CN112374817B

CN112374817B - Concrete for bridge construction and preparation method thereof

Info

Publication number: CN112374817B
Application number: CN202011281250.9A
Authority: CN
Inventors: 范文栋; 叶强强; 岳晓伟
Original assignee: Huzhou Shangjian Huayu Concrete Co ltd
Current assignee: Huzhou Shangjian Huayu Concrete Co ltd
Priority date: 2020-09-16
Filing date: 2020-11-16
Publication date: 2022-07-12
Anticipated expiration: 2040-11-16
Also published as: CN112374817A

Abstract

The application discloses concrete for bridge construction and a preparation method thereof, wherein the concrete for bridge construction comprises the following raw materials in parts by weight: cement: 100 and 160 parts; fine aggregate: 130-170 parts; stone: 230- > 290 parts; water: 28-36 parts; water reducing agent: 1.5-2.0 parts; a first component: air entraining agent: 0.2-0.4 part; a second component: hydrophobic filler: 1.5-3.6 parts; the hydrophobic filler is prepared from the following raw materials in parts by weight: adhesive: 0.2-0.3 part; polysiloxane: 0.1-0.2 parts; fly ash: 1.2-3.1 parts. The concrete for the bridge building has the effects of good anti-permeability performance and stable and uniform quality; the preparation method has the advantages of improving the impermeability and quality stability of the concrete.

Description

Concrete for bridge construction and preparation method thereof

Technical Field

The application relates to the technical field of concrete, in particular to concrete for bridge construction and a preparation method thereof.

Background

When the bridge is built on water, the flowing water is seriously eroded, and the flowing water gradually permeates a concrete layer of a pier part to cause the corrosion of reinforcing steel bars inside the pier and reduce the strength and the service life of the bridge, so that the bridge concrete not only needs to have high strength and high durability, but also needs to have certain impermeability.

For example, chinese patent application publication No. CN107021685A discloses a concrete for building bridges, which comprises the following raw materials in parts by mass: 60-75 parts of cement, 20-30 parts of sand, 20-35 parts of fly ash, 5-12 parts of calcium phosphate, 6-10 parts of magnesium silicate, 15-20 parts of stones, 1-2.5 parts of polypropylene fibers and a proper amount of water; the particle size of the stones is 5-8 mm; the grain diameter of the sand is 0.5-2 mm.

In the concrete in the related art, the inventor believes that gaps are formed between the raw materials after the concrete is cured due to the coarse particle size of the concrete raw materials, the gaps cause the concrete to have certain permeability, and water easily permeates into bridge pier parts of a bridge under water pressure to corrode a reinforcing steel bar structure in the bridge pier where the concrete is poured.

Disclosure of Invention

In order to improve the anti-permeability performance of the bridge pier and reduce the possibility of water permeating into the concrete of the bridge pier, the application provides concrete for bridge construction and a preparation method thereof.

In a first aspect, the present application provides a concrete for bridge construction, which adopts the following technical scheme:

the concrete for the bridge construction comprises the following raw materials in parts by weight:

cement: 100 and 160 parts;

fine aggregate: 130-170 parts;

stone: 230- > 290 parts;

water: 28-36 parts;

water reducing agent: 1.5-2.0 parts;

glass fiber: 10-15 parts;

hydrophobic filler: 15-36 parts;

the hydrophobic filler is prepared from the following raw materials in parts by weight:

adhesive: 2-3 parts of a solvent;

polysiloxane: 1-2 parts;

fly ash: 12-31 parts.

By adopting the technical scheme, because the polysiloxane has the hydrophobic and waterproof effect, the hydrophobic filler has the waterproof and anti-permeability effect, and the hydrophobic filler is used for filling gaps in concrete, so that the anti-permeability performance of the concrete can be effectively improved.

The glass fiber is distributed in the concrete structure, so that the connection effect between concrete raw materials can be effectively improved, the compression resistance and the cracking resistance of the concrete are further improved, and the generation of gaps is reduced. In addition, the glass fiber can be used as a carrier in a concrete structure, so that the hydrophobic filler is adhered to the glass fiber, and the filling effect of the hydrophobic filler on gaps is improved.

Further, the adhesive is a composition of organic silicon resin and furan resin with the weight ratio of 20 (5-9).

By adopting the technical scheme, the organic silicon resin and the furan resin are both hot-melt adhesives with poor water solubility, and the adhesives are gradually solidified and bonded with polysiloxane in the cooling process. The organic silicon resin has good hydrophobic and moisture-proof properties, so that the adhesive has certain waterproof and anti-permeability properties; after being cured, the furan resin has good corrosion resistance and thermal stability, and the service life of the adhesive in a complex water quality environment is prolonged.

