C60 high-strength high-pumping continuous steel reinforced concrete and preparation method thereof

Abstract

The application relates to the field of concrete, and particularly discloses a C60 high-strength high-pumping continuous steel structure concrete and a preparation method thereof. The C60 high-strength high-pumping continuous steel structure concrete comprises cement, coarse aggregate, fine aggregate, a composite water reducing agent, fly ash, reinforcing fiber and water; and the preparation method comprises the following steps: uniformly mixing the cement, the coarse aggregate, the fine aggregate, the composite water reducing agent, the fly ash, the reinforcing fiber and steel slag, adding water, and mixing and stirring to obtain the C60 high-strength high-pumping continuous steel structure concrete. The C60 high-strength high-pumping continuous steel structure concrete can be used in engineering construction, and has the advantages of preventing cracks of concrete in a hydration process.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of concrete, more particularly, it relates to a C60 high-strength high-pumping continuous steel structure concrete and a preparation method thereof. BACKGROUND

[0002] High-strength concrete, as a new building material, has been widely used in high-rise building structures, large-span bridge structures and some special structures due to its high compressive strength, strong deformation resistance, large density and low porosity. The compressive strength of high-strength concrete is generally 4-6 times that of ordinary strength concrete, so it is most suitable for high-rise buildings. High-strength concrete is more expensive than ordinary concrete, but the structure weight is reduced due to the reduced cross section, which is of great significance to buildings whose self-weight accounts for a large part of the load.

[0003] During the hydration process of high-strength concrete, the hydration reaction is an exothermic reaction. The concrete quickly forms and increases the strength and elastic modulus during the temperature rise stage, but the thermal expansion effect of the volume of the concrete begins to appear. After the concrete reaches the temperature peak, the concrete itself shrinks and the volume decreases as the temperature decreases.

[0004] The superposition of various factors such as the increase of early strength mineral components C and S content in cement, the increase of grinding fineness, etc. causes the temperature to rise significantly during the early hardening process of concrete, and the concrete that loses water seriously during the temperature drop period is prone to shrinkage stress, which causes a large number of cracks in the concrete, seriously affecting the mechanical properties and service life of the concrete. SUMMARY

[0005] In order to prevent cracks in the concrete during the hydration process, the present application provides a C60 high-strength high-pumping continuous steel structure concrete and a preparation method thereof

[0006] The C60 high-strength high-pumping continuous steel structure concrete provided by the present application adopts the following technical scheme:

[0007] A C60 high-strength high-pumping continuous steel structure concrete, comprising 300-400 parts by weight of cement, 700-800 parts of coarse aggregate, 600-700 parts of fine aggregate, 50-100 parts of composite water reducing agent, 100-150 parts of fly ash, 80-140 parts of reinforcing fiber and 100-200 parts of water.

[0008] By adopting the technical scheme, the water-cement ratio is adjusted to improve the strength of the concrete, the coarse aggregate and the fine aggregate are used together to play a good skeleton and support role in the concrete, the strength of the concrete is improved, the cement usage is reduced by using the composite water reducing agent, the composite water reducing agent has excellent water retention capacity, the speed of hydration heat release is reduced in the initial stage of the hydration reaction of the concrete, the internal heat of the concrete is balanced, in the concrete cooling and shrinking process, the good water retention capacity of the composite water reducing agent reduces the probability of cracks caused by excessive water loss, the addition of fly ash also reduces the speed of the hydration reaction, avoids the internal intense heat release of the concrete, and the addition of the reinforcing fiber improves the anti-cracking capacity of the concrete, so that the application has the effect of preventing the concrete from cracking in the hydration process.

[0009] Optionally, the composite water reducing agent comprises sulfonated melamine formaldehyde resin powder and high-strength carbon nanofiber aerogel powder.

[0010] By adopting the technical scheme, the sulfonated melamine formaldehyde resin powder is a high-efficiency water reducing agent, is easy to dissolve in water, has good dispersibility for powdery materials, has high water-reducing rate, and has good fluidity and self-repairing property; the high-strength carbon nanofiber aerogel powder has high structural strength and a large number of microporous structures itself, has excellent water retention capacity, and will not be damaged due to external force in the concrete because of the high structural strength, and the use of the high-strength carbon nanofiber aerogel powder in combination with the sulfonated melamine formaldehyde resin powder makes the concrete have good water retention capacity and functional stability, and the high-strength carbon nanofiber aerogel powder is resistant to high temperature, and can enhance the high-temperature resistance of the concrete.

