CN110627449A - C60 expansion self-compaction high-strength concrete and preparation method thereof - Google Patents

Abstract

The invention discloses C60 expansion self-compaction high-strength concrete and a preparation method thereof, relating to the technical field of concrete, and the technical scheme is characterized in that the C60 expansion self-compaction high-strength concrete comprises the following components in parts by weight: 440 parts of cement 420-sand-containing material, 760 parts of fine aggregate 740-sand-containing material, 965 parts of coarse aggregate 945-sand-containing material, 170 parts of water 150-sand-containing material, 13-14 parts of admixture, 18-24 parts of fly ash, 55-65 parts of mineral powder and 35-40 parts of fiber expansion anti-cracking waterproof agent. The invention can balance the fluidity and the segregation resistance of the self-compacting concrete through the reasonable mixture ratio design, can reduce air holes in the concrete through the fiber expansion anti-cracking waterproof agent, and improves the compactness of the concrete, thereby improving the durability of the concrete.

Description

C60 expansion self-compaction high-strength concrete and preparation method thereof

Technical Field

The invention relates to the technical field of concrete, in particular to C60 expansion self-compaction high-strength concrete and a preparation method thereof.

Background

The common concrete is cement concrete which is prepared by mixing cement serving as a cementing material, sand and stone serving as aggregates and water according to a certain proportion and stirring; concrete is mainly divided into two stages and states: plastic state before setting and hardening, namely fresh concrete or concrete mixture; hardened, i.e. hardened concrete or concrete. Self-compacting concrete refers to concrete which can flow and be compact under the action of self gravity, can completely fill a template even if compact steel bars exist, and simultaneously obtains good homogeneity without additional vibration. The self-compacting concrete does not need to be vibrated, so that the concrete pouring time can be shortened, the labor intensity of workers is reduced, and the production efficiency is improved, so that the self-compacting concrete is more and more widely applied.

In the prior art, a patent application with application number publication number CN107162499A discloses a high-strength self-compacting concrete and a preparation method thereof, wherein the high-strength self-compacting concrete comprises the following raw material components in parts by weight: 850 parts of cement, 210 parts of glass beads, 65 parts of silica fume, 460 parts of shale ceramsite, 585 parts of clay ceramsite, 395 parts of ceramic sand, 70 parts of floating beads, 420 parts of river sand, 75 parts of water reducing agent, 0.3 part of shrinkage reducing agent, 1.5 parts of stabilizing agent and 480 parts of water.

Although the self-compacting concrete is compacted through self-flowing of the self-compacting concrete, when the shape of the pouring template is more complex, the self-compacting concrete can generate a phenomenon of separation of mortar bones due to the increase of resistance in the flowing process, so that the concrete can generate a layering phenomenon, and the segregation resistance of the self-compacting concrete is reduced; in contrast, the viscosity of the mixture can be increased by adding a tackifier to reduce the delamination phenomenon, but after the viscosity is increased, air bubbles remaining in the concrete are not easily discharged, and after the concrete is hardened, the compactness of the concrete is reduced due to the presence of the air bubbles, and in a cold environment, the drying shrinkage rate of the self-compacting concrete is increased, so that the durability of the self-compacting concrete is deteriorated.

Disclosure of Invention

One of the purposes of the invention is to provide C60 expansive self-compacting high-strength concrete, which can balance the fluidity and the segregation resistance of the self-compacting concrete through the reasonable mixture ratio design of the invention, can reduce air bubbles and air holes in the concrete through the fiber expansive anti-cracking waterproof agent, and can improve the compactness of the concrete, thereby improving the durability of the concrete.

The technical purpose of the invention is realized by the following technical scheme:

the C60 expanded self-compacting high-strength concrete comprises the following components in parts by weight: 440 parts of cement 420-sand-containing material, 760 parts of fine aggregate 740-sand-containing material, 965 parts of coarse aggregate 945-sand-containing material, 170 parts of water 150-sand-containing material, 13-14 parts of admixture, 18-24 parts of fly ash, 55-65 parts of mineral powder and 35-40 parts of fiber expansion anti-cracking waterproof agent.

