Concrete is one of the most essential building materials in existence, so manufacturers have created numerous concrete types for a wide variety of applications. These concrete types vary by strength, quality, and reaction to environmental conditions.
From plain concrete that builders use in general construction to specialized concrete like reinforced concrete, prestressed concrete, high-strength concrete and self-compacting concrete, each type of concrete contains unique advantages. Understanding the difference in concrete types is vital for the success of building projects for both professionals and innovative DIYers.
There are diverse types of concrete that concrete producers create for general and specific building purposes.
- Plain Concrete
- Normal Strength Concrete
- Reinforced Concrete
- Prestressed Concrete
- Precast Concrete
- Lightweight Concrete
- High-Strength Concrete
- Self-Compacting Concrete
- High-Density Concrete
- Air-Entrained Concrete
- Ready Mix Concrete
- Rapid Strength Concrete
- Fiber Reinforced Concrete
- Polymer Concrete
- Pervious Concrete
- High-Performance Concrete
- Ultra High-Performance Concrete
- Asphalt Concrete
- Stamped Concrete
Plain concrete, also called traditional concrete, is composed of cement, aggregate, and water. The cement binds the mixture of aggregates such as gravel or sand together when it is mixed with water.
Plain concrete is popular because it is inexpensive compared to more specialized concrete mixtures. It is widely available and it can be mixed on-site and molded into many forms. The disadvantages of concrete are its low tensile strength, which makes it subject to cracking. Plain concrete is common in small projects like foundations, floors, driveways, and patio slabs.
Normal Strength Concrete
The term normal strength concrete (NSC) is sometimes used interchangeably with plain concrete, though there are some subtle differences. Normal strength concrete refers to concrete with a minimum compressive strength of 20 to 40 megapascals (MPa) or 3,000 to 6,000 pounds per square inch (psi). Some plain concrete will fall within this range, but NSC can include additives to modify its specific properties.
Reinforced concrete is a type of concrete that incorporates steel bars. The addition of these bars improves the overall strength and durability of normal concrete as it combines the tensile strength of steel bars or steel mesh with the compressive strength of concrete.
Builders introduce the steel reinforcement bars (rebar) or steel mesh into the concrete mixture while it is wet. They place them in strategic areas where the tensile forces are the greatest, such as the bottom of beams or the tension sides of slabs.
Reinforced concrete has a wide building application. Builders use it for large and complex structures as it is resistant to cracking. It can even be specialized to withstand seismic activity, making it ideal for earthquake-prone areas. Reinforced concrete is more expensive initially, though because of its durability, it does not have to be replaced as often as normal concrete. It may also require more periodic maintenance as well as having some potential for corrosion if the steel comes into contact with moisture or air.
Prestressed concrete is a concrete type that incorporates internal stresses during manufacturing to counteract the stresses that it will experience during use. Thus, the tensile stress that would develop during the concrete’s service is neutralized.
Like reinforced concrete, this concrete type contains steel bars or tendons. Cement companies subject both the concrete and steel bars to compression before use. This limits the amount of cracking that concrete experiences during use and allows for greater flexibility of use. This type of concrete is stronger which allows builders to use less material and reduce the cost overall, though the initial cost of materials is higher.
Precast concrete is concrete that has been molded in a specific form and cured off-site and then transported to the site to be assembled. This is one of the best concrete types if the project has a quick timeline. Examples of common precast concrete elements include columns, beams, walls, and slabs.
Lightweight concrete is characterized by a lower density than normal concrete. This is due to the type of aggregate that manufacturers use to create the concrete. Common lightweight aggregates include expanded shale, pumice, perlites, or foam. These replace normal concrete aggregates like sand and gravel which are heavier.
Lightweight concrete is easier to handle and transport. It is often used to protect steel structures and for the construction of long-span bridges. Lightweight concrete is more expensive and does have reduced strength compared to normal concrete.
Manufacturers craft high-strength concrete (HSC) to have a higher compressive strength than normal concrete. In general, if a concrete type has a compressive strength of over 40 megapascals (MPa), experts consider it a high-strength concrete. Manufacturers use specialized cementitious ingredients to create HSC including ordinary Portland cement with a higher tricalcium silicate content or other additives like silica fume, fly ash, or blast furnace slag.
This concrete has higher strength and durability than normal concrete, but HSC is also more expensive. Achieving good workability in HSC can also be a challenge for many construction professionals due to the low water and high cement content.
Self-compacting concrete is a fluid type of concrete that can easily fill and compact itself into dense and intricate areas without external compaction or vibration. This property makes it suitable for use in detailed architectural designs. The mixture of aggregates and cementitious materials is carefully selected for flowability and stability. Manufacturers add plasticizers to the mix to improve the workability. Because of the specialized mix of ingredients, this concrete is more expensive than normal cement.
High-density concrete is formulated to have a density between 3000-4000 kg/m3 compared to the density of normal concrete which is between 2300-2500 kg/m3. Concrete producers manufacture high-density concrete by using high-density additives and aggregates which create heavier and denser concrete.
This is an essential concrete in nuclear power plants and medical research facilities as the density in this concrete helps to absorb radiation waves. This concrete also has sound insulating qualities and enhanced structural stability. The benefits of high-density concrete come at the cost of limited workability and higher expense.
