Ultra-high performance concrete for wind power hybrid tower segments and method of making the same

Abstract

The application relates to the technical field of concrete, and specifically discloses an ultra-high performance concrete for a wind power tower piece and a preparation method thereof. The ultra-high performance concrete provided by the application specifically comprises the following components in parts by weight: cement 800-920 parts, quartz sand 1000-1200 parts, microbeads 90-130 parts, silica fume 100-140 parts, fly ash 40-60 parts, steel fiber 145-170 parts, additive 10-20 parts, water reducing agent 9-13 parts, retarder 4-8 parts, and water 140-175 parts. The quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 1-5:1-5. The additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin. The concrete prepared by the application has good working performance, excellent slump spread performance, high early strength, good anti-cracking performance and durability.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of concrete, in particular to an ultra-high performance concrete for a wind power tower piece and a preparation method thereof. BACKGROUND

[0002] With the rapid development of the wind power industry, the performance requirements for wind power tower drums are getting higher and higher. Ultra-high performance concrete (UHPC) has become an ideal choice for wind power tower drum materials due to its excellent mechanical properties, durability and working performance.

[0003] The wind power tower drum connecting conversion section is complex in stress and has higher requirements for crack resistance. The existing ultra-high performance concrete can meet the crack resistance requirements of the connecting conversion section of the general specification wind power tower drum, but for the ultra-high wind power tower drum, the crack resistance of the existing ultra-high performance concrete needs to be further improved.

[0004] In addition, in order to speed up the mold turnover rate and improve the production efficiency of enterprises, the wind power industry not only requires high strength and good durability for the prefabricated concrete, but also requires high early strength, good workability, super-long operation time, further accelerates the construction progress, shortens the construction period and improves the economic benefits. Therefore, improving the early strength and working performance of the concrete is an effective technical approach to improve the production efficiency of the prefabricated concrete wind power tower drum component and reduce the production cost. SUMMARY

[0005] In order to solve the above technical problems, the application provides an ultra-high performance concrete for a wind power tower piece and a preparation method thereof.

[0006] The application provides an ultra-high performance concrete, which specifically comprises the following components in parts by weight: cement 800-920 parts, quartz sand 1000-1200 parts, microbeads 90-130 parts, silica fume 100-140 parts, fly ash 40-60 parts, steel fiber 145-170 parts, additive 10-20 parts, water reducing agent 9-13 parts, retarder 4-8 parts, and water 140-175 parts.

[0007] The quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 1-5:1-5.

[0008] The steel fiber has a diameter of 0.18-0.22 mm and a length-diameter ratio of less than or equal to 65.

[0009] The additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin.

[0010] The present application selects the quartz sand composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand mixed in a weight ratio of 1-5:1-5, the additive obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin, and the steel fiber of a specific specification and other raw materials mixed according to a specific weight part, and the prepared concrete has good workability, excellent slump spread performance, can be self-compact forming, also has high early strength, and the concrete prepared by the present application has good anti-cracking performance, better durability.

[0011] The present application can significantly improve the hardness and wear resistance of concrete by adding different specifications of quartz sand; quartz sand has high hardness and excellent wear resistance, which enables it to play the role of aggregate in concrete, enhancing the compressive strength and durability of concrete. At the same time, the chemical stability of quartz sand can resist possible chemical reactions in concrete, thereby maintaining the stability of the concrete structure.

[0012] The introduction of steel fiber brings significant toughening effect to concrete. Steel fibers form a network structure in concrete, which can effectively prevent crack propagation and improve the anti-cracking performance of concrete when subjected to external forces. In addition, steel fibers can also enhance the tensile strength and impact resistance of concrete, making it exhibit better toughness and durability under dynamic load.

[0013] The addition of calcined magnesium oxide in the additive of the present application can significantly improve the early strength and anti-cracking mechanical properties of concrete. In different environments, calcined magnesium oxide can remain stable, effectively prevent the destruction of concrete structure, better resist external environmental erosion, maintain long-term firmness and beauty, thereby prolonging the service life of the building. Secondly, the introduction of hydroxyethyl cellulose brings better viscosity and water retention to concrete, improving the operability in the construction process, so that the prepared concrete has good workability, excellent slump spread performance, and can be self-compact forming; at the same time, its good water retention helps to reduce the water loss of concrete during transportation and pouring, ensuring the stability of the quality of concrete. In addition, the addition of ABS resin endows the concrete with excellent water absorption performance; during the hardening process of concrete, the superabsorbent resin can absorb and store a large amount of water, and then gradually release it when needed, providing continuous maintenance for concrete; this unique water absorption performance helps to reduce the cracks caused by drying of concrete, improves the anti-cracking performance, durability and overall performance of concrete.

