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Asphalt batch mix plant A machine laying asphalt concrete, fed from a dump truck. Asphalt concrete (commonly called asphalt, [1] blacktop, or pavement in North America, and tarmac or bitumen macadam in the United Kingdom and the Republic of Ireland) is a composite material commonly used to surface roads, parking lots, airports, and the core of embankment dams. [2]
The variable density is normally described in kg per m 3, where regular concrete is 2400 kg/m 3. Variable density can be as low as 300 kg/m 3 , [ 18 ] although at this density it would have no structural integrity at all and would function as a filler or insulation use only.
Several tons of bagged cement, about two minutes of output from a 10,000 ton per day cement kiln Portland cement is the most common type of cement in general usage. It is a basic ingredient of concrete, mortar , and many plasters . [ 43 ]
Parking lots are highly impervious.. Impervious surfaces are mainly artificial structures—such as pavements (roads, sidewalks, driveways and parking lots, as well as industrial areas such as airports, ports and logistics and distribution centres, all of which use considerable paved areas) that are covered by water-resistant materials such as asphalt, concrete, brick, stone—and rooftops.
Pervious concrete consists of cement, coarse aggregate (size should be 9.5 mm to 12.5 mm) and water with little to no fine aggregates. The addition of a small amount of sand will increase the strength. The mixture has a water-to-cement ratio of 0.28 to 0.40 with a void content of 15 to 25 percent. [8]
An asphalt concrete surface will generally be constructed for high-volume primary highways having an average annual daily traffic load greater than 1,200 vehicles per day. [19] Advantages of asphalt roadways include relatively low noise, relatively low cost compared with other paving methods, and perceived ease of repair.
As mostly no coarse aggregate is used for production of foam concrete the correct term would be called mortar instead of concrete; it may be called "foamed cement" as well. The density of foam concrete usually varies from 400 kg/m 3 to 1600 kg/m 3. The density is normally controlled by substituting all or part of the fine aggregate with the foam.
The excavation of the underground aqueduct of Megara revealed that a reservoir was coated with a pozzolanic mortar 12 mm thick. This aqueduct dates back to c. 500 BCE. [9] Pozzolanic mortar is a lime based mortar, but is made with an additive of volcanic ash that allows it to be hardened underwater; thus it is known as hydraulic cement.