CN113149577A

CN113149577A - Impervious concrete and preparation method thereof

Info

Publication number: CN113149577A
Application number: CN202110444991.2A
Authority: CN
Inventors: 屈慧
Original assignee: Shanghai Lianding New Material Technology Co ltd
Current assignee: Shanghai Lianding New Material Technology Co ltd
Priority date: 2021-04-24
Filing date: 2021-04-24
Publication date: 2021-07-23

Abstract

The application relates to the technical field of concrete, in particular to impervious concrete and a preparation method thereof. The impervious concrete is prepared from the following raw materials in parts by weight: water; sulphoaluminate cement; clay; red mud geopolymer; fly ash; an air entraining agent; an additive; fine stones; sand; concretion; the red mud geopolymer consists of the following raw materials in parts by weight: red mud; slag; water glass; water; the preparation method of the impervious concrete comprises the following steps: mixing sulphoaluminate cement, clay, red mud geopolymer, fine stone, sand and fly ash fully to obtain a mixture A; adding the admixture and the air entraining agent into water, stirring and mixing to obtain a mixture B; the mixture B is added to the mixture A and continuously stirred and mixed. The anti-permeability concrete system obtained by the application is compact and has the effect of improving the anti-permeability of concrete.

Description

Impervious concrete and preparation method thereof

Technical Field

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

Background

The concrete is artificial stone which is prepared by taking cement as a main cementing material, mixing water, sand, fine stone, chemical additives and mineral admixtures if necessary, uniformly stirring, densely molding, curing and hardening.

At present, because the concrete has the characteristics of abundant raw materials, low cost and simple production process, and simultaneously has good plasticity and higher strength, the concrete is widely applied to underground building waterproofing and waterproofing projects such as swimming pools, cement warehouses, septic tanks and the like.

In the related art, in order to obtain certain plasticity and fluidity of common concrete, the water content of the common concrete is far greater than the theoretical water demand. Excess water escapes from the concrete leaving voids in the concrete. The more water mixed, the more pores are formed. Therefore, in the environment where the underground building is waterproof, such as a swimming pool or a cement silo, and the like, which requires long-term water immersion, the water permeability of ordinary concrete is large, resulting in poor durability.

Disclosure of Invention

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

In a first aspect, the present application provides an impermeable concrete, using the following technical scheme:

the impervious concrete is prepared from the following raw materials in parts by weight:

200 portions of water and 300 portions of water;

200 portions and 300 portions of sulphoaluminate cement;

80-120 parts of clay;

80-100 parts of red mud geopolymer;

100 portions of fly ash and 200 portions of fly ash;

5-7 parts of an air entraining agent;

5-10 parts of an additive;

900 portions of fine stone;

700 portions of sand and 800 portions of sand;

80-120 parts of agglomerated stone;

the red mud geopolymer consists of the following raw materials in parts by weight:

60-80 parts of red mud;

20-40 parts of slag;

2-6 parts of water glass;

40-60 parts of water.

By adopting the technical scheme, the sulphoaluminate cement is used as a main bonding material and is mainly used for bonding fine stones and sand, and the sulphoaluminate cement, the fine stones and the sand are jointly used as main raw materials of concrete. The ceramic clay is waste powder generated by grinding and polishing the ceramic polished brick in the production process, in a system of the ceramic clay, the fly ash and the sulphoaluminate cement, the particle size of the ceramic clay is smaller than that of the sulphoaluminate cement, and the ceramic clay with smaller particle size and the fly ash can be filled in gaps among sulphoaluminate cement particles, so that the concrete forms a self-compact stacking system with a compact filling structure and a fine layer, and the homogeneity and compactness of the system are effectively improved. Meanwhile, the travertine takes industrial wastes such as slag, coal ash and the like as raw materials, belongs to a silicon-aluminum system, can replace part of cement, is dense in a transition region of a concrete interface doped with the travertine and ceramic mud, is low in coarse pore porosity and has strong curing capability on chloride ions, and the permeability of the chloride ions in the concrete is effectively reduced, so that the impermeability and the chemical corrosion resistance of the concrete are improved.