[0011] Optionally, the sulfonated melamine formaldehyde resin: high-strength carbon nanofiber aerogel powder = 2:3.

[0012] By adopting the technical scheme, the water retention performance of the composite water reducing agent is improved by adjusting the ratio of the sulfonated melamine formaldehyde resin and the high-strength carbon nanofiber aerogel.

[0013] Optionally, the preparation process of the high-strength carbon nanofiber aerogel powder is as follows:

[0014] S1, 100 parts of nanometer plant fiber dispersion liquid by weight is added into 0.5 mol / L dilute hydrochloric acid, stirred uniformly and placed for 12-18 h to prepare nanofiber gel;

[0015] S2, the nanofiber gel is freeze-dried, and then high-temperature carbonization is performed at 500-800 DEG C under the protection of protective gas to obtain high-strength carbon nanofiber aerogel;

[0016] S3, the high-strength carbon nanofiber aerogel is ground and crushed, and then sieved through an 80-mesh sieve to obtain high-strength carbon nanofiber aerogel powder.

[0017] By adopting the technical scheme, the carbon nanofiber aerogel has good structural strength and water retention capacity.

[0018] Optionally, the coarse aggregate is calcined at 200-300 DEG C for 2-3 hours.

[0019] By adopting the technical scheme, the porous structure in the coarse aggregate is shrunk by activating and calcining the coarse aggregate, the strength of the coarse aggregate is improved, and the compressive strength of the concrete is improved after the coarse aggregate is added to the concrete.

[0020] Optionally, the steel slag is 50-80 parts, and the steel slag is the steel slag after iron removal, and the iron content is 1-5%.

[0021] By adopting the technical scheme, the steel slag is dispersed in the cement base material, has the advantages of high later strength, low hydration heat, good wear resistance, high bonding force with steel bars, and prevents cracks in the hydration process of the concrete.

[0022] Optionally, the reinforcing fiber includes one or more of glass fiber, basalt fiber and polypropylene chopped fiber.

[0023] By adopting the technical scheme, the reinforcing fiber can improve the anti-cracking ability of the concrete, disperse internal stress, improve the strength of the concrete, and prevent cracking in the hydration process of the concrete.

[0024] The application provides a preparation method of C60 high-strength high-pumping continuous steel structure concrete.

[0025] The preparation method of the C60 high-strength high-pumping continuous steel structure concrete comprises the following steps: uniformly mixing cement, coarse aggregate, fine aggregate, composite water reducing agent, fly ash, reinforcing fiber and steel slag according to weight ratio, and then adding water, and mixing and stirring to obtain the C60 high-strength high-pumping continuous steel structure concrete.

[0026] By adopting the technical scheme, only the raw materials are used according to the weight parts, and the process is simple and fast.

[0027] In summary, the application has the following beneficial effects:

[0028] 1. This application improves concrete strength by adjusting the water-cement ratio. The coarse and fine aggregates work together to provide a good skeleton and support in the concrete, thus increasing its strength. The composite water-reducing agent reduces the amount of cement used. The composite water-reducing agent has excellent water retention capacity, which slows down the rate of heat release during the initial stage of concrete hydration and balances the internal heat of the concrete. During the cooling and shrinkage process of the concrete, the good water retention capacity of the composite water-reducing agent reduces the probability of cracking due to excessive water loss. The addition of fly ash also slows down the rate of hydration reaction and avoids violent heat release inside the concrete. The addition of reinforcing fibers improves the crack resistance of the concrete. Therefore, this application has the effect of preventing concrete from cracking during the hydration process.

[0029] 2. In this application, high-strength carbon nanofiber aerogel powder is preferred. It has high structural strength and a large number of microporous structures, which have excellent water retention capacity. Due to its high structural strength, it will not be affected by external forces in concrete and its porous structure will not be damaged. When used in combination with sulfonated melamine formaldehyde resin powder, it gives the concrete good water retention capacity and functional stability. At the same time, the high-strength carbon nanofiber aerogel powder is resistant to high temperature and can enhance the high temperature resistance of concrete.