Further, the hydrophobic filler is prepared according to the following process:

step A1, spraying the fused adhesive on the fly ash, and stirring the fly ash at the condition of 500-800rpm while spraying to obtain a viscous carrier;

step A2, spraying liquid polysiloxane on the viscous carrier, and stirring the fly ash under the conditions of 100-180rpm while spraying to prepare the hydrophobic filler.

By adopting the technical scheme, the coal ash is used as a carrier, the polysiloxane is adhered to the surface of the coal ash through the hot-melt adhesive, and the curing of the polysiloxane can be accelerated by the temperature of the adhesive to form a waterproof layer, so that the hydrophobic filler with the filling effect and the waterproof effect is obtained. The particle size of the particles can be reduced as much as possible by adopting a spraying process, and the filling effect is ensured. The stirring speed is controlled, the shearing force is reduced, the solidified adhesive is prevented from being broken as far as possible, and the filling effect is ensured.

Further, the temperature of the adhesive is controlled to decrease at a constant speed of 0.8-1.5 ℃/min during the stirring process.

By adopting the technical scheme, the cooling speed is controlled, and the cooling and curing time of the adhesive is adjusted, so that the curing time is reduced as much as possible while a more uniform and compact polysiloxane layer is formed on the particles, the shrinkage stress of the polysiloxane layer during cooling and curing is reduced, and the phenomenon of cracking of the polysiloxane layer is avoided as much as possible.

Further, the average particle size of the fly ash is 1-10 μm.

By adopting the technical scheme, the average particle size of the fly ash particles is far smaller than that of the cement particles, the content is small, but the number of the particles is large, so that the fly ash has a better filling effect, and the anti-permeability performance is improved.

Furthermore, the raw materials of the concrete for bridge construction also comprise 0.2-0.4 part of air entraining agent.

Through adopting above-mentioned technical scheme, adopt the air-entraining agent, reducible mix water, improve the peaceability, prevent concrete bleeding to reduce the production in gap. Meanwhile, a large amount of tiny and closed bubbles can be generated in the concrete by adding the air entraining agent, and on one hand, under the dispersion effect of the bubbles, the hydrophobic filler is distributed more uniformly; on the other hand, the air bubbles can enter the capillary channels generated by the solidification and shrinkage of the concrete, and the capillary channels are cut off and blocked, so that the permeation phenomenon is not easy to generate even under higher hydrostatic pressure; in addition, the hydrophobic filler is distributed more uniformly in the concrete through the dispersion effect of the bubbles, and the impermeability of each part of the concrete after pouring is stable and uniform and has small difference.

Further, the raw material of the concrete for the bridge building also comprises 0.01-0.03 part of foam stabilizer, wherein the foam stabilizer is hydroxyethyl cellulose.

By adopting the technical scheme, the hydroxyethyl cellulose can improve the quality of the foam, increase the strength and elasticity of the liquid film, and reduce the air permeability of the liquid film to improve the stability of the foam.

Further, the fine aggregate is composed of coarse sand, medium sand and stone powder in a weight ratio of 3:2 (0.5-1).

By adopting the technical scheme, the total surface area of the sand can be reduced by selecting the medium coarse sand, so that the consumption of cement and water is reduced, the hydration heat is reduced, the purpose of preventing temperature cracks is achieved, and the impermeability of the concrete is improved. The stone powder is coated on the surface of the sand, so that the internal resistance is reduced, and the compactness of the concrete is improved, thereby improving the impermeability and the durability.

In a second aspect, the present application provides a method for preparing a concrete for a beam building, which adopts the following technical scheme:

a preparation method of concrete for bridge construction comprises the following preparation steps:

s1: uniformly stirring the fine aggregate and the cement, adding water and a water reducing agent, and uniformly mixing to prepare a first mixed material;

s2: adding hydrophobic filler and glass fiber into the first blend, and stirring for 5min at 25-30rpm to obtain a second blend;

s3: adding the stones into the second mixed material, and uniformly stirring to obtain a third mixed material;

s4: and sequentially adding the air entraining agent and the foam stabilizer into the third blend, and stirring for 3-6min at 6-10rpm to prepare the concrete for the beam building.