Through adopting above-mentioned technical scheme, in the template of pouring the shape complicacy, the fibre in the anti waterproofing agent of fibre inflation still has good mobility, can fill to each connection corner of template, and the anti waterproofing agent of fibre inflation is at the in-process that self-compaction concrete flows, can get rid of the bubble that is detained in the concrete and fill the gas pocket in the concrete, improve the compactness of concrete, in order to prevent the shrinkage phenomenon after the concrete hardening, thereby improve the intensity of concrete, impervious anti-cracking performance, and because the reduction of the inside gas pocket of concrete, the improvement of compactness, can improve the freeze proof cold resistance of concrete, and then improve the durability of concrete.

Further, the paint comprises the following components in parts by weight: 430 parts of cement, 751 parts of fine aggregate, 955 parts of coarse aggregate, 160 parts of water, 13.75 parts of additive, 21 parts of fly ash, 60 parts of mineral powder and 39 parts of fiber expansion crack-resistant waterproof agent.

By adopting the technical scheme, the flowability and the segregation resistance of the self-compacting concrete can be balanced through the reasonable mixture ratio design, the bubbles and the air holes in the concrete can be reduced through the fiber expansion anti-cracking waterproof agent, the compactness of the concrete is improved, and the durability of the concrete is improved.

Further, the fine aggregate is formed by mixing machine-made coarse sand and natural extra-fine sand in a weight ratio of 7: 3.

By adopting the technical scheme, the machine-made sand is mainly sand processed by the sand making machine and other accessory equipment, the cost of the machine-made sand is lower than that of natural sand, and the machine-made sand has higher bonding strength with cementing materials such as cement and the like; the price of the machine-made sand is lower than that of the natural sand, so that the problem of insufficient supply of the natural sand can be solved; the problems of poor grading characteristics and particle shape defects of the machine-made sand can be solved by compounding the natural river sand and the machine-made sand; machine-made coarse sand with fineness modulus of 3.7-3.1 and natural superfine sand with fineness modulus of 1.5-0.7 are adopted according to the weight ratio of 7:3, the fine aggregate obtained by mixing the components in the weight ratio can be filled into a framework built by the coarse aggregate, so that the compactness of the concrete is improved; through the matching of the natural superfine sand, the mineral powder and the fly ash, the viscosity of the concrete can be increased, the layering phenomenon can be reduced, and the contradiction between the fluidity and the segregation resistance of the concrete can be balanced, so that the high fluidity and the high filling property of the concrete can be realized, and the layering phenomenon of the self-compacting concrete can be reduced.

Furthermore, the fineness of the coarse aggregate is 8-16mm of continuously graded broken stone.

By adopting the technical scheme, the continuously graded aggregate can be stacked to form a densely filled lap joint framework, the strength of the concrete is improved, and the clearance of the framework is filled by matching the continuously graded aggregate with the fine aggregate, the fly ash and the slag powder, so that the compactness of the concrete is improved, and the porosity of the concrete is reduced.

Further, the additive is a retarding high-performance water reducing agent.

By adopting the technical scheme, the retarding high-performance water reducing agent has the characteristics of retarding, plastic retaining and high water reducing rate, has remarkable pumpability, can remarkably increase the fluidity of concrete, improves the workability of newly-mixed concrete, avoids the cold joint phenomenon of construction binding layers, and can effectively improve the anti-cracking and waterproof performance of the concrete.

Further, the fly ash is class F II fly ash; the mineral powder is S95 mineral powder.

By adopting the technical scheme, the rheological property of the concrete can be adjusted by adding the mineral powder and the fly ash, the plastic adhesion of the concrete is improved, the slurry-solid ratio of a mixture is improved, the workability of the concrete is improved, the homogeneity of the concrete is improved, the friction force among coarse and fine aggregate particles is reduced, and the through resistance capability of the concrete is improved.

