Whether you’re building or repairing, understanding the different types of concrete will help you make the right choices for your project. This article will cover the basics of concrete types, including their strength, durability, and cost.
High-strength concrete is ideal for structures that require significant loads because it can withstand high amounts of pressure. It also has low permeability, which protects it against moisture damage and pests.
Plain Concrete
Concrete is used in a huge number of construction projects, including driveways and patios. It is extremely durable and requires very little maintenance. It can also be coloured to suit your home or garden design.
Plain concrete is a mixture of cement, fine and coarse aggregates, and water. It is often augmented with admixtures to improve its properties and performance.
For example, fly ash and slag can be added to the mix to enhance its strength, durability, or chemical resistance. They can also reduce the amount of water required to create concrete.
The type of aggregate used in concrete is highly variable. It can include rocky materials, crushed stone, loose gravel, and sand. Aggregate helps to increase the strength of concrete by filling the spaces between the particles. Aggregate sizes vary, with larger stones being used for strength and smaller stones adding texture.
The main difference between plain and reinforced concrete is that the former does not contain any steel bars or fibres (also called reinforcement). Plain concrete can have a low tensile strength which means it may crack under pressure. However, this can be improved by reinforcing it with rebar. A benefit of plain concrete is that it is very easy to construct as the mix has a high self-consolidating ability, allowing it to form into shape within its mould without any further help.
Reinforced Concrete
Concrete is a highly versatile construction material and is used in a wide range of structures from building foundations to roof structures. It is incredibly strong in compression and when combined with steel reinforcement offers excellent tensile strength. This makes it a popular choice for large scale projects like bridges, dams and piers as well as for the footings and foundations of everyday dwellings.
Reinforced concrete is a special type of concrete where steel rods, wires, cables or a mesh is embedded in the concrete to improve its strength and durability. This helps it resist tensile forces that could otherwise cause it to crack or break and also increases its ductility. This means that it can better withstand seismic activity and other natural events that may affect the structure.
The presence of the steel reinforcement also gives reinforced concrete its characteristic low permeability and allows it to resist chemicals dissolved in water such as sulfates, chlorides, carbon dioxide and other toxic substances without serious deterioration. This also makes it a great construction material for underground and underwater applications such as canals, dams and linings.
Depending on your needs you can add a wide variety of materials to concrete to improve its strength and performance including fly ash, ground granulated blast furnace slag, waste glass, reclaimed asphalt, recycled aggregates, crushed bricks, plastics, tires and other industrial byproducts. This reduces the need for virgin materials and also lowers production costs. Adding steel fibers to the mix is another way of improving its tensile strength and increasing ductility.
High-Strength Concrete
High-strength concrete, like regular concrete, can be used for construction projects, but it also has a number of special characteristics that set it apart. In addition to a higher compressive strength, this type of concrete has a greater modulus of elasticity and better durability.
The use of high-strength concrete allows builders to reduce the slab depth in a structure, which means less material and lower costs. It also lets them construct taller buildings without the need for support columns that would take up valuable floor space. High-strength concrete also sets much more quickly than traditional concrete, which can lead to fewer delays during construction.
However, using high-strength concrete does present some challenges to concrete contractors. The mix typically has a very low water-cement ratio, which can result in a concrete that is difficult to place and compact. To avoid this problem, concrete contractors must ensure that all of the concrete ingredients are properly sized and have the correct gradation.
In addition, high-strength concrete may require the use of specific admixtures to help achieve desired compressive strengths. These admixtures can include mineral by-products such as fly ash and ground granulated blast furnace slag, as well as silica fume. The addition of these admixtures also helps to reduce the amount of water needed to reach required strengths. The resulting concrete is more workable, but it still requires careful handling and placement to prevent segregation and honey combs.
Ready Mix Concrete
Ready mix concrete is a type of concrete that is mixed in the cement factory (Batching plant) according to a specific set of proportions and delivered to construction sites in trucks with mixers. This allows for specialty concrete mixtures to be designed and implemented into projects, but it also means that a high level of consistency is maintained throughout production and delivery.
This form of concrete is generally recommended for larger projects, despite the higher costs that come with it. This is because a higher quality is offered, with variation between batches reduced significantly when concrete is prepared in the plant environment.
Another benefit of ready-mix concrete is that it requires less equipment to be brought to the construction site compared with on-site mixing. The materials and equipment necessary to make concrete on-site are much more expensive, and storing tonnes of concrete at the construction site can be problematic due to weather conditions or vandalism.
The only disadvantage of using ready mix concrete is that the concrete must be used within 3.5 hours after it has been batched, which can present problems on congested job sites where traffic delays may occur. However, if effective logistics and transportation are in place between the plant and the construction site, this is rarely an issue. Choosing the right concrete for your construction project can help you to meet deadlines and stay on budget.