CN111454033B

CN111454033B - C80 ultrahigh pumping concrete and preparation method thereof

Info

Publication number: CN111454033B
Application number: CN202010446763.4A
Authority: CN
Inventors: 林智峰
Original assignee: Shaanxi Hongji Concrete Component Co ltd
Current assignee: Shaanxi Hongji Concrete Component Co ltd
Priority date: 2020-05-23
Filing date: 2020-05-23
Publication date: 2022-05-27
Anticipated expiration: 2040-05-23
Also published as: CN111454033A

Abstract

The invention discloses C80 ultra-high pumping concrete and a preparation method thereof, wherein the concrete comprises the following raw materials in parts by weight: 270-; 690-720 parts of sand; 950 and 990 parts of gravel; 240 portion and 260 portions of mineral admixture; 8.5-10.5 parts of a polycarboxylic acid water reducing agent; 25-56 parts of graphite powder; 10-20 parts of coal gangue extra-fine powder; 0.0145-0.145 parts of air entraining agent; 2.4-2.6 parts of an excitant; and 147 parts of water 135-. The preparation method comprises the following steps: weighing cement, sand, broken stone, fly ash, zeolite powder, graphite powder, mirabilite, hydrated lime and coal gangue superfine powder in corresponding parts by weight, and stirring and mixing the materials uniformly to obtain a first mixture; and uniformly mixing water, a water reducing agent and an air entraining agent, adding into the first mixture, and uniformly stirring to obtain the C80 ultrahigh pumping concrete. The C80 ultra-high pumping concrete has the advantages of good fluidity and easiness in pumping while ensuring the strength.

Description

C80 ultrahigh pumping concrete and preparation method thereof

Technical Field

The invention relates to the field of concrete, in particular to C80 ultra-high pumping concrete and a preparation method thereof.

Background

The ultra-high pumping concrete is smoothly transported to the specified height of a building at one time by pumping equipment, so that the concrete has better fluidity, high cohesiveness, water retention and segregation and bleeding resistance, C80 concrete refers to concrete with the compressive strength of 80-85 MPa, and belongs to one of high-strength concrete, and the high-strength concrete is widely applied to high-rise building structures, large-span bridge structures and certain special structures by taking the advantages of high compressive strength, strong deformation resistance, large density and low porosity as a new building material.

The Chinese patent with application publication number CN110183161A discloses a high-strength concrete mixture, which is prepared from the following raw materials in parts by weight: 240-445 parts of cement, 938-1200 parts of broken stone for building, 625-700 parts of medium sand for building, 200-245 parts of building waste residues, 37-53 parts of slag micro powder, 22-29 parts of fiber, 3-5 parts of pumping aid, 5-7 parts of concrete gel reducer, 4-6 parts of anti-mud agent, 8-15 parts of water reducer and 79.04-149.6 parts of water; the cement mortar has the advantages that the cement consumption can be saved under the condition of using raw materials with higher mud content, the basic performance of concrete mixtures is not influenced, and the cost is saved.

The defects of the technical scheme are as follows: the cement, slag micropowder and other cementing materials can generate hydration reaction in the mixing process with water, so that the viscosity of the concrete is improved, the strength of the concrete is enhanced, and the fluidity of the concrete is reduced while the strength is improved; the high-performance concrete is easy to generate larger deformation in the pumping process, and the shear strength is small, namely the yield value is larger than the ultimate shear strength, so that larger loss can be generated in the flowing process of the high-performance concrete by overcoming the friction with the pipe wall.

Disclosure of Invention

In view of the defects in the prior art, the first object of the present invention is to provide a C80 ultra-high pumping concrete, which has the advantages of good fluidity and easy pumping while ensuring strength.

A second object of the present invention is to provide a method for preparing C80 ultra-high pumpable concrete, which facilitates the manufacture of concrete having good fluidity and pumpability while maintaining strength, and which can reduce loss during pumping.