[0014] Preferably, the ultra high performance concrete comprises the following components by weight: cement 840-880 parts, quartz sand 1050-1150 parts, microbead 100-120 parts, silica fume 110-130 parts, fly ash 45-55 parts, steel fiber 150-165 parts, additive 13-18 parts, water reducing agent 10-12 parts, retarder 5-7 parts, and water 150-165 parts.

[0015] Preferably, the quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 4-5:1-2.

[0016] Preferably, the steel fiber is composed of steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 10-30 in a weight ratio of 10-20:1-3.

[0017] Preferably, the steel fiber is composed of steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 10-30 in a weight ratio of 13-17:1.5-2.5.

[0018] Through experimental analysis, it is found that the concrete prepared by the steel fiber with the above weight ratio can further improve the performance of the concrete.

[0019] Preferably, the additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose, and ABS resin in a weight ratio of 8-14:1-5:0.2-0.8.

[0020] Preferably, the additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose, and ABS resin in a weight ratio of 10-12:2-4:0.4-0.6.

[0021] In some specific embodiments, the weight ratio of the calcined magnesium oxide, hydroxyethyl cellulose and ABS resin can also be 8:1:0.5, 10:1:0.5, 11:1:0.5, 12:1:0.5, 14:1:0.5, 10:2:0.5, 11:2:0.5, 12:2:0.5, 14:2:0.5, 8:3:0.5, 10:3:0.5, 11:3:0.5, 12:3:0.5, 14:3:0.5, 10:4:0.5, 11:4:0.5, 12:4:0.5, 14:4:0.5, 10:5:0.5, 11:5:0.5, 12:5:0.5, 10:1:0.2, 11:1:0.2, 12:1:0.2, 14:1:0.2, 8:2:0.4, 10:2:0.4, 11:2:0.4, 12:2:0.4, 8:3:0.5, 10:3:0.5, 11:3:0.5, 12:3:0.5, 8:4:0.6, 10:4:0.6, 11:4:0.6, 12:4:0.6, 8:5:0.8, 10:5:0.8, 11:5:0.8, 12:5:0.8, 14:5:0.8.

[0022] Through experimental analysis, it is found that the calcined magnesium oxide, hydroxyethyl cellulose and ABS resin with the above weight ratio can further improve the performance of the concrete when used as an additive for preparing the concrete.

[0023] Preferably, the preparation method of the calcined magnesium oxide comprises: mixing magnesium carbonate, konjac powder and water according to a weight ratio of 10-15:0.5-1.5:50, reacting at 50-70℃ for 8-16h, then drying and calcining at 500-650℃ for 2-4h.

[0024] Preferably, the particle size of the microbead is ≤10μm, the bulk density is 0.7kg / cm 3 , the average particle size of the silica fume is 0.15μm, the SiO2 content is ≥88%, the water reducing agent is HS-209 type polycarboxylic acid water reducing agent, and the retarder is sodium gluconate.

[0025] In a second aspect, the application provides a preparation method of the above-mentioned ultra-high performance concrete, which specifically comprises the following steps in sequence:

[0026] Respective raw material components are weighed, the cement, quartz sand, microbead, silica fume, fly ash and steel fiber are added to water, mixed uniformly, then the additive, retarder and water reducing agent are added and mixed uniformly, and the ultra-high performance concrete is obtained after curing.

[0027] In summary, the technical scheme of the application has the following effects:

[0028] The present application selects the quartz sand composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand mixed in a weight ratio of 1-5:1-5, the additive prepared by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin, and the steel fiber of a specific specification and other raw materials mixed according to a specific weight part, and the prepared concrete has good working performance, excellent slump spread performance, can be self-flowing compacted, also has high early strength, and the concrete prepared by the present application has good anti-cracking performance and durability. DETAILED DESCRIPTION

[0029] The present application will be further described in detail below in combination with examples, comparative examples and performance test experiments, and these examples cannot be understood as limiting the scope of the present application.

