Friday, October 27, 2006

Concrete


In construction, concrete is a composite building material made from the mixture of aggregate and a cement binder.
The most common form of concrete consists of Portland cement, mineral aggregates and water.
Concrete does not solidify from drying after mixing and placement, the water reacts with the cement in a chemical process known as hydration. This water is absorbed by cement, which hardens, gluing the other components together and eventually creating a stone-like material. When used in the generic sense, this is the material referred to by the word concrete.
Concrete is used more than any other man-made material on the planet. It is used to construct pavements, building structures, foundations, and motorways/roads, overpasses, parking structures, brick/block walls and bases for gates, fences and poles.

Tuesday, October 17, 2006

Aluminium

Aluminium or aluminum is a silvery and ductile member of the poor metal group of chemical elements. In the periodic table it has the symbol Al and atomic number 13.Aluminium is found primarily in the bauxite ore and is remarkable for its resistance to corrosion and its light weight. Aluminium is used in many industries to manufacture a large variety of products and is very important to the world economy. Structural components made from aluminium and its alloys are vital to the aerospace industry and very important in other areas of transportation and building.

Monday, October 09, 2006

Manhattan refers to both the Island of Manhattan and encompasses most of the Borough of Manhattan, one of the five boroughs of New York City. The commercial, financial, and cultural center of the city, Manhattan has many famous landmarks, tourist attractions, museums and universities. It is also home to the headquarters of the United Nations and the seat of city government.
The borough of Manhattan is coterminous with New York County, which is also the most densely populated county in the United States. Postal addresses within the borough are typically designated as "New York, NY."
Manhattan has the largest central business district in the United States and is the site of most of the city's corporate headquarters and the New York Stock Exchange. Although its population is third largest of the five boroughs, after Brooklyn and Queens, and it is geographically the smallest, Manhattan is the borough that many visitors most closely associate with New York City.