In order to achieve the first object, the invention provides the following technical scheme: the C80 ultra-high pumping concrete comprises the following raw materials in parts by weight:

270-;

690-720 parts of sand;

950 and 990 parts of gravel;

240 portion and 260 portions of mineral admixture;

8.5-10.5 parts of a polycarboxylic acid water reducing agent;

25-56 parts of graphite powder;

10-20 parts of coal gangue extra-fine powder;

0.0145-0.145 parts of air entraining agent;

2.4-2.6 parts of an excitant;

and 147 parts of water 135-.

By adopting the technical scheme, the mineral admixture is used for replacing cement, the water consumption required by mixing concrete is reduced, and the hydration heat of mass concrete can be obviously reduced, so that the workability, the strength and the durability of the concrete are improved, and the strength grade of the concrete is adjusted; in addition, because the activity of the mineral admixture is low, the exciting agent is also added to excite the activity of the mineral admixture, so that the early strength of the concrete is improved; the graphite powder has lubricity and is insoluble in water, the fluidity of a mixture can be increased when the graphite powder is mixed in concrete, the water requirement of the mixture can be reduced, and the pumpability of the concrete can be improved and the working performance can be enhanced when the graphite powder is mixed with a mineral admixture; the water reducing mechanism of the polycarboxylate superplasticizer is that polycarboxylate molecules are adsorbed on the surfaces of cement particles, the cement particles are prevented from contacting with each other by utilizing the charge repulsion and the steric hindrance effect, flocculated water molecules among the cement particles are released, and the strength of concrete is increased when the water content is reduced; when the coal gangue extra fine powder is mixed with concrete, the coal gangue extra fine powder reacts with calcium hydroxide and the like separated out by cement hydration to generate substances such as hydrated calcium silicate, hydrated aluminum silicate and the like, the hydrates can be condensed and hardened in the air and can be continuously hardened in water, the hydration heat can be obviously reduced, the concrete is prevented from cracking, and the compactness and the workability of the concrete can be improved simultaneously under the condition that the early strength of the concrete is not reduced by mixing the coal gangue extra fine powder; the air entraining agent is also called air entraining agent, is a hydrophobic surfactant, is added into a concrete mixture after being dissolved in water, can generate a large amount of tiny and independent bubbles in the stirring process, the spherical bubbles enable the concrete workability to be improved to a great extent like balls, and the workability, plasticity and cohesiveness of the air entraining concrete are remarkably improved as the bubbles increase the slurry volume and the lubrication effect on a mixed material and increase the viscosity and yield stress of the slurry, and the tiny bubbles introduced by the air entraining agent are like tiny aggregates and have a compensation effect on poor gradation, particularly on the tiny aggregates lacking in tiny particles, so that the concrete can be in mortar surplus; the tiny air bubbles are bonded and supported on cement particles to fill gaps among the cement particles, so that water flow around cement and aggregate particles is prevented or reduced, bleeding, settlement and segregation of concrete are reduced, meanwhile, due to the 'poking-out' or 'dispersing' action of the air bubbles, the free (non-condensation) surface area of the cement or fine aggregate is greatly increased, the workability of a mixture is enhanced, and due to the fact that the cohesion of the concrete and the lubricating action among materials are increased through air entraining, the swelling flow is reduced, excessive segregation and bleeding cannot occur during pumping, and therefore the pumpability of fresh concrete can be improved through air entraining.

Further, the feed comprises the following raw materials in parts by weight:

280 parts of cement;

705 parts of sand;

970 parts of gravel;

250 parts of mineral admixture;

9 parts of a polycarboxylic acid water reducing agent;

40 parts of graphite powder;

20 parts of coal gangue extra fine powder;

0.0075 parts of an air entraining agent;

2.5 parts of an excitant;

and 145 parts of water.

By adopting the technical scheme, the water-cement ratio of the prepared concrete is 0.25, and the strength requirement of C80 concrete is met; meanwhile, the water cement ratio is 0.52, so that the concrete has a good pumping effect, when the water cement ratio is less than 0.4, the pumping resistance of the concrete is increased rapidly, and when the water cement ratio is more than 0.6, the concrete is easy to bleed, delaminate and isolate, and the pumping effect is also influenced.

Further, the mineral admixture is at least one of fly ash, mineral powder, silica powder and zeolite powder.