By adopting the technical scheme, firstly, the polysiloxane particles are uniformly dispersed, so that the hydrophobic filler is filled in the capillary channel of the concrete; then the air entraining agent is added and stirred to generate a large amount of micro bubbles, and part of the bubbles are broken due to mutual impact. At the initial stage of stirring, the amount of generated bubbles is far greater than the amount of generated bubbles, the amount of the generated bubbles is gradually increased, and the impermeability of the concrete is improved; along with the increase of the stirring time, the amount of generated bubbles is less than the amount of generated bubbles, the amount of the bubbles tends to be reduced, and the impermeability of the concrete is reduced; stirring at low speed can reduce foam breaking caused by shearing action.

In summary, the present application has the following beneficial effects:

1. in the application, the hydrophobic filler and the glass fiber are matched together, so that the impermeability of the obtained bridge construction concrete can be improved. Under the same test condition, compared with the concrete test piece prepared without adding the hydrophobic filler and the air entraining agent, the average water seepage height of the concrete test piece prepared by adopting the hydrophobic filler and the air entraining agent is reduced by 24.3mm, which shows that the impermeability of the concrete for bridge construction is obviously improved by adopting the hydrophobic filler and the glass fiber.

2. In the application, the air entraining agent is adopted to obviously improve the uniformity and the stability of the impermeability of the concrete for bridge construction. Under the same test condition, the variance of the concrete test piece prepared by adopting the air entraining agent is 0.21, and the variance of the concrete test piece prepared by adopting the air entraining agent is 1.69; the concrete prepared by the air entraining agent has uniform impermeability and good stability.

3. In the application, compared with the hydrophobic filler prepared by a common mixing method, the hydrophobic filler prepared by the spraying method has a more compact and uniform polysiloxane waterproof layer and a better filling effect. Under the same test conditions, compared with a concrete test piece prepared by adopting the spraying method, the average water seepage height of the concrete test piece prepared by adopting the spraying method is reduced by 11.3mm compared with that of the concrete test piece prepared by adopting no spraying method, and the variance of the water seepage height among the test pieces is reduced by 0.38, which shows that the spraying method can achieve better anti-seepage effect.

4. In the application, when the air entraining agent is added, more bubbles can be obtained by controlling the stirring speed to be 500-800rpm and the stirring time to be 3-6min, so that the hydrophobic filler is distributed more uniformly. Under the same test conditions, the stirring speed is controlled to be 500-800rpm, the stirring time is controlled to be 3-6min, and compared with the stirring speed of 100rpm, the stirring time is 10min, the penetration height variance of 6 prepared concrete samples is reduced to 0.21 from 1.13; the concrete prepared under the conditions has higher bubble content, and the hydrophobic filler is distributed more uniformly in the stirring process.

Detailed Description

The present application is described in further detail below.

Example 1: the concrete for the bridge building is prepared according to the following process.

(1) The hydrophobic filler is prepared by the following process:

step A1: melting polyaryl organic silicon resin (organic silicon resin) and furfuryl alcohol phenolic resin (furan resin) in a weight ratio of 20:7 at 280 ℃, and uniformly stirring to prepare an adhesive; taking 2.5 kg of adhesive and 29 kg of fly ash with the average particle size of 5 microns, spraying the molten adhesive on the surfaces of fly ash particles in a spray form by using a glue sprayer, stirring the fly ash at 500rpm while spraying for 2min to obtain an adhesive carrier;

step A2: when the temperature of the adhesive carrier is reduced to 180 ℃, the adhesive carrier is placed in a dryer, 1.5 kg of liquid pentadecafluorononyltrimethoxysilane (polysiloxane) is taken and sprayed on the adhesive carrier through an atomizing spray head, the adhesive carrier is stirred at 100rpm while spraying, the temperature in the dryer is controlled to be reduced at a constant speed of 1.2 ℃/min, and the temperature is reduced from 180 ℃ to 25 ℃, so that the finished hydrophobic filler is prepared.

(2) Preparing the concrete for the bridge building:

s1: taking 160 kg of fine aggregate and 120 kg of cement, putting the fine aggregate and the cement into a stirrer, uniformly stirring, wherein the weight ratio of coarse sand to medium sand to stone powder in the fine aggregate is 3:2:0.8, adding 30 kg of water and 1.8 kg of calcium lignosulfonate water reducing agent, and uniformly stirring to obtain a first mixture;

s2: sieving the hydrophobic filler prepared in the step A2, selecting 32 kg of particles with the particle size of less than or equal to 30 micrometers, adding the particles and 10 kg of glass fiber into the first mixed material, and stirring at 30rpm for 10min to prepare a second mixed material;

s3: adding 255 kilograms of cobbles with the average particle size of 25mm into the second blend, and uniformly stirring to obtain a third blend;

s4: 0.28 kg of sodium lauryl sulfate (air entraining agent) and 0.015 kg of hydroxyethyl cellulose (foam stabilizer) were added to the third blend and stirred at 6rpm for 4min to obtain the bridge construction concrete.

