7 Common Special Concrete Types

Impermeable concrete

Impermeable concrete refers to concrete with a impermeability grade not lower than P6, which can resist the static water pressure of 0.6MPa without any water permeability phenomenon. Impermeable concrete improves the density and pore structure of concrete, thereby reducing permeability channels and improving impermeability.

1.Heat resistant concrete

Heat-resistant concrete refers to a special type of concrete that can maintain the required physical and mechanical properties under high temperatures (200-900 ℃) for a long time. According to the different cementitious materials used, heat-resistant concrete is often used for blast furnace foundations, coke oven foundations, thermal equipment foundations and enclosure structures, lining, chimneys, etc.

2.Acid resistant concrete

The corrosion of concrete is mostly in acidic media. Concrete that has corrosion resistance under the action of acidic media is called acid resistant concrete. Acid resistant concrete is widely used in acid proof tanks, electroplating tanks, etc. in the chemical industry.

3.Polymer concrete

Polymer concrete is a concrete composed of organic polymers, inorganic cementitious materials, and aggregates. Compared with ordinary cement concrete, it has advantages such as high strength, corrosion resistance, wear resistance, and strong adhesion.

4.fiber reinforced concrete

The commonly used fiber materials include steel fibers, glass fibers, asbestos fibers, carbon fibers, and synthetic fibers. The fibers used must have characteristics of alkali resistance, seawater resistance, and climate change resistance. There is a lot of research and application of steel fibers both domestically and internationally, because steel fibers have the best effect on inhibiting the formation of concrete cracks, improving concrete tensile and bending resistance, and increasing toughness. However, the cost is relatively high. Therefore, in recent years, there has been more research on the application technology of synthetic fibers, which may become one of the main varieties of fiber reinforced concrete.

Fiber reinforced concrete is made with concrete as the matrix and various fiber materials added externally. The purpose of adding fibers is to improve the tensile, flexural, and impact toughness of concrete, and can also effectively improve the brittle properties of concrete. The commonly used fiber materials include steel fibers, glass fibers, asbestos fibers, carbon fibers, and synthetic fibers. At present, fiber reinforced concrete is mainly used in projects with complex stress structural components and high impact resistance requirements, such as runway, expressway, bridge deck, pipeline, etc.

5.Radiation resistant concrete

Can mask x γ Concrete that is harmful to human health, such as radiation, is called radiation resistant concrete. It is prepared from cement, water, and heavy aggregates, with an apparent density generally above 3000kg per cubic meter. The heavier the concrete, the more protective it is γ The better the performance of the radiation, and the thickness of the protective structure can be reduced. But for the protection of neutron flow, in addition to the heavy concrete, it also needs to contain enough of the lightest element - hydrogen.

When preparing radiation resistant concrete, it is advisable to use cement with strong bonding strength and high hydration water content, such as Portland cement, and it is best to use heavy cement such as strontium silicate. Cooling measures need to be taken when using high alumina cement for construction. Common heavy aggregates mainly include barite (BaSO4), limonite (2Fe2O3 · 3H2O), magnetite (Fe3O4), hematite (Fe2O3), etc. In addition, adding boron, boride and lithium salt can also effectively improve the protective performance of concrete.

Anti radiation concrete is mainly used in the atomic energy industry and in devices that apply radioactive isotopes, such as reactors, accelerators, radiochemical devices, customs, hospitals, and other protective structures.

6.Colored concrete

Colored concrete, also known as surface colored concrete. Usually, colored cement or white cement mixed with pigments are used to prepare colored decorative fabrics in a certain proportion. They are first laid on the bottom of the mold, with a thickness of no less than 10mm, and then ordinary concrete is poured on top of it. This is called one-step reverse molding. It can also be stamped into shape. In addition, it is also possible to dry sprinkle coloring hardener on the surface of newly poured concrete for color rendering, or to use chemical colorants to penetrate into the pores of hardened concrete to generate insoluble and wear-resistant colored precipitates for color rendering.

At present, colored concrete is mostly used to make pavement bricks, including sidewalk bricks and roadway bricks, which can be divided into ordinary bricks and special-shaped bricks according to their shapes. Road bricks also have natural color bricks. There are various types of regular floor tiles, such as square and hexagonal, whose surfaces can be made into various patterns and patterns. After laying irregular road tiles, interlocking effects occur between the bricks, hence they are also known as interlocking bricks. There are various ways to arrange interlocking bricks, and different arrangements form different patterns of road surfaces. The use of colored paving bricks on the road surface can create colorful and beautiful patterns and permanent traffic management signs, which have the effect of beautifying the city.

7.Rroller compacted concrete

Roller compacted cement concrete is an ultra dry and hard concrete prepared with a low cement content and a small water cement ratio. It is compacted by mechanical vibration and is commonly referred to as roller compacted concrete. This type of concrete is mainly used for paving road surfaces and dams, and has advantages such as high strength, high density, good durability, and low cost.

economic performance:

(1) Cement saving: Under equal strength conditions, roller compacted concrete can save more than 30% of cement usage compared to ordinary concrete. (2) High work efficiency and accelerated construction progress: The application of roller compacted concrete in pavement engineering can improve the work efficiency by about 2 times compared to ordinary concrete. Due to its high early strength, it can shorten the maintenance period, accelerate construction progress, and open up traffic early. (3) Reduce construction and maintenance costs: When roller compacted concrete is applied to large volume concrete projects, due to its low hydration heat, it can greatly simplify cooling measures and save cooling costs. For concrete pavement engineering, the maintenance cost is much lower than that of asphalt concrete pavement, and the service life is longer.