By adopting the technical scheme, the fly ash, the mineral powder, the silicon powder and the zeolite powder are common mineral admixtures, the cement dosage can be independently replaced to mix the concrete, meanwhile, due to the difference of the sizes and the performances of the four mineral admixtures, the hydration reaction rates are different, so that the early strength of the concrete is different, when the four mineral admixtures are mixed for use, the grain composition in the concrete can be improved, the integral grain accumulation of the concrete is more compact and reasonable, the workability of the concrete admixture and the structure of hardened concrete are improved, the admixture has good fluidity and higher mechanical property under the common cooperation of different mineral admixtures, and the loss in the pumping process is reduced.

Further, the mineral admixture comprises, by weight, 166-206 parts of fly ash and 54-74 parts of zeolite powder.

By adopting the technical scheme, the zeolite powder is a volcanic ash material formed by grinding natural zeolite rocks and contains a large amount of active SiO₂And Al₂O₃Zeolite, a cheap and easily mined mineral, has general applicability and economy as a mineral admixture for concrete; on the one hand, under the alkaline excitation, the zeolite powder can be separated from Ca (OH) when being hydrated with cement₂The reaction generates hydrated calcium silicate gel to promote the cement hydration reaction; on the other hand, because the natural zeolite has a grid structure, the interior of the natural zeolite is filled with holes and channels with uniform sizes, and the natural zeolite has great openness, has a large specific surface area after being ground, and can adsorb a large amount of water in a natural stateThe additive and the gas are balanced with the relative humidity of the atmosphere, and can absorb the redundant mixing water in the concrete when being doped into the concrete, thereby overcoming the bleeding property of the concrete over time, increasing the viscosity of the concrete and improving the slurry wrapping amount of aggregate, thereby improving the workability of the concrete; the zeolite powder can balance the segregation caused by the graphite powder, and meanwhile, the graphite powder can react with the zeolite powder to enable the zeolite powder to be better combined with the fly ash, so that the pumpability of concrete is improved, and the working performance is enhanced.

Further, 1.1-1.3 parts of mirabilite and 1.2-1.4 parts of hydrated lime.

By adopting the technical scheme, the slaked lime is Ca (OH)₂Is alkali-activated, mirabilite (Na)₂SO₄·10H₂O) belongs to sulfate excitation; because the aluminosilicate glass body can only show activity in an alkaline environment, the activity of the fly ash must be excited in order to improve the early strength of concrete, and the key of the activity excitation of the fly ash is to break Si-O and Al-O bonds which are mainly influenced by the concentration of OH < - >; the composite chemical excitation method of alkali excitation and sulfate excitation can promote the depolymerization of fly ash vitreous body, corrode the surface of fly ash particles, promote the breakage of Si-O and Al-O bonds and the honeycombing of the particle surface, thereby improving the content of the fly ash and Ca (OH)₂The hydration process of (1). Meanwhile, in order to meet the requirements on the durability and the volume stability of the fly ash concrete, 1.1 to 1.3 parts of mirabilite and 1.2 to 1.4 parts of hydrated lime are adopted.

Furthermore, grinding aid with the weight portion of 1.6-2.0 parts is added into the components.

By adopting the technical scheme, because the surface layer of the mineral admixture particles is provided with the hard and dense vitreous shell, the hydration reaction is slow after the mineral admixture particles are contacted with water, so that the early strength of concrete is low, in order to improve the activity of the mineral admixture, the mineral admixture particles such as fly ash and the like can be refined, grinding efficiency can be improved by adding a grinding aid in the grinding process, as the surfaces of new particles have unbalanced electrovalence, silicon oxygen anions are easily combined with hydrogen ions provided by water in the air and generate particle adhesion through the generation of hydrogen bonds, and the surfactant contains hydrophilic groups and oleophylic groups, when the surfactant is contacted with the surfaces of the new particles, the hydrophilic groups are adsorbed on the surfaces of the particles, and the hydrophobic groups are outward, so that the adsorption among the particles can be hindered, and a certain grinding effect is shown.

