CN112830742B - High-impermeability concrete and preparation method thereof - Google Patents

Abstract

The application relates to the field of concrete, and particularly discloses high-impermeability concrete and a preparation method thereof. The high-impermeability concrete comprises, by weight, 50-90 parts of Portland cement, 200 parts of aggregate 150-containing materials, 30-50 parts of fly ash, 7-15 parts of additives and 25-45 parts of water; the admixture comprises (2-7) by weight: (3-6): (3-11): (0.3-0.7) cellulose, hydrophobic fumed silica, polydimethylsiloxane, and a surfactant; the preparation method comprises the following steps: s1, uniformly mixing cellulose, hydrophobic fumed silica, polydimethylsiloxane and a surfactant to obtain an additive; and S2, uniformly mixing the admixture, portland cement and water, adding aggregate and fly ash, and uniformly mixing to obtain the high-impermeability concrete. The concrete has the advantages that the impermeability and the frost resistance of the concrete are improved, and meanwhile, the strength of the concrete is improved.

Description

High-impermeability concrete and preparation method thereof

Technical Field

The application relates to the field of concrete, in particular to high-impermeability concrete and a preparation method thereof.

Background

The common concrete is prepared by mixing and stirring cement, sand, stones and water according to a certain proportion, in a water seepage environment, micro-particles in the concrete setting period are easy to wash and run off, gaps in the cured concrete are more, and the concrete has poor water resistance due to the large single-particle bonding brittleness and easy water seepage, so that the concrete building needs to have certain impermeability when soaked in water for a long time. At present, a method for solving the water seepage of concrete mainly comprises the addition of a waterproof agent, but the formula of the existing waterproof agent is unreasonable, and the waterproof property of the concrete is not ideal after the concrete is added, so that the problem that the surface layer of a building built by the existing concrete is easy to seep and fall off is solved, and the service life of the concrete building is short.

For example, the invention patent with the publication number of N108249855A provides an impervious concrete mixture and a construction method thereof, wherein the impervious concrete mixture comprises the following raw materials in parts by weight: 240 parts of Portland cement, 65-80 parts of fly ash, 850 parts of sand, 1000 parts of gravel, 1080 parts of water reducing agent, 5-10 parts of calcium sulphoaluminate expanding agent, 1-3 parts of other auxiliary agents and 160-90 parts of water.

In view of the above-mentioned related art, the inventors found in practical use that: the calcium sulphoaluminate expanding agent used in the concrete formula can cause higher hydration heat of concrete, cause the internal temperature of a concrete structure to rise, cause large temperature difference between the inside and the outside of the concrete structure, cause larger shrinkage deformation of the concrete and cause the concrete to be easy to crack and permeate.

Disclosure of Invention

In order to improve the impermeability of concrete, the application provides high-impermeability concrete and a preparation method thereof.

In a first aspect, the present application provides a high-impermeability concrete, which adopts the following technical scheme:

the high-impermeability concrete comprises, by weight, 50-90 parts of Portland cement, 200 parts of aggregate 150, 30-50 parts of fly ash, 7-15 parts of an additive and 25-45 parts of water; the admixture comprises (2-7) by weight: (3-6): (3-11): (0.3-0.7) cellulose, hydrophobic fumed silica, polydimethylsiloxane and a surfactant.

By adopting the technical scheme, due to the synergistic effect of the additive, the cellulose, the hydrophobic fumed silica and the polydimethylsiloxane in the additive, the shrinkage deformation of the concrete is reduced, the uniformity of the distribution of air holes in the concrete is improved, and capillary channels in the concrete are cut off, so that the impermeability and frost resistance of the concrete are enhanced, the interaction with the surfactant is realized, the compatibility among all raw materials of the concrete is improved, the uniformity of the air holes in the concrete is further enhanced, and the strength of the concrete is improved.

Preferably, the polydimethylsiloxane has a viscosity of 100-500cs at 25 ℃.

By adopting the technical scheme, the synergistic effect among cellulose, hydrophobic gas-phase silicon dioxide and polydimethylsiloxane can be promoted by controlling the viscosity of polydimethylsiloxane, and the shrinkage deformation among concrete is further reduced, so that the impermeability, frost resistance and strength of the concrete are improved.