Examples 2 to 6: the bridge building concrete is different from the concrete in example 1 in the content of each raw material component, and the corresponding components and the quality are shown in table 1.

Table 1 examples 1-6 concrete compositions and proportions (kg) for bridge construction

TABLE 2 compositions of hydrophobic fillers and schedules (kilograms) for examples 1-6

Example 7, a bridge construction concrete, was different from example 1 in that the average particle size of fly ash in step a1 was 1 μm.

Example 8 is a bridge construction concrete different from example 1 in that the average particle sizes of fly ashes in the step a1 are 50 μm, respectively.

Example 9 a concrete for bridge construction, which is different from example 1 in that a hydrophobic filler is prepared according to the following steps:

step B1: melting the organic silicon resin and the furan resin in a weight ratio of 20:7 at 280 ℃, and uniformly stirring to prepare the adhesive; taking 2.5 kg of adhesive and 26 kg of coal ash with average particle size of 5 mu m, and stirring the coal ash under the condition of 500rpm to obtain an adhesive carrier;

step B2: when the temperature of the viscous carrier is reduced to 180 ℃, putting the semi-finished hydrophobic filler into a dryer, taking 1 kg of liquid polysiloxane to mix with the viscous carrier, stirring the fly ash under the condition of 100rpm, and controlling the temperature in the dryer to reduce at a constant speed of 1 ℃/min until the temperature is reduced to 25 ℃ to obtain the finished hydrophobic filler;

example 10, a bridge construction concrete, differs from example 1 in that the adhesive carrier is controlled to descend at a constant speed of 1.5 ℃/min during the stirring in step a 2.

Example 11, a concrete for bridge construction, which is different from example 1 in that the viscous carrier is naturally cooled during the stirring in the step a2, and the viscous carrier descends at a constant speed of 3-6 ℃/min,

embodiment 12, a concrete for bridge construction, differs from embodiment 1 in that in step S4, stirring at 8rpm for 2min is modified to stirring at 8rpm for 6 min.

Embodiment 13, a concrete for bridge construction, differs from embodiment 1 in that in step S4, stirring at 8rpm for 2min is modified to stirring at 100rpm for 10 min.

Example 14, a concrete for bridge construction, was different from example 1 in that no air-entraining agent was added.

Comparative example 1, a concrete for bridge construction, which is different from example 1 in that a hydrophobic filler is not added.

Comparative example 2, a concrete for bridge construction, which is different from example 1 in that glass fiber is not added.

Comparative example 3, a concrete for bridge construction, which is different from example 1 in that a hydrophobic filler and glass fiber are not added.

Comparative example 4, a concrete for bridge construction, which is different from example 14 in that a hydrophobic filler and glass fiber were not added.

Comparative example 5, using a formulation according to the related art: 75 parts of cement, 25 parts of sand, 25 parts of fly ash, 10 parts of calcium phosphate, 10 parts of magnesium silicate, 18 parts of pebbles, 2.5 parts of polypropylene fiber and 20 parts of water, and stirring and mixing to obtain the concrete.

Experiment 1: and (3) concrete water penetration resistance test: the test refers to a water penetration resistance test-water penetration height method in GB/T50082-2009, wherein the water penetration height method is used for measuring the water penetration resistance of concrete expressed by the average water penetration height of a hardened concrete test piece under constant water pressure; meanwhile, the variance of the penetration height of each test piece of the same example or comparative example was measured to show the stability and uniformity of the water resistance of the concrete.

In this test, 6 test pieces were prepared for the same batch of concrete of each example or comparative example, and the permeation height of each test piece was measured under a constant water pressure of 1.2Mpa, and the test results are shown in table 3.

TABLE 3 mean water penetration heights and variances for examples 1-11 and comparative examples 1-6

Comparing examples 1 to 14 with comparative example 1, the raw materials of the concrete for bridge construction in examples 1 to 14 were all added with hydrophobic filler, and the raw materials of the concrete for bridge construction in comparative example 1 were not added with hydrophobic filler; as can be seen from Table 3, the penetration heights of the test pieces of examples 1 to 14 were within a range of 16.6 to 28.8mm, and the average penetration height was within a range of 17.3 to 27.8mm, which was less than the average penetration height of 35.2mm of comparative example 1. Therefore, the hydrophobic filler is added into the raw materials of the concrete for the bridge building, so that the impermeability of the concrete for the bridge building is obviously improved.