Further, the fiber expansion anti-cracking waterproof agent is prepared by the following method: taking 100-120 parts of kaolinite, 20-30 parts of dolomite, 20-30 parts of alunite and 5-10 parts of gypsum by weight part, calcining for 8-10h at the temperature of 850-950 ℃, and grinding to obtain an expansion clinker; heating 3-5 parts of stearic acid, 1-2 parts of N- (beta-aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 1-2 parts of sodium gluconate, 0.5-1 part of 3-chloro-2-hydroxypropyl sodium sulfonate and 30-40 parts of absolute ethyl alcohol at the temperature of 50-55 ℃ for 2-3 hours to obtain a modified solution; thirdly, adding 5-10 parts of lignin fiber, 3-5 parts of sepiolite fiber and 5-10 parts of polypropylene fiber into the modified liquid, and stirring for 3-5 hours under heat preservation; then adding the expansion clinker, stirring and drying to obtain the fiber expansion anti-cracking waterproof agent.

By adopting the technical scheme, after the fiber expansion anti-cracking waterproof agent is doped into concrete, a large number of fibers can be distributed in the concrete, and when a template with a complex shape is poured, the fibers can be filled into each connecting corner of the template along with the self-flowing property of the concrete, and in the flowing process, bubbles remained in the concrete can be removed and filled in the concrete, so that the compactness of the concrete is improved, and the dispersed fibers can reduce the stress of plastic shrinkage of the concrete and improve the anti-cracking performance of the concrete; the fiber network formed by the fiber expansion anti-cracking waterproof agent can improve the cohesiveness of concrete, improve the layering phenomenon of the concrete and improve the segregation resistance of the concrete; in addition, the expansion component in the fiber expansion anti-cracking waterproof agent can be expanded properly to compensate the phenomenon of shrinkage cracking of concrete, so that the anti-cracking and anti-permeability performance of the concrete is improved, and the durability of the concrete is further improved.

The invention also aims to provide a preparation method of the C60 expansive self-compacting high-strength concrete.

The technical purpose of the invention is realized by the following technical scheme:

a preparation method of C60 expansive self-compacting high-strength concrete comprises the following steps: 440 parts of cement 420-440, 760 parts of fine aggregate 740-965 parts of coarse aggregate 945-965, 170 parts of water 150-170, 13-14 parts of admixture, 18-24 parts of fly ash, 55-65 parts of mineral powder and 35-40 parts of fiber expansion anti-cracking waterproof agent are taken and uniformly stirred.

In summary, compared with the prior art, the invention has the following beneficial effects:

1. in the pouring of the template with a complex shape, the fiber in the fiber expansion anti-cracking waterproof agent still has good fluidity and can be filled into each connecting corner of the template, and in the flowing process of the self-compacting concrete, the fiber expansion anti-cracking waterproof agent can remove air bubbles remained in the concrete and fill air holes in the concrete, so that the compactness of the concrete is improved, the shrinkage phenomenon after the concrete is hardened is prevented, the strength, the impermeability and anti-cracking performance of the concrete are improved, and the frost resistance and cold resistance of the concrete can be improved due to the reduction of the air holes in the concrete and the improvement of the compactness, so that the durability of the concrete is improved;

2. the machine-made sand is mainly sand processed by a sand making machine and other accessory equipment, and compared with natural sand, the machine-made sand has more regular shape; machine-made coarse sand with fineness modulus of 3.7-3.1 and natural superfine sand with fineness modulus of 1.5-0.7 are adopted according to the weight ratio of 7:3, the fine aggregate obtained by mixing the components in the weight ratio can be filled into a framework built by the coarse aggregate, so that the compactness of the concrete is improved; through the matching of the natural superfine sand, the mineral powder and the fly ash, the viscosity of the concrete can be increased, the layering phenomenon can be reduced, and the contradiction between the fluidity and the segregation resistance of the concrete can be balanced, so that the high fluidity and the high filling property of the concrete can be realized, and the layering phenomenon of the self-compacting concrete can be reduced.

Detailed Description

The present invention will be described in further detail below.