The red mud is industrial waste residue generated by producing alumina in industrial production, and the red mud contains higher ferric oxide content, so that the alkalinity in the red mud is higher; firstly, the content of alumina and alumina in the ceramic mud and the fly ash is higher than that in the red mud, and the red mud, the slag, the ceramic mud and the fly ash are combined according to a certain amount, so that the requirement on the silica-alumina ratio in the concrete can be met, the consumption of sulphoaluminate cement in the concrete can be replaced, the energy is saved, the emission is reduced, and the compressive strength and the corrosion resistance of the concrete can be further improved. And secondly, the silicon dioxide and the aluminum oxide can perform secondary hydration reaction with calcium hydroxide which is one of main hydration products of the sulphoaluminate cement to generate hydrated calcium silicate and hydrated calcium aluminate, so that the loss of the quantity of the hydration products caused by the reduction of sulphoaluminate cement clinker in the sulphoaluminate cement is supplemented, the compactness of the concrete is improved, and the impermeability and the frost resistance of the concrete are improved.

The air entraining agent can introduce a large amount of micro closed bubbles when the concrete is stirred, and reduce the surface tension of the concrete mixture, thereby changing the workability of the concrete mixture and simultaneously improving the strength of the concrete. Due to the obstruction of the bubbles, the evaporation route of free water in the concrete becomes tortuous, fine and dispersed, the difficulty of hydration reaction between carbon dioxide and the concrete is increased, and the improvement of the compactness of the concrete is facilitated, so that the frost resistance and the impermeability of the concrete are improved.

The air entraining agent introduces a large amount of micro closed bubbles to change the workability of concrete mixture, and the clay and the fly ash can be filled in gaps among sulphoaluminate cement particles. At the moment, the water glass is used for exciting the separation of aluminum and silicon in the red mud geopolymer consisting of the red mud, the mineral powder and the water and generating polymerization reaction to generate amorphous aluminosilicate polymer, thereby reducing the loss of concrete caused by hydration reaction. After the activity of the red mud geopolymer is excited, the slump and the fluidity of the concrete are further reduced after the red mud geopolymer, the mineral powder, the fine stone, the sand, the clay, the fly ash, the sulphoaluminate cement, the agglomerated stone and the additive are mixed, the later strength of the concrete is improved, and the concrete with high strength, corrosion resistance and chemical performance is formed. Meanwhile, free sodium oxide in the water glass can accelerate hydration reaction in the concrete, and the silicon dioxide and aluminum oxide in the ceramic mud and the fly ash can perform secondary hydration reaction with calcium hydroxide which is one of main hydration products of the sulphoaluminate cement, so that the ceramic mud, the fly ash, the red mud, the slag, the water glass, the curbstone and the sulphoaluminate cement have synergistic effect, the generation amount of gypsum and ettringite can be reduced, the expansion and cracking of the concrete are reduced, the interface effect generated by the secondary hydration reaction can improve the transition region of an aggregate-sulphoaluminate cement interface, the compactness of the concrete is improved, and meanwhile, the permeability of chloride ions in the concrete can be effectively reduced, so that the permeability, the frost resistance and the corrosion resistance of the concrete are improved.

Preferably, the red mud geopolymer is prepared by the following steps: crushing the red mud blocks, calcining, and mixing the calcined red mud with slag, water glass and water to obtain the red mud geopolymer.

By adopting the technical scheme, the red mud blocks are conveniently and fully mixed with slag, water glass and water after being crushed, and because the activity of the red mud is lower than that of the slag, the high temperature can promote the decomposition of calcium carbonate into calcium oxide which is easy to generate activation reaction through reasonable calcination, the activity of the red mud can be effectively improved, the red mud geopolymer can be favorably used in concrete, the compactness of the concrete is improved, and the impermeability of the concrete is improved.

Preferably, the red mud cake has a pulverized particle size of 0.06mm or less.

By adopting the technical scheme, the activity of mineral components in the red mud can be improved by physically grinding the red mud, and the impermeability of the concrete when the red mud is used for the concrete can be effectively improved.

Preferably, the calcination temperature is 600-800 ℃, and the calcination time is 50-70 min.