Preferably, the surfactant has an HLB value of 2.1 to 6.7.

By adopting the technical scheme, the HLB value of the surfactant is controlled, so that the interaction between the surfactant and each component of the admixture is stronger, the effect between the surfactant and each raw material of the concrete is enhanced, and the impermeability, frost resistance and strength of the concrete are further improved.

Preferably, the particle size of the hydrophobic fumed silica is 1000-1800 meshes.

By adopting the technical scheme, the hydrophobic fumed silica has stronger hydrophobicity, the compatibility of the additive and each raw material of the concrete is improved by controlling the particle size of the hydrophobic fumed silica, the synergistic effect among the cellulose, the hydrophobic fumed silica and the polydimethylsiloxane is promoted, and the impermeability, the frost resistance and the strength of the concrete are improved.

Preferably, the admixture further comprises magnesium aluminum silicate, and the weight ratio of the magnesium aluminum silicate to the polydimethylsiloxane is (0.1-0.3): 1.

by adopting the technical scheme, although the magnesium aluminum silicate has hydrophilicity, the addition of the magnesium aluminum silicate improves the compatibility of each component of the additive and promotes the synergistic effect among the cellulose, the hydrophobic fumed silica and the polydimethylsiloxane.

Preferably, the admixture comprises the following components in a weight ratio of 5: 5: 10: 0.4: 2 cellulose, hydrophobic fumed silica, polydimethylsiloxane, a surfactant and magnesium aluminum silicate.

By adopting the technical scheme, the action effect between the admixture and each raw material of the concrete is enhanced by controlling the composition of each raw material of the admixture.

Preferably, the aggregate is a mixture of fine aggregate and coarse aggregate, and the weight ratio of the coarse aggregate to the fine aggregate is 1: (0.5-0.7).

By adopting the technical scheme, the weight ratio of the coarse aggregate to the fine aggregate is controlled, the compatibility among the raw materials can be improved, and the action between the admixture and the raw materials of the concrete is enhanced.

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

a preparation method of high-impermeability concrete comprises the following preparation steps:

s1, uniformly mixing cellulose, hydrophobic fumed silica, polydimethylsiloxane and a surfactant to obtain an additive;

and S2, uniformly mixing the admixture, portland cement and water, adding aggregate and fly ash, and uniformly mixing to obtain the high-impermeability concrete.

By adopting the technical scheme, the additive is added into the concrete, so that the impermeability and frost resistance of the concrete are improved, and the strength of the concrete is improved.

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

1. due to the synergistic effect of the additive, the cellulose, the hydrophobic fumed silica and the polydimethylsiloxane in the additive, the shrinkage deformation of the concrete is reduced, the uniformity of the distribution of air holes in the concrete is improved, and capillary channels in the concrete are cut off, so that the impermeability and frost resistance of the concrete are enhanced, the compatibility among various raw materials of the concrete is improved due to the interaction of the capillary channels and the surfactant, the uniformity of the air holes in the concrete is further enhanced, and the strength of the concrete is improved.

2. In the application, the surfactant with the HLB value of 2.1-6.7 is preferably adopted, so that the interaction between the surfactant and each component of the admixture is stronger, the effect between the surfactant and each raw material of the concrete is enhanced, and the impermeability, frost resistance and strength of the concrete are further improved.

3. According to the method, the admixture is added into the concrete, the preparation method is simple, and the impermeability and frost resistance of the concrete are improved while the strength of the concrete is improved.

Detailed Description

The present application is described in further detail below with reference to preparation examples and examples.

Preparation examples of Admixture

Preparation example 1

An additive for high impervious concrete is prepared from (by weight ratio) 7: 4: 5: 0.3 of cellulose, hydrophobic fumed silica, polydimethylsiloxane and surfactant are uniformly mixed to prepare the composite material;

the cellulose is hydroxyethyl cellulose, the type of the hydroxyethyl cellulose is WTM0008, and the cellulose is purchased from Beijing Wan Diamingming science and technology Limited; the particle size of the hydrophobic fumed silica is 800 meshes, and the hydrophobic fumed silica is purchased from New Material Co., Ltd of Hippocastricco; the polydimethylsiloxane had a viscosity of 50cs at 25 ℃ and was purchased from Guangzhou Shuichong import & export company; the surfactant is Tween 20, has an HLB value of 13.5, and is purchased from Anhui Zhonghong bioengineering Co., Ltd.

