CN116730677A

CN116730677A - Impervious anti-cracking concrete and preparation method thereof

Info

Publication number: CN116730677A
Application number: CN202310650418.6A
Authority: CN
Inventors: 邓伟锋; 邓超威; 朱洪亮
Original assignee: Guangzhou Xingyao Concrete Co ltd
Current assignee: Guangzhou Xingyao Concrete Co ltd
Priority date: 2023-06-03
Filing date: 2023-06-03
Publication date: 2023-09-12
Anticipated expiration: 2043-06-03
Also published as: CN116730677B

Abstract

The application relates to the field of concrete, in particular to impervious and anti-cracking concrete and a preparation method thereof. The impervious anti-cracking concrete comprises the following raw materials in parts by mass: 150-170 parts of water, 340-360 parts of silicate cement, 950-1100 parts of coarse aggregate, 700-800 parts of fine aggregate, 0-8 parts of water reducer, 25-60 parts of admixture, 3-6 parts of lysine bacillus, 0.1-1 part of bacillus mucilaginosus, 15-25 parts of bamboo fiber and 5-10 parts of apocynum venetum fiber; the preparation method comprises the following steps: uniformly mixing the coarse aggregate and the fine aggregate to obtain a primary mix; mixing water, portland cement, an admixture, lysine bacillus, bacillus mucilaginosus, bamboo fibers and apocynum venetum fibers to obtain a mixture; and uniformly mixing the primary mixing material, the mixing material and the water reducing agent to obtain a finished product. The application has the advantage of improving the cracking resistance of the concrete.

Description

Impervious anti-cracking concrete and preparation method thereof

Technical Field

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

Background

Concrete is simply referred to as "concrete" and refers to a collective term for engineering composite materials in which aggregate is consolidated into a whole by a cementitious material. The term concrete is generally used as cement as cementing material, sand and stone as aggregate, and water and other materials in certain proportion. Concrete is widely used in civil engineering due to the advantages of easily available raw materials, abundant raw materials, excellent performance and the like.

In our life, concrete is ubiquitous, and places such as roads, bridges, ports, wharfs and the like have its statues. Due to the structural characteristics of the concrete, a large number of capillary holes and tiny cracks exist in the concrete; when the concrete is applied to the sea or places with abundant rainwater, a large amount of water vapor often enters the interior of the concrete through the capillary holes and gaps, so that the concrete is caused to crack, and the building structure is influenced. Therefore, there is still a need for improvement.

Disclosure of Invention

In order to improve the cracking resistance of concrete, the application provides impervious cracking-resistant concrete and a preparation method thereof.

In a first aspect, the application provides an anti-seepage and anti-cracking concrete, which adopts the following technical scheme:

the impervious anti-cracking concrete comprises the following raw materials in parts by mass: 150-170 parts of water, 340-360 parts of silicate cement, 950-1100 parts of coarse aggregate, 700-800 parts of fine aggregate, 0-8 parts of water reducer, 25-60 parts of admixture and 3-6 parts of additive

Lysine bacillus, 0.1-1 part of bacillus mucilaginosus, 15-25 parts of bamboo fiber and 5-10 parts of apocynum venetum fiber.

Through adopting above-mentioned technical scheme, under lysine bacillus, bacillus mucilaginosus's co-ordination, its mineralization deposit generates special product, and some special product can block or stop the mesopore, makes the inside pore structure of concrete obtain optimizing improvement, reduces the quantity of mesopore, blocks the capillary pore passageway in a part of concrete for outside water is difficult to permeate inside the concrete, thereby improves impervious strength.

When cracks are formed on the surface of the concrete, external water vapor and carbon dioxide enter the cracks, metabolism of lysine bacillus and bacillus mucilaginosus is further promoted, mineralized products are generated to fill the cracks, and accordingly crack diffusion is slowed down, and good anti-cracking effect is achieved.

Under the common cooperation of the bamboo fibers and the apocynum fibers, the formed network structure is inserted between holes in the concrete, mineralized products generated by lysine bacillus and bacillus mucilaginosus are attached to the network structure, the nucleation sites are increased, the structure of the mineralized products is more stable, the number of the mineralized products is more, and the concrete structure and the compressive strength are improved more stably and for a long time.

Preferably, the mass ratio of the lysine bacillus to the bacillus mucilaginosus is 1: (0.1-0.2).

