steel in construction

Advantages of Steel

·                     Steel has the highest strength to weight ratio of any building material.

·                     Provides consistent material quality; because it is produced in strict accordance with national standards, there is no regional variance in quality.

·                     Simplified foundation construction.

·                     Provides for straight walls, square corners, and allows doors to open and close properly.

·                     Fire resistant, does not burn and will not contribute fuel to the spread of fire.

·                     Inorganic; it will not rot, split, crack or creep.

·                     No twisting or warping.

·                     Fire parapets can be eliminated.

·                     Easily disassembled for repairs/alterations/relocation Vandal resistant.

·                     Produces less scrap and waste (2% for steel vs. 15-20% for wood).

·                     Scrap is 100% recyclable.

·                     Slower aging process with less maintenance.

·                     Enhanced resale value.

Each year, the North American steel industry recycles millions of tons of steel scrap from recycled cans, appliances, automobiles, and construction materials. This scrap is re-melted to produce new steel. 64% of all steel products are recycled--more than any other material in the U.S. including glass, paper, plastic and aluminum combined. Steel recycling programs reduce the solid waste stream resulting in saved landfill space, and help to conserve our natural resources. Steel recycling saves the energy equivalent of electrical power for about one-fifth of U.S. households or about 18 million homes for one year. All steel framing contains a minimum of 25% recycled steel.

Disadvantages

1.      Thermal Conductivity-Steel buildings have a poor resistance to heat. Heat conductivity has always been a common problem of steel buildings

2.      Corrosion- Steel components have a tendency to corrode, especially in marine climates, according to Infoforbuilding.com. When steel comes in contact with water, the iron part of the steel chemically reacts to the oxygen contained in the water. This reaction is the main reason why rust forms in steel buildings.

3.      Prone to Fracture- Just like most construction materials, steel is prone to fracture. Constant tension and stress caused by the overall weight of a building contributes to the wear and tear of the steel.

Manufacturing- Steel is manufactured by mixing iron and carbon in a specific ratio, in which the percentage of carbon may range from 0.2 percent to 2.14 percent of the total weight. Other than carbon, the alloying materials used in manufacturing steel include chromium, manganese, vanadium and tungsten. Among all these materials, carbon is the most cost-effective element. Alloying material performs the function of hardening the metal during cooling.

 

Physical Properties of Steel

One of the major properties of steel is the ability to cool down rapidly from an extremely hot temperature after being subjected to water or oil. Physical properties depend on the percentage composition of the constituent elements and the manufacturing process.

The physical properties of steel include high strength, low weight, durability, flexibility and corrosive resistance. Steel, as we all know, offers great strength though it is light in weight. In fact, the ratio of strength to weight for steel is the lowest than any other building material as of now. By the term flexibility, it means steel can easily be molded to form any desired shape.

Unlike the constituent element iron, steel does not corrode easily, on being exposed to moisture and water. Steel is a good conductor of electricity. The deciding factor for the grade of steel is basically the hardness of the metal, which differs depending upon the amount of carbon content. The higher the carbon content, the harder and stronger is the steel metal.

There are other types of steel such as galvanized steel and stainless steel (corrosion-resistant steel). Galvanized steel is coated with zinc to protect it from corrosion, whereas stainless steel contains about 10 % of chromium in its composition. The major advantage of steel is the ability to recycle it effectively, without destroying or losing any of its physical properties in the recycling process.