A building material made by grinding calcined limestone and clay to a fine powder, which can be mixed with water and poured to set as a solid mass or used as an ingredient in making mortar or concrete.
Portland cement (often referred to as OPC, from Ordinary Portland Cement) is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco and most non-specialty grout. It usually originates from limestone. It is a fine powderproduced by grinding Portland cement clinker (more than 90%), a limited amount of calcium sulfate (which controls the set time) and up to 5% minor constituents as allowed by various standards such as the European Standard EN197-1:
a general name for a group of cements containing not less than 20 percent active mineral additives. The term “pozzolan cement” is derived from the name of a friable volcanic rock—pozzolana—used in ancient Rome as an additive to lime in the production of hydraulic cement.
In modern construction, the major type of pozzolan cement is portland-pozzolan cement, produced by grinding together portland cement clinker (60–80 percent), an active mineral additive (20–40 percent), and a small amount of gypsum. It differs from ordinary portland cement in its higher resistance to corrosion (especially in soft or sulfate waters), reduced rate of hardening, and lower frost resistance. Pozzolan cement is used mainly to produce concretes used in underwater and underground structures.
any of various loose, particulate materials, as sand, gravel,or pebbles, added to a cementing agent to make concrete,plaster, etc.
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atomsconnected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseousstate (water vapor or steam).
Concrete is a composite construction material composed primarily of aggregate, cement and water. There are many formulations that have varied properties. Concrete is widely used for making architectural structures, foundations, brick/block walls, pavements, bridges/overpasses, motorways/roads, runways,parking structures, dams, pools/reservoirs, pipes, footings for gates, fences and poles and even boats.
The environmental impact of concrete is a complex mixture of not entirely negative effects; while concrete is a major contributor to greenhouse gas emissions, recycling of concrete is increasingly common in structures that have reached the end of their life. Structures made of concrete can have a long service life. As concrete has a high thermal mass and very low permeability, it can make for energy efficient housing.
Reinforced concrete is concrete in which the undesirably low tensile strength and elasticity of the concrete component are averted by including reinforcing structures of high tensile strength in the mass of the concrete. Such structures usually, though not necessarily, are reinforcing bars of steel (rebar) and also usually, though also not necessarily, are embedded passively in the concrete before it sets. Such reinforcing structures are designed to take up working stresses that otherwise would have placed the concrete mass under unacceptable tension. Modern concrete reinforcing structures however, may contain non-steel materials with high tensile strength, and also may be permanently stressed before or after the mass sets, so as to improve the behaviour of the final structure under working loads.
A rebar (short for reinforcing bar), also known as reinforcing steel, reinforcement steel, rerod, a deformed bar, reo, or reo bar, is a commonsteel bar, and is commonly used as a tensioning device in reinforced concrete and reinforced masonry structures holding the concrete in...
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