Preparation examples 2 to 3

Preparation examples 2 to 3 are based on preparation example 1 and differ from the preparation examples only in that: the raw materials have different proportions, and are shown in table 1.

TABLE 1 preparation examples 1-3 raw material ratios

Preparation example	Preparation example 1	Preparation example 2	Preparation example 3
				Cellulose, hydrophobic fumed silica, polydimethylsiloxane and surfactant (weight ratio)	7：4：5：0.3	5：3：11：0.7	2：6：3：0.5

Preparation examples 4 to 6

Preparation examples 4 to 6 are based on preparation example 1, differing from preparation example 1 only in that: the viscosities of the polydimethylsiloxanes used at 25 ℃ differ, as shown in Table 2.

TABLE 2 preparation examples 4-6 viscosity of polydimethylsiloxane

Preparation example	Preparation example 4	Preparation example 5	Preparation example 6
				Viscosity of polydimethylsiloxane at 25 DEG C	100cs	500cs	400cs

Polydimethylsiloxanes with viscosities of 100cs, 500cs, and 400cs at 25 ℃ were obtained from Guangzhou Shuichong Ind.

Preparation example 7

Preparation 7 is based on preparation 6 and differs from preparation 6 only in that: the surfactant is sorbitan palmitate with a model of S-40 and an HLB value of 6.7, and is purchased from Haian petrochemical plant of Jiangsu province.

Preparation example 8

Preparation 8 is based on preparation 6 and differs from preparation 6 only in that: the surfactant is sorbitan tristearate with a model number of S-65 and an HLB value of 2.1, and is purchased from Haian petrochemical plants of Jiangsu province.

Preparation example 9

Preparation 9 is based on preparation 6 and differs from preparation 6 only in that: the surfactant is glyceryl monostearate, has HLB value of 5.5 and CAS number of 31566-31-1, and is available from Jiangsu Baiweijia scientific and technological Co.

Preparation examples 10 to 12

Preparation examples 10 to 12 are based on preparation example 10, differing from preparation example 10 only in that: the particle size of the hydrophobic fumed silica used varies, and is shown in Table 3.

TABLE 3 particle diameters of hydrophobic fumed silicas of preparation examples 10 to 12

Preparation examples	Preparation example 10	Preparation example 11	Preparation example 12
				Hydrophobic fumed silica particle size (mesh)	1000	1800	1300

Preparation examples 13 to 15

Preparation examples 13 to 15 are based on preparation example 12 and differ from preparation example 12 only in that: the additive is prepared by mixing magnesium aluminum silicate with other raw materials in different weight ratios of magnesium aluminum silicate to polydimethylsiloxane, and concretely, the CAS number of the magnesium aluminum silicate is 71205-22-6, which is purchased from Jinan Yun Baihui Biotech limited company.

TABLE 4 preparation examples 13-15 weight ratios of magnesium aluminum silicate to polydimethylsiloxane

Preparation example	Preparation example 13	Preparation example 14	Preparation example 15
				Magnesium aluminum silicate polydimethylsiloxane (weight ratio)	0.1：1	0.3：1	0.2：1

Preparation example 16

Preparation 16 is based on preparation 15, differing from preparation 15 only in that: the weight ratio of the cellulose, hydrophobic fumed silica, polydimethylsiloxane, surfactant and magnesium aluminum silicate is 5: 5: 10: 0.4: 2.

comparative preparation example 1

Comparative example preparation example 1 is based on preparation example 1, differing from preparation example 1 only in that: the hydrophilic fumed silica with equal mass is used for replacing hydrophobic fumed silica, the type of the hydrophilic fumed silica is YJ-A5200, and the hydrophilic fumed silica is purchased from Shanghai Yangjiang chemical industry Co.