[0030] 3. In this application, it is preferred to disperse steel slag into the cementitious material, which has the advantages of high later strength, low heat of hydration, good wear resistance, and high bonding force with steel bars, thus preventing cracks from forming in the concrete during the hydration process. Detailed Implementation

[0031] The present application will be further described in detail below with reference to the embodiments.

[0032] Preparation example of high-strength carbon nanofiber aerogel

[0033] Preparation Example 1

[0034] The preparation process of high-strength carbon nanofiber aerogel is as follows:

[0035] S1. Add 100g of nano-plant fiber dispersion by weight to 0.5mol / L dilute hydrochloric acid, stir evenly and let stand for 16h to obtain nano-fiber gel.

[0036] S2. Freeze-dry the nanofiber gel, then introduce a protective gas and carbonize it at 500°C to obtain a high-strength carbon nanofiber aerogel.

[0037] S3. Grind and pulverize the high-strength carbon nanofiber aerogel, and pass it through an 80-mesh sieve to obtain high-strength carbon nanofiber aerogel powder.

[0038] Preparation Example 2

[0039] The preparation process of the high-strength carbon nanofiber aerogel is as follows:

[0040] S1, 100g of nanometer plant fiber dispersion liquid by weight part is added into 0.5mol / L dilute hydrochloric acid, stirred uniformly and placed for 16h to prepare nanofiber gel;

[0041] S2, the nanofiber gel is freeze-dried, and then high-temperature carbonization is carried out at 800℃ under the protection of gas to obtain high-strength carbon nanofiber aerogel;

[0042] S3, the high-strength carbon nanofiber aerogel is ground and crushed, and then passed through an 80-mesh sieve to obtain high-strength carbon nanofiber aerogel powder.

[0043] Preparation Example 3

[0044] The preparation process of the high-strength carbon nanofiber aerogel powder is as follows:

[0045] S1, 100g of nanometer plant fiber dispersion liquid by weight part is added into 0.5mol / L dilute hydrochloric acid, stirred uniformly and placed for 16h to prepare nanofiber gel;

[0046] S2, the nanofiber gel is freeze-dried, and then high-temperature carbonization is carried out at 650℃ under the protection of gas to obtain high-strength carbon nanofiber aerogel;

[0047] S3, the high-strength carbon nanofiber aerogel is ground and crushed, and then passed through an 80-mesh sieve to obtain high-strength carbon nanofiber aerogel powder.

[0048] Example

[0049] Example 1

[0050] A preparation method of C60 high-strength high-pumping continuous steel structure concrete comprises the following steps:

[0051] 3000g of cement, 7000g of coarse aggregate, 6000g of fine aggregate, 500g of composite water reducing agent, 1000g of fly ash, 800g of polypropylene short fiber and 500g of steel slag are uniformly mixed, and then 1000g of water is added, and after mixing and stirring, C60 high-strength high-pumping continuous steel structure concrete is obtained.

[0052] The high-strength carbon nanofiber aerogel powder in the composite water reducing agent is prepared by Preparation Example 1.

[0053] Example 2

[0054] A preparation method of C60 high-strength high-pumping continuous steel structure concrete comprises the following steps:

[0055] Mix 4000g cement, 8000g coarse aggregate, 7000g fine aggregate, 1000g composite water reducing agent, 1500g fly ash, 1400g polypropylene short fiber and 800g steel slag uniformly, then add 2000g water, and obtain C60 high-strength high-pumping continuous steel structure concrete after mixing and stirring.

[0056] The high-strength carbon nanofiber aerogel powder in the composite water reducing agent is prepared by the preparation example 1.

[0057] Example 3

[0058] A preparation method of a C60 high-strength high-pumping continuous steel structure concrete comprises the following steps:

[0059] Mix 3500g cement, 7500g coarse aggregate, 6500g fine aggregate, 800g composite water reducing agent, 1300g fly ash, 1100g polypropylene short fiber and 650g steel slag uniformly, then add 1500g water, and obtain C60 high-strength high-pumping continuous steel structure concrete after mixing and stirring.