[0030] The cement used in the present application adopts P·O 42.5 cement; the particle size of microbeads is ≤10 μm, and the bulk density is 0.7 kg / cm 3 ; the average particle size of silica fume is 0.15 μm, and the SiO2 content is ≥88%; the fly ash adopts F type II grade fly ash, the fineness is 15.6%, the water demand ratio is 97%, and the loss on ignition is 3.8%; the copper-plated micro-fine high-strength steel fiber has a tensile strength of ≥2500 MPa, a length of ≤13 mm, and a diameter of 0.18-0.22 mm; the hydroxyethyl cellulose and ABS resin are purchased from Shanghai Yuan Ye Biological Technology Co., Ltd.; the water reducing agent is HS-209 type polycarboxylic acid water reducing agent; the retarder is sodium gluconate; the konjac extract is purchased from Fen Hewe Biological Technology Co., Ltd.; and the remaining raw materials can be obtained by commercial purchase.

[0031] EXAMPLE

[0032] Examples 1-3

[0033] Examples 1-3 respectively provide an ultra-high performance concrete and a preparation method thereof.

[0034] The difference between the above examples is that the amount of each component in the ultra-high performance concrete is different, and the specific amount is shown in Table 1.

[0035] The preparation method of the ultra-high performance concrete in the above examples is as follows:

[0036] Preparation of calcined magnesium oxide: magnesium carbonate, konjac extract powder and water are mixed in a weight ratio of 12:1:50, reacted at 60℃ for 12h, then dried, and calcined at 600℃ for 3h to obtain.

[0037] According to Table 1, the corresponding weight of each raw material component was weighed, cement, quartz sand (quartz sand was composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 4:1), microbeads, silica fume, fly ash, steel fiber (composed of steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 10-30 in a weight ratio of 15:2) were added to water, mixed uniformly, then the additive (the additive was obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose with a viscosity of 5500-6500 mpas, and ABS resin in a weight ratio of 11:3:0.5), sodium gluconate retarder, HS-209 polycarboxylic acid water reducer were added, stirred and mixed uniformly, and then cured to obtain the ultra-high performance concrete.

[0038] Table 1: Amount of each raw material component of the ultra-high performance concrete in Examples 1-3 and Comparative Examples 1-2

[0039]

[0040]

[0041] Examples 4-7

[0042] Examples 4-7 respectively provide an ultra-high performance concrete and a preparation method thereof.

[0043] The difference between the above examples and Example 2 is that the types of quartz sand are different, which are as follows.

[0044] In Example 4: the quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 5:1.

[0045] In Example 5: the quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 4:2.

[0046] In Example 6: the quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 1:4.

[0047] In Example 7: the quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 1:1.

[0048] The other process parameters in the above examples are the same as those in Example 2.

[0049] Examples 8-11

[0050] Examples 8-11 respectively provide an ultra-high performance concrete and a preparation method thereof.

[0051] The difference between the above embodiment and embodiment 2 is that the type of steel fiber is different, which is shown as follows.

[0052] In embodiment 8, the steel fiber is composed of steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 10-30 at a weight ratio of 13:2.5.

[0053] In embodiment 9, the steel fiber is composed of steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 10-30 at a weight ratio of 17:1.5.

[0054] In embodiment 10, the steel fiber is composed of steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 10-30 at a weight ratio of 10:3.

[0055] In embodiment 11, the steel fiber is composed of steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 10-30 at a weight ratio of 20:1.

[0056] In the above embodiments, other process parameters are the same as those in embodiment 2.

[0057] Embodiments 12-16

[0058] Embodiments 12-16 respectively provide an ultra-high performance concrete and a preparation method thereof.

[0059] The difference between the above embodiment and embodiment 2 is that the type of steel fiber is different, which is shown as follows.

[0060] In embodiment 12, the preparation method of calcined magnesium oxide is that magnesium carbonate, konjac powder and water are mixed at a weight ratio of 10:1.5:50, reacted at 50℃ for 16h, then dried and calcined at 600℃ for 3h to obtain; the additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin at a weight ratio of 8:5:0.8.

[0061] In embodiment 13, the preparation method of calcined magnesium oxide is that magnesium carbonate, konjac powder and water are mixed at a weight ratio of 15:0.5:50, reacted at 70℃ for 8h, then dried and calcined at 600℃ for 3h to obtain; the additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin at a weight ratio of 14:1:0.2.

[0062] In Example 14: the admixture is obtained by mixing magnesium carbonate, hydroxyethyl cellulose with a viscosity of 5500-6500 mpa.s, and ABS resin in a weight ratio of 11:3:0.5.

[0063] In Example 15: preparation of calcined magnesium oxide: magnesium carbonate is calcined at 600℃ for 3h; the admixture is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose with a viscosity of 5500-6500 mpa.s, and ABS resin in a weight ratio of 11:3:0.5.

[0064] In Example 16: preparation of calcined magnesium oxide: magnesium carbonate, konjac powder, and water are mixed in a weight ratio of 12:1:50, reacted at 60℃ for 12h, then dried and calcined at 600℃ for 3h; the admixture is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose with a viscosity of 1000-1500 mpa.s, and ABS resin in a weight ratio of 3:12:1.5.

[0065] In the above examples, other process parameters are the same as in Example 2.

[0066] Comparative Example 1-1

[0067] Comparative Example 1-2

[0068] Comparative Example 1-2 provides a kind of ultra high performance concrete and preparation method thereof.

[0069] Comparative Example 1-2 and Example 2 are different in that the amount of each component in the ultra high performance concrete is different, as shown in Table 1.

[0070] In the above examples, other process parameters are the same as in Example 1.

[0071] Comparative Example 3-6

[0072] Comparative Example 3-6 provides a kind of ultra high performance concrete and preparation method thereof.

[0073] Comparative Example 3-6 and Example 2 are different as shown below.

[0074] In Comparative Example 3: quartz sand is composed of 5-15 mesh sand and 100-150 mesh sand in a weight ratio of 5:1.

[0075] In Comparative Example 4: the diameter of steel fiber is 0.18-0.22mm, and the aspect ratio is 65-85.

[0076] In Comparative Example 5: equal amount of basalt fiber (diameter of 0.18-0.22mm, aspect ratio of 35-65) is used instead of steel fiber.

[0077] In Comparative Example 6: the admixture was obtained by mixing calcined magnesium oxide and hydroxyethyl cellulose at a weight ratio of 11:3.

[0078] The other process parameters in the above comparative examples were the same as in Example 1.

[0079] Performance test

[0080] (1) The performance of the concrete mixture was tested according to GB / T50080-2016 "Standard Test Methods for Performance of Ordinary Concrete Mixtures".

[0081] (2) The compressive strength and splitting tensile strength of the concrete were determined according to GB / T50081-2019 "Standard Test Methods for Mechanical Properties of Ordinary Concrete".

[0082] (3) The complex stress of the concrete was simulated by applying wind power tower cylinder connection conversion section, and the wall crack situation was observed.

[0083] (4) Aging resistance (80℃, 720h) performance: the concrete sample was placed at 80℃ for 720h, and the splitting tensile strength of the concrete was determined according to GB / T50081-2019 "Standard Test Methods for Mechanical Properties of Ordinary Concrete", and the aging resistance = splitting tensile strength after aging test / 28d splitting tensile strength of the original sample x 100%.

[0084] Test results: as shown in Table 2.

[0085] Table 2: Test results of concrete in examples and comparative examples

[0086]

[0087]

[0088] From the performance test results of the concrete in the examples and comparative examples in Table 2, it can be seen that the concrete prepared by the technical scheme of the present application has good working performance, excellent slump spread performance representing filling property and gap passing property, can be self-compacting, has high early strength, 3d compressive strength greater than 43MPa, and the concrete prepared by the present application has good anti-cracking performance and better durability.

[0089] By comparing the test results of Examples 1-3 and Comparative Examples 1-2, it can be seen that the amount of each raw material component in the concrete has a great influence on the performance of the concrete, and the performance of the concrete is obviously improved by reasonably controlling the amount of each raw material component.