Comparative preparation example 2

Comparative example preparation example 2 is based on preparation example 1, differing from preparation example 1 only in that: replacing polydimethylsiloxane by hydroxyethyl cellulose with equal mass; the hydroxyethyl cellulose is of the type WTM0008 and is available from Beijing Wan Diamingming technology Co.

Comparative preparation example 3

Comparative example preparation 3 is based on preparation 1, differing from preparation 1 only in that: replacing cellulose with polydimethylsiloxane of equal mass; the polydimethylsiloxane had a viscosity of 50cs at 25 ℃ and was purchased from Guangzhou Shuichong Ind.

Examples

Example 1

The preparation method of the high-impermeability concrete comprises the following steps: taking 7g of the additive prepared in preparation example 1, uniformly mixing with 70g of Portland cement and 35g of water, adding 180g of aggregate and 40g of fly ash, and uniformly mixing to obtain the high-impermeability concrete;

the portland cement is P.O 42.5.5 ordinary portland cement which is purchased from compliant cement limited company; the aggregate is a mixture of coarse aggregate and fine aggregate, and the mass ratio of the coarse aggregate to the fine aggregate is 1: 1, the particle size of the coarse aggregate is 20mm, the product number is 0074, the coarse aggregate is purchased from a brilliant color stone factory in Liuhe district of Nanjing city, and the particle size of the fine aggregate is 4mm, and the fine aggregate is purchased from the Jinrong chemical engineering Ministry of Hunan district of Hengyang city; the fly ash has a silicon dioxide content of 60wt% and is purchased from processing plants of mineral products in Lingshou county.

Examples 2 to 4

Examples 2 to 4 are based on example 1 and differ from example 1 only in that: the types and the amounts of the raw materials are different, and the specific table is shown in table 5.

TABLE 5 examples 1-5 sources and amounts of raw materials

Examples	Example 1	Example 2	Example 3	Example 4
					Portland cement (g)	70	90	50	70
Aggregate (g)	180	150	200	180
					Fly ash (g)	40	30	50	40
Water (g)	35	45	25	35
					Admixture (g)	7	10	15	7
Source of additive	Preparation example 1	Preparation example 1	Preparation example 2	Preparation example 3

Example 5

Example 5 is based on example 1 and differs from example 1 only in that: the weight ratio of the coarse aggregate to the fine aggregate in the used aggregate is 1: 0.5.

example 6

Example 6 is based on example 1 and differs from example 1 only in that: the weight ratio of the coarse aggregate to the fine aggregate in the used aggregate is 1: 0.7.

examples 7 to 19

Examples 7 to 19 are based on example 1 and differ from example 1 only in that: the sources of the additives used are different and are shown in Table 6.

TABLE 6 sources of additives for examples 7-19

Examples	Source of additive	Examples	Source of additive
				Example 7	Preparation example 4	Example 14	Preparation example 11
Example 8	Preparation example 5	Example 15	Preparation example 12
				Example 9	Preparation example 6	Example 16	Preparation example 13
Example 10	Preparation example 7	Example 17	Preparation example 14
				Example 11	Preparation example 8	Example 18	Preparation example 15
Example 12	Preparation example 9	Example 19	Preparation example 16
				Example 13	Preparation example 10	/	/

Comparative example

Comparative examples 1 to 3

Comparative examples 1 to 3 are based on example 2 and differ from example 2 only in that: the sources of the additives used are different and are shown in Table 7.

TABLE 7 sources of additives for comparative examples 1-3

Comparative example	Comparative example1	Comparative example 2	Comparative example 3
				Source of additive	Comparative preparation example 1	Comparative preparation example 2	Comparative preparation example 3

Comparative example 4

Comparative example 4 is based on example 2 and differs from example 2 only in that: the additive is replaced by an anti-permeability agent with equal mass, the model of the anti-permeability agent is HD025, and the anti-permeability agent is purchased from Kamambera (Beijing) science and technology Limited company.

Detection method

The following performance tests were performed on the highly impervious concretes prepared in examples 1 to 19 and comparative examples 1 to 4, respectively.