By adopting the technical scheme, the red mud is calcined at a reasonable temperature and within a reasonable time, so that the activity of mineral components in the red mud can be improved, the subsequent activation of the red mud by water glass is facilitated, the prepared red mud geopolymer is used in concrete, and the impermeability of the concrete can be improved.

Preferably, the water glass is formed by mixing silicon dioxide and sodium oxide according to the weight ratio of 1 (1.9-2.4).

By adopting the technical scheme, when the silica and the sodium oxide with the weight ratio within the range are mixed with the calcined red mud and the slag, the silica and the sodium oxide can be quickly dissolved in the red mud, water and the slag, and the activity of the red mud and the slag is effectively promoted.

Preferably, the additive is formed by mixing desulfurized gypsum and a naphthalene-based high-efficiency water reducing agent, and the weight ratio of the desulfurized gypsum to the naphthalene-based high-efficiency water reducing agent is 1 (1-1.4).

By adopting the technical scheme, the main component of the desulfurized gypsum is calcium sulfate dihydrate, the desulfurized gypsum has the characteristics of reproducibility, small granularity, stable components, low content of harmful impurities, high purity and the like, and the content of calcium in the concrete containing the red mud oligomer can be effectively improved by doping a small amount of desulfurized gypsum, so that the compressive strength of the concrete containing the red mud oligomer is improved. The water reducing agent is added into the concrete, the water consumption is reduced under the condition of not changing the ratio of various raw materials and the slump of the concrete, and the strength of the concrete can be greatly improved under the combined action of the naphthalene-based high-efficiency water reducing agent and the desulfurized gypsum.

Preferably, the air entraining agent is formed by mixing a tea saponin air entraining agent and sodium alkyl benzene sulfonate, and the weight ratio of the tea saponin air entraining agent to the sodium dodecyl benzene sulfonate is 1 (1-1.2).

By adopting the technical scheme, the bending tensile strength of the concrete can be obviously improved by doping the high-quality tea saponin air entraining agent and the sodium dodecyl benzene sulfonate. Along with the increase of the air content of the concrete, the frost resistance and the salt-freezing corrosion resistance of the concrete are obviously improved; meanwhile, the adverse effects of doped fly ash and slag on the frost resistance and salt-freezing corrosion resistance of the concrete can be effectively solved through reasonable air entraining.

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

a preparation method of impervious concrete comprises the following steps:

s1, mixing sulphoaluminate cement, clay, red mud geopolymer, fine stone, sand and fly ash fully to obtain a mixture A;

s2, adding the admixture and the air entraining agent into water, stirring and mixing to obtain a mixture B;

s3, adding the mixture B into the mixture A and mixing the mixture A with continuous stirring.

By adopting the technical scheme, the raw materials are stirred in multiple steps, so that the sulphoaluminate cement can better bond sand and fine stones, the dispersibility of each raw material component in a concrete mixture is improved, and the impermeability and strength of the concrete are improved.

Preferably, in the step S3, the stirring temperature is set to be 50-60 ℃, and the stirring time is set to be 2-3 h.

By adopting the technical scheme, the raw materials are stirred within a better temperature and time range, the workability of the concrete mixture is improved, and the prepared concrete has better compression resistance and crack resistance.

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

1. according to the application, the ceramic mud and the concretion are dispersed in the gaps of the sulphoaluminate cement, so that the compactness of the concrete is improved, the permeability of chloride ions in the concrete is reduced, meanwhile, silicon oxide and aluminum oxide in the red mud geopolymer and calcium hydroxide are subjected to secondary hydration reaction to generate hydrated calcium silicate and hydrated calcium aluminate, so that the loss of the quantity of hydration products caused by the reduction of the sulphoaluminate cement clinker in the sulphoaluminate cement is supplemented, the compactness of the concrete is improved again, and the ceramic mud, the concretion and the red mud geopolymer are synergistic, so that the impermeability, the chemical corrosion resistance and the frost resistance of the concrete are improved, and the durability of the concrete is improved.

2. In the preparation process of the red mud geopolymer, the red mud geopolymer is crushed, calcined and calcined for a long time, so that the decomposition of calcium carbonate in the red mud into calcium oxide which is easy to generate activation reaction can be promoted, and after the red mud is mixed with slag, the activity of the red mud can be improved by water glass, so that the red mud geopolymer can be used in concrete, the impermeability and the chemical corrosion resistance of the concrete can be improved, and the effect of improving the durability of the concrete can be achieved.

