CN112358252A

CN112358252A - Anti-freezing cracking concrete and preparation method thereof

Info

Publication number: CN112358252A
Application number: CN202011251259.5A
Authority: CN
Inventors: 黄安良; 曾永成; 张志君; 方炳新; 刘梓骏
Original assignee: Guangzhou Guangfeng Concrete Co ltd
Current assignee: Guangzhou Guangfeng Concrete Co ltd
Priority date: 2020-11-11
Filing date: 2020-11-11
Publication date: 2021-02-12

Abstract

The application relates to the field of concrete, and particularly discloses frost crack resistant concrete and a preparation method thereof. The concrete comprises polyoxyethylene sorbitan monostearate, di-sec-octyl maleate sodium sulfonate, coarse aggregate, fine aggregate, cement and water. The preparation method of the concrete comprises the following steps: step 1), adding polyoxyethylene sorbitan monostearate and sodium di-sec-octyl maleate sulfonate into water, and heating to 75-80 ℃ to obtain a first mixture; and 2) adding the first mixture, cement and fine aggregate into the coarse aggregate, and uniformly mixing to obtain the frost cracking resistant concrete. The frost crack resistant concrete can improve frost resistance and impermeability of the concrete. The preparation method can improve the workability of the concrete mixture.

Description

Anti-freezing cracking concrete and preparation method thereof

Technical Field

The application relates to the field of concrete, in particular to frost crack resistant concrete and a preparation method thereof.

Background

Concrete is one of the most important civil engineering materials of the present generation. The artificial stone is prepared by a cementing material, granular aggregate, water, an additive and an admixture which are added if necessary according to a certain proportion, and is formed by uniformly stirring, compacting, forming, curing and hardening. The concrete has the characteristics of rich raw materials, low price and simple production process, so that the consumption of the concrete is increased more and more.

In cold areas in northern China, most of concrete damage is related to freezing and thawing action, and the damage of a concrete structure under the action of freezing and thawing cycle is related to the problems of the aspects of the service life of buildings, the engineering quality, the operation safety and the like.

When water in the pores or cracks of the concrete freezes into ice, the volume of the water expands, so that the water generates great pressure on the concrete crack wall surrounding the water, and the temperature difference cracks of the concrete are deepened and widened. When the ice melts, the enlarged cracks of the water penetrate into the concrete more deeply, and meanwhile, the water amount is also increased and the water is frozen into the ice again, so that the freezing and thawing are frequently carried out, the cracks are continuously enlarged, and the concrete is cracked.

In view of the above-mentioned related technologies, the inventor believes that when the freeze-thaw phenomenon occurs, the expansion-resistant strength of the concrete is low, the internal crack is gradually deepened, the cracking speed is accelerated, and water is more likely to permeate into the concrete, so that the frost resistance of the concrete is increasingly poor, and the safety of the concrete building is affected.

Disclosure of Invention

In order to improve the frost resistance of concrete, the application provides frost crack resistant concrete and a preparation method thereof.

In a first aspect, the application provides a frost cracking resistant concrete, which adopts the following technical scheme:

the frost cracking resistant concrete is prepared from the following raw materials in parts by weight:

15-20 parts of polyoxyethylene sorbitan monostearate;

12-18 parts of di-sec-octyl maleate sodium sulfonate;

1600 portions and 1800 portions of coarse aggregate;

30-220 parts of fine aggregate;

cement 300-;

200 portions of water and 250 portions of water;

the molecular weight of the polyoxyethylene sorbitan monostearate is 1200-1400.

By adopting the technical scheme, the emulsifying power is strong by adding the polyoxyethylene sorbitan monostearate, the concrete raw material does not need to be heated at high temperature, and the mixed concrete raw material can be emulsified at low temperature.

By adding the di-sec-octyl maleate sodium sulfonate, the di-sec-octyl maleate sodium sulfonate has the effects of compensating concrete drying and compacting concrete and improving the impermeability of the concrete, and has the advantages of good durability, stable expansion performance and strength improvement.

