash, 30-50 parts of mineral powder, 180-260 parts of machine-made sand, 100-150 parts of river sand, 350-500 parts of gravel, 85-100 parts of water, 3-15 parts of ethyl palmitate, and 2-8 parts of tea polyphenols; The weight ratio of the palmitic acid ethyl ester to the tea polyphenols is (0.8-1.6): 1; The tea polyphenols are tea polyphenol-porous calcium carbonate microspheres, which are prepared by tea polyphenols and calcium carbonate in a weight ratio of 1: (1.5-3.5); It also includes β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles, wherein the content of the β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 0.2-1.5wt% of the cement content.

2. The environmentally friendly fly ash and mineral powder co-mixed concrete according to claim 1, characterized in that: The specific surface area of ​​the calcium carbonate is 360-580m 2 / g.

3. The environmentally friendly fly ash and mineral powder co-mixed concrete according to claim 1, characterized in that: The average particle size of the calcium carbonate is no more than 300 nm.

4. The environmentally friendly fly ash and mineral powder co-mixed concrete according to claim 1, characterized in that: The content of the β-cyclodextrin polyethylene glycol hydroxycamptothecin nanoparticles is 0.8-1wt% of the amount of cement used.

5. The environmentally friendly fly ash and mineral powder co-mixed concrete according to claim 1, characterized in that: The cement is silicate cement.

6. The environmentally friendly fly ash and mineral powder co-mixed concrete according to claim 1, characterized in that: The fineness modulus of the machine-made sand is 2.3-2.

8.

7. The environmentally friendly fly ash and mineral powder co-mixed concrete according to claim 1, characterized in that: The fineness modulus of the river sand is 1.2-1.5.

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