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Cracks development occurs when early-age concrete is insufficiently protected against desiccation and too much water evaporates with heat because of unfavorable meteorological conditions: e.g, high temperature, direct solar insolation, dry air, low relative humidity, and high wind speed during summer, or in hot conditions. Curing is intended to ...
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]
Similar to the atmospheric needs of medical and scientific research laboratories, the production of discrete semiconductor devices and integrated circuits is undertaken in a cleanroom atmosphere where low levels of environmental pollutants such as particulates and airborne microbes are strictly minimised and most preferably eliminated. [2]
Concrete has a relatively high thermal mass, meaning that it takes a long time to respond to changes in ambient temperature. [9] This is a disadvantage when rooms are heated intermittently and require a quick response, as it takes longer to warm the entire building, including the slab.
Conversely, cool air falls to the floor as it is heavier than the surrounding warmer air. [citation needed] In a stratified building, temperature differentials of up to 1.5°C per vertical foot is common, and the higher a building's ceiling, the more extreme this temperature differential can be. [2]
The graphic below shows the all-time coldest temperature on record in each state, according to NOAA. Those record-low benchmarks range from single digits and teens below zero in some Southeast ...
Over the past 100 years, the average July temperature in