Portal:Concrete

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Introduction

Exterior of the Roman Pantheon, finished 128 AD, the largest unreinforced concrete dome in the world.

Concrete, usually Portland cement concrete, is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens over time—most frequently a lime-based cement binder, such as Portland cement, but sometimes with other hydraulic cements, such as a calcium aluminate cement. It is distinguished from other, non-cementitious types of concrete all binding some form of aggregate together, including asphalt concrete with a bitumen binder, which is frequently used for road surfaces, and polymer concretes that use polymers as a binder.

When aggregate is mixed together with dry Portland cement and water, the mixture forms a fluid slurry that is easily poured and molded into shape. The cement reacts chemically with the water and other ingredients to form a hard matrix that binds the materials together into a durable stone-like material that has many uses. Often, additives (such as pozzolans or superplasticizers) are included in the mixture to improve the physical properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials (such as rebar) embedded to provide tensile strength, yielding reinforced concrete.

Selected general articles

Did you know...

  • ... that One Kemble Street was built using precast cruciform concrete blocks to avoid the use of scaffolding?
  • ... that Canal Lake Concrete Arch Bridge, a National Historic Site of Canada, is an example of a "transitional structure" between stone arch bridges and reinforced bridges?
  • ... that when Whitefoord Russell Cole threatened striking workers with dismissal and pension loss in 1921, his house was "bombarded with bottles until its concrete porch was littered with glass"?
  • ... that Viaduto do Chá, São Paulo's first viaduct, was originally constructed from German iron before being replaced by a concrete span?
  • ... that the floor tiles of the Kerr Cultural Center were made with a now-rare mix of cement and white marble dust?
  • ... that the Milam Building was both the tallest brick and reinforced concrete structure and first office building with built in air conditioning in the United States when it opened in 1928?

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