[0060] The high-strength carbon nanofiber aerogel powder in the composite water reducing agent is prepared by the preparation example 1.

[0061] Example 4

[0062] A preparation method of a C60 high-strength high-pumping continuous steel structure concrete comprises the following steps:

[0063] Mix 3500g cement, 7500g coarse aggregate, 6500g fine aggregate, 800g composite water reducing agent, 1300g fly ash, 1100g polypropylene short fiber and 650g steel slag uniformly, then add 1500g water, and obtain C60 high-strength high-pumping continuous steel structure concrete after mixing and stirring.

[0064] The high-strength carbon nanofiber aerogel in the composite water reducing agent is prepared by the preparation example 2.

[0065] Example 5

[0066] A preparation method of a C60 high-strength high-pumping continuous steel structure concrete comprises the following steps:

[0067] Mix 3500g cement, 7500g coarse aggregate, 6500g fine aggregate, 800g composite water reducing agent, 1300g fly ash, 1100g polypropylene short fiber and 650g steel slag uniformly, then add 1500g water, and obtain C60 high-strength high-pumping continuous steel structure concrete after mixing and stirring.

[0068] The high-strength carbon nanofiber aerogel powder in the composite water reducing agent is prepared by the preparation example 3.

[0069] Example 6

[0070] A preparation method of C60 high-strength high-pumping continuous steel structure concrete comprises the following steps:

[0071] 3500g of cement, 7500g of coarse aggregate, 6500g of fine aggregate, 800g of composite water reducing agent, 1300g of fly ash, 1100g of glass fiber and 650g of steel slag are uniformly mixed, and then 1500g of water is added, and after mixing and stirring, C60 high-strength high-pumping continuous steel structure concrete is obtained.

[0072] The high-strength carbon nanofiber aerogel powder in the composite water reducing agent is prepared by the preparation example 1.

[0073] Example 7

[0074] A preparation method of C60 high-strength high-pumping continuous steel structure concrete comprises the following steps:

[0075] 3500g of cement, 7500g of coarse aggregate, 6500g of fine aggregate, 800g of composite water reducing agent, 1300g of fly ash, 1100g of basalt fiber and 650g of steel slag are uniformly mixed, and then 1500g of water is added, and after mixing and stirring, C60 high-strength high-pumping continuous steel structure concrete is obtained.

[0076] The high-strength carbon nanofiber aerogel powder in the composite water reducing agent is prepared by the preparation example 1.

[0077] Comparative Example

[0078] Comparative Example 1

[0079] 3500g of cement, 7500g of coarse aggregate, 6500g of fine aggregate, 800g of water reducing agent, 1300g of fly ash, 1100g of polypropylene short fiber and 650g of steel slag are uniformly mixed, and then 1500g of water is added, and after mixing and stirring, C60 high-strength high-pumping continuous steel structure concrete is obtained.

[0080] The water reducing agent is sulfonated melamine formaldehyde resin.

[0081] Comparative Example 2

[0082] 3500g of cement, 7500g of coarse aggregate, 6500g of fine aggregate, 800g of composite water reducing agent, 1300g of fly ash, 1100g of polypropylene short fiber and 650g of steel slag are uniformly mixed, and then 1500g of water is added, and after mixing and stirring, C60 high-strength high-pumping continuous steel structure concrete is obtained.

[0083] The high-strength carbon nanofiber aerogel powder in the composite water reducing agent is prepared by the preparation example 1, and the coarse aggregate is not subjected to calcination treatment.

[0084] Comparative Example 3

[0085] A preparation method of C60 high-strength high-pumping continuous steel structure concrete comprises the following steps:

[0086] 3500 g of cement, 7500 g of coarse aggregate, 6500 g of fine aggregate, 800 g of composite water reducing agent, 1300 g of fly ash and 1100 g of polypropylene short fiber are uniformly mixed, and then 1500 g of water is added, and after mixing and stirring, C60 high-strength high-pumping continuous steel structure concrete is obtained.

[0087] The high-strength carbon nanofiber aerogel powder in the composite water reducing agent is prepared by the preparation example 1.

