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The word comes from the Latin word "concretus" (meaning compact or condensed), the passive participle of "concrescere", from "con-" (together) and "crescere" (to grow). Ancient concrete: Found and used by Romans for more than 7 hundred years before widely used in the world Until 1453, Roman concrete was made from quicklime, pozzolana and an aggregate of pumice. Modern concrete: mix consistency is fluid allowing it to be poured into forms; added integral reinforcing steel to achieve greater strength in tension. Reinforced concrete was invented in 1849 by Joseph Monier.
Composition � � �
Aggregate: large chunks of material in a concrete mix, generally a coarse gravel or crushed rocks Cement: commonly Portland cement, serve as a binder for the aggregate. Water: mixed with the dry composite, produces a semi-liquid that can turn into any form. Through a chemical process called hydration, the water reacts with the cement that bonds the other components together.
� Chemical admixtures: added to achieve varied properties, may speed or slow down the rate at which the concrete hardens and impart many other useful properties. � Reinforcement: to improve tensile strength, usually with materials that are strong in tension(i.e.steel).
Manufacture process 1. Prepare the cement (usually Portland cement) 2. the other ingredients: aggregates (e.g.sand or gravel), admixtures (chemical additives), any necessary fibers, and water—are mixed together with the cement to form concrete. 3. shipped to the work site and placed, compacted, and cured.
Applications � � �
Specific to different applications (e.g rebuilding, mending and construction) Modern use: include dams, bridges, swimming pools, homes, streets, patios, basements, balustrades, plain cement tiles, mosaic tiles, pavement blocks… Ready mixed concrete is proportioned and mixed off the project site. It finds application in foundations and slabs-on-ground, walls, beams, columns, floors, roofs, bridges, pavements, and other infrastructure. Decorative purpose; white topping (used in airport pavements, highways, secondary roads, etc.)
Pros and Cons: Pro: eco-friendly � � � � � � �
They use less energy in production compared to any other flooring type. No trees need to be cut down. Concrete is recyclable. Minimize waste (formable) Long lasting; easy to maintain Energy-saving capabilities: they can make you feel cooler in the summer and during the winter, concrete floors absorb the heat from the sun. Improves indoor air quality
Cons: � � � �
Professional messy installation (can not complete by individual) Hard and cold, uncomfortable Transmits sound easily and create echoes Cost could be expensive
Notes http://iti.northwestern.edu/cement/monograph/Monograph3_1.html http://www.madehow.com/Volume-1/Concrete.html#ixzz2RW1GzeeW http://www.ce.memphis.edu/1101/notes/concrete/section_2_history.html http://www.auburn.edu/academic/architecture/bsc/classes/bsc314/timeline/timeline.htm http://flooring.about.com/od/Flooring-Pros-And-Cons/a/An-In-Depth-Look-At-Concrete-Flooring.htm