Concrete - How Concrete is Made and the History of Concrete

Concrete is the most widely used manmade product in the world. It powers a $35 billion industry, one of the largest on Earth. Concrete is used to make a variety of structures a which you use everyday.

Concrete is a construction material that consists of, in its most common form, cement, gravel and sand, and water. Concrete is the most highly used manmade product on Earth. It is used to make pavements, building structures, foundations, motorways/roads, overpasses, parking structures, brick/block walls and footings for gates, fences and poles. Approximately six billion cubic metres of concrete are produced every year, which is one cubic metre per person on Earth! Concrete commands a $35 billion worldwide industry and employs, in the United States alone, 2 million people.

The origins of concrete can be traced back to the Babylonians, who used a clay-mix similar to concrete. However, the modern-day form of concrete was not invented till 1756, when British engineer John Smeaton pioneered the use of cement in concrete. His ingredients included pebbles and powdered brick as aggregate. Nowadays, recycled materials are becoming increasingly more popular as ingredients in concrete due to higher public awareness about ecological sustainability and environmental damage.

The composition of concrete is traditionally relatively simple. However, modern concrete is often a complicated mix, ensuring durability and longevity. Cement is the main ingredient in concrete. Portland cement is the most common cement in circulation, which is just a basic mix of mortar and plaster.

Water is another ingredient in the manufacture of concrete. The w/c ratio (mass ratio of water to cement) is the key factor that determines the strength of Concrete. A lower w/c ratio will yield a concrete which is stronger, while a higher w/c ratio yields a concrete with a lower strength. Water also affects the workability and consistency of a concrete.This water and cement paste hardens over time, and both fine and coarse aggregates are added to provide bulk. Widely used aggregates include sand, gravel and crushed stone. Decorative stones such as, small river stones or crushed glass are sometimes added to the surface of concrete for a decorative "exposed aggregate" finish, popular among landscape designers.

Ad mixtures are also added to a concrete mix to give it certain characteristics not obtainable by basic production. Admixtures come in powder or paste form and generally consist of no more than 5% of the entire mixture.Concrete has many characteristics including:

Workability – ability to mould to certain shapes
Curing – keeping concrete under certain conditions till it hydrates
Strength – high compressive strength, low tensile strength
Elasticity – relatively low
Expansion and shrinkage – provisions must be made for both
Cracking – abnormal drying rate will result in cracks
Creep – the permanent movement of a slab of concrete

Concrete is used for many structures. Mass concrete structures are structures built with one, giant concrete slab so that there are no weak points, such as dams or shelters. Reinforced concrete structures have bars of steel running through the concrete to ensure strength and stability. Pre stressed concrete structures have a predetermined stress level which will never be exceeded, as they will only carry their own weight. Concrete is an amazingly versatile material. Whether you are building some of the largest structures in the world or a small pathway, the evolution and discovery of concrete has changed our world

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Types of Building Materials

Cement, bricks and tiles are the main building materials used in the construction of buildings. Today, increase in the demand for various building materials have led to many building material manufacturing companies. Many new building materials are environmental hazards, which have become a big concern to all.

Traditionally, the basic types of building materials used for construction were mud, stone and brush. Mud was used for filling the spaces between bricks and acted as a concrete and insulation. Centuries ago, houses were made entirely of dirt and clay. This was followed by the use of rocks (mainly granite) as building material. From the Neolithic period through the medieval age to modern times, granite has been commonly used as a building material. Brush structures were commonly seen in tropical areas and were made entirely from plant parts such as branches, bark, twigs and leaves. These structures were often used by Native Americans as resting places.

Stones and bricks were also common in construction. Different types of bricks have been and are still used for masonry. This includes specially shaped bricks for joints, striking and tooling, as well as glazed or rubbed bricks for decorative purposes.

Thatch is one of the oldest types of building material used for roofing. Another generic building material is wood. Because of the diverse character of different types of wood, it can be used for any type of structure in most climates. Even though wood structures were very common in earlier times, they disappeared with the approach of concrete structures.

Concrete is a composite building material comprised of aggregate and a binder (cement). Concrete finds good use in all types of building construction. Fly ash is a major ingredient in the concrete mix because of its lightweight and high thermal insulation.

More recently, new types of building materials are being used. These include metals (for the structural framework of larger buildings), plastics, asbestos and fabrics. Tar-based waterproof materials, paper linoleum, polyvinyl chloride clay and solvent coatings for inner wall are other building materials.

Building Materials provides detailed information on Building Materials, Building Material Manufacturers, Recycled Building Materials, Deck Building Materials and more. Building Materials is affiliated with Home Buildings.

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