Bricks are small rectangular blocks used in buildings and other structures and are typically made of fired or sun-dried clay. They are sharp with true right-angled corners and their surface are regular and even. For brick to be considered proper, it must have a uniform and bright appearance. The most common color for a brick is red. The color varies from dark red to light red. Very dark red colored bricks are said to be over burnt and if the bricks are of yellowish color, they are under burnt.
Bricks are usually used to manufacture load bearing walls. An Ideal brick must provide proper insulation against hear, cold and noise. The heat and sound conductivity of a brick varies highly with their density and porosity. Bricks that are very dense and heavy conduct sound and heat at a greater rate. Bricks must be properly designed for it to be considered ideal and proper for construction purposes. They must be made in such a way that they are strong, light and give adequate insulation. Bricks are a very durable and low cost construction material. It also has high compressive strength and is also fire resistant. It can also resist weathering effects to an adequate level and are of low maintenance.
Types of bricks for construction
There are several types of bricks for construction that are found today. Types of bricks for construction based on their manufacturing processes are as follows:
- Unburnt Bricks
2. Burnt Bricks
3. Fly Ash Bricks
4. Concrete Blocks
5. Engineered bricks
6. Sand/Lime Bricks
- Unburnt bricks:
Unburnt bricks are the ones that are sun-dried. They are first molded and after the molding process, the bricks are taken out in the sun and kept there for several hours for the heat of the sun to dry them. These kinds of bricks are not very durable and are usually used for temporary structures. They are not very strong and are very less water and fire-resistant. Hence, they are not used for the construction of permanent structures.
2. Burnt Bricks:
Burnt bricks are the bricks that are made in molds are laid out to dry for a little while and then are stacked to form a kiln. These bricks are burnt in the fire for them to harden and become stronger in comparison to the unburnt bricks. Since they are hard, they are more durable. The mud that is used to make such bricks is collected directly from the homestead. These bricks are good quality bricks, but however, they have some drawbacks as well. These type of bricks are divided into four categories which are as follows:
i. First Class Bricks
ii. Second Class Bricks
iii. Third Class Bricks
iv. Fourth Class bricks
i. First Class Bricks:
These are the best quality bricks in comparison to all the other classes. They are table molded and burnt in large kilns. Hence, these bricks have a great shape, uniform color, and smooth surfaces with sharp edges. They are the most durable and have great strength. These types of bricks are usually used to construct permanent structures. Since they are considered to be top-quality bricks, these types of bricks are costlier than the other classes.
ii. Second Class Bricks:
Second-class bricks are molded by ground molding processes and are of moderate quality. These types of bricks do not have an even shape and smooth surfaces as they are molded on the ground. However, these bricks are also burnt in kilns. Even though these bricks are not top quality like the first-class bricks, but they also give proper results in strength and durability. Smooth Plastering must be done on the brick structure when such types of bricks are used.
iii. Third Class Bricks:
These bricks are a category of burnt bricks that are considered to be of poor quality. They are used generally for temporary structures just like unburnt bricks. They are ground molded brick type but are burnt in clamps and not in kilns. These types of bricks are not recommended for rainy areas at all. The surfaces of these types of bricks are rough and they also do not have sharp edges.
iv. Fourth Class Bricks:
These bricks are of very poor quality. They are not used for permanent as well as temporary structures. These bricks are made when the bricks are over burnt to a high extent, due to which the bricks become brittle in nature. Hence these types of bricks are crushed and used as aggregates in the making of concrete.
3. Fly Ash Bricks:
As the name suggests, these types of bricks are manufactured using fly ash and water. They have much better properties in comparison to clay bricks. These bricks are considered to have higher fire resistance and high strength in comparison to clay bricks. They are also more uniform and hence are better for joints and plastering. These type of bricks does not require soaking in water before masonry construction as they have lower water penetration. Fly ash bricks contain a high concentration of calcium oxide that is used in the production of cement. These bricks also help reduce the self-weight of a structure as they are considered to be very lightweight in comparison to other types of bricks.
4. Concrete Bricks:
Concrete bricks or concrete blocks are made using concrete and other ingredients that include cement, sand, coarse aggregates, and water. These types of bricks can be manufactured in the construction site itself that helps to reduce the vehicular charge in the carrying of bricks from the manufacturing site to the construction site. These bricks can be made in sizes as per the client’s requirements and can also be made in a variety of colors. Concrete bricks are used for the construction of masonry and framed structures. They can also be used for the making of facades, fences, etc.
5. Engineered Bricks:
In structures where high strength, acid resistance, frost resistance, and low porosity is required, engineered bricks are used. They are the bricks with the highest compressive strength and are used for special applications. Such bricks are usually used for damp proofing and areas such as the basement where chemical or water attacks are most prevalent.
6. Sand/Lime Bricks:
Calcium Silicate bricks or Sand Lime bricks are bricks made of sand and lime and other aggregates. These types of bricks are mostly used in ornamental works in structures and also for aesthetic purposes. They are also used in masonry work but aren’t very popularly used for them.
Bricks are one of the most widely used construction materials for various purposes. As we now know, there are various types of bricks for construction, but just because there are various types, one must know what type of brick will suit what type of construction. Good quality bricks that are the burnt bricks, mainly first-class and second-class bricks are mainly used in the construction of structures, tunnels, and all kinds of permanent structures. The third class bricks and unburnt bricks are used for temporary structures and the fourth class of bricks is used as aggregates. Bricks are also used for aesthetic purposes that is to improve the look of a building.