Preparation of fiber expansion anti-cracking waterproofing agent

Preparation example 1: firstly, 100kg of kaolinite, 20kg of dolomite, 20kg of alunite and 5kg of gypsum are taken, calcined for 8 hours at the temperature of 850 ℃, and ground to obtain an expansion clinker; heating 3kg of stearic acid, 1kg of N- (beta-aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 1kg of sodium gluconate, 0.5kg of 3-chloro-2-hydroxypropyl sodium sulfonate and 30kg of absolute ethyl alcohol at the temperature of 50 ℃ for 2 hours to obtain a modified solution; thirdly, adding 5kg of lignin fiber, 3kg of sepiolite fiber and 5kg of polypropylene fiber into the modified liquid, and stirring for 3 hours under heat preservation; then adding the expansion clinker, stirring, and drying for 8 hours at the temperature of 70 ℃ to obtain the fiber expansion anti-cracking waterproof agent.

Preparation example 2: firstly, taking 110kg of kaolinite, 25kg of dolomite, 25kg of alunite and 7.5kg of gypsum, calcining for 9 hours at the temperature of 900 ℃, and grinding to obtain an expansion clinker; heating 4kg of stearic acid, 1.5kg of N- (beta-aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 1.5kg of sodium gluconate, 0.75kg of 3-chloro-2-hydroxypropyl sodium sulfonate and 35kg of absolute ethyl alcohol at 53 ℃ for 2.5 hours to obtain a modified solution; thirdly, adding 7.5kg of lignin fiber, 4kg of sepiolite fiber and 7.5kg of polypropylene fiber into the modified liquid, and stirring for 4 hours under heat preservation; then adding the expansion clinker, stirring, and drying for 8 hours at the temperature of 70 ℃ to obtain the fiber expansion anti-cracking waterproof agent.

Preparation example 3: firstly, calcining 120kg of kaolinite, 30kg of dolomite, 30kg of alunite and 10kg of gypsum at 950 ℃ for 10 hours, and grinding the calcined gypsum to obtain expanded clinker; heating 5kg of stearic acid, 2kg of N- (beta-aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 2kg of sodium gluconate, 1kg of 3-chloro-2-hydroxypropyl sodium sulfonate and 40kg of absolute ethyl alcohol at the temperature of 55 ℃ for 3 hours to obtain modified liquid; thirdly, adding 10kg of lignin fiber, 5kg of sepiolite fiber and 10kg of polypropylene fiber into the modified liquid, and stirring for 5 hours under heat preservation; then adding the expansion clinker, stirring, and drying for 8 hours at the temperature of 70 ℃ to obtain the fiber expansion anti-cracking waterproof agent.

Preparation example 4: the difference between the preparation example and the preparation example 1 is that the raw material does not contain the modifying solution of the step II.

Preparation example 5: the difference between the preparation example and the preparation example 1 is that the modification solution obtained in the step (II) does not contain stearic acid, sodium gluconate and sodium 3-chloro-2-hydroxypropyl sulfonate.

Preparation example 6: the difference between the preparation example and the preparation example 1 is that the lignin fiber and the sepiolite fiber in the raw material of the step (c) are replaced by the same amount of polypropylene fiber.

Second, the cement in the following examples is selected from P. O42.5R ordinary portland cement provided by Jidong cement Chongqing Hechuan company Limited; the admixture adopts a retarding high-performance water reducing agent provided by Chongqing branch of Tangshan Jidong cement admixture GmbH; the fly ash is selected from class F II fly ash provided by Chongqing Lopa Huang power plant; the mineral powder is selected from mineral powder of grade S95 provided by Chongqing Xiangzhong novel building materials Co.Ltd; the origin of the crushed stone is the Tuo feldspar tail wharf of Tangjia.

Example 1: the C60 expanded self-compacting high-strength concrete is prepared by the following method:

430kg of cement, 751kg of fine aggregate, 955kg of coarse aggregate, 160kg of water, 13.75kg of additive, 21kg of fly ash, 60kg of mineral powder and 39kg of fiber expansion anti-cracking waterproof agent (selected from preparation example 1) are taken and stirred uniformly.

Example 2: the C60 expanded self-compacting high-strength concrete is prepared by the following method:

420kg of cement, 740kg of fine aggregate, 945kg of coarse aggregate, 150kg of water, 13kg of additive, 18kg of fly ash, 55kg of mineral powder and 35kg of fiber expansion anti-cracking waterproof agent (selected from preparation example 2) are taken and uniformly stirred.