By adopting the technical scheme, the matching proportion of the lysine bacillus and the bacillus mucilaginosus is further limited, and the lysine bacillus, air and water perform a series of reactions to generate calcium carbonate ions combined with calcium ions to form a precipitate so as to fill cracks. The excessive calcium carbonate ions can become calcium dioxide, and the carbon dioxide can be utilized by bacillus mucilaginosus to promote transformation into more mineralized precipitation products, so that the cracks are filled more quickly. The mass ratio of the lysine bacillus to the bacillus mucilaginosus reaches an equilibrium state under the preset condition, and the optimal anti-seepage and anti-cracking effects are achieved.

Preferably, the mass ratio of the bamboo fiber to the apocynum fiber is 1: (0.3-0.5).

By adopting the technical scheme, the mass ratio between the bamboo fiber and the apocynum venetum fiber is further optimized, a special network structure is formed for the lysine bacillus and the bacillus mucilaginosus to adhere more firmly, and the compressive strength of the concrete is also improved.

Preferably, the admixture comprises one or more of fly ash, slag powder, steel slag powder, kaolin and zeolite powder.

Preferably, the admixture is fly ash and slag powder, and the mass ratio of the fly ash to the slag powder is 1: (0.5-0.8).

By adopting the technical scheme, proper admixture is selected and the dosage is further limited, so that the water consumption required by a system can be reduced, and the performance of the concrete is improved.

In a second aspect, the application provides a preparation method of anti-seepage and anti-cracking concrete, which adopts the following technical scheme:

a preparation method of impervious anti-cracking concrete comprises the following steps:

uniformly mixing the coarse aggregate and the fine aggregate to obtain a primary mix;

mixing water, portland cement, an admixture, lysine bacillus, bacillus mucilaginosus, bamboo fibers and apocynum venetum fibers to obtain a mixture;

and uniformly mixing the primary mixing material, the mixing material and the water reducing agent to obtain a finished product.

Preferably, the lysine bacillus and the bacillus mucilaginosus are diluted to the concentration of (1.8-2.0) x 10 by physiological saline ⁸ Adding bamboo fiber and apocynum venetum fiber into the diluted solution, and uniformly mixing under the conditions of 2000-2500r/min, 500-600w and 0.7-0.9 MPa; then drying to obtain a compound;

and mixing the compound with water, silicate cement and admixture to obtain the admixture.

In actual production, along with the progress of cement hydration, the pH value in the concrete often can surge to 13 or more, and under the severe condition, the survival rate of lysine bacillus and bacillus mucilaginosus is greatly influenced, so that the anti-cracking and anti-seepage effect is not obvious.

By adopting the technical scheme, the special lysine bacillus and bacillus mucilaginosus are selected to be matched with the special bamboo fibers and the apocynum venetum fibers, the special means are used for loading the lysine bacillus and bacillus mucilaginosus on the bamboo fibers and the apocynum venetum fibers, the alkali-resistant property of the bamboo fibers and the apocynum venetum fibers is skillfully utilized to retain the activity of the lysine bacillus and the bacillus mucilaginosus, the aging of the compound in the concrete is prolonged, and the anti-cracking and anti-permeability effects are effectively improved.

In addition, when water seepage is carried out, the special combination of the bamboo fiber and the apocynum fiber can absorb surrounding water to form combined water, so that free water penetrating and diffusing into the concrete is reduced, and the anti-seepage and anti-cracking effects are further improved.

Preferably, after drying, the obtained material is soaked in a water glass solution, and then dried again to obtain the compound.

Through adopting above-mentioned technical scheme, use the soluble glass solution to carry lysine bacillus, bacillus mucilaginosus's bamboo fibre, apocynum venetum fibre to handle, make lysine bacillus, bacillus mucilaginosus be difficult to drop, further guarantee the activity, the product that the production is more in quantity, the structure is more stable is in order to pack the gap.

In summary, the application has the following beneficial effects:

1. under the co-cooperation of the lysine bacillus and the bacillus mucilaginosus, special products for blocking or blocking macropores are generated, the internal pore structure of the concrete is improved, and external water is difficult to permeate into the concrete, so that the impervious strength is improved; meanwhile, the special products can be filled in the cracking gaps to play a role in cracking resistance.