3. According to the method, the raw materials of the concrete are mixed by stirring step by step, so that the dispersibility of each component in the concrete mixture is better, the impermeability of the concrete is improved, and the durability of the concrete is improved.

Detailed Description

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

The sulphoaluminate cement adopted in the embodiment of the application is collected from a Lufeng Qingqing waterproof material factory;

the fly ash is collected from Lingshou county Xin Tuo mineral processing Co., Ltd, and the density is 2.57g/cm³Fineness of 6.4%, loss on ignition of 3.0% and water demand ratio of 92.0%;

the ceramsite is collected from Brilliant ceramsite company, and the mud content is less than or equal to 3 percent;

the travertine was collected from Weifang travertine landscape cement Co., Ltd;

the red mud is collected from Shandongyue new red mud ecological environmental protection company Limited;

the tea saponin air entraining agent is collected from Changshan Xianhshan mountain source agriculture science and technology limited;

sodium dodecyl benzene sulfonate is collected from Nanjing Milan chemical Co.Ltd;

the desulfurized gypsum is collected from Shandong Xinhongyue chemical Co., Ltd;

the naphthalene series high-efficiency water reducing agents are all obtained from Jinan Hui Chuan chemical Co., Ltd;

the stirrer is a chemical stirrer produced by Qingzhou city and Liyuan building material machinery factory;

the calcining kiln is obtained from Gannan forest drying engineering Co., Ltd, Changzhou, and has a model of DHZY of 0.78 × 8.0.

Preparation examples of raw materials

Preparation example 1: the red mud geopolymer is prepared by the following steps: crushing red mud blocks by a crusher to obtain red mud blocks with the particle size of less than 0.06mm, putting the crushed red mud into a calcining kiln for calcining at 700 ℃ for 60min, and sequentially adding slag, water and water glass into the calcined red mud to obtain the red mud geopolymer.

Preparation examples 2 to 3: a red mud geopolymer is different from that of preparation example 1 in that each component and the corresponding weight thereof are shown in Table 1.

TABLE 1 Components and weights (kg) thereof in preparation examples 1-5

Preparation example 4: the red mud geopolymer is different from the red mud geopolymer prepared in the preparation example 1 in that the calcining temperature is 600 ℃ and the calcining time is 50 min.

Preparation example 5: the red mud geopolymer is different from the red mud geopolymer prepared in the preparation example 1 in that the calcining temperature is 800 ℃ and the calcining time is 70 min.

Examples

Example 1: the impervious concrete comprises the following components in parts by weight as shown in Table 2, and is prepared by the following steps:

s1, crushing the ceramsite by using a crusher, controlling the particle size to be below 5mm to obtain clay, and fully mixing the crushed clay with sulphoaluminate cement, curbstone, red mud geopolymer, fine stone, sand and fly ash to obtain a mixture A;

and S3, adding the mixture B into the mixture A under the conditions that the temperature is 55 ℃ and the rotating speed is 200rpm, and continuously stirring and mixing for 2.5 h.

Wherein the red mud geopolymer is prepared by the preparation example 1.

The additive is formed by mixing desulfurized gypsum and a naphthalene-based high-efficiency water reducing agent according to the weight ratio of 1: 1.2.

The air entraining agent is formed by mixing tea saponin air entraining agent and sodium dodecyl benzene sulfonate according to the weight ratio of 1: 1.1.

Examples 2 to 6: an impermeable concrete was different from example 1 in that the components and their respective parts by weight are shown in table 1.

TABLE 2 Components and weights (kg) thereof in examples 1-6

Example 7: an impervious concrete, which is different from example 1 in that red mud geopolymer was prepared according to preparation example 2.

Example 8: an impervious concrete, which is different from example 1 in that red mud geopolymer was prepared by preparative example 3.

Example 9: an impervious concrete, which is different from example 1 in that red mud geopolymer was prepared by preparative example 4.

Example 10: an impervious concrete, which is different from example 1 in that red mud geopolymer was prepared according to preparation example 5.