Example 3: the C60 expanded self-compacting high-strength concrete is prepared by the following method:

440kg of cement, 760kg of fine aggregate, 965kg of coarse aggregate, 170kg of water, 14kg of additive, 24kg of fly ash, 65kg of mineral powder and 40kg of fiber expansion anti-cracking waterproof agent (selected from preparation example 3) are taken and uniformly stirred.

Third, comparative example

Comparative example 1: this comparative example is different from example 1 in that the fiber swelling crack resistance waterproofing agent is prepared by selecting from preparation example 4.

Comparative example 2: this comparative example is different from example 1 in that the fiber swelling crack resistance waterproofing agent is prepared by selecting from preparation example 5.

Comparative example 3: this comparative example is different from example 1 in that the fiber swelling crack resistance waterproofing agent is prepared by selecting from preparation example 6.

Fourthly, performance test

The properties of the concrete prepared in examples 1 to 3 and comparative examples 1 to 3 were measured according to the general concrete mix design rule JGJ55-2011, and the results are shown in Table 1.

Slump is an index for evaluating the workability of concrete to determine the fluidity of a concrete mixture, and when the slump is more than 220mm, the evaluation diameter after concrete expansion, namely slump expansion, can be used as the fluidity index; the slump test was performed while evaluating the cohesion and water retention of the concrete: lightly tapping the side surface of the concrete cone which is already collapsed by using a tamper, wherein if the cone gradually sinks, the cohesiveness is good; if the cone collapses, partially collapses or segregates, this indicates poor cohesiveness. Water retention is assessed as the degree of dilute cement slurry precipitation in the concrete mix: after the slump cone is lifted, if more dilute cement slurry is separated out from the bottom and the aggregate is exposed due to slurry loss of the concrete mixture at the cone part, the water retention property of the concrete mixture is poor; if no dilute cement paste or only a small amount of dilute cement paste is separated out from the bottom after the slump cone is lifted, the water retention of the concrete mixture is good.

The compressive strength adopts the method in the standard of ordinary concrete mechanical property test method GB/T50081-2016; the expansion rate is limited by adopting a method in the concrete expanding agent GB/T23439-2009; the impermeability is measured by a step-by-step pressurization method in the standard of test methods for long-term performance and durability of ordinary concrete GB/T50082-2009, and the method is rapid; and measuring the penetration depth of the chlorine ion by a chloride ion migration coefficient method. The frost resistance is measured by the specification in SL 191-plus 2008 design Specification for Hydraulic concrete structures.

TABLE 1

As can be seen from the data in Table 1, the slump of the concrete of the invention is 260mm and the slump expansion is 760mm, which shows that the concrete prepared by the invention has good fluidity; as can be seen from the data in Table 1, the concrete prepared by the invention has good cohesiveness and water retention, which shows that the concrete prepared by the invention can balance the contradiction between the fluidity and the segregation resistance of the concrete and reduce the delamination phenomenon of the self-compacting concrete. The concrete has 28d compressive strength of more than 74MPa, is C60 strength grade concrete, has the impermeability grade of P12 and the frost resistance grade of F150, and shows that the concrete prepared by the invention has excellent compressive strength and impermeability, and has certain frost resistance and cold resistance; the concrete prepared by the proportion of the invention has higher compactness, thereby improving the strength and the crack resistance of the concrete and further improving the durability of the concrete.

The fiber swelling anti-cracking waterproofing agent of comparative example 1 is prepared by selecting the raw material prepared in preparation example 4, wherein the raw material does not contain the modification solution of the step II; compared with example 1, the slump and the slump expansion degree in the comparative example 1 are increased, which shows that the fluidity of the concrete is increased, but the cohesiveness and the water-retaining property of the concrete are deteriorated, and the compressive strength, the impermeability and the freezing resistance are obviously deteriorated, which shows that the fiber expansion crack resistance agent prepared by adding the modifying liquid balances the contradiction between the fluidity and the segregation resistance of the concrete, reduces the layering phenomenon of the self-compacting concrete, and thus can obviously improve the durability of the concrete.

