Bricks are the oldest building materials, and the evolution of the construction industry has resulted in numerous types of bricks. Precast concrete bricks are one of them, and they have been on the rise due to their unique properties, numerous advantages, and wide range of applications. Here, we look at precast concrete bricks and everything you need to know about them.
What are Precast Concrete Bricks?
It is a concrete masonry unit (CMU), that is shaped and hardened before being brought to the construction site. This brick is made of cement, aggregate, sand, and water and is manufactured in a factory using advanced machinery preserved in a controlled environment. They are available as full or hollow bricks of different shapes and sizes.
Manufacturing Process
Preparation of Raw Materials
The raw materials, such as cement, sand, aggregates, and additional fillers, are chosen based on the required quality. The selected materials are tested in the laboratory for required standards, and adequate proportions of the ingredients are determined.
Mixing and Blending
The cement, sand, and aggregates are mixed using mechanical mixers, adding water until they achieve a uniform and homogeneous mixture. An adequate proportion of additives (fly ash or other pigments) is blended in to achieve the desired properties.
Moulding
The cement mortar is poured into the moulds of the required shapes and sizes. Vibrators are used to eliminate pore gaps, and a hydraulic press compresses the mixture into a moulded brick. The mortar is maintained in the mould throughout the drying and curing process for days until the bricks are completely solidified.
Curing & Drying
After moulding, the concrete bricks are cured using water, air, or steam in a controlled environment to improve hydration and strength. The cured bricks are then removed from the moulds and dried to remove excessive moisture content.
Quality Checks
Inspections are conducted throughout the manufacturing process, from start to finish. At different stages, many quality checks are performed in the laboratory to ensure the quality of the bricks.
Dimensions of Precast/Prefabricated Concrete Bricks
Precast concrete units are available in numerous shapes and sizes. However, the standard dimensions of precast bricks are
- Length- 400 to 600 mm
- Height- 100 to 200 mm
- Width- 50 to 300 mm.
Applications of Precast Concrete Bricks
- Due to their high load-bearing capacity, these bricks are used to construct walls and other structural elements of buildings.
- These bricks are highly durable and attractive, making them suitable for exterior cladding and facades.
- These bricks are widely used to construct bridge piers, abutments and deck slabs.
- These bricks are used to construct retaining walls, tunnels, and highways.
- They are also used in constructing parking structures, traffic barriers, manholes and catch basins.
Advantages of Using Precast Concrete Bricks
Superior Quality
Precast bricks are produced with the utmost care and quality assurance in a controlled environment. As the bricks must pass many quality checks, there is a reduced chance of producing defective and low-quality bricks. Due to the controlled production, these bricks are a perfect option for a stable, reliable and durable structure.
No Skilled labour
Precast bricks are designed to make construction easier and ready to install. These bricks require no skilled or extra labour, reducing the time and cost spent on skilled labourers.
Cost-effective
These bricks are highly cost-effective compared to other brick types, comparing the size and construction cost. It reduces the cost of skilled labour, as they are easy to install. These bricks are readily available, reducing the cost spent on onsite manufacturing. These bricks are highly durable, reducing the maintenance and repair costs.
Rapid Construction
As the bricks are readily available for construction and are of large size, the time spent on construction is significantly reduced, ensuring that the project meets tight deadlines.
Design Flexibility
Another advantage of precast concrete is the design flexibility, as numerous types of precast bricks are readily available, which can meet different construction needs.
Fire Resistant
These precast bricks are highly resistant to fire, preventing the structure from catching fire. The hollow bricks have porous gaps within the structure and acts as an insulator that helps to maintain the room temperature.
Aesthetic look
These bricks can be custom-made and are available in numerous shapes, designs, patterns, colours, and physical characteristics. Adding slight creativity to the bricks helps build visually appealing structures.
Conclusion
Precast bricks are widely popular in the modern construction industry. They provide numerous advantages, such as high compressive strength, thermal resistance, stability, and durability. Due to their unique properties, they are used in various construction projects. These concrete bricks are at the forefront of modern construction, and their continuous evolution makes them an easy and reliable choice. It would be no surprise if concrete bricks completely replaced clay bricks in the future.
FAQs
Precast bricks are made of cement, sand, aggregates, gravel, and additives such as fly ash or rice husk.
The precast bricks manufacturing process involves six steps: preparing the raw materials, mixing, moulding, curing, cubing, and quality control.
Ordinary Portland Cement is the most widely used cement for manufacturing precast bricks. However, the quality standards vary based on the grades used. The most common grades are OPC 33, OPC 43, and OPC 53.
Yes, Precast Bricks are generally more cost-effective than traditional clay bricks. However, the price may vary depending on production, quantity, project type, and availability.