And (3) testing the water permeability resistance: the water penetration depth of the standard test piece is tested according to a step-by-step pressurization method in GB/T50082-2009 Standard test method for the long-term performance and the durability of common concrete, and the test results are shown in Table 8.

And (3) testing the chloride ion penetration resistance: the aluminum ion penetration depth of the standard test piece is tested according to a rapid aluminum ion migration coefficient method in GB/T50082-2009 test method Standard for Long-term Performance and durability of ordinary concrete, and the test result is shown in Table 8.

And (3) testing the seepage resistance pressure: the permeation resistance pressure of the standard test piece is tested according to GB/T50082-2009 Standard test method for testing the long-term performance and the durability of the common concrete, and the test result is shown in Table 8.

And (3) testing the freeze-thaw resistance: and (3) performing a freeze-thaw cycle test on the standard test piece maintained for 28d according to a slow freezing method in GB/T50082-2009 standard test method for long-term performance and durability of common concrete, and evaluating by using the maximum number of freeze-thaw cycles, wherein the test result is shown in Table 8.

And (3) testing the compressive strength: standard test pieces are manufactured according to GB/T50082-2009 Standard test method for testing the long-term performance and the durability of common concrete, the test pieces maintained for 7d and 28d are subjected to compressive strength test, and the test results are shown in Table 8.

TABLE 8 test results of examples 1-19 and comparative examples 1-4

Test piece	Depth of penetration (mm)	Depth of penetration (mm) of chloride ions	Anti-seepage pressure (MPa)	Maximum number of freeze/thaw cycles (times)	28d compressive Strength (MPa)
						Example 1	4.2	1.9	3.8	398	72.3
Example 2	4.3	2	3.7	387	72.2
						Example 3	4.2	1.9	3.8	388	72.3
Example 4	4.2	1.9	3.7	388	72.3
						Example 5	3.9	1.7	3.9	401	72.8
Example 6	3.8	1.6	3.9	405	72.9
						Example 7	3.5	1.3	4.5	425	76.3
Example 8	3.5	1.3	4.4	425	76.3
						Example 9	3.4	1.2	4.5	427	76.4
Example 10	3.1	1	4.7	436	77.8
						Example 11	3.1	0.9	4.8	436	77.9
Example 12	3	0.9	4.8	437	77.9
						Example 13	2.7	0.7	5.1	451	79.1
Example 14	2.6	0.7	5.1	450	79.1
						Example 15	2.6	0.6	5.2	451	79.2
Example 16	2.2	0.4	5.4	462	81.5
						Example 17	2.2	0.4	5.4	461	81.6
Example 18	2.1	0.3	5.5	463	81.6
						Example 19	1.8	0.2	5.8	475	83.4
Comparative example 1	8.9	4.5	2.1	381	59.6
						Comparative example 2	8.2	4.7	2.5	372	51.2
Comparative example 3	8.5	4.3	2.7	365	49.9
						Comparative example 4	5.3	2.5	3.1	385	46.3

Analyzing the data to know that:

comparing the data of examples 1-4, the high-impermeability concrete prepared by the method has higher impermeability, frost resistance and strength, and example 1 is the best example of examples 1-4.

Comparing the data of example 2 with comparative examples 1-4, it can be seen that the admixture used in the present application can reduce the shrinkage deformation of concrete, and improve the uniformity of the pore distribution inside the concrete, and cut off the capillary channels inside the concrete, thereby enhancing the impermeability and frost resistance of the concrete. The cellulose, the hydrophobic fumed silica and the polydimethylsiloxane in the additive are cooperated to form a cross-linked network structure, so that the shrinkage deformation of the concrete is reduced, the cellulose, the hydrophobic fumed silica and the polydimethylsiloxane interact with the surfactant, the compatibility among the raw materials of the concrete is improved, the uniformity of air holes in the concrete is further enhanced, and the strength of the concrete is improved.

Comparing the data of examples 5 to 6 with example 1, it can be seen that the compatibility between the raw materials is improved by controlling the weight ratio of the coarse aggregate to the fine aggregate, and the effect between the admixture and the raw materials of the concrete is enhanced, thereby further improving the anti-permeability performance of the concrete.