By adding the coarse aggregate, when the concrete bears compressive load, the stress is transmitted by the regenerated coarse aggregate in the concrete, and when the concrete is damaged under the action of external load, cracks hardly penetrate through the regenerated coarse aggregate but bypass the regenerated coarse aggregate to appear around the aggregate, so that the strength of the concrete is improved.

By adding the fine aggregate, the regenerated fine aggregate can fill gaps among the regenerated coarse aggregate, and the strength of the concrete is increased.

Through the matching of the polyoxyethylene sorbitan monostearate and the di-sec-octyl maleate sodium sulfonate in a specific proportion, the hydration heat of cement is reduced, the hydration reaction is accelerated, and meanwhile, the temperature rise amplitude is reduced, so that the early-stage expansion resistance is improved, the frost cracking resistance of concrete can be greatly improved, and the occurrence of temperature difference cracks of concrete buildings is relieved.

Preferably, the concrete further comprises the following components in parts by weight:

3-8 parts of pumping agent.

By adopting the technical scheme, the pumping agent can improve the fluidity of the concrete mixture, so that better workability is kept in the concrete conveying process. The pumping agent can adopt sodium potassium tartrate, borax, diethanol monoisopropanolamine and glycerol carbonate.

6-9 parts of retarder.

By adopting the technical scheme, the retarder can delay cement solidification, prolong the solidification time of concrete, does not influence the quality of concrete, and can improve the water reducing rate of the concrete when used together with a water reducing agent. The retarder can be sodium borate, calcium sulfate, sodium pyrophosphate, sucrose, and rapeseed oil.

4-8 parts of an air entraining agent.

By adopting the technical scheme, the air entraining agent can improve the durability of concrete and the rheological property of fresh concrete, and adjust the setting and hardening properties and the gas content of the concrete. The air entraining agent can adopt sodium dodecyl sulfate, pentaerythritol and neopentyl glycol.

3-5 parts of a water reducing agent.

By adopting the technical scheme, the water reducing agent can greatly reduce the water consumption of the mixture, has a dispersing effect on cement particles after being added into concrete, saves the cement, and has low mixing amount, high water reducing rate and better economic benefit. The water reducing agent can be isopropanol, acrylamide, sodium acrylate, ferrous sulfate, sodium tripolyphosphate, or sodium lactate polymethacrylate.

7-9 parts of a seepage-proofing agent.

By adopting the technical scheme, the anti-seepage agent can obviously improve the wear resistance and durability of the concrete base surface, solidify the sand surface and improve the surface strength of the concrete pavement. The anti-seepage agent can adopt triethanolamine and tetrakis hydroxymethyl phosphonium sulfate.

Preferably, the anti-seepage agent comprises the following components in parts by mass:

3-4 parts of triethanolamine;

4-5 parts of tetrakis hydroxymethyl phosphonium sulfate.

By adopting the technical scheme, the triethanolamine is added, so that the wear resistance and the scratch resistance of the concrete can be improved, and the dust generated by the concrete is reduced.

By adding the tetrakis (hydroxymethyl) phosphonium sulfate, the tetrakishydroxymethyl phosphonium sulfate can greatly improve the pumpability and impermeability of concrete and slow down the corrosion of chloride ions and sulfate, a layer of molecular chemical protective film can be formed on the surface of a steel bar of the concrete, the corrosion of the steel bar caused by various reasons such as chloride, sulfate, carbonization or stray current is slowed down, the durability of the concrete is improved, and the service life of a concrete building is prolonged.

The triethanolamine and the tetrakis hydroxymethyl phosphonium sulfate are matched in a specific proportion, so that a waterproof film can be formed on concrete, the concrete building has waterproof and anticorrosion effects, the conditions of water leakage, moisture regain, water seepage and the like of the concrete building are relieved, and the service life of the concrete building is effectively prolonged.

and 15-20 parts of neopentyl glycol.

By adopting the technical scheme, the neopentyl glycol has good water resistance, weather resistance and thermal stability. The neopentyl glycol is matched with the polyoxyethylene sorbitan monostearate and the di-sec-octyl maleate sodium sulfonate according to a specific proportion, so that the strength of the concrete is still higher after multiple times of freeze thawing, the expansion pressure generated by water icing in the concrete can be buffered, and the frost resistance of the concrete is further enhanced.