Example 11: the impermeable concrete is different from the concrete in example 1 in that the admixture is formed by mixing desulfurized gypsum and a naphthalene-based superplasticizer in a weight ratio of 1:1.

Example 12: the impermeable concrete is different from the concrete in example 1 in that the admixture is formed by mixing desulfurized gypsum and a naphthalene-based superplasticizer in a weight ratio of 1: 1.4.

Example 13: the impermeable concrete is different from the impermeable concrete in example 1 in that the air entraining agent is formed by mixing tea saponin air entraining agent and sodium dodecyl benzene sulfonate according to the weight ratio of 1: 1.0.

Example 14: the impermeable concrete is different from the impermeable concrete in example 1 in that the air entraining agent is formed by mixing tea saponin air entraining agent and sodium dodecyl benzene sulfonate according to the weight ratio of 1: 1.2.

Example 15: an impermeable concrete was different from example 1 in that the concrete S3 was prepared at a stirring temperature of 50 ℃ for a stirring time of 2 hours.

Example 16: an impermeable concrete was different from example 1 in that the concrete S3 was prepared at a stirring temperature of 60 ℃ for a stirring time of 3 hours.

Comparative example

Comparative example 1: a concrete was different from that of example 1 in that the content of clay was 0kg, the content of red mud geopolymer was 120kg, and the content of agglomerated stone was 120 kg.

Comparative example 2: a concrete was different from example 1 in that the red mud geopolymer content was 0kg, the agglomerated stone content was 120kg, and the clay content was 120 kg.

Comparative example 3: a concrete was different from example 1 in that the content of agglomerated stone was 0kg, the content of red mud geopolymer was 120kg, and the content of clay was 120 kg.

Comparative example 4: a concrete was produced in the same manner as in example 1 except that the content of clay was 0kg, the content of red mud geopolymer was 0kg, and the content of agglomerated stone was 0 kg.

Comparative example 5: the concrete is different from the concrete in example 1 in that the additive is prepared by mixing desulfurized gypsum and a naphthalene-based superplasticizer according to the weight ratio of 1: 0.8.

Comparative example 6: the concrete is different from the concrete in example 1 in that the additive is prepared by mixing desulfurized gypsum and a naphthalene-based superplasticizer according to the weight ratio of 1: 1.6.

Comparative example 7: the concrete is different from the concrete in the embodiment 1 in that the air entraining agent is prepared by mixing tea saponin air entraining agent and sodium dodecyl benzene sulfonate according to the weight ratio of 1: 0.8.

Comparative example 8: the concrete is different from the concrete in the embodiment 1 in that the air entraining agent is prepared by mixing tea saponin air entraining agent and sodium dodecyl benzene sulfonate according to the weight ratio of 1: 1.6.

Comparative example 9: the difference between the concrete and the concrete in the embodiment 1 is that the calcination temperature is 400 ℃ and the calcination time is 40min in the preparation process of the red mud geopolymer.

Comparative example 10: the difference between the concrete and the concrete in the embodiment 1 is that the calcination temperature is 900 ℃ and the calcination time is 80min in the preparation process of the red mud geopolymer.

Performance test

The concrete prepared in examples 1 to 16 and comparative examples 1 to 10 were used as test objects, and the water permeation resistance, the chloride ion permeation resistance and the compressive strength were measured.

The water penetration resistance is tested according to a step-by-step pressurization method in GB/T50082-2009 Standard test method standards for the long-term performance and durability of ordinary concrete.

The chloride ion penetration resistance is tested according to the rapid chloride ion migration coefficient method in GB/T50082-2009 test method Standard for the long-term performance and durability of ordinary concrete.

The compressive strength is tested according to GB/T50081 and 2019 Standard of mechanical Properties test method of ordinary concrete, and a cubic standard test piece with the specification of 150 multiplied by 150mm is selected as a test sample.

The test results are shown in Table 3 below.

As can be seen from the test data in table 3:

the concrete standard test pieces or standard test blocks prepared in the examples 1 to 16 have the water penetration depth of less than 3.8mm, the chloride ion penetration depth of less than 3.5mm and the compressive strength of more than 40 MPa. Among them, examples 3 and 4 are the most preferable examples, and the concrete obtained has the best impermeability.