2. Under the common cooperation of the bamboo fibers and the apocynum fibers, the formed network structure is inserted between holes in the concrete, mineralized products generated by lysine bacillus and bacillus mucilaginosus are attached to the network structure, the nucleation sites are increased, the structure of the mineralized products is more stable, the number of the mineralized products is more, and the concrete structure and the compressive strength are improved more stably and for a long time.

3. According to the application, the specific lysine bacillus and the specific bacillus mucilaginosus are selected to be matched with the specific bamboo fiber and the specific apocynum venetum fiber, the lysine bacillus and the specific bacillus mucilaginosus are loaded on the bamboo fiber and the apocynum venetum fiber by using a special means, the activity of the lysine bacillus and the activity of the bacillus mucilaginosus are reserved by utilizing the alkali resistance of the bamboo fiber and the apocynum venetum fiber, the acting time of the compound in the concrete is prolonged, and the anti-cracking and anti-seepage effects are effectively improved.

Detailed Description

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

The raw materials used in the following examples and comparative examples are all commercially available products.

Examples

Example 1

An impervious anti-cracking concrete comprises the following raw materials: water, silicate cement, coarse aggregate, fine aggregate, water reducer, admixture, lysine bacillus, bacillus mucilaginosus, bamboo fiber and apocynum venetum fiber.

The coarse aggregate is crushed gravel with an average particle size of 10-15 mm.

The fine aggregate is river sand.

The water reducer is a polycarboxylic acid water reducer.

The admixture is fly ash and slag powder.

The specific amounts of the raw materials are shown in Table 1.

The embodiment of the application also provides a preparation method of the anti-seepage and anti-cracking concrete, which comprises the following steps:

step 1): preparing a compound:

step 1 a): diluting the lysine bacillus and the bacillus mucilaginosus with physiological saline with the mass fraction of 0.9% to the concentration of 1.8x10 ⁸ cell/mL, a dilution was obtained.

Step 1 b): soaking bamboo fiber and herba Apocyni Veneti fiber in diluent, mixing at 2200r/min, 550w and 0.8MPa, and vacuum adsorbing for 30min.

Step 1 c): and then the bamboo fiber and the apocynum fiber in the step 1 b) are placed in a baking oven at 45 ℃ for baking. And repeating the soaking and drying cycle for several times until the bacterial liquid is sucked dry, and obtaining an intermediate product.

Step 1 d): uniformly spraying water glass solution with the mass fraction of 80% on the surface of the intermediate product, curing for 1d, and then drying in a drying oven at 40 ℃ to obtain the compound.

Step 2): mixing the coarse aggregate and the fine aggregate, and stirring to be uniform to obtain the primary stirring material.

Step 3): mixing water, silicate cement, admixture and compound, and stirring to uniformity to obtain the admixture.

Step 4): and mixing the primary mixing material, the mixing material and the water reducing agent, and stirring until the mixture is uniform to obtain a finished product.

Example 2

An impervious crack-resistant concrete is different from example 1 in that the specific amounts of the raw materials are shown in Table 1.

The preparation method of the anti-seepage and anti-cracking concrete is different from the embodiment 1 in that:

in step 1 a), dilute to 2.0 x 10 ⁸ cell/mL。

In the step 1 b), the mixture is uniformly mixed under the conditions of 2000r/min, 600w and 0.7 MPa.

In step 1 d), the mass fraction of the water glass solution is 85%.

Example 3

in the step 1 b), the mixture is uniformly mixed under the conditions of 2500r/min, 500w and 0.9 MPa.

In step 1 d), the mass fraction of the water glass solution is 75%.

Example 4

The impervious and crack resistant concrete is different from the concrete in the embodiment 1 in that the mass ratio of lysine bacillus to colloid bacillus is 1:0.1, i.e., the amount of lysine bacillus was 4.2kg, and the amount of bacillus mucilaginosus was 0.4kg.

The mass ratio of the bamboo fiber to the apocynum fiber is 1:0.3, namely the usage amount of the bamboo fiber is 21.5kg, and the usage amount of the apocynum fiber is 6.5kg.

Example 5

The impervious and crack resistant concrete is different from the concrete in the embodiment 1 in that the mass ratio of lysine bacillus to colloid bacillus is 1:0.2, i.e., the amount of lysine bacillus used was 3.8kg, and the amount of bacillus mucilaginosus used was 0.8kg.