Air-entrained concrete is a type of concrete that contains bubbles in the structure of the concrete. Manufacturers introduce air bubbles during the mixing process which consist of 3%-6% of the quantity of the mixture.
The intentional incorporation of air bubbles helps to improve the workability of the concrete and its ability to stand up to challenging environmental conditions like freeze-thaw cycles and salt exposure. It is important to note that the introduction of air bubbles can slightly decrease the strength of the concrete.
Ready Mix Concrete
Ready-mix concrete is a type that concrete manufacturers mix and deliver to a building site in a ready-to-use state. This delivery involves specialized trucks called agitators or transit mixers. These trucks have a rotating drum that keeps concrete agitated to maintain its consistency for optimum workability.
This is a particularly quick and convenient concrete option for builders who don’t have the time, materials, or expertise to mix concrete themselves. This makes it a popular option in the building industry.
Rapid Strength Concrete
Rapid strength concrete, also high early strength or fast setting concrete, is concrete that gains strength faster than normal concrete. This allows builders to have a quicker construction schedule allowing for expedited timelines.
This concrete has more cementitious materials like fly ash or silica fumes to accelerate the setting time. The quick setting of rapid-strength concrete may generate more heat than normal concrete, so cooling measures may be necessary to ensure the proper curing of this concrete to avoid cracking.
Fiber Reinforced Concrete
Fiber-reinforced concrete is a type of concrete that is strengthened by the incorporation of fibers like glass or steel or synthetic and natural fibers like nylon and sisal.
The concrete producers disperse the fibers throughout the mixture to enhance the mechanical properties of the concrete like its tensile strength, durability, and abrasion and impact resistance. The type of fiber depends on the exact application as each fiber brings different qualities to the concrete mixture.
Limecrete is a type of concrete that uses lime as a binder rather than cement. This was the traditional binder before the creation of cement as a binder.
Lime concrete has excellent workability and flexibility. This concrete also can heal itself over time. Lime concrete is popular in historic renovation and in the creation of buildings that have a historic character. A few disadvantages of lime concrete are its lower compressive strength and its slower set time. This concrete also needs protection from harsh weather as it is susceptible to damage from freeze and thaw cycles.
Polymer concrete is another type of concrete with an alternative binding agent. This type uses polymer resins rather than cement to bind the aggregate materials. This has some advantages over normal concrete due to its increased strength and chemical resistance. It also has a rapid curing time and reduced permeability. Polymer concrete is ideal in applications with chemical or moisture exposure like water tanks, bridges, and marine structures.
Pervious concrete, also permeable concrete, is a concrete type that is porous by design. Pervious concrete contains interconnected water pores that allow water to pass through it, which is valuable in water management. Permeable concrete is particularly valuable in places where there is heavy rainfall. This concrete allows the rainfall to percolate into the ground rather than running off into low areas or creating standing water.
The composition of pervious concrete coarse aggregates and cementitious materials. There are few, if any, fine aggregates. The coarse aggregates provide the space that allows the water to pass through. This concrete has lower strength, so it is not suitable for load-bearing structures.
High-performance concrete (HPC) is a specialized concrete type that concrete producers create with enhanced mechanical, durability, and aesthetic properties. HPC has higher compressive strength because it uses supplementary cementitious materials like fly ash and silica fumes. The composition has less permeability than normal concrete, so it is more durable in all environmental conditions and is resistant to abrasion and aggressive chemicals.
Architects regularly use HPC for high-rise structures, bridges, dams, tunnels, and marine applications.
Ultra High-Performance Concrete
Ultra high-performance concrete (UHPC) is known for its exceptional strength, durability, and unique mechanical properties. Manufacturers create this highly specialized concrete with an exact selection and apportionment of materials and specialized manufacturing processes. Common ingredients include silica fume, quartz powder, and fine silica sand. This concrete does not require the inclusion of rebar to reinforce the structure.
UHPC has a compressive strength ranging from 150 to 250 megapascals (MPa) or 22,000-36,000 psi. This allows for thinner structural elements that are still exceptionally strong and durable. UPHC has a high density, so it is extremely durable against penetration from chemicals or moisture. Unlike some specialized concrete, it also has superior workability. Builders use UHPC for skyrise structures, off-shore applications, precast elements, industrial floors, and architectural facades.
Asphalt concrete is a type of concrete that contains an asphalt binder, like bitumen, aggregates, and sometimes other additives. This is a common concrete choice for roads, parking lots, driveways, and other surfaces. Bitumen is a sticky, black material derived from crude oil production. This gives asphalt concrete its characteristic black color.
This type of concrete has some distinct advantages over normal concrete. It is durable, flexible, and resistant to many kinds of weather conditions. It offers a smoother ride, better noise control, and greater skid resistance. Asphalt concrete can also be recycled and reused. This makes it a sustainable choice for infrastructure development.
Stamped concrete is a popular design technique where builders imprint and color concrete to mimic the look of stone, brick, tile, or wood. This is a popular concrete type with building professionals and DIYers because it is more cost-effective than using natural materials.
Concretes with varied ingredients are used for stamped concrete depending on the exact application. Most often builders use normal concrete and vary the aggregate mixture to achieve a certain consistency. Sometimes builders use fiber-reinforced concrete or high-performance concrete in specific circumstances to enhance durability, strength, and crack resistance.