In the olden days, people built their houses by using mud. Bamboo was used to give support. Roof was thatched with different kinds of leaves. People made bamboo and rope bridges to cross canals and rivers.
Today, to make buildings and other structures, we use cement, sand, gravel, bricks, steel rods, marble and tiles. Many professionals are also involved in their construction.
People at Work
An engineer who plans buildings and bridges is concerned with the base structure of the building. He maps out the arrangement of steel rods, the consumption of concrete, etc. He calculates the cost of construction and advises what type of materials should be used for the construction of a bridge or a building.
An architect designs the building. The design is called a plan. The art and the shape are planned by an architect. An architect is a person trained in the planning, designing and supervision of the construction of buildings and bridges. Masons work with cement, sand, gravel, concrete, bricks, marbles, tiles and iron rods. It is the mason who builds the buildings or bridges. He uses different kinds of tools to do his work.
Trowel is used to take and spread the cement and other materials. Floats are used to give smoothness to the area. Plumb bob is used to check whether the wall is straight or not.
Carpenters work with wood. They make doors, windows and furniture. They make them in desired shape and design. The tools used by carpenters are hammer, wrench, screwdriver, chisels, saw and drill.
A plumber fixes taps, pipes and other sanitary fittings. He uses screwdriver, wrench pliers, hammer and pipe cutter.
Electricians fix plugs, switches, lights, fans and electric wires. They use pliers, screwdriver and tester.
The walls are painted by painters. They use brushes, paints and rollers.
Labourers help the masons and carpenters to mix cement and sand, to shape steel rods and carry materials to the work place.
Brick Making
Bricks are the basic materials used for the construction of houses and dams. Bricks are made of clay. Clay is easily available in plenty on the banks of lakes and rivers. The clay is ground to small even particles. It is mixed with water to make it soft. Then the clay is put into moulds and left to dry. When it dries, it is carefully removed from the moulds.
Later, it is dried in the sun and baked inside a furnace. The furnace or oven used to make bricks is a big chamber with fire burning inside it. This brick-baking chamber is called a kiln and the process is called firing.
Bridges
Bridges are structures constructed across roads and waterways for transporting people, vehicles and goods from one side to another. Engineers and architects plan and design the bridges. All over the world, we see different types of beautiful bridges.
Concrete bridges are built with expensive materials. They are strong and last for many years. Heavy vehicles like buses, trucks and trains move on these bridges.
Bamboo and rope bridges can be seen in some villages and hilly regions even today. People make their own traditional bridges using ropes, bamboo and logs of wood.
Today, the bridges are made of stones and bricks. They have a concrete and steel framework. They usually have two supports at both the ends. Long bridges have pillars, called piers, in between for additional support.
Suspension Bridge
Suspension bridges hang on steel cables which are connected with high towers on its either sides. The steel cables which hang from the towers are called main cables. Inside the main cables there are many small cables known as hanger cables.
Movable Bridge
Movable bridges are bridges in which a portion of the bridge can be moved up or slided sideways to allow ships and boats to pass through. They are found on busy waterways.
Arch Bridge
An arch bridge is semi circular in structure. These bridges were earlier made of bricks and stones, but nowadays concrete and steel are used.
Beam Bridge
In a beam bridge, a horizontal structure of steel and concrete, called beam, rests on support on either ends. If the beam bridge is long, it has many pillars to support the beam.
Cantilever Bridge
A cantilever bridge is similar to beam bridge. It has support only at one end.
