Concrete is a popular choice for construction projects. It consists of cement, sand and coarse aggregate that are mixed with water to form a tough material when it hardens from the hydration process.
There are various types of concrete based on their characteristics. The type you choose should depend on your project requirements.
Normal Strength Concrete
This type of concrete is used in most construction projects. It typically has a normal strength of around 4000 psi (28 MPa) and can be used in residential and commercial buildings, floor slabs, water tanks, and road surfaces. Normal strength concrete is made using standard cement and aggregates including sand, rock, foamed slag and crushed stones.
In most cases, this type of concrete is categorized by its grade which is indicated by the letter M followed by a number that signifies the specific mix proportion of the concrete such as M15. This mixes 1 part cement, 2 parts sand and 4 parts coarse aggregates with a water-cement ratio of around 0.6.
While it takes longer for this type of concrete to reach its full strength, it can withstand significant loads. It also has low permeability which helps it resist wear and tear, chemical attack and corrosion.
In addition, this concrete can set quickly and is highly resistant to cold temperatures, which makes it ideal for projects that need to be completed in short durations. Additionally, it requires less material than other types of concrete, allowing contractors to save money on construction costs. It is also easy to use since it can be shaped in any manner. It can be placed in a formwork or in a precast mold, which speeds up the construction process.
Reinforced Concrete
Reinforced concrete is a common construction material that is used in almost all structures in the world. It consists of the traditional cement concrete mixed with steel bars or rods that give it strength. It has high compressive strength and good resistance to tensile stress. It is also quite resistant to fire and water. In terms of cost, it is a fairly economical building material compared to other materials.
It is very durable and requires little maintenance to keep it in good condition. It is also environmentally friendly. It is a versatile building material that can be cast into many different shapes and sizes at the construction site. It can be easily combined with other construction materials such as wood, brick and steel.
Standard concrete responds poorly to tensile stress, so it is reinforced to improve its strength. Reinforcement is made of steel, which has a higher tensile strength than concrete. The combination of concrete and steel allows the structure to resist all types of loading, including compression and tensile stress.
The strength of reinforcement concrete is largely determined by the proportions of the concrete mix, its age and the way it is loaded. For example, the values of the compressive strength of concrete obtained from tests on cubes are only about 80 % of those that can be expected from a design mix.
Plain Concrete
Plain concrete is the most basic type of concrete used in construction. It is a mix of cement, aggregates, and water following a 1:2:4 proportion. It’s often used in pavements and other areas that don’t need a high level of tensile strength. However, this isn’t the ideal material for buildings because it can easily crack and break under tension.
Shear failure is one of the biggest issues with this material. Because it’s brittle and lacks ductility, shear stresses can develop within the concrete, turning it into a pile of rubble in the blink of an eye. In order to improve shear performance, you need to include steel-fibre reinforcement into the mix.
Another issue with plain concrete is that it is slow to set, which can cause delays in construction projects. This can be overcome by using rapid-set concrete, which accelerates the curing process so that it can be used on site sooner.
Pre-stressed concrete is a special type of concrete that is able to hold more weight than normal concrete because it’s been put under stress before being used. This is done by placing pre-stressed bars or tendons into the concrete before it’s used, which makes it stronger and less susceptible to defection under heavy loads. This type of concrete is commonly used in bridges and other large structures.
High-Density Concrete
This type of concrete is designed to be lighter than normal concrete, but also has greater strength. This is important as it allows construction crews to move faster on projects by reducing the amount of material needed. It also reduces the amount of time required for concrete to harden.
High-density concrete, or heavyweight concrete, is used for specific purposes such as radiation shielding. It has a lower compressive strength than traditional concrete, but it is much thicker and offers excellent protection against harmful radiation. It is also more cost-effective than other options such as lead or steel shields.
When making this type of concrete, it is essential to carefully consider the material selection process. This includes choosing the right mix ratio, as well as ensuring that all aggregates are free of alkali reactive materials. The mixing process can be done either manually or through machine-based methods.
The most common method is to use a concrete mixer. This type of machine mixes the water, cement and aggregate together in a controlled way to produce fresh concrete. Alternatively, workers can mix the concrete by hand using special tools.
In terms of durability, high-density concrete is highly resistant to abrasion and impact damage. It is also durable against chemical corrosion and environmental degradation, such as acid rain. However, it is important to note that this type of concrete is not as able to resist tensile stresses, so it must be reinforced with other materials.