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Concrete is a composite material composed of aggregate bonded together with a fluid cement that cures to a solid over time. Concrete is the second-most-used substance in the world after water, [1] and is the most widely used building material. [2] Its usage worldwide, ton for ton, is twice that of steel, wood, plastics, and aluminium combined. [3]
They do not have any sort of pre-defined configuration in the way that a Pratt truss does. Rather, bents are simply cross-sectional templates of structural members, i.e., rafters, joists, posts, pilings, etc., that repeat on parallel planes along the length of the structure. The term bent is not restricted to any particular material.
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]
The most common use for portland cement is in the production of concrete. [17] Concrete is a composite material consisting of aggregate (gravel and sand), cement, and water. As a construction material, concrete can be cast in almost any shape desired, and once hardened, can become a structural (load bearing) element.
Concrete is the most widely used material in existence and is behind only water as the planet's most-consumed resource. [ 2 ] Cements used in construction are usually inorganic , often lime - or calcium silicate -based, and are either hydraulic or less commonly non-hydraulic , depending on the ability of the cement to set in the presence of ...
Also Abrams' water-cement ratio law. A law which states that the strength of a concrete mix is inversely related to the mass ratio of water to cement. As the water content increases, the strength of the concrete decreases. abrasion The process of scuffing, scratching, wearing down, marring, or rubbing away a substance or substrate. It can be intentionally imposed in a controlled process using ...
Regular concrete is the lay term for concrete that is produced by following the mixing instructions that are commonly published on packets of cement, typically using sand or other common material as the aggregate, and often mixed in improvised containers. The ingredients in any particular mix depends on the nature of the application.
Concrete has a limited lifespan between batching / mixing and curing. This means that ready-mixed concrete should be placed within 30 to 45 minutes of the batching process to hold slump and mix design specifications in the US, [15] though in the UK, environmental and material factors, plus in-transit mixing, allow for up two hours to elapse. [16]