In a second aspect, the application provides a preparation method of frost cracking resistant concrete, which adopts the following technical scheme:

a preparation method of frost crack resistant concrete comprises the following steps:

step 1), adding polyoxyethylene sorbitan monostearate and sodium di-sec-octyl maleate sulfonate into water, and heating to 75-80 ℃ to obtain a first mixture;

and 2) adding the first mixture, cement and fine aggregate into the coarse aggregate, and uniformly mixing to obtain the frost cracking resistant concrete.

By adopting the technical scheme, the polyoxyethylene sorbitan monostearate and the di-sec-octyl maleate sodium sulfonate are heated and mixed, so that the fluidity of each component can be improved, and the components are dispersed in water more uniformly.

Preferably, in the step 1), neopentyl glycol, triethanolamine and tetrakis (hydroxymethyl) phosphonium sulfate are also added into the first mixture;

in the step 2), a pumping aid, a retarder, an air entraining agent and a water reducing agent are also added into the coarse aggregate.

By adopting the technical scheme, the components are uniformly mixed to form a stable state, and the effect of each component is better exerted.

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

1. because the polyoxyethylene sorbitan monostearate and the di-sec-octyl maleate sodium sulfonate are matched in a specific proportion, the hydration heat of the cement is reduced, the hydration reaction is accelerated, and meanwhile, the temperature rise amplitude is reduced, so that the strength development rate is improved, the frost cracking resistance of the concrete can be greatly improved, and the occurrence of temperature difference cracks of a concrete building is relieved.

2. In the application, neopentyl glycol is preferably matched with polyoxyethylene sorbitan monostearate and di-sec-octyl maleate sodium sulfonate in a specific proportion, so that the early expansion resistance is improved, the deformation amount of the concrete after multiple times of freeze thawing is small, the expansion pressure generated by icing of water in the concrete can be buffered, the cracking of the concrete is slowed, and the frost resistance of the concrete is further enhanced.

3. The preferable triethanolamine of adopting in this application and the cooperation of four hydroxyl methyl phosphoric acid with specific proportion can form the water proof membrane at the concrete for concrete building has waterproof, anticorrosive effect, slows down the concrete building and appears leaking, gets damp, infiltration etc. the condition, improves the life who effectively prolongs concrete building.

Detailed Description

The present application will be described in further detail with reference to examples.

The information on the source of each raw material component in the following examples and comparative examples is shown in Table 1.

TABLE 1

Examples 1 to 3: the frost crack resistant concrete comprises the following components:

polyoxyethylene sorbitan monostearate, di-sec-octyl maleate sodium sulfonate, coarse aggregate, fine aggregate, cement and water.

The coarse aggregate is the compound of medium sand and fine stone.

The fine aggregate is the compound of fly ash and mineral powder.

In examples 1-3, the amounts (in Kg) of the ingredients added are specified in Table 2.

TABLE 2

	Example 1	Example 2	Example 3
				Polyoxyethylene sorbitan monostearate	2	6	10
Di-sec-octyl maleate sodium sulfonate	2	3	4
				Medium sand	850	900	950
Fine stone	750	800	850
				Fly ash	5	67	130
Mineral powder	25	85	145
				Cement	300	325	350

The method of making the freeze crack resistant concrete of examples 1-3 includes the steps of:

step 1), adding polyoxyethylene sorbitan monostearate and sodium di-sec-octyl maleate sodium sulfonate and water into a first stirrer, heating to 77 ℃, rotating at the speed of 200r/min, and continuously stirring for 30min to obtain a first mixture;

and 2) adding cement, medium sand, fine stone, fly ash and mineral powder into a first stirrer together according to the formula, rotating at the speed of 200r/min, and continuously stirring for 30min to obtain the frost cracking resistant concrete.

The molecular weight of the polyoxyethylene sorbitan monostearate was 1200.

Example 4

Compared with the concrete in the example 2, the concrete is different only in that:

in the step 1), polyoxyethylene sorbitan monostearate and sodium di-sec-octyl maleate are taken and added into a first stirrer together with water, and the mixture is heated to 75 ℃.

