Fiber-reinforced cement-based composite material suitable for large-temperature-difference, dry and highly-corrosive environment

Abstract

The invention discloses a fiber reinforced cement-based composite material suitable for a large-temperature-difference, dry and highly corrosive environment. The fiber-reinforced cement-based composite material is prepared by mixing the following raw materials in parts by mass: 40-50 parts of cement, 15-20 parts of a mineral admixture, 10-15 parts of sand, 5-10 parts of a functional component, 13-25 parts of water and 0.5-5 parts of fiber. The fiber-reinforced cement-based composite material has strong corrosion resistance, and is suitable for concrete structure post-cast strip pouring, kerf-free pavement connection, concrete structure node reinforcement and bridge hogging moment areas in a large-temperature-difference, dry and strong-corrosion environment. Compared with a fiber reinforced cement-based composite material, the salt corrosion resistance is improved by 80% or above.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a fiber-reinforced cement-based composite material suitable for environments with large temperature differences, dryness and strong corrosion. Background Art

[0002] Cement-based materials will seriously damage the durability of concrete structures in large temperature difference, dry and highly corrosive environments, greatly reducing service life and safety. Existing cement-based composite materials are not specifically designed for this situation, and the actual use effect is not ideal. Therefore, the preparation of fiber-reinforced cement-based composite materials suitable for large temperature difference, dry and highly corrosive environments is of great significance to improve the durability of concrete structures and ensure engineering safety. Summary of the invention

[0003] In order to solve the above problems, the object of the present invention is to provide a fiber reinforced cement-based composite material suitable for large temperature difference, dry and highly corrosive environment.

[0004] The above purpose can be achieved through the following technical solutions: A fiber-reinforced cement-based composite material suitable for large temperature difference, dry and highly corrosive environments, characterized in that it is mixed with the following raw materials in a mass ratio: 40-50 parts of cement, 15-20 parts of mineral admixtures, 10-15 parts of sand, 5-10 parts of functional components, 13-25 parts of water, and 0.5-5 parts of fiber.

[0005] And / or, the cement is ferroaluminate cement; And / or, the mineral admixture is a combination of nano silicon dioxide, fly ash and slag; And / or, the sand is river sand or machine-made sand, and the maximum particle size is less than 0.6 mm; And / or, the functional component is a combination of a polycarboxylate water reducer, an expander, a water retaining agent, and a retarder; And / or, the fibers are galvanized steel fibers.

[0006] In some embodiments, the mineral admixture is composed of 30-40 parts of nano-silicon dioxide, 30-40 parts of fly ash, and 30-40 parts of slag in a mass ratio.

[0007] In some embodiments, the expansion agent is a combination of calcium sulfoaluminate and calcium oxide, the water retaining agent is a cellulose compound with a molecular weight greater than 300,000, and the retarder is boric acid.

[0008] In some embodiments, the functional components are composed of 20-25 parts of polycarboxylic acid water reducer, 60-70 parts of expansion agent, 2-7 parts of water retaining agent, and 5-10 parts of retarder in terms of mass ratio.

[0009] And / or, the fiber has a diameter of 0.12 mm and a length of 10 to 14 mm.

[0010] The fiber-reinforced cement-based composite material prepared by the present invention has high salt corrosion resistance and high crack resistance, and is suitable for large temperature difference, dry and strong corrosion environment. Compared with ordinary fiber-reinforced cement-based composite materials, the salt corrosion resistance is improved by more than 80%. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clearly understood, the present invention is further described in detail below in conjunction with preferred embodiments. Here, the illustrative embodiments of the present invention and their description are used to explain the present invention, but are not intended to limit the present invention.

[0012] The present invention first provides a fiber-reinforced cement-based composite material suitable for large temperature difference, dry and highly corrosive environment, which is mixed with the following raw materials: cement, mineral admixture, sand, functional component, water, fiber. The principle of achieving high corrosion resistance in the present invention is: the cement uses ferroaluminate cement; by optimizing the raw material components and gradation, the mortar density is improved and the corrosive ion permeability is reduced; by the mix ratio design and fiber incorporation, the mortar shrinkage is reduced and the crack resistance is improved; galvanized steel fiber is used, on the one hand, the fiber modulus is similar to the mortar modulus, and on the other hand, the fiber's own corrosion resistance is improved. The principle of being suitable for large temperature difference is: by controlling the cement components and the setting rate, on the one hand, the temperature difference between the inside and outside of the mortar is reduced, and on the other hand, the mortar strength increases quickly and the crack resistance is improved. The principle of being suitable for dry environment is: by optimizing the raw material components and gradation, the mortar density is improved and the water loss rate is reduced.

[0013] The following is a detailed description of the specific implementation of a fiber-reinforced cement-based composite material proposed by the present invention that is suitable for large temperature difference, dry and highly corrosive environments.

[0014] Embodiment: The components are as follows by weight: 44 parts of cement, 16 parts of mineral admixture, 13 parts of sand, 7.5 parts of functional components, 16 parts of water, and 3.5 parts of fiber. Among them, the mineral admixture components are composed of 33 parts of nano-silicon dioxide, 34 parts of fly ash, and 33 parts of slag by weight; the functional components are composed of 23 parts of polycarboxylate water reducer, 65 parts of expansion agent, 6 parts of water retaining agent, and 6 parts of retarder by weight.

[0015] Comparative example: Fiber-reinforced cement-based composite materials of the same strength grade from a certain brand on the market.

[0016] In order to evaluate the performance of the fiber reinforced cement-based composite material proposed in the present invention that is suitable for large temperature difference, dry and strong corrosion environment, tests were carried out in various salt solutions with reference to the "Test Method for Sulfate Attack Resistance of Cement" (GB / T 749-2008). The test results are shown in Table 1.

[0017]

[0018] It can be seen from Table 1 that, compared with the comparative example, the fiber reinforced cement-based composite material prepared by the present invention and suitable for large temperature difference, dry and strong corrosion environment has excellent salt corrosion resistance.

[0019] Illustrative embodiments are described above, and it should be understood that various changes, modifications and improvements will be easily conceived by those skilled in the art. Such changes, modifications and improvements are intended to form a part of the present disclosure and are intended to fall within the spirit and scope of the present invention. Although some examples presented here relate to specific combinations of functions or structures, it should be understood that these functions and structures can be combined in other ways according to the present invention to achieve the same or different purposes. In particular, the actions, elements and features discussed in conjunction with one embodiment are not intended to be excluded from similar or other roles in other embodiments. In addition, the structures and components herein can be further divided into additional components or combined together to form fewer components for performing the same function. Therefore, the foregoing description is only by way of example and is not intended to be limiting, and the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A fiber-reinforced cement-based composite material suitable for large temperature difference, dry and highly corrosive environments, characterized in that: The following raw materials are mixed in a mass ratio: 40-50 parts of cement, 15-20 parts of mineral admixture, 10-15 parts of sand, 5-10 parts of functional components, 13-25 parts of water, and 0.5-5 parts of fiber.

2. The fiber-reinforced cement-based composite material according to claim 1, characterized in that: The cement is ferroaluminate cement; The mineral admixture is a combination of nano silicon dioxide, fly ash and slag; The sand is river sand or machine-made sand, and the maximum particle size is less than 0.6 mm; The functional component is a combination of a polycarboxylate water reducer, an expansion agent, a water retaining agent, and a retarder; The fibers are galvanized steel fibers.

3. The mineral admixture according to claim 2, characterized in that: The mineral admixture is composed of 30-40 parts of nano silicon dioxide, 30-40 parts of fly ash and 30-40 parts of slag in terms of mass ratio.

4. The functional component according to claim 2, characterized in that: The expansion agent is a combination of calcium sulfoaluminate and calcium oxide, the water retaining agent is a cellulose compound with a molecular weight greater than 300,000, and the retarder is boric acid.

5. The functional component according to claim 2, characterized in that: The functional components are composed of 20-25 parts of polycarboxylic acid water reducer, 60-70 parts of expansion agent, 2-7 parts of water retaining agent and 5-10 parts of retarder in terms of mass ratio.

6. The fiber according to claim 2, characterized in that The fiber has a diameter of 0.12 mm and a length of 10 to 14 mm.

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