משתמש:CatlinFerrante417

מתוך ויקי עמותת המקור
גרסה מ־22:35, 29 במרץ 2012 מאת CatlinFerrante417 (שיחה | תרומות) (דף חדש: Concrete is usually a composite construction stuff composed mostly of aggregate, cement and drinking water. There are quite a few formulations which have diversified homes. The aggreg…)
(הבדל) → הגרסה הקודמת | הגרסה האחרונה (הבדל) | הגרסה הבאה ← (הבדל)

Concrete is usually a composite construction stuff composed mostly of aggregate, cement and drinking water. There are quite a few formulations which have diversified homes. The aggregate is mostly a coarse gravel or crushed rocks this sort of as limestone, or granite, coupled with a great aggregate such as sand. The cement, typically Portland cement, and also other cementitious components this kind of as fly ash and slag cement, serve being a binder to the aggregate. Different chemical admixtures may also be extra to attain various attributes. Water is then mixed with this particular dry composite which allows it for being shaped (typically poured) and then solidified and hardened into rock-hard energy through a chemical course of action referred to as hydration. The drinking water reacts when using the cement which bonds the other factors with each other, ultimately producing a robust stone-like content. Concrete has relatively large compressive power, but significantly decrease tensile strength. This is why is generally reinforced with elements which have been solid in stress (usually metal). Concrete could be ruined by numerous processes, this sort of because freezing of trapped drinking water.

Concrete is widely used for earning 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 in many cases boats. Well known concrete structures involve the Burj Khalifa (world's tallest constructing), the Hoover Dam, the Panama Canal as well as the Roman Pantheon.

Concrete technological innovation was known with the Ancient Romans and was widely employed in the Roman Empire. Just after the Empire passed, usage of concrete became scarce right up until the technological innovation was re-pioneered inside the mid-18th century.

The environmental impression of concrete is actually a complex mixture of not totally adverse consequences; while concrete is usually a main contributor to greenhouse fuel emissions, recycling of concrete is increasingly frequent in structures which have reached the conclude of their living. Structures designed of concrete might have an extended company lifestyle. As concrete includes a large thermal mass and very lower permeability, it may make for energy productive housing.

Historical past

The term concrete originates from the Latin term "concretus" (meaning compact or condensed), an excellent passive participle of "concrescere", from "con-" (collectively) and "crescere" (to expand).

Concrete was useful for construction in lots of historical structures.

During the Roman Empire, Roman concrete (or opus caementicium) was created from quicklime, pozzolana and an aggregate of pumice. Its widespread use in lots of Roman structures, a key event while in the historical past of architecture termed the Roman Architectural Revolution, freed Roman development in the limits of stone and brick stuff and allowed for innovative new styles regarding equally structural complexity and dimension. Hadrian's Pantheon in Rome is surely an case in point of Roman concrete building.

   Concrete, for the reason that Romans knew it, was a fresh and groundbreaking material. Laid during  the condition of arches, vaults and domes, it speedily hardened into a rigid mass, absolutely free from lots of  with the inside thrusts and strains that troubled the 

builders of similar structures in stone or brick.

Present day assessments indicate that opus caementicium had as considerably compressive strength as modern-day Portland-cement concrete (ca. two hundred kg/cm2). Even so, due to absence of steel reinforcement, its tensile energy was significantly reduce and its mode of application was also distinct:

   Modern structural concrete differs from Roman concrete in two significant details. First, its  mix consistency is fluid and homogeneous, making it possible for it for being poured into varieties rather than  necessitating hand-layering with each other together with the placement 

of aggregate, which, in Roman practice, typically consisted of rubble. 2nd, integral reinforcing metal presents modern day concrete assemblies excellent strength in stress, whereas Roman concrete could depend only upon the power of your concrete bonding to resist tension.

The prevalent use of concrete in many Roman structures has ensured that lots of survive for the current day. The Baths of Caracalla in Rome are merely one instance. Quite a few Roman aqueducts and bridges have masonry cladding on a concrete core, as does the dome from the Pantheon.

Some have stated that the secret of concrete was lost for thirteen generations until finally 1756, when the British engineer John Smeaton pioneered the use of hydraulic lime in concrete, employing pebbles and powdered brick as aggregate. However, the Canal du Midi was developed using concrete in 1670. Also there are concrete structures in Finland that day again into the sixteenth century.[citation needed] Portland cement was 1st utilized in concrete in the early 1840s.

Additives

Concrete additives have already been made use of considering that Roman and Egyptian occasions, when it was found that including volcanic ash for the mix allowed it to set under water. Similarly, the Romans knew that adding horse hair produced concrete considerably less liable to crack although it hardened and including blood created it more frost-resistant.

In contemporary periods, researchers have experimented with all the addition of other materials to generate concrete with enhanced properties, this sort of as increased energy or electrical conductivity.

Composition

You will discover many styles of concrete readily available, produced by various the proportions with the most important ingredients under. In this manner or by substitution for your cemetitious and aggregate phases, the completed product is usually tailor-made to its software with various energy, density, or chemical and thermal resistance qualities.

Not too long ago the usage of recycled materials as concrete substances may be attaining recognition because of more and more stringent environmental legislation. Essentially the most conspicuous of these is fly ash, a by-product of coal- fired electricity plants. This use decreases the amount of quarrying and landfill area essential for the reason that ash acts for a cement substitute as a result minimizing the quantity of cement necessary.

The mix style depends over the type of composition currently being constructed, how the concrete is going to be combined and delivered and exactly how it will be placed to kind this construction.

Ready-mixed concrete share is continually growing during the structure of concrete output and working with. In European Union the share of ready-mixed concrete reached ninety three.39% in 2010.

More info on concrete at Colored Concrete Champaign IL and Decatur IL Decorative Concrete Article by fox and austin masonry