Further, the air entraining agent comprises at least one of fatty alcohol-polyoxyethylene ether, fatty alcohol-polyoxyethylene sodium sulfonate and fatty alcohol sodium sulfate.

By adopting the technical scheme, the air entraining agent is an ether air entraining agent, the polyether air entraining agent has good foaming and foam stabilizing effects, and has good compatibility with the polycarboxylic acid water reducing agent, and the concrete slump loss formed by mixing is less over time, thereby being beneficial to the pumping effect of concrete.

In order to achieve the second object, the invention provides the following technical scheme:

a preparation method of C80 ultra-high pumping concrete comprises the following steps:

weighing cement, sand, broken stone, fly ash, zeolite powder, graphite powder, mirabilite, hydrated lime and coal gangue superfine powder in corresponding parts by weight, and uniformly stirring and mixing the cement, sand, broken stone, fly ash, zeolite powder, graphite powder, mirabilite, hydrated lime and coal gangue superfine powder to obtain a first mixture;

and step two, uniformly mixing water, a water reducing agent and an air entraining agent, adding the mixture into the first mixture, and uniformly stirring to obtain the C80 ultrahigh pumping concrete.

By adopting the technical scheme, aggregate such as gel material, gravel and the like in the concrete is weighed and then fully mixed, and then water, water reducing agent and air entraining agent are mixed with the obtained first mixture, so that the gel material is subjected to activity excitation, and water is added for hydration reaction after the gel material and the aggregate are fully mixed, so that the gel material is fully contacted with the water, and the strength and the fluidity of the concrete are ensured.

Further, in the step one, the fly ash and the grinding aid are mixed and ground in advance.

By adopting the technical scheme, the premixing grinding of the grinding aid and the fly ash can refine the particles of the fly ash, destroy hard and dense vitreous shells on the surface layers of the particles which obstruct the volcanic ash effect of the fly ash, and increase the participation of the fly ashSurface area of volcanic ash effect, which is favorable for Ca2⁺Ion permeation and dissolution of silicon and aluminum in the glass body; from a microscopic perspective, the grinding can promote the primary crystal lattices of the fly ash particles to be deformed and damaged, cut off Si-O bonds and Al-O bonds in a network, generate atomic groups with high activity and charged sections, improve the degree of structural irregularity and defects, and increase the reaction activity; from the energy perspective, the grinding can improve the chemical energy of the fly ash particles, increase the chemical instability of the fly ash particles, increase the activity of the fly ash particles, improve the activity of the fly ash particles and improve the early strength of the concrete.

In conclusion, the invention has the following beneficial effects:

firstly, the mineral admixture is preferably prepared by matching fly ash and zeolite powder, and simultaneously adding graphite powder, because the zeolite powder can adsorb a large amount of water molecules and gas in a natural state with a latticed structure and is balanced with the relative humidity of the atmosphere, when the mineral admixture is doped into concrete, the mineral admixture can absorb redundant mixing water in the concrete, overcomes the problem of over-time bleeding of the concrete, increases the viscosity of the concrete, improves the slurry wrapping amount of aggregate, and can improve the workability of the concrete; the zeolite powder can balance the segregation caused by the graphite powder, and meanwhile, the graphite powder can react with the zeolite powder to enable the zeolite powder to be better combined with the fly ash, so that the pumpability of concrete is improved, and the working performance is enhanced.

Secondly, because the invention adopts the polycarboxylate water reducing agent to be matched with the ether air entraining agent, and because the ether air entraining agent and the polyether air entraining agent have good foaming and foam stabilizing effects, the foaming is generated to enhance the workability and pumpability of the concrete, and in addition, the ether air entraining agent and the polycarboxylate water reducing agent have good compatibility, the slump loss of the concrete formed by mixing is less with time, and the pumping effect of the concrete is facilitated.

Thirdly, the method of the invention mixes and grinds the fly ash and the grinding aid in advance, then fully mixes the gelled material and the aggregate to obtain a first mixture, fully mixes the gelled material and the aggregate, and then adds water for hydration reaction, thereby realizing the full contact of the gelled material and the water and ensuring the strength and the fluidity of the concrete.

