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Concrete recycling is the use of rubble from demolished concrete structures. Recycling is cheaper and more ecological than trucking rubble to a landfill . [ 1 ] Crushed rubble can be used for road gravel, revetments , retaining walls, landscaping gravel, or raw material for new concrete.
Demolition of the cooling towers of a power station, Athlone, Cape Town, South Africa, 2010. Building demolition and natural disasters such as earthquakes often release a large amount of concrete dust into the local atmosphere. Concrete dust was concluded to be the major source of dangerous air pollution following the Great Hanshin earthquake. [5]
Fired bricks were being used to build durable masonry across Europe, Asia and North Africa by 1200 BC and still remain an important building material. [42] Modern fired clay bricks are formed from clays or shales, shaped and then fired in a kiln for 8–12 hours at a temperature of 900–1150 °C.
Much building waste is made up of materials such as bricks, concrete and wood damaged or unused during construction. Observational research has shown that this can be as high as 10 to 15% of the materials that go into a building, a much higher percentage than the 2.5-5% usually assumed by quantity surveyors and the construction industry. Since ...
In itself carbonated concrete is a very solid material because its compressive strength increases due to its porosity decrease by the precipitation of calcium carbonate (calcite, CaCO 3). In the absence of steel reinforcement bars and without the formation of expansive reaction products inducing tensile stress inside the concrete matrix, pure ...
South Africa Connect, the country’s national broadband policy of 2013, mandates the introduction of a broadband connection (with a download speed of at least 100 Mbps) to every primary school and secondary school as part of an initiative to ensure the countrywide availability of broadband internet access by the year 2030. [44]
In the South the unemployment rate is more than double (6.7% in the North against 14.9% in the South). [134] A study by Censis blames the pervasive presence of criminal organizations for the delay of Southern Italy, estimating an annual loss of wealth of 2.5% in the South in the period between 1981–2003 due to their presence, and that without ...