The mass ratio of the bamboo fiber to the apocynum fiber is 1:0.5, namely the usage amount of the bamboo fiber is 18.7kg, and the usage amount of the apocynum fiber is 9.3kg.

TABLE 1

Example 6

The preparation method of the anti-seepage and anti-cracking concrete is different from the embodiment 1 in that: step 1) is omitted. In the step 3), water, silicate cement and admixture are directly mixed with lysine bacillus, bacillus mucilaginosus, bamboo fiber and apocynum venetum fiber.

Example 7

The preparation method of the anti-seepage and anti-cracking concrete is different from the embodiment 1 in that: in step 1 b), mixing under conditions of 2200r/min, 550w and 0.8MPa was omitted. The bamboo fiber and the apocynum fiber are soaked in the diluent, and then are adsorbed for 30min by adopting a vacuum adsorption mode.

Example 8

The preparation method of the anti-seepage and anti-cracking concrete is different from the embodiment 1 in that: omitting step 1 d), i.e. the intermediate product of step 1 c) is the complex.

Comparative example

Comparative example 1

The concrete with anti-seepage and anti-cracking properties is different from that of example 1 in that the lysine bacillus is replaced by the bacillus subtilis, namely, the usage amount of the lysine bacillus is 0kg, and the usage amount of the bacillus subtilis is 4kg.

Comparative example 2

The impervious and crack-resistant concrete is different from the concrete in the embodiment 1 in that bacillus mucilaginosus is replaced by saccharomycetes, namely, the using amount of bacillus mucilaginosus is 0kg, and the using amount of saccharomycetes is 0.6kg.

Comparative example 3

The impervious and crack resistant concrete is different from the concrete in the embodiment 1 in that the mass ratio of lysine bacillus to colloid bacillus is 1:1, namely, the using amount of lysine bacillus is 2.3kg, and the using amount of bacillus mucilaginosus is 2.3kg.

Comparative example 4

The concrete resistant to permeation and crack is different from example 1 in that the bamboo fiber is replaced with the polyester fiber, that is, the usage amount of the bamboo fiber is 0kg, and the usage amount of the polyester fiber is 20kg.

Comparative example 5

The concrete resistant to cracking and permeation is different from example 1 in that the kendir fiber is replaced by sisal fiber, namely, the use amount of the kendir fiber is 0kg, and the use amount of the sisal fiber is 8kg.

Comparative example 6

The impervious and crack-resistant concrete is different from the concrete in the embodiment 1 in that the mass ratio of the bamboo fiber to the apocynum fiber is 1:1, namely the usage amount of the bamboo fiber is 14kg, and the usage amount of the apocynum fiber is 14kg.

Performance test

1. Compressive strength: the compressive strength of the concrete samples of examples 1 to 8 and comparative examples 1 to 6 was measured according to GB/T50081-2019 Standard of test method for mechanical Properties of ordinary concrete, and the compressive strength was recorded for 28 days.

2. Barrier properties: the concrete samples of examples 1 to 8 and comparative examples 1 to 6 were tested according to the "water penetration resistance test-6.1 water penetration height method" in GB/T50082-2009 "test method Standard for Long term Properties and durability of ordinary concrete", and the water penetration height was recorded.

3. Crack resistance: the concrete of examples 1-8, comparative examples 1-6 were made into flat sheet test pieces having dimensions of 800 x 600 x 100mm, three test pieces per group. After the molding and curing were completed, the test piece was left for 28 days under conditions of 70% humidity and 40 ℃.

After taking out the test piece, referring to a test result calculation part in a 9 early crack resistance test in GB/T50082-2009 "method Standard for testing the long-term performance and durability of common concrete", the number of cracks per unit area and the total cracking area per unit area of the test piece are calculated.

The results of the above tests 1-3 are detailed in Table 2.