Detailed Description

All materials referred to in the examples of the present invention are commercially available.

The specifications of the samples used in the examples are shown in table 1.

TABLE 1 sample specifications used in all the following examples and comparative examples

Example 1: the components and the corresponding parts by weight of the components in the raw materials of the C80 ultra-high pumping concrete are shown in the table 2.

The preparation method of the C80 ultra-high pumping concrete comprises the following steps:

weighing 310kg of cement of 270-sand, 720kg of medium-fine sand of 690-sand, 50-990kg of broken stone, 206kg of fly ash of 166-sand, 54-74kg of zeolite powder, 25-56kg of graphite powder, 1.1-1.3kg of mirabilite, 1.2-1.4kg of hydrated lime and 10-30kg of coal gangue extra-fine powder shown in the table 1, and uniformly stirring and mixing to obtain a first mixture;

step two, uniformly mixing 147kg of 135-charge tap water, 8.5-10.5kg of polycarboxylic acid water reducing agent and 0.0075-0.145kg of ether air entraining agent, adding into the first mixture, and uniformly stirring to obtain the C80 ultrahigh pumping concrete.

Examples 2 to 3: the C80 ultra-high pumping concrete is different from the concrete in example 1 in the content of components, and the raw materials and the corresponding parts by weight are shown in Table 2.

Example 4: a C80 ultra-high pumping concrete, which is different from the concrete of example 1 in component content, is shown in Table 2, and the mineral admixture is 250kg/m³Ground granulated blast furnace slag from wuhan steel company.

Example 5: c80 ultra-high pumping concrete, which is different from the concrete in example 1 in component contentIn contrast, as shown in Table 2, the mineral blend used was 250kg/m³The silica fume produced by Wuhan silicon steel factories.

Example 6: a C80 ultra-high pumping concrete, which is different from the concrete of example 1 in component content, is shown in Table 2, and the mineral admixture is 250kg/m³The Jinxuan mineral product-001I-grade fly ash.

Example 7: a C80 ultra-high pumping concrete, which is different from example 1 in component content, is prepared by mixing mineral admixture 250kg/m as shown in Table 2³The Wanhong WH002 size is 200 meshes of zeolite powder.

Example 8: a C80 ultra-high pumping concrete is different from the concrete in example 1 in component content, and as shown in Table 2, the adding amount of graphite powder is 25kg/m³。

Example 9: a C80 ultra-high pumping concrete is different from the concrete in example 1 in component content, and as shown in Table 2, the addition amount of graphite powder is 56kg/m³。

Example 10: the C80 ultra-high pumping concrete is different from the concrete in example 1 in component content, and as shown in Table 2, the addition amount of the coal gangue extra-fine powder is 10kg/m³。

Example 11: the C80 ultra-high pumping concrete is different from the concrete in example 1 in component content, and as shown in Table 2, the addition amount of the coal gangue extra-fine powder is 30kg/m³。

Example 12: a C80 ultra-high pumping concrete is different from that in example 1 in component content, and as shown in Table 2, the addition amount of a polycarboxylate superplasticizer is 8.5kg/m³。

Example 13: a C80 ultra-high pumping concrete is different from that in example 1 in component content, and as shown in Table 2, the addition amount of a polycarboxylate superplasticizer is 10.5kg/m³。

Example 14: a C80 ultra-high pumping concrete is different from the concrete of example 1 in the content of components, and as shown in Table 2, 1.8kg/m is added³The grinding aid of (1).

Practice ofExample 15: a C80 ultra-high pumping concrete is different from the concrete of example 1 in the content of components, and as shown in Table 2, 1.6kg/m is added³The grinding aid of (1).

Example 16: a C80 ultra-high pumping concrete is different from the concrete of example 1 in component content, and as shown in Table 2, 2kg/m is added³The grinding aid of (1).

Table 2, components and parts by weight of the C80 ultra-high pumping concrete in examples 1 to 16

Comparative example

Comparative example 1: the difference between the C80 ultra-high pumpable concrete and example 1 is that graphite powder was added in an amount of 0 as shown in table 3.

