A high-toughness concrete material with low shrinkage, its preparation method and application

Abstract

The present invention provides a low-shrinkage high-toughness concrete material, its preparation method and application, belonging to the technical field of concrete materials. The low-shrinkage high-toughness concrete material provided by the present invention comprises the following components in parts by weight: 300-500 parts of cement; 600-800 parts of fly ash; 30-50 parts of silica fume; 200-400 parts of quartz sand; 10-50 parts of anti-dry-shrinkage functional material; 200-400 parts of water; 10-50 parts of water reducer; 5-20 parts of thickener; 10-50 parts of PVA fiber; wherein, the anti-dry-shrinkage functional material is formed by carbonizing recycled concrete fine powder. The present invention uses carbonized recycled concrete fine powder to prepare aragonite whiskers, which intersect with PVA fibers to form a network, restricting the shrinkage of concrete, and can be well applied to the pavement material of assembled pavements. Moreover, the use of recycled concrete realizes the reuse of construction (structure) waste, meeting the requirements of energy conservation and environmental protection.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete materials, and particularly relates to a high-toughness concrete material with low shrinkage, a preparation method thereof, and an application thereof. Background Art

[0002] As a kind of rapid pavement, precast cement concrete pavement is widely used in scenarios such as temporary road construction and rapid repair of old pavements. In related technologies, ECC (Engineered Cementitious Composites) is usually used to make precast cement concrete pavement. ECC is composed of materials such as portland cement, fine silica sand, water, and fine synthetic fibers, and has characteristics such as good flexural toughness and excellent crack resistance. However, generally only quartz sand is used as aggregate in ECC, lacking coarse aggregate, which leads to higher shrinkage strain during its service process and is prone to large dry shrinkage under water loss conditions, reducing the performance of precast cement concrete pavement.

[0003] Construction waste generally contains a large amount of waste concrete, mortar, stones, and bricks and tiles. These components can be considered as aggregates in newly made concrete. However, in the prior art, these components are usually directly discarded without being effectively utilized, not meeting the development requirements of energy conservation and environmental protection.

[0004] Therefore, it is necessary to provide a high-toughness concrete material with low shrinkage, a preparation method thereof, and an application thereof to solve the above problems. Summary of the Invention

[0005] The present invention provides a high-toughness concrete material with low shrinkage, a preparation method thereof, and an application thereof. Vaterite whiskers are prepared using carbonized recycled concrete fine powder and interlaced with PVA fibers to form a three-dimensional network structure, restricting the dry shrinkage of the concrete. Moreover, the use of recycled concrete realizes the reuse of construction (structure) waste, meets the requirements of energy conservation and environmental protection, and can effectively solve at least one technical problem involved in the background art.

[0006] In order to solve the above technical problems, the present invention is implemented as follows:

[0007] A high-toughness concrete material with low shrinkage comprises the following components in parts by weight:

[0008] 300 - 500 parts of cement; 600 - 800 parts of fly ash; 30 - 50 parts of silica fume; 200 - 400 parts of quartz sand; 10 - 50 parts of anti-dry-shrinkage functional material; 200 - 400 parts of water; 10 - 50 parts of water reducer; 5 - 20 parts of thickening agent; 10 - 50 parts of PVA fiber; wherein, the anti-dry-shrinkage functional material is generated by carbonizing recycled concrete fine powder;

[0009] The anti-dry-shrinkage functional material is prepared by the following method:

[0010] Dissolve diethylenetriamine in water to obtain a solution with a concentration of 1 - 3 mol / L;

[0011] Add recycled concrete micropowder to the solution to make the solid-liquid ratio 50 - 100 g / L to form a mixed liquid. Continuously introduce carbon dioxide into the mixed liquid, heat the mixed liquid and maintain it at a temperature of 40 - 80 °C, so that the recycled concrete micropowder undergoes carbonization under the action of carbon dioxide to generate calcium carbonate, and the generated calcium carbonate generates aragonite whiskers under the influence of diethylenetriamine. After the reaction lasts for 1 - 4 h, centrifuge and dry the slurry to obtain a dry-shrinkage-resistant functional material.

[0012] As a preferred improvement, the water reducer is a polycarboxylate-based water reducer with a water reduction efficiency greater than 20%.

[0013] As a preferred improvement, the thickener is hydroxypropyl methylcellulose.

[0014] As a preferred improvement, the particle size range of the quartz sand is 10 - 600 μm, and the average particle size is 100 - 140 μm.

[0015] As a preferred improvement, the PVA fiber has a length of 9 - 15 mm, a diameter of 30 - 40 μm, and a density of 1.2 - 1.4 g / cm 3 。

[0016] As a preferred improvement, the particle size of the recycled concrete micropowder is less than 600 μm.

[0017] As a preferred improvement, the calcium content of the fly ash is less than 10%; the silica content of the silica fume is above 90%.

[0018] A preparation method of the above-mentioned low-shrinkage and high-toughness concrete material includes the following steps:

[0019] Take 300 - 500 parts of cement, 600 - 800 parts of fly ash, 30 - 50 parts of silica fume, 200 - 400 parts of quartz sand, 10 - 50 parts of dry-shrinkage-resistant functional material, 200 - 400 parts of water, 10 - 50 parts of water reducer, 5 - 20 parts of thickener, and 10 - 50 parts of PVA fiber by mass; mix the cement, fly ash, and silica fume, continue to mix after adding water and the water reducer, then add the quartz sand and mix, then add 2 / 3 of the dry-shrinkage-resistant functional material and PVA fiber and mix, and finally add the remaining 1 / 3 of the dry-shrinkage-resistant functional material and PVA fiber and mix to obtain a low-shrinkage and high-toughness concrete material.

[0020] An application of the above-mentioned low-shrinkage and high-toughness concrete material is used as a pavement material for an assembled pavement.

[0021] The beneficial effects of the present invention are as follows:

[0022] (1) Prepare aragonite whiskers using carbonized recycled concrete fine powder, which intersects with PVA fibers to form a three-dimensional network structure, restricting the shrinkage of concrete.

[0023] (2) Add DETA during the carbonization process of recycled concrete fine powder. By changing the crystallization orientation of calcium carbonate, the carbonization product of recycled concrete fine powder, with DETA, the generation of aragonite whiskers can be controlled, and aragonite whiskers with a large aspect ratio can be obtained.

[0024] (3) Use recycled concrete fine powder to replace part of the PVA fiber material, reducing the proportion of PVA in concrete. The cost of recycled concrete fine powder is much lower than that of PVA fiber material, which can achieve the purpose of cost reduction and improve the practicability of high-toughness concrete materials with low shrinkage.

[0025] (4) The use of recycled concrete realizes the reuse of construction (structure) waste. During the carbonization process of recycled fine aggregate, the gas carbon dioxide is absorbed and becomes a solid precipitate. The content of carbon dioxide in the atmosphere is reduced, and carbon is stabilized in solid materials, reducing carbon emissions, which meets the development requirements of energy conservation and emission reduction. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, where:

[0027] Figure 1 SEM image showing aragonite crystals. Detailed Embodiments

[0028] The following will combine the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] This embodiment provides a high-toughness concrete material with low shrinkage, including the following components in parts by weight:

[0030] 300 - 500 parts of cement; 600 - 800 parts of fly ash; 30 - 50 parts of silica fume; 200 - 400 parts of quartz sand; 10 - 50 parts of anti - dry - shrinkage functional material; 200 - 400 parts of water; 10 - 50 parts of water - reducing agent; 5 - 20 parts of thickening agent; 10 - 50 parts of PVA fiber; among which, the anti - dry - shrinkage functional material is formed after the carbonization of recycled concrete powder.

[0031] Specifically, the water - reducing agent is a polycarboxylate - based water - reducing agent with a water - reducing efficiency greater than 20%; the thickening agent is hydroxypropyl methylcellulose; the particle size range of quartz sand is 10 - 600 μm, and the average particle size is 100 - 140 μm; the length of PVA fiber is 9 - 15 mm, the diameter is 30 - 40 μm, and the density is 1.2 - 1.4 g / cm 3 ; the particle size of recycled concrete powder is less than 600 μm; the calcium content of fly ash is less than 10%; the silica content of silica fume is above 90%.

[0032] The recycled concrete powder is processed from concrete, mortar, stone, bricks and tiles in building (structure) waste, realizing the reuse of building (structure) waste and achieving the purpose of resource recycling. It should be noted that in this embodiment, there is no clear requirement for the ratio of concrete, mortar, stone, and bricks and tiles in the recycled concrete powder, and the conventional technology in this field can be adopted. The reason is that the recycled concrete powder is for the reuse of waste, and the content of relevant components in the waste has a large randomness. Therefore, once the relevant content is limited, it will restrict the application of the recycled concrete powder and violate the original intention of circular use.

[0033] After the carbonization of the recycled concrete powder, aragonite whiskers are formed. The aragonite whiskers have a large aspect ratio and intersect with PVA fibers to form a three - dimensional network structure, enabling the concrete material to obtain a lower density and a higher porosity, being able to significantly reduce the weight while maintaining high strength, and reducing the risk of damage during transportation and hoisting. The dry shrinkage of the concrete material is mainly caused by the loss of internal water resulting in volume shrinkage. The three - dimensional network structure has good self - supporting stability. In the case of a large amount of water loss, the negative pressure generated by water loss can be resisted by the mutual support of the network fibers, which can greatly inhibit the dry shrinkage phenomenon of the concrete. After being prepared into an assembled cement concrete pavement, the service life of the pavement can be extended.

[0034] In addition, the aspect ratios and moduli of PVA fibers and aragonite whiskers are different, which can play a complementary role within the system. Aragonite whiskers belong to inorganic fibers, with a larger modulus, a smaller aspect ratio, and a shorter length compared to PVA fibers. Under dry conditions, the water in concrete is lost, leading to easy drying shrinkage and causing cracks. Aragonite whiskers have a relatively large stiffness, which can improve the strength of concrete and resist concrete shrinkage. PVA fibers have a relatively small stiffness but high toughness, which can play a bridging role when cracks occur in concrete and inhibit the further development of cracks. At the same time, the relatively small size of aragonite whiskers can inhibit the development of microcracks, while the relatively long length of PVA fibers can inhibit the development of macro-cracks. The two types of fibers are distributed in a three-dimensional disorderly manner, inhibiting the development of cracks from different scales and aspects, thereby improving the dry shrinkage resistance of concrete.

[0035] After the recycled concrete powder is carbonized and replaces PVA fibers, the amount of PVA fibers can be reduced, greatly lowering the preparation cost and significantly expanding the application scope of high-toughness concrete, enabling it to be more widely used in engineering construction.

[0036] The dry shrinkage-resistant functional material is prepared in the following manner:

[0037] Dissolve diethylenetriamine in water to obtain a solution with a concentration of 1 - 3 mol / L;

[0038] Add recycled concrete powder to the solution to make the solid-liquid ratio 50 - 100 g / L to form a mixed solution. Continuously introduce carbon dioxide into the mixed solution, heat the mixed solution and maintain it at a temperature of 40 - 80 °C, so that the recycled concrete powder undergoes carbonization under the action of carbon dioxide to generate calcium carbonate, and the generated calcium carbonate generates aragonite whiskers under the influence of diethylenetriamine. After the reaction lasts for 1 - 4 h, centrifuge and dry the slurry to obtain the dry shrinkage-resistant functional material.

[0039] A preparation method for the above-mentioned low-shrinkage and high-toughness concrete material includes the following steps:

[0040] Take 300 - 500 parts of cement, 600 - 800 parts of fly ash, 30 - 50 parts of silica fume, 200 - 400 parts of quartz sand, 10 - 50 parts of dry shrinkage-resistant functional material, 200 - 400 parts of water, 10 - 50 parts of water reducer, 5 - 20 parts of thickener, and 10 - 50 parts of PVA fibers by mass; mix the cement, fly ash, and silica fume, then continue mixing after adding water and the water reducer, then add quartz sand and mix, then add 2 / 3 of the dry shrinkage-resistant functional material and PVA fibers and mix, and finally add the remaining 1 / 3 of the dry shrinkage-resistant functional material and PVA fibers and mix to obtain the low-shrinkage and high-toughness concrete material.

[0041] The dry shrinkage-resistant functional material and PVA fibers are added slowly in two portions to promote the uniform dispersion of the fibers and avoid the generation of agglomeration phenomena that affect the performance of concrete.

[0042] Application of the above-mentioned low-shrinkage and high-toughness concrete material as a pavement material for prefabricated pavements.

[0043] Example 1

[0044] Mix 396 parts of cement, 683 parts of fly ash, and 30 parts of silica fume by mass for two minutes, add 285 parts of water and 20 parts of water reducer and mix for two minutes, then add 270 parts of quartz sand and mix for two minutes, add 16 parts of PVA fiber, mix for five minutes, and finally add the remaining 8 parts of PVA fiber and mix for five minutes to obtain low-shrinkage and high-toughness concrete. Pour the concrete slurry into a mold, remove the internal air bubbles by manual vibration to make the surface flat, cover it with plastic wrap and cure for 24 h and then demold, and then place it in a standard curing room (temperature is 20±2°C, relative humidity is about 95%) and cure for 28 d to obtain samples.

[0045] Example 2

[0046] Dissolve diethylenetriamine (DETA) in water at a concentration of 1 mol / L, add recycled concrete powder to the solution to make the solid-liquid ratio 50 g / L to form a mixed solution, continuously introduce carbon dioxide into the mixed solution at a flow rate of 0.2 L / min / 100 ml. Heat and maintain the mixed solution at 60°C. After the reaction lasts for 2 h, centrifuge and dry the slurry to obtain a dry-shrinkage-resistant functional material.

[0047] Mix 396 parts of cement, 683 parts of fly ash, and 30 parts of silica fume by mass for two minutes, add 285 parts of water and 20 parts of water reducer, mix for two minutes, then add 270 parts of quartz sand and mix for two minutes, add 12 parts of PVA fiber and 4 parts of dry-shrinkage-resistant functional material, mix for five minutes, and finally add the remaining 6 parts of PVA fiber and 2 parts of dry-shrinkage-resistant functional material and mix for five minutes to obtain low-shrinkage and high-toughness concrete. Pour the low-shrinkage and high-toughness concrete slurry into a mold, remove the internal air bubbles by manual vibration to make the surface flat, cover it with plastic wrap and cure for 24 h and then demold, and then place it in a standard curing room (temperature is 20±2°C, relative humidity is about 95%) and cure for 28 d to obtain samples.

[0048] Example 3

[0049] The difference between this example and Example 2 is that the concentration of diethylenetriamine is 2 mol / L, and the other conditions are exactly the same as those in Example 2.

[0050] Example 4

[0051] The difference between this example and Example 2 is that the concentration of diethylenetriamine is 3 mol / L, and the other conditions are exactly the same as those in Example 2.

[0052] Example 5

[0053] The difference between this example and Example 3 is that the temperature during the carbonization process is maintained at 40°C, and the other conditions are exactly the same as those in Example 3.

[0054] Example 6

[0055] The difference between this example and Example 3 is that the temperature during the carbonization process is maintained at 80°C, and the other conditions are exactly the same as those in Example 3.

[0056] Example 7

[0057] The preparation process of the anti-dry shrinkage functional material in this example is exactly the same as that in Example 6, and the difference lies in that the concrete preparation process is slightly different:

[0058] Mix 396 parts of cement, 683 parts of fly ash, and 30 parts of silica fume by mass for two minutes, add 285 parts of water and 20 parts of water reducer, mix for two minutes, then add 270 parts of quartz sand and mix for two minutes, add 8 parts of PVA fiber and 8 parts of anti-dry shrinkage functional material, mix for five minutes, and finally add the remaining 4 parts of PVA fiber and 4 parts of anti-dry shrinkage functional material, mix for five minutes to obtain low-shrinkage and high-toughness concrete. Pour the concrete slurry into the mold, use manual vibration to remove internal air bubbles, make the surface flat, cover it with plastic wrap and cure for 24h, then demold it, and then place it in a standard curing room (temperature is 20±2°C, relative humidity is about 95%) and cure for 28d to obtain the sample.

[0059] Example 8

[0060] The preparation process of the anti-dry shrinkage functional material in this example is exactly the same as that in Example 6, and the difference lies in that the concrete preparation process is slightly different:

[0061] Mix 396 parts of cement, 683 parts of fly ash, and 30 parts of silica fume by mass for two minutes, add 285 parts of water and 20 parts of water reducer, mix for two minutes, then add 270 parts of quartz sand and mix for two minutes, add 4 parts of PVA fiber and 12 parts of anti-dry shrinkage functional material, mix for five minutes, and finally add the remaining 2 parts of PVA fiber and 6 parts of anti-dry shrinkage functional material, mix for five minutes to obtain low-shrinkage and high-toughness concrete. Pour the concrete slurry into the mold, use manual vibration to remove internal air bubbles, make the surface flat, cover it with plastic wrap and cure for 24h, then demold it, and then place it in a standard curing room (temperature is 20±2°C, relative humidity is about 95%) and cure for 28d to obtain the sample.

[0062] The samples prepared in Examples 1 to 8 were tested for aspect ratio, axial tensile strength, axial tensile ultimate strain, and dry shrinkage value, and the test results are shown in Table 1.

[0063] Table 1 Performance Test Table of Samples in Examples 1 - 8

[0064]

[0065] Comparing the test results of Comparative Example 1 and other examples, it can be seen that after adding the anti - dry - shrinkage functional material, the dry - shrinkage value of the sample at 28 days decreased significantly, with a maximum decrease of more than 50%. This indicates that the present invention can effectively inhibit the dry - shrinkage phenomenon of concrete.

[0066] Comparing the test results of Comparative Examples 2, 3, and 4, it can be seen that the concentration of diethylenetriamine has a significant effect on the aspect ratio of the anti - dry - shrinkage functional material. When the concentration is 2 mol / L, the aspect ratio is the highest, which is most conducive to forming a three - dimensional network structure with PVA fibers. Therefore, both the tensile strength and tensile strain are relatively high, and at the same time, the dry - shrinkage value is the lowest. The reason is that after carbon dioxide is introduced into the recycled concrete micropowder slurry, amorphous calcium carbonate is first formed and then transformed into calcium carbonate crystals. Without adding diethylenetriamine, calcite is preferentially formed. After adding diethylenetriamine, the organic amine ions in diethylenetriamine will adsorb on the surface of amorphous calcium carbonate. As the crystal gradually forms, the organic amine ions adsorbed on the (0 1 1) crystal plane will hinder the growth of calcium carbonate in the direction perpendicular to the c - axis and preferentially grow in the c - axis direction, forming needle - shaped aragonite crystals. Aragonite whiskers belong to the orthorhombic crystal system, and the crystal grows along the c - axis direction during crystal growth, so the shape is fibrous with a relatively high aspect ratio. Its crystal structure is as Figure 1 shown. With the increase of the concentration of diethylenetriamine, the aspect ratio of aragonite whiskers increases. However, when the concentration of diethylenetriamine is too high, the promotion effect on the aspect ratio of aragonite whiskers is not obvious. Therefore, in the present invention, when its concentration is 2 mol / L, a relatively high aspect ratio can be achieved.

[0067] Comparing the test results of Comparative Examples 3, 5, and 6, it can be seen that the higher the temperature, the larger the aspect ratio of the generated anti - dry - shrinkage functional material. The aspect ratio generated at 80 °C is the highest, the axial tensile strength and axial tensile strain are the highest, and the dry - shrinkage value is the smallest. The reason is that the higher the aspect ratio of the anti - dry - shrinkage functional material, the higher the axial tensile strength and axial tensile strain of the concrete. When cracks occur due to dry - shrinkage of the concrete, the stronger the restriction effect of the concrete on the crack propagation, and thus the smaller the dry - shrinkage value.

[0068] From the test results of Comparative Examples 6, 7, and 8, it can be seen that: the higher the percentage of the anti-dry shrinkage functional material replacing PVA fiber, the lower the axial tensile strength and axial tensile strain. When the replacement percentage is 50%, the dry shrinkage value is the smallest, which is 408 µm / m, and the axial tensile strength and axial tensile strain are also relatively high. The reason is that: the anti-dry shrinkage material contains aragonite whiskers, and the modulus of aragonite whiskers is larger than that of PVA fibers, which is not conducive to the development of cracks during axial tension. Therefore, the axial tensile strength and axial tensile strain decrease with the increase in the dosage of the anti-dry shrinkage material. However, the aragonite whiskers have a large stiffness, which can improve the concrete strength and limit the shrinkage of concrete under dry conditions. Therefore, appropriately increasing the dosage of the anti-dry shrinkage material can reduce dry shrinkage. But if the dosage is too high, the toughness of the concrete decreases significantly, so the limiting effect on shrinkage under dry conditions weakens and the dry shrinkage increases. Therefore, the optimal dosage is 50%.

[0069] Taking everything into consideration, the component ratio and preparation process conditions adopted in Example 7 are the most optimal. Example 7 can be selected as the theoretical basis for practical engineering applications to guide the preparation of high-toughness concrete with low shrinkage in practical engineering application scenarios.

[0070] The embodiments of the present invention have been described above. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims, and all of them belong to the protection scope of the present invention.

Claims

1. A high-toughness concrete material with low shrinkage, characterized in that, It comprises the following components in parts by weight: 300 - 500 parts of cement; 600 - 800 parts of fly ash; 30 - 50 parts of silica fume; 200 - 400 parts of quartz sand; 10 - 50 parts of anti - dry - shrinkage functional material; 200 - 400 parts of water; 10 - 50 parts of water - reducing agent; 5 - 20 parts of thickening agent; 10 - 50 parts of PVA fiber; wherein, the anti - dry - shrinkage functional material is produced by carbonizing recycled concrete powder; The anti - dry - shrinkage functional material is prepared by the following method: Dissolve diethylenetriamine in water to obtain a solution with a concentration of 1 - 3 mol / L; Add recycled concrete powder into the solution to make the solid - liquid ratio 50 - 100 g / L to form a mixed solution. Continuously introduce carbon dioxide into the mixed solution, heat the mixed solution and keep it at a temperature of 40 - 80 °C. Make the recycled concrete powder carbonize under the action of carbon dioxide to generate calcium carbonate, and the generated calcium carbonate generates aragonite whiskers under the influence of diethylenetriamine. After the reaction lasts for 1 - 4 h, centrifuge and dry the slurry to obtain the anti - dry - shrinkage functional material.

2. The low-shrinkage high-toughness concrete material according to claim 1, wherein The water - reducing agent is a polycarboxylate - based water - reducing agent with a water - reducing efficiency greater than 20%.

3. The low-shrinkage and high-toughness concrete material according to claim 1, characterized in that The thickening agent is hydroxypropyl methylcellulose.

4. The low-shrinkage and high-toughness concrete material according to claim 1, wherein The particle size range of the quartz sand is 10 - 600 μm, and the average particle size is 100 - 140 μm.

5. The low-shrinkage high-toughness concrete material according to claim 1, characterized in that The PVA fiber has a length of 9 - 15 mm, a diameter of 30 - 40 μm, and a density of 1.2 - 1.4 g / cm 3 .

6. The low-shrinkage high-toughness concrete material according to claim 1, wherein, The particle size of the recycled concrete powder is less than 600 μm.

7. The low-shrinkage and high-toughness concrete material according to claim 1, characterized in that, The calcium content of the fly ash is less than 10%; the silica content of the silica fume is above 90%.

8. A method for preparing a high-toughness concrete material with low shrinkage according to any one of claims 1-7, characterized in that, It comprises the following steps: Take 300 - 500 parts of cement, 600 - 800 parts of fly ash, 30 - 50 parts of silica fume, 200 - 400 parts of quartz sand, 10 - 50 parts of anti - dry - shrinkage functional material, 200 - 400 parts of water, 10 - 50 parts of water - reducing agent, 5 - 20 parts of thickening agent, 10 - 50 parts of PVA fiber according to mass parts; mix the cement, fly ash, and silica fume, continue to mix after adding water and the water - reducing agent, then add the quartz sand and mix, then add 2 / 3 of the anti - dry - shrinkage functional material and PVA fiber and mix, and finally add the remaining 1 / 3 of the anti - dry - shrinkage functional material and PVA fiber and mix to obtain a low - shrinkage and high - toughness concrete material.

9. Use of a high-toughness concrete material with low shrinkage as described in any one of claims 1-7, characterized in that, It is used as a pavement material for prefabricated pavements.

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