TABLE 2

As can be seen from comparison of the test data of example 1 and comparative examples 1-2 in Table 2, when the combination of lysine bacillus and colloid bacillus was destroyed (comparative examples 1 and 2), the produced concrete was greatly affected in compressive strength, permeation resistance and crack resistance. As is clear from the test data of comparative example 3, even though the combination of lysine bacillus and bacillus mucilaginosus is maintained, the amounts and ranges of the two are not mixed within the specific ranges (comparative example 3), and the prepared concrete cannot have good anti-seepage and anti-cracking effects. The special coordination of the lysine bacillus and the bacillus mucilaginosus with the bamboo fiber and the apocynum venetum fiber with specific dosage can generate mineralized products, improve the internal pore structure of the concrete, fill up cracks and further endow the concrete with crack resistance and impermeability.

From the examination data of example 1 and comparative examples 4 to 5 in Table 2, it is understood that the kind of fiber is also important when the amounts of lysine bacillus and mucilaginosus are determined. When substituted with other types of fibers (comparative examples 4-5), the resulting concrete performance was not as good as example 1. Comparative example 6 the properties of the concrete obtained after changing the ratio between the apocynum fibers and the bamboo fibers were slightly improved as compared with comparative examples 4 and 5, but they were not as good as in example 1. The specific fiber species has better matching effect with lysine bacillus and bacillus mucilaginosus.

According to comparison of the detection data of examples 1, 4-5 and example 6 in Table 2, the effects of alkaline environment of cement hydration on the activity of the lysine bacillus and the bacillus mucilaginosus can be slowed down by loading the lysine bacillus and the bacillus mucilaginosus on the bamboo fiber and the apocynum venetum fiber in advance, so that the anti-cracking and anti-permeability effects are effectively improved.

As can be seen from comparison of the test data of example 1 and example 7 in table 2, when the lysine bacillus, the bacillus mucilaginosus, the bamboo fiber and the apocynum venetum fiber are mixed, the lysine bacillus and the bacillus mucilaginosus are more firmly attached to the bamboo fiber and the apocynum venetum fiber under specific conditions, so that a series of reactions can be generated in concrete to fill cracks.

As can be seen from comparison of the test data of example 1 and example 8 in Table 2, after the intermediate product is obtained, the operation of spraying the water glass solution can make the properties of the obtained composite more stable, further improve the stability of the composite, and further improve the compression resistance, crack resistance and impermeability of the concrete.

The present embodiment is only for explanation of the present application and is not to be construed as limiting the present application, and modifications to the present embodiment, which may not creatively contribute to the present application as required by those skilled in the art after reading the present specification, are all protected by patent laws within the scope of claims of the present application.

Claims

1. The impervious anti-cracking concrete is characterized by comprising the following raw materials in parts by weight: 150-170 parts of water, 340-360 parts of silicate cement, 950-1100 parts of coarse aggregate, 700-800 parts of fine aggregate, 0-8 parts of water reducer, 25-60 parts of admixture, 3-6 parts of lysine bacillus, 0.1-1 part of bacillus mucilaginosus, 15-25 parts of bamboo fiber and 5-10 parts of apocynum venetum fiber.

2. The anti-seepage and anti-cracking concrete according to claim 1, wherein: the mass ratio of the lysine bacillus to the bacillus mucilaginosus is 1: (0.1-0.2).

3. The anti-seepage and anti-cracking concrete according to claim 1, wherein: the mass ratio of the bamboo fiber to the apocynum fiber is 1: (0.3-0.5).

4. The anti-seepage and anti-cracking concrete according to claim 1, wherein: the admixture comprises one or more of fly ash, slag powder, steel slag powder, kaolin and zeolite powder.

5. The anti-seepage and anti-cracking concrete according to claim 4, wherein: the admixture is coal ash and slag powder, and the mass ratio of the coal ash to the slag powder is 1: (0.5-0.8).

6. A method of preparing an anti-seepage and anti-crack concrete based on any one of claims 1-5, comprising the steps of:

7. The method for preparing the anti-seepage and anti-cracking concrete according to claim 6, wherein the method comprises the following steps: diluting the lysine bacillus and bacillus mucilaginosus with normal saline to the concentration of (1.8-2.0) x 10 ⁸ cell/mL, obtaining a diluent;

then adding bamboo fiber and apocynum fiber into the diluted solution, and uniformly mixing under the conditions of 2000-2500r/min, 500-600w and 0.7-0.9 MPa; then drying to obtain a compound;

8. The method for preparing the anti-seepage and anti-cracking concrete according to claim 7, wherein the method comprises the following steps: and after drying, soaking the obtained material in a water glass solution, and then drying to obtain the compound.