[0090] By comparing the test results of comparative example 2 and comparative example 3, it can be known that the application uses the quartz sand raw material composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand mixed in a weight ratio of 1-5:1-5, which obviously improves the performance of the concrete; further, the application controls the quartz sand to be composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand mixed in a weight ratio of 4-5:1-2.

[0091] By comparing the test results of comparative example 2 and comparative examples 4-5, it can be known that the application uses the steel fiber composed of the steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 35-65 and the steel fiber with a diameter of 0.18-0.22 mm and an aspect ratio of 10-30 mixed in a weight ratio of 10-20:1-3, which obviously improves the performance of the concrete.

[0092] By comparing the test results of comparative example 2 and comparative example 6, it can be known that the application uses the additive obtained by mixing the calcined magnesium oxide, the hydroxyethyl cellulose and the ABS resin in a weight ratio of 8-14:1-5:0.2-0.8, which obviously improves the performance of the concrete.

[0093] Although the application has been described in detail with general description and specific embodiments above, some modifications or improvements can be made on the basis of the application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the application, all belong to the scope of the application claimed.

Claims

1. An ultra-high performance concrete, characterized in that, Specifically comprising the following components by weight: cement 800-920 parts, quartz sand 1000-1200 parts, microbead 90-130 parts, silica fume 100-140 parts, fly ash 40-60 parts, steel fiber 145-170 parts, additive 10-20 parts, water reducing agent 9-13 parts, retarder 4-8 parts, and water 140-175 parts; The quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 1-5:1-5. The steel fiber has a diameter of 0.18-0.22 mm and a length-diameter ratio of ≤65. The additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin.

2. The ultra-high performance concrete according to claim 1, characterized in that Specifically comprising the following components by weight: cement 840-880 parts, quartz sand 1050-1150 parts, microbead 100-120 parts, silica fume 110-130 parts, fly ash 45-55 parts, steel fiber 150-165 parts, additive 13-18 parts, water reducing agent 10-12 parts, retarder 5-7 parts, and water 150-165 parts.

3. The ultra-high performance concrete according to claim 1, characterized in that, The quartz sand is composed of 20-40 mesh quartz sand and 40-70 mesh quartz sand in a weight ratio of 4-5:1-2.

4. The ultra-high performance concrete according to claim 1, characterized in that, The steel fiber is composed of steel fiber with a diameter of 0.18-0.22 mm and a length-diameter ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and a length-diameter ratio of 10-30 in a weight ratio of 10-20:1-3.

5. The ultra-high performance concrete according to claim 1, characterized in that, The steel fiber is composed of steel fiber with a diameter of 0.18-0.22 mm and a length-diameter ratio of 35-65 and steel fiber with a diameter of 0.18-0.22 mm and a length-diameter ratio of 10-30 in a weight ratio of 13-17:1.5-2.

5.

6. The ultra-high performance concrete of claim 1, wherein The additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin in a weight ratio of 8-14:1-5:0.2-0.

8.

7. The ultra-high performance concrete according to claim 6, characterized in that The additive is obtained by mixing calcined magnesium oxide, hydroxyethyl cellulose and ABS resin in a weight ratio of 10-12:2-4:0.4-0.

6.

8. The ultra-high performance concrete according to claim 6, characterized in that The preparation method of the calcined magnesium oxide comprises the following steps: mixing magnesium carbonate, konjac powder and water in a weight ratio of 10-15:0.5-1.5:50, reacting at 50-70 ℃ for 8-16 h, then drying, and calcining at 500-650 ℃ for 2-4 h.

9. The ultra-high performance concrete of claim 1, wherein, The particle size of the microbead is ≤10 µm, the bulk density is 0.7 kg / cm 3 ; the average particle size of the silica fume is 0.15 µm, the SiO2 content is ≥88%; the water reducing agent is HS-209 polycarboxylic acid water reducing agent; and the retarder is sodium gluconate.

10. Process for the preparation of the ultra high performance concrete according to any one of claims 1-9, characterized in that, Specifically comprising the following steps in sequence: Respectively weigh the corresponding weight of each raw material component, add the cement, quartz sand, microbead, silica fume, fly ash, steel fiber into the water, mix uniformly, then add the additive, retarder, water reducing agent, mix uniformly, and after curing, the super high performance concrete is obtained.

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