Comparative example 2: a C80 ultra-high pumping concrete, which is different from the concrete of example 1 in that, as shown in Table 3, the adding amount of graphite powder is 60kg/m³。

Comparative example 3: a C80 ultra-high pumping concrete, which is different from the concrete of example 1 in that, as shown in Table 3, the adding amount of graphite powder is 20kg/m³。

Comparative example 4: a C80 ultra-high pumpable concrete, which is different from example 1 in that the amount of the activator added is 0 as shown in Table 3.

Comparative example 5: the difference between the C80 ultra-high pumping concrete and the concrete in example 1 is that the addition amount of the coal gangue extra fine powder is 0 as shown in Table 3.

Comparative example 6: the C80 ultra-high pumping concrete is different from the concrete in example 1 in that a rosin resin air entraining agent is adopted as an air entraining agent as shown in Table 3.

The components and parts by weight of the C80 ultra-high pumping concrete in the table 3 and the comparative examples 1 to 6.

Performance test

The detection method adopted by the C80 ultra-high pumping concrete prepared in the above embodiments is as follows:

test one: slump and T500 test

Test samples: concrete mixtures obtained in examples 1 to 16 were used as test samples 1 to 16.

The test method comprises the following steps: the slump of the C80 ultra-high pump concrete prepared in each example and the time required for the slump expansion to reach 500mm when the concrete is taken out of the machine were measured according to the specifications in GB/T50080 Standard for testing the Performance of ordinary concrete mixtures.

And (3) test results: the test results of test samples 1 to 16 are shown in Table 4.

And (2) test II: test for compressive Strength

Test samples: concrete mixtures obtained in examples 1 to 7 were used as test samples 1 to 7.

The test method comprises the following steps: the concrete mixtures of the test samples 1 to 7 are prepared into concrete test blocks, and the compressive strength (MPa) of 7d and 28d of the recycled concrete is detected according to the compressive strength test in GB/T50081-2002 Standard test method for mechanical Properties of ordinary concrete.

The test instrument: pressure testing machine

And (3) test results: the test results of comparative samples 1-6 are shown in Table 5.

Table 4, results of performance testing of the C80 ultra-high pumping concrete prepared in examples 1-16.

Table 5, comparative examples 1-6, results of performance testing of the C80 ultra-high pumping concrete.

From table 4, comparing the test samples 1-7, when the mineral admixture is selected from one of fly ash, mineral powder, silica powder and zeolite powder, the fly ash needs to be used in combination with an activity activator to activate the activity due to its low activity, and when the volcanic activity of the fly ash is gradually exerted, the fly ash 28 has high strength and has a strong late growth tendency; the 3d strength of the concrete doped with the mineral powder is higher than that of the concrete doped with the fly ash, the 28d strength is opposite, and the promotion effect of the fly ash on the later strength is better than that of slag; the silicon powder can promote the early strength of concrete due to the small size, but also can deteriorate the fluidity of the concrete and prolong the time required for the slump expansion to reach 500 mm; the zeolite powder is matched with concrete, and has a grid structure, the interior of the zeolite powder is full of holes and channels with uniform sizes, and has very large openness, and the zeolite powder has a large specific surface area after being ground, can adsorb a large amount of water molecules and gas in a natural state, and is balanced with the relative humidity of the atmosphere, so that when the zeolite powder is doped into the concrete, the redundant mixing water in the concrete can be absorbed, the bleeding property of the concrete during the process of aging is overcome, the viscosity of the concrete is increased, the slurry wrapping amount of aggregate is increased, and the workability of the concrete can be improved. When the fly ash and the zeolite powder are selected for matching use, the early strength and the fluidity of the concrete are superior to those of the single mineral admixture.