[0088] Performance detection test

[0089] Detection method

[0090] According to the requirements of the ordinary concrete mechanics performance test method standard GB / T 50081-2002 and the ordinary concrete long-term performance and durability test GB / T 50082-2009, the 28d strength test of the C60 high-strength high-pumping continuous steel structure concrete prepared in the application is carried out. The experimental data is shown as follows:

[0091] Table 1 test data of examples 1-7 and comparative examples 1-3

[0092]

[0093]

[0094] It can be seen from the combination of example 3 and comparative example 1 and table 1 that the tensile strength and compressive strength of the concrete in comparative example 1 are decreased without adding high-strength carbon nanofiber aerogel powder compared with example 3, and cracking occurs in the 28d test, while no cracks occur in example 3, which proves that the strength of the concrete is effectively improved after adding high-strength carbon nanofiber aerogel powder, and the problem of cracks in the hydration process of the concrete is solved.

[0095] It can be seen from the combination of example 3 and comparative example 2 and table 1 that the coarse aggregate is activated after high-temperature calcination, and the strength of the concrete is improved after adding the concrete, and the compressive strength and tensile strength of the concrete prepared in example 3 are higher than those of the concrete without activated coarse aggregate.

[0096] It can be seen from the combination of example 3 and comparative example 3 and table 1 that the tensile strength and compressive strength of the concrete are slightly decreased compared with comparative example 3 without adding steel slag, and fine cracks occur, which shows that the steel slag has the advantage of high late strength in the concrete system, and prevents cracks in the hydration process of the concrete.

[0097] It can be seen from the combination of Embodiments 3-5 and Table 1 that the high-strength carbon nanofiber aerogel powder prepared at 500 DEG C has the best reinforcing effect on the concrete, and significantly improves the compressive strength and tensile strength of the concrete.

[0098] It can be seen from the combination of Embodiments 3 and 6-7 and Table 1 that when the polypropylene short-cut fiber is selected in the concrete, the tensile strength of the concrete is higher than that of the glass fiber and the basalt fiber, and the selection of the polypropylene short-cut fiber as the reinforcing fiber is the optimal scheme of the embodiments.

[0099] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution according to the needs after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A C60 high strength high pumping continuous ferroconcrete, characterized in that: It comprises 300-400 parts by weight of cement, 700-800 parts of coarse aggregate, 600-700 parts of fine aggregate, 50-100 parts of composite water reducing agent, 100-150 parts of fly ash, 80-140 parts of reinforcing fiber and 100-200 parts of water; the composite water reducing agent comprises sulfonated melamine formaldehyde resin powder and high-strength carbon nanofiber aerogel powder, the sulfonated melamine formaldehyde resin: high-strength carbon nanofiber aerogel powder is compounded at a mass ratio of 2:3; the preparation process of the high-strength carbon nanofiber aerogel powder is as follows: S1, 100 parts by weight of nanometer plant fiber dispersion liquid is added into 0.5 mol / L dilute hydrochloric acid, stirred uniformly and placed for 12-18 h to prepare nanofiber gel; S2, the nanofiber gel is freeze-dried, then protective gas is introduced and high-temperature carbonization is carried out at 500-800 DEG C to obtain high-strength carbon nanofiber aerogel; S3, the high-strength carbon nanofiber aerogel is ground and crushed, and is passed through an 80-mesh screen to obtain high-strength carbon nanofiber aerogel powder.

2. The C60 high strength high pumping continuous ferroconcrete according to claim 1, characterized in that: The coarse aggregate is calcined at 200-300 DEG C for 2-3 h.

3. The C60 high strength high pumping continuous ferroconcrete according to claim 1, characterized in that: It also comprises 50-80 parts of steel slag, the steel slag is the steel slag after iron removal, and the iron content is 1-5%.

4. The C60 high strength high pumping continuous ferroconcrete according to claim 1, characterized in that: The reinforcing fiber comprises one or more of glass fiber, basalt fiber and polypropylene chopped fiber.

5. A method of producing a C60 high-strength high-pumping continuous steel reinforced concrete as claimed in any one of claims 1 to 4, characterized by: It comprises the following steps: The cement, coarse aggregate, fine aggregate, composite water reducing agent, fly ash, reinforcing fiber and steel slag are mixed uniformly at a weight ratio, then water is added, and C60 high-strength high-pumping continuous steel structure concrete is obtained after mixing and stirring.

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