Comparing comparative examples 1 to 3 with example 1, the raw material of the concrete for bridge construction in comparative example 1 is not added with hydrophobic filler, comparative example 2 is not added with glass fiber, comparative example 3 is not added with hydrophobic filler and glass fiber, and example 1 is added with hydrophobic filler and glass fiber; as can be seen from Table 3, the average penetration heights of the test pieces of comparative example 1, comparative example 2, comparative example 3 and example 1 were 35.2mm, 25mm, 41.6mm and 17.3mm, respectively. Therefore, the hydrophobic filler and the glass fiber have a synergistic effect, and the impermeability of the concrete for the bridge building prepared by the hydrophobic filler and the glass fiber is obviously improved.

Comparing the embodiment 1 with the embodiment 14, the embodiment 1 is added with the hydrophobic filler, the glass fiber and the air entraining agent at the same time, and the embodiment 14 is not added with the air entraining agent; from the test results of table 3, it can be seen that: the average penetration heights of the concrete for bridge construction are 17.3mm and 22.3mm respectively in the embodiment 1 and the embodiment 14, which shows that the addition of the air entraining agent is beneficial to improving the impermeability of the concrete for bridge construction; example 1 the variances of the test pieces of example 14 and comparative example 4 are 0.21 and 1.69 respectively, which shows that the dispersibility of the hydrophobic filler can be obviously improved by adopting the air entraining agent, and the stability and uniformity of the impermeability of the concrete are obviously improved.

The test results of comparative example 1 and example 9 show that the average water penetration height of the concrete test piece is reduced from 28.6mm to 17.3mm, and the variance between the test pieces is reduced from 0.59 to 0.21, so that the polysiloxane outer layer formed on the hydrophobic filler prepared by the spraying method is more uniform and compact, the filling effect is better, and the impermeability is higher.

The test results of comparative example 1, example 5 and example 6 show that compared with the single-component silicone resin and furan resin, the hydrophobic filler prepared by using the adhesive formed by compounding the silicone resin and the furan resin has better waterproof and anti-permeability effects.

The test results of comparative example 1 and example 13 show that after the air entraining agent is added, under the conditions of stirring speed of 6-10rpm and stirring time of 3-6min, more air bubbles can be introduced into the concrete, the air bubbles and the hydrophobic filler are distributed more uniformly, the impermeability of the concrete is obviously improved, and the stable uniformity of the concrete quality is improved.

The present embodiment is only for explaining the present application, and it is not limited to the present application, 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 application.

Claims

1. The concrete for the bridge building is characterized by comprising the following raw materials in parts by weight:

cement: 100 and 160 parts;

fine aggregate: 130-170 parts of organic silicon;

stone: 230- > 290 parts;

water: 28-36 parts;

water reducing agent: 1.5-2.0 parts;

glass fiber: 10-15 parts;

air entraining agent: 0.2-0.4 part;

foam stabilizer: 0.01 to 0.03 portion

Hydrophobic filler: 15-36 parts;

the fine aggregate consists of coarse sand, medium sand and stone powder in a weight ratio of 3:2 (0.5-1);

the foam stabilizer is hydroxyethyl cellulose;

adhesive: 2-3 parts of a solvent;

polysiloxane: 1-2 parts;

fly ash: 12-31 parts;

the hydrophobic filler is prepared by the following process:

step A1, melting the adhesive, spraying the melted adhesive on the fly ash, and stirring the fly ash under the conditions of 500-800rpm while spraying to obtain a viscous carrier;

step A2, spraying liquid polysiloxane on the viscous carrier, and stirring the viscous carrier under the condition of 100-180rpm while spraying to prepare the hydrophobic filler;

the adhesive is a composition of organic silicon resin and furan resin with the weight ratio of 20 (5-9).

2. The bridge construction concrete according to claim 1, wherein the temperature of the adhesive agent is controlled to decrease to 25-35 ℃ at a constant speed of 0.8-1.5 ℃/min during the stirring of the adhesive carrier in step A2.

3. The bridge building concrete according to claim 1, wherein the fly ash has an average particle size of 1 to 10 μm.

4. The bridge building concrete according to claim 1, wherein the air entraining agent is sodium lauryl sulfate.

5. A method of producing a bridge construction concrete according to any one of claims 1 to 4, characterized by comprising the following production steps: