Mass concrete suitable for large-temperature-difference, dry and highly corrosive environment

Abstract

The invention discloses mass concrete suitable for a large-temperature-difference, dry and highly-corrosive environment. The mass concrete is prepared by mixing the following raw materials in parts by mass: 10-20 parts of cement, 4-9 parts of a mineral admixture, 20-30 parts of sand, 40-50 parts of stones, 1-3 parts of a functional component and 5-10 parts of water. The mass concrete has the characteristics of low hydration heat and high crack resistance, is suitable for desert environments with high saline-alkaline corrosion, extreme dryness and large day and night temperature difference, and solves the problem of pouring of mass aluminoferrite concrete.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, in particular to large-volume concrete suitable for environments with large temperature differences, dryness and strong corrosion. Background Art

[0002] Although ferroaluminate cement has good corrosion resistance, its hydration rate is too fast. Especially in desert environments with ultra-high saline-alkali corrosion, extreme dryness and large temperature difference between day and night, the internal hydration heat is high, making it difficult to pour large-volume concrete, which seriously restricts the promotion and application of ferroaluminate cement. It is urgent to develop key functional materials for early hydration heat regulation of ferroaluminate concrete, break through the technical bottleneck of large temperature difference and large early heat release leading to large internal and external temperature difference when pouring large-volume concrete, which is of great significance to improving the durability of large-volume concrete in desert saline-alkali areas in western my country and ensuring the safety of major national strategic projects. Summary of the invention

[0003] In order to solve the above problems, the object of the present invention is to provide a large volume concrete suitable for large temperature difference, dry and highly corrosive environment.

[0004] The above purpose can be achieved through the following technical solutions: A large volume concrete suitable for large temperature difference, dry and highly corrosive environment, characterized in that it is mixed with the following raw materials in mass ratio: 10-20 parts of cement, 4-9 parts of mineral admixture, 20-30 parts of sand, 40-50 parts of gravel, 1-3 parts of functional components and 5-10 parts of water.

[0005] And / or, the cement is ferroaluminate cement; And / or, the mineral admixture is iron tailings powder, steel slag powder, zeolite powder; And / or, the sand is river sand or machine-made sand, which is medium sand; And / or, the stones are continuously graded; And / or, the functional component is a combination of polycarboxylic acid water reducer, expansion agent, retarder, polyhydroxyalkanoate, polyhydroxybutyrate, ultrafine copper oxide powder and ultrafine iron oxide powder.

[0006] In some embodiments, the iron tailings powder has a particle size of 200-400 mesh; In some embodiments, the steel slag powder has a specific surface area greater than 400 m2 / kg; In some embodiments, the zeolite powder has a particle size of 100-200 mesh; In some embodiments, the mineral admixture is composed of 20-30 parts of iron tailings powder, 30-40 parts of steel slag powder, and 30-40 parts of zeolite powder in a mass ratio.

[0007] And / or, the expansion agent is a combination expansion agent of calcium sulfoaluminate and calcium oxide; And / or, the retarder is boric acid.

[0008] In some embodiments, the functional components are composed of 7 to 15 parts of polycarboxylic acid water reducer, 80 to 85 parts of expansion agent, 1 to 5 parts of retarder, 0.2 to 0.8 parts of polyhydroxyalkanoate, 0.7 to 1.2 parts of polyhydroxybutyrate, 0.5 to 1.5 parts of ultrafine copper oxide powder and 0.8 to 1.2 parts of ultrafine iron oxide powder.

[0009] The mass concrete prepared by the present invention has high salt corrosion resistance and crack resistance, and is suitable for large temperature difference, dry and strong corrosion environment. The temperature rise value of the concrete casting body based on the mold entry temperature can be ≤50°C; the cooling rate of the concrete casting body is ≤2.0°C / d. DETAILED DESCRIPTION

[0010] 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.

[0011] The present invention first provides a large volume concrete suitable for large temperature difference, dry and highly corrosive environment, which is mixed with the following raw materials: cement, mineral admixtures, sand, gravel, functional components, and water. The principle of achieving high corrosion resistance in the present invention is: the cement uses ferroaluminate cement; by optimizing the raw material components and grading, the compactness of the concrete is improved and the permeability of corrosive ions is reduced; by the mix design and the addition of expansion agents, the shrinkage of the concrete is reduced and the crack resistance is improved. The principle of being suitable for large temperature difference is: by controlling the cement hydration rate through functional materials and by adding porous zeolite powder to reduce the thermal conductivity, on the one hand, the temperature difference between the inside and outside of the mortar is reduced, and on the other hand, the strength of the concrete is increased quickly and the crack resistance is improved. The principle of being suitable for dry environment is: by optimizing the raw material components and grading, the compactness of the concrete is improved and the water loss rate is reduced.

[0012] The specific implementation of the large-volume concrete suitable for large temperature difference, dry and highly corrosive environment proposed by the present invention is described in detail below.

[0013] Embodiment: The components are as follows by mass: 14.4 parts of cement, 6.6 parts of mineral admixture, 27 parts of sand, 43 parts of gravel, 1.8 parts of functional components, and 7.2 parts of water. Among them, the mineral admixture components are composed of 25 parts of iron tailings powder, 35 parts of steel slag powder, and 40 parts of zeolite powder by mass ratio; the functional components are composed of 10.8 parts of polycarboxylic acid water reducer, 83.3 parts of expansion agent, 2.4 parts of retarder, 0.47 parts of polyhydroxyalkanoate, 0.88 parts of polyhydroxybutyrate, 0.95 parts of ultrafine copper oxide powder, and 1.2 parts of ultrafine iron oxide powder by mass ratio. Cast a large volume of 2m´2m´2m concrete, and bury a temperature sensor in the center of the concrete to measure the temperature rise and temperature drop. The results show that the temperature rise value of the concrete casting body based on the mold entry temperature is ≤50℃; the cooling rate of the concrete casting body is ≤2.0℃ / d. It can be seen that the large-volume concrete prepared by the present invention, which is suitable for large temperature difference, dry and highly corrosive environments, can effectively control the influence of internal temperature.

[0014] 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 large volume concrete suitable for large temperature difference, dry and highly corrosive environment, characterized in that: The following raw materials are mixed in a mass ratio: 10-20 parts of cement, 4-9 parts of mineral admixture, 20-30 parts of sand, 40-50 parts of gravel, 1-3 parts of functional components, and 5-10 parts of water.

2. The mass concrete according to claim 1, characterized in that: The cement is ferroaluminate cement; The mineral admixtures are iron tailings powder, steel slag powder, and zeolite powder; The sand is river sand or machine-made sand, which is medium sand; The stone is continuously graded; The functional component is a combination of polycarboxylic acid water reducer, expansion agent, retarder, polyhydroxyalkanoate, polyhydroxybutyrate, ultrafine copper oxide powder and ultrafine iron oxide powder.

3. The mineral admixture according to claim 2, characterized in that: The particle size of the iron tailings powder is 200-400 mesh; The specific surface area of ​​the steel slag powder is greater than 400m 2 / kg; The particle size of the zeolite powder is 100-200 mesh; The mineral admixture is composed of 20-30 parts of iron tailings powder, 30-40 parts of steel slag powder and 30-40 parts of zeolite powder in terms of mass ratio.

4. The functional component according to claim 2, characterized in that: The expansion agent is a combination of calcium sulphoaluminate and calcium oxide; The retarder is boric acid.

5. The functional component according to claim 2, characterized in that: The functional components are composed of 7-15 parts of polycarboxylic acid water reducer, 80-85 parts of expansion agent, 1-5 parts of retarder, 0.2-0.8 parts of polyhydroxyalkanoate, 0.7-1.2 parts of polyhydroxybutyrate, 0.5-1.5 parts of ultrafine copper oxide powder and 0.8-1.2 parts of ultrafine iron oxide powder in a mass ratio.