In order to help you understand, we need to break down a few things first. Civil Structures mean any sort of constructed structure or building made by civil engineers, contractors, and workers. It can be residential, commercial, entertainment and countless other types. Masonry means the type of civil structure. It is divided into two main types, brick masonry or stone masonry. Both types are self-explanatory. We are going to talk about brick masonry in civil structures in this article.
What is a brick?
A brick is a block of clay molded to suitable shape and size. Its dimensions are 9inch length, 4.5inch width and 3inch height.
Types of bricks:
There are mainly two types of bricks:
- Sun dried bricks:
These are the bricks that are dried in the sun after molding. They are used only for temporary and light structures. Moreover, these types of bricks are vulnerable to weathering effects like rain, sun, and wind.
- Burnt bricks:
As the name explains, these bricks are burned in the kiln for a certain period of time to make them strong. After that, they are cooled down slowly and then supplied to the markets. These bricks are generally stronger than sun dried bricks. However, their strength varies, it can be strong or weak depending on the material used, type of kiln, the amount of heat provided, the interval of heat and the composition. Burnt bricks are further divided to four types depending on their quality:
- First class bricks:
These are well burnt bricks that have uniform color and shape as well as smooth texture and sharp edges. They have negligible scars or cracks and produce a metallic sound when struck with each other. Moreover, their applications include heavy foundations, houses, construction of load bearing walls, facial work, reinforced brick work, pavements, walk-a-ways, and flooring.
- Second class bricks:
These are slightly unburnt bricks that have definite size and shape, but edges are slightly unequal. They have certain irregularities on the surface with mild cracks and distortions. Additionally, they emit a ringing sound when struck with each other. Their applications include being used as brick ballast in foundation, and in single story houses.
- Third class bricks:
These are under burnt bricks with cracks and rough surface. They are light colored, soft, and have distorted shape. If you strike two third class bricks together, they emit a dull sound. And it goes without saying, they have undefined edges and corners. As far as applications are concerned, they are used in the constructions of low height structures, where the loads are much less, such as construction of huts, sheds, etc. They are used in the construction of boundary walls, used in the areas where it is not exposed to rain.
- Overburnt bricks:
Those bricks placed too close to the kiln are known as overburnt bricks. They have light grey, dark grey or black color. These cannot be used in civil structures. Their only application is usage in inferior construction works like aggregate, road metal, water bound and gravels for floor works.
Brick manufacturing is a lengthy and sensitive operation. It can be divided into four phases.
Preparing Brick earth:
As the name explains, it is the first step into brick making, it is further stepped into 5 parts:
We remove the top 20 cm organic matter of soil and free it from gravel, coarse sand, lime etc.
Different additives are spread, soil is excavated, puddled, watered, and left over for weathering.
The soil heaps are left for one month for oxidation and to wash away of excessive salts in rain.
Sandy earth and calcareous earth are mixed in right proportions with right amount of water.
It is the kneading of blended soil with feet or with a pug mill to improve plasticity and homogeneity.
- Molding the bricks:
Definite dimensions of mold are made, and the brick earth is placed into it which produces a definite shape. There are two types of molding techniques.
- Hand molding:
It includes ground molding and table molding.
- Machine molding:
Either plastic method or dry press method is used.
- Drying bricks:
There are two types of brick dryings:
- Natural Drying:
Bricks are dried in natural sunlight. It is a very time taking process.
- Artificial drying:
The bricks are dried in a kiln or a special tunnel.