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The environmental impactof concrete, its manufacture, and its applications, are complex, driven in part by direct impacts of construction and infrastructure, as well as by CO2emissions; between 4-8% of total global CO2emissions come from concrete.[1] Many depend on circumstances. A major component is cement, which has its own environmental and ...
H2SO4 + Ca (OH)2 → CaSO4 · 2H2O. When concrete is carbonated by atmospheric carbon dioxide (CO 2), or if limestone aggregates are used in concrete, H2SO4 reacts with calcite (CaCO3) and water to also form gypsum while releasing CO 2 back to the atmosphere: H2SO4 + CaCO3 + H2O → CaSO4 · 2H2O + CO2.
Gypsum concrete is a building material used as a floor underlay [ 43 ] used in wood-frame and concrete construction for fire ratings, [ 43 ] sound reduction, [ 43 ] radiant heating, [ 44 ] and floor leveling. It is a mixture of gypsum, Portland cement, and sand. [ 43 ] One of its advantages is the lightweight nature.
Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as 101,325 Pa (1,013.25 hPa ), which is equivalent to 1,013.25 millibars , [ 1 ] 760 mm Hg , 29.9212 inches Hg , or 14.696 psi . [ 2 ]
Atmospheric instability is a condition where the Earth's atmosphere is considered to be unstable and as a result local weather is highly variable through distance and time. [ clarification needed ] [ 1 ] Atmospheric instability encourages vertical motion, which is directly correlated to different types of weather systems and their severity.
Average yearly temperature is 22.4 °C, ranging from an average minimum of 12.2 °C to a maximum of 29.9 °C. The average temperature range is 11.4 °C. [6] Variability throughout the year is small (standard deviation of 2.31 °C for the maximum monthly average and 4.11 °C for the minimum). The graph also shows the typical phenomenon of ...
Human activities over the past two centuries have increased the amount of carbon in the atmosphere by nearly 50% as of year 2020, mainly in the form of carbon dioxide, both by modifying ecosystems' ability to extract carbon dioxide from the atmosphere and by emitting it directly, e.g., by burning fossil fuels and manufacturing concrete. [3] [7]
The value of 615 ppm above the outdoor concentration indicates approximately 15 cubic feet per minute of outdoor air per adult occupant doing sedentary office work where outdoor air contains over 400 ppm [118] (global average as of 2023). In classrooms, the requirements in the ASHRAE standard 62.1, Ventilation for Acceptable Indoor Air Quality ...