Combining examples 1, 2, 3, 4, 5 and 6 and comparative examples 1, 2, 3 and 4, and combining table 3, it can be seen that in examples 1, 2, 3, 4, 5 and 6, the water penetration depth of the concrete standard test piece or the concrete standard test block is less than 5.0mm, the chloride ion penetration depth is less than 2.4mm, and the compressive strength is greater than 43.9 MPa; in comparative examples 1 to 4, the concrete standard test pieces or test blocks had water penetration depths of more than 10.3mm, chloride ion penetration depths of more than 4.5mm, and compressive strengths of less than 36.1MPa, as shown in Table 3, the water penetration resistance, chloride ion penetration depth, and compressive strength of the concrete were improved by adding the ceramic clay, red mud geopolymer, and agglomerated stone, thereby increasing the durability of the concrete.

By combining examples 11 and 12 and comparative examples 5 and 6, and by combining Table 3, it can be seen that when the admixture, which is formed by mixing desulfurized gypsum and naphthalene based superplasticizer in a weight ratio of 1 (1-1.4), is used in concrete, the impermeability, chloride ion penetration depth resistance and compressive strength of the concrete can be improved, thereby prolonging the durability of the concrete.

By combining examples 13 and 14 and comparative examples 7 and 8 and by combining Table 3, it can be seen that the air entraining agent prepared by mixing the tea saponin air entraining agent and the sodium dodecyl benzene sulfonate according to the weight ratio of 1 (1-1.2) is used in concrete, and can improve the impermeability, chloride ion penetration depth resistance and compressive strength of the concrete, thereby prolonging the durability of the concrete.

Combining examples 1, 9 and 10 and comparative examples 9 and 10, and combining table 3, it can be seen that the optimum calcination temperature is 600-800 ℃ and the calcination time is 50-70min in the preparation process of the red mud geopolymer, and the red mud geopolymer prepared under the conditions can be used in concrete to improve the impermeability, the chloride ion penetration depth and the compressive strength of the concrete.

Table 3 results of performance testing

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 impervious concrete is characterized by being prepared from the following raw materials in parts by weight:

200 portions of water and 300 portions of water;

200 portions and 300 portions of sulphoaluminate cement;

80-120 parts of clay;

80-100 parts of red mud geopolymer;

100 portions of fly ash and 200 portions of fly ash;

5-7 parts of an air entraining agent;

5-10 parts of an additive;

900 portions of fine stone;

700 portions of sand and 800 portions of sand;

80-120 parts of agglomerated stone;

60-80 parts of red mud;

20-40 parts of slag;

2-6 parts of water glass;

40-60 parts of water.

2. The impermeable concrete according to claim 1, characterized in that the red mud geopolymer is obtained by: crushing the red mud blocks, calcining, and mixing the calcined red mud with slag and water glass to obtain the red mud geopolymer.

3. The impervious concrete of claim 2, wherein the red mud cake has a crushed particle size of 0.06mm or less.

4. The impermeable concrete according to claim 2, characterized in that the calcination temperature is 600-800 ℃ and the calcination time is 50-70 min.

5. The impervious concrete of claim 1, wherein the water glass is formed by mixing silica and sodium oxide in a weight ratio of 1 (1.9-2.4).

6. The impervious concrete of claim 1, wherein the admixture is formed by mixing desulfurized gypsum and a naphthalene-based high-efficiency water reducing agent, and the weight ratio of the desulfurized gypsum to the naphthalene-based high-efficiency water reducing agent is 1 (1-1.4).

7. The impervious concrete of claim 1, wherein the air entraining agent is formed by mixing a tea saponin air entraining agent and sodium dodecyl benzene sulfonate, and the weight ratio of the tea saponin air entraining agent to the sodium alkyl benzene sulfonate is 1 (1-1.2).

8. A method of preparing an impermeable concrete according to any one of claims 1 to 7, characterised in that it comprises the following steps:

9. The method for preparing impermeable concrete according to claim 8, wherein in the step S3, the stirring temperature is set to 50-60 ℃ and the stirring time is set to 2-3 h.