By combining table 4 and table 5, comparing test sample 1, test sample 8, test sample 9 and comparison samples 1-3, it can be seen that when the amount of graphite powder in the concrete is changed between 25-56, the fluidity of the concrete is changed along with the change of the amount of graphite powder, and the graphite powder can better combine zeolite powder and fly ash, so that the strength is ensured, and the fluidity is increased, thereby improving the pumpability of the concrete; when the graphite powder consumption is 0 or less than 25kg/m³The effect of increasing the fluidity of the concrete by the graphite powder is not obvious, and the concrete has high viscosity and poor fluidity; when the consumption of the graphite powder is more than 56kg/m³In the process, even if zeolite powder for enhancing cohesiveness exists, the graphite powder is not dissolved, so that the slurry and the aggregate are separated, the pipe blockage phenomenon is easy to occur in the pumping process, and the pumping effect is influenced.

Combining table 4 and table 5, it can be seen from comparison of test sample 1, test sample 10, test sample 11, and comparison sample 5 that the incorporation of the ultrafine coal gangue powder can improve the compactness and fluidity of the concrete without reducing the early strength of the concrete.

By combining table 4 and table 5, it can be known by comparing test sample 1, test sample 12 and test sample 13 that the early strength of the concrete is increased and the strength of the concrete is ensured along with the increase of the amount of the polycarboxylate superplasticizer under the premise that the water-to-cement ratio is not changed.

Combining tables 4 and 5, it can be seen from comparison of test samples 1 and 6 that when the rosin resin air entraining agent is used instead of the ether air entraining agent, the water reducing effect of the concrete is poor, the fluidity is high, but the strength is low due to incompatibility with the polycarboxylic acid water reducing agent.

By combining table 4 and table 5, comparing test sample 1 and test samples 14-16, it can be seen that, with the addition of the grinding aid, the grinding aid is mixed with the fly ash in advance for grinding, so that the particles of the fly ash can be refined, the reactivity of the fly ash can be increased, and the early strength of the concrete can be improved.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.

Claims

1. The C80 ultra-high pumping concrete is characterized by comprising the following raw materials in parts by weight:

270-310 parts of cement;

690-720 parts of sand;

950 and 990 parts of gravel;

240-260 parts of mineral admixture;

8.5-10.5 parts of a polycarboxylic acid water reducing agent;

25-56 parts of graphite powder;

10-20 parts of coal gangue extra-fine powder;

0.0145-0.145 parts of air entraining agent;

2.4-2.6 parts of an excitant;

and 147 parts of 135-147 parts of water;

the mineral admixture is composed of, by weight, 166-206 parts of fly ash and 54-74 parts of zeolite powder;

the excitant comprises 1.1-1.3 parts of mirabilite and 1.2-1.4 parts of hydrated lime.

2. The C80 ultra-high pumping concrete as claimed in claim 1, which comprises the following raw materials in parts by weight:

310 parts of cement;

690 parts of sand;

950 parts of crushed stone;

260 parts of a mineral admixture;

10.5 parts of a polycarboxylic acid water reducing agent;

56 parts of graphite powder;

10 parts of coal gangue extra fine powder;

0.0075 parts of an air entraining agent;

2.4 parts of an excitant;

and 135 parts of water;

the mineral admixture is composed of 206 parts of fly ash and 54 parts of zeolite powder by weight;

the excitant comprises 1.1 parts of mirabilite and 1.3 parts of hydrated lime.

3. The C80 ultra-high pumpable concrete according to claim 1, wherein a grinding aid is further added to the raw material in an amount of 1.6-2.0 parts by weight.

4. The C80 ultra-high pumping concrete as set forth in claim 1, wherein the air entraining agent comprises at least one of fatty alcohol-polyoxyethylene ether, sodium fatty alcohol-polyoxyethylene sulfonate, and sodium fatty alcohol sulfate.

5. The method for preparing the C80 ultra-high pumping concrete according to any one of claims 1, 2 and 4, comprising the following steps:

weighing cement, sand, broken stone, fly ash, zeolite powder, graphite powder, mirabilite, hydrated lime and coal gangue superfine powder in corresponding parts by weight, and stirring and mixing uniformly to obtain a first mixture;

6. The method for preparing the C80 ultra-high pumping concrete, as recited in claim 5, wherein in the first step, 1.6-2.0 parts by weight of grinding aid is added to the raw materials, and the fly ash and the grinding aid are mixed and ground in advance.