Comparing the data of examples 7 to 9 with that of example 6, it is known that controlling the viscosity of polydimethylsiloxane promotes the synergistic effect among cellulose, hydrophobic fumed silica and polydimethylsiloxane, and further reduces the shrinkage deformation among the concrete, thereby improving the impermeability, frost resistance and strength of the concrete.

Comparing the data of examples 10 to 12 with that of example 9, it can be seen that when the HLB value of the surfactant is 2.1 to 6.7, the interaction between the surfactant and each component of the admixture is stronger, especially when the HLB value of the surfactant is 5.5, the interaction between the surfactant and each component of the admixture is strongest, so that the effect of the surfactant on each raw material of the concrete is enhanced, and the impermeability, frost resistance and strength of the concrete are further improved.

Comparing the data of examples 13 to 15 with the data of example 12, it can be seen that the hydrophobic fumed silica has strong hydrophobicity, and by controlling the particle size, on one hand, the compatibility between the admixture and each raw material of the concrete is improved, and on the other hand, the synergistic effect among the cellulose, the hydrophobic fumed silica and the polydimethylsiloxane is further promoted, so that the shrinkage deformation of the concrete is reduced, the pore distribution inside the concrete is more uniform, and the impermeability, the freezing resistance and the strength of the concrete are improved.

Comparing the data of examples 16-18 with the data of example 15, it can be seen that, although the magnesium aluminum silicate has hydrophilicity, the addition of the magnesium aluminum silicate improves the compatibility of each component of the admixture, promotes the synergistic effect among cellulose, hydrophobic fumed silica and polydimethylsiloxane, reduces the shrinkage deformation of the concrete, makes the internal pores of the concrete distributed uniformly, and improves the impermeability, frost resistance and strength of the concrete.

Comparing the data of example 19 and example 18, it can be seen that by controlling the raw material composition of the admixture, when the weight ratio of the cellulose, the hydrophobic fumed silica, the polydimethylsiloxane, the surfactant and the magnesium aluminum silicate is 5: 5: 10: 0.4: 2, the synergistic effect among the cellulose, the hydrophobic fumed silica and the polydimethylsiloxane is stronger, the effect between the admixture and each raw material of the concrete is stronger, and the impermeability and the frost resistance of the concrete are improved while the strength of the concrete 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 (7)

1. The high-impermeability concrete is characterized in that the raw materials comprise, by weight, 50-90 parts of Portland cement, 200 parts of aggregate 150-; the admixture comprises (2-7) by weight: (3-6): (3-11): (0.3-0.7) cellulose, hydrophobic fumed silica, polydimethylsiloxane, and a surfactant; the additive also comprises magnesium aluminum silicate, and the weight ratio of the magnesium aluminum silicate to the polydimethylsiloxane is (0.1-0.3): 1.

2. the high impermeability concrete according to claim 1, wherein: the viscosity of the polydimethylsiloxane at 25 ℃ is 100-500 cs.

3. The high impermeability concrete according to claim 1, wherein: the HLB value of the surfactant is 2.1-6.7.

4. The high impermeability concrete according to claim 1, wherein: the particle size of the hydrophobic fumed silica is 1000-1800 meshes.

5. The high impermeability concrete according to claim 4, wherein: the admixture comprises the following components in percentage by weight: 5: 10: 0.4: 2 cellulose, hydrophobic fumed silica, polydimethylsiloxane, a surfactant and magnesium aluminum silicate.

6. The high impermeability concrete according to claim 1, wherein: the aggregate is a mixture of fine aggregate and coarse aggregate, and the weight ratio of the coarse aggregate to the fine aggregate is 1: (0.5-0.7).

7. The method for preparing a high impervious concrete according to any one of claims 1 to 6, which comprises the following steps:

s1, uniformly mixing cellulose, hydrophobic fumed silica, polydimethylsiloxane and a surfactant to obtain an additive;

and S2, uniformly mixing the admixture, portland cement and water, adding aggregate and fly ash, and uniformly mixing to obtain the high-impermeability concrete.