The molecular weight of the polyoxyethylene sorbitan monostearate was 1300.

Example 5

A concrete using recycled concrete aggregate, which differs from example 2 only in that:

in the step 1), polyoxyethylene sorbitan monostearate and sodium di-sec-octyl maleate are taken and added into a first stirrer together with water, and the mixture is heated to 80 ℃.

The molecular weight of the polyoxyethylene sorbitan monostearate is 1400.

Examples 6 to 8

the concrete also comprises an impermeable agent.

The anti-seepage agent is a compound of triethanolamine and tetrakis hydroxymethyl phosphonium sulfate.

In examples 6 to 8, the amounts (in Kg) of the components added are specified in Table 3.

TABLE 3

	Example 6	Example 7	Example 8
				Triethanolamine	3	3.5	4
Tetrakis (hydroxymethyl) phosphonium sulfate	4	4.5	5

Triethanolamine, tetrakis (hydroxymethyl) phosphonium sulfate were added to the first mixer in step 1) along with polyoxyethylene sorbitan monostearate.

Examples 9 to 11

the concrete also comprises neopentyl glycol as a component.

In examples 9 to 11, the amounts (in Kg) of the components added are specified in Table 4.

TABLE 4

	Example 9	Example 10	EXAMPLE 11
				Neopentyl glycol	15	17	20

Neopentyl glycol was added to the first mixer in step 1) together with polyoxyethylene sorbitan monostearate.

Examples 12 to 14

the concrete also comprises pumping aid, retarder, air entraining agent and water reducing agent.

The pumping agent is the compound of sodium potassium tartrate and borax;

the retarder is sodium borate;

the air entraining agent is a compound of sodium dodecyl sulfate and pentaerythritol;

the water reducing agent is isopropanol.

In examples 12 to 14, the amounts (in Kg) of the components added are specified in Table 5.

TABLE 5

Triethanolamine, tetrakis (hydroxymethyl) phosphonium sulfate, neopentyl glycol were added to the first mixer in step 1) along with polyoxyethylene sorbitan monostearate.

The pumping aid, the retarder, the air entraining agent and the water reducing agent are added into the first stirrer together with the cement in the step 2).

Comparative example 1

Compared with example 2, the difference is only that:

in the step 1), polyoxyethylene sorbitan monostearate and sodium di-sec-octyl maleate sulfonate are equivalently replaced by fine stones.

Comparative example 2

Compared with example 2, the difference is only that:

in the step 1), polyoxyethylene sorbitan monostearate is replaced by fine stone with the same amount.

Comparative example 3

Compared with example 2, the difference is only that:

in the step 1), fine stones are equivalently used to replace di-sec-octyl maleate sodium sulfonate.

Experiment 1

The concrete samples prepared in the examples and comparative examples were taken according to T0551 "method for producing Cement concrete samples and sampling hardened Cement concrete on site", and the Cement concrete Frost resistance test was performed according to JTGE30-2005 Standard works Cement and Cement concrete test Specification ". Relative dynamic elastic modulus P ═ f of concrete specimen_n ²/f₀ ²) 100, wherein P is the relative dynamic elastic modulus (%) of the test piece after n freeze-thaw cycles, f_nIs the transverse fundamental frequency (Hz), f of the test piece after n cycles of freeze thawing₀The transverse fundamental frequency (Hz) of the test piece before the test. The average of 3 test pieces is taken as the test result, and the result is accurate to 0.1%.

Experiment 2

The concrete samples prepared in the examples and comparative examples were subjected to a cement concrete impermeability test according to JTGE30-2005 Highway engineering cement and cement concrete test Specification, and the impermeability rating of the concrete was expressed as the maximum water pressure at which water permeation was not observed in 4 of 6 samples per group. And the impermeability grade S is 10H-1, wherein S is the impermeability grade of concrete, and H is the water pressure (MPa) when the top surface of the third test piece begins to have water seepage. Concrete impermeability grades are S2, S4, S6, S8, S10, S12.

The data from experiments 1-2 are detailed in Table 6.

TABLE 6

	Relative dynamic elastic modulus P/%)	Concrete impermeability grade
			Example 1	75.1	S4
Example 2	75.2	S4
			Example 3	75.1	S4
Example 4	75.3	S4
			Example 5	75.2	S4
Example 6	75.1	S6
			Example 7	75.4	S6
Example 8	75.3	S6
			Example 9	61.8	S4
Example 10	61.7	S4
			Example 11	61.8	S4
Example 12	61.7	S6
			Example 13	61.9	S6
Example 14	61.7	S6
			Comparative example 1	91.5	S4
Comparative example 2	91.4	S4
			Comparative example 3	91.4	S4

According to the comparison of the data of comparative example 2 and comparative example 1 in the table 6, the addition of the sodium di-sec-octyl maleate sulfonate has no obvious change in relative dynamic elastic modulus, and the sodium di-sec-octyl maleate sulfonate has no obvious influence on the frost resistance of the concrete.

According to the comparison of the data of comparative example 3 and comparative example 1 in Table 6, the addition of the polyoxyethylene sorbitan monostearate has no obvious change of the relative dynamic elastic modulus, and the polyoxyethylene sorbitan monostearate has no obvious influence on the frost resistance of the concrete.

According to the comparison of the data of the example 2 and the comparative example 1 in the table 6, the addition of the sodium di-sec-octyl maleate sulfonate and the polyoxyethylene sorbitan monostearate has small relative dynamic elastic modulus and small deformation amount of the concrete per freeze-thaw at low temperature, and the combination of the sodium di-sec-octyl maleate sulfonate and the polyoxyethylene sorbitan monostearate proves that the concrete is not easy to crack at low temperature and the frost resistance of the concrete can be greatly improved.

According to the comparison of the data of examples 9-11 and example 2 in Table 6, the relative dynamic elastic modulus of neopentyl glycol and di-sec-octyl maleate sodium sulfonate and polyoxyethylene sorbitan monostearate is further reduced, and the concrete has no obvious cracking phenomenon, thus proving that neopentyl glycol can further enhance the frost resistance of the concrete.

According to the comparison of the data of the examples 6-8 and the example 2 in the table 6, the permeation resistance grade is improved by adding the permeation resistant agent, and the permeation resistant agent is proved to be capable of slowing down the situations of water leakage, moisture regain, water seepage and the like of concrete, so that the service life of a concrete building is effectively prolonged.

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 frost cracking resistant concrete is characterized in that: the concrete is prepared from the following raw materials in parts by mass:

15-20 parts of polyoxyethylene sorbitan monostearate;

12-18 parts of di-sec-octyl maleate sodium sulfonate;

1600 portions and 1800 portions of coarse aggregate;

30-220 parts of fine aggregate;

cement 300-;

200 portions of water and 250 portions of water;

the molecular weight of the polyoxyethylene sorbitan monostearate is 1200-1400.

2. A frost crack resistant concrete according to claim 1, wherein: the concrete also comprises the following components in parts by weight:

3-8 parts of pumping agent.

3. A frost crack resistant concrete according to claim 1, wherein: the concrete also comprises the following components in parts by weight:

6-9 parts of retarder.

4. A frost crack resistant concrete according to claim 1, wherein: the concrete also comprises the following components in parts by weight:

4-8 parts of an air entraining agent.

5. A frost crack resistant concrete according to claim 1, wherein: the concrete also comprises the following components in parts by weight:

3-5 parts of a water reducing agent.

6. A frost crack resistant concrete according to claim 1, wherein: the concrete also comprises the following components in parts by weight:

7-9 parts of a seepage-proofing agent.

7. A frost crack resistant concrete according to claim 6, wherein: the anti-seepage agent comprises the following components in parts by mass:

3-4 parts of triethanolamine;

4-5 parts of tetrakis hydroxymethyl phosphonium sulfate.

8. A frost crack resistant concrete according to claim 1, wherein: the concrete also comprises the following components in parts by weight:

and 15-20 parts of neopentyl glycol.

9. The method of claim 1, wherein the concrete is prepared by: the method comprises the following steps:

10. The method of claim 9, wherein the concrete is prepared by: in the step 1), neopentyl glycol, triethanolamine and tetrakis hydroxymethyl phosphonium sulfate are also added into the first mixture;