People have constructed buildings from ancient times as homes to provide shelter, monuments or places of worship. Earth, wood and stone have always been used as building materials. Bricks, hardened clay, were first used in the Middle East in about 3000 BC. Concrete is made by mixing sand, cement and water. Reinforced concrete dates from the late 1800s. Often used in modern buildings, it contains steel wires or rods to provide extra strength.
Buildings belong to one of two types. The first type has solid walls, called load-bearing walls that support the floors and roof of the building. The second type has a framework of wood, steel or concrete that bears the weight of the building.
Most buildings need foundations (a solid base) to prevent them from sinking into the ground or falling over. Foundations can be footings (underground walls), flat rafts, or underground supporting pillars called piles that are driven into the ground.
TALL STRUCTURES
The Great Pyramid at Giza in Egypt was the world’s tallest structure for nearly 4000 years, until the great age of cathedral building began in medieval Europe. Lincoln Cathedral in England, which was built in 1311, had a great spire that made it slightly taller than the pyramid, although it was blown down in a storm in 1549. The Washington Monument in Washington, USA, became the world’s tallest structure in 1884, before the Eiffel Tower in Paris, France, almost doubled the record five years later. The skyscrapers of the 20th century claimed the honour until the CN Tower, still the world’s tallest self-supporting structure, was built in Toronto in 1976.
Picture Credit : Google