The fiber swelling anti-cracking waterproofing agent of comparative example 2 was prepared from the raw materials of preparation example 5, which included stearic acid, sodium gluconate and sodium 3-chloro-2-hydroxypropyl sulfonate; compared with the example 1, the slump and the slump expansion degree in the comparative example 2 are increased, which shows that the fluidity of the concrete is increased, the cohesiveness of the concrete is kept good, but the water retention is poor, and the compressive strength, the impermeability and the freezing resistance are obviously poor, and shows that after stearic acid, sodium gluconate and 3-chloro-2-hydroxypropyl sodium sulfonate are added into the modification liquid, the prepared fiber expansion crack resistance agent can improve the water retention of the concrete, reduce the delamination phenomenon of the self-compacting concrete and further obviously improve the durability of the concrete.

The fiber swelling crack-resistant waterproofing agent of comparative example 3 was selected from those prepared in preparation example 6, in which lignin fibers and sepiolite fibers in the prepared raw materials were replaced with equal amounts of polypropylene fibers; the compressive strength and the impermeability were reduced in comparative example 3 compared to example 2, indicating that the addition of the lignin fibers and sepiolite fibers contributes to the improvement of the durability of the concrete.

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 (8)

1. A C60 expansion self-compaction high-strength concrete, which is characterized in that: the paint comprises the following components in parts by weight: 440 parts of cement 420-sand-containing material, 760 parts of fine aggregate 740-sand-containing material, 965 parts of coarse aggregate 945-sand-containing material, 170 parts of water 150-sand-containing material, 13-14 parts of admixture, 18-24 parts of fly ash, 55-65 parts of mineral powder and 35-40 parts of fiber expansion anti-cracking waterproof agent.

2. The C60 expanded self-compacting high strength concrete according to claim 1, wherein: the paint comprises the following components in parts by weight: 430 parts of cement, 751 parts of fine aggregate, 955 parts of coarse aggregate, 160 parts of water, 13.75 parts of additive, 21 parts of fly ash, 60 parts of mineral powder and 39 parts of fiber expansion crack-resistant waterproof agent.

3. The C60 expanded self-compacting high strength concrete according to claim 1, wherein: the fine aggregate is formed by mixing machine-made coarse sand and natural extra-fine sand in a weight ratio of 7: 3.

4. The C60 expanded self-compacting high strength concrete according to claim 1, wherein: the fineness of the coarse aggregate is 8-16mm of continuously graded broken stone.

5. The C60 expanded self-compacting high strength concrete according to claim 1, wherein: the additive is a retarding high-performance water reducing agent.

6. The C60 expanded self-compacting high strength concrete according to claim 1, wherein: the fly ash is F-class II fly ash; the mineral powder is S95 mineral powder.

7. The C60 expansive self-compacting high-strength concrete according to claim 1, wherein the fiber expansive anti-cracking waterproof agent is prepared by the following method: taking 100-120 parts of kaolinite, 20-30 parts of dolomite, 20-30 parts of alunite and 5-10 parts of gypsum by weight part, calcining for 8-10h at the temperature of 850-950 ℃, and grinding to obtain an expansion clinker; heating 3-5 parts of stearic acid, 1-2 parts of N- (beta-aminoethyl) -gamma-aminopropylmethyldimethoxysilane, 1-2 parts of sodium gluconate, 0.5-1 part of 3-chloro-2-hydroxypropyl sodium sulfonate and 30-40 parts of absolute ethyl alcohol at the temperature of 50-55 ℃ for 2-3 hours to obtain a modified solution; thirdly, adding 5-10 parts of lignin fiber, 3-5 parts of sepiolite fiber and 5-10 parts of polypropylene fiber into the modified liquid, and stirring for 3-5 hours under heat preservation; then adding the expansion clinker, stirring and drying to obtain the fiber expansion anti-cracking waterproof agent.

8. A method of preparing the C60 expanded self-compacting high strength concrete according to any one of claims 1-7, wherein: the method comprises the following steps: taking 440 parts of cement 420-760 parts, 740-760 parts of fine aggregate, 965 parts of coarse aggregate 945-965 parts, 170 parts of water 150-14 parts, 13-24 parts of additive, 18-24 parts of fly ash, 55-65 parts of mineral powder and 35-40 parts of fiber expansion anti-cracking waterproof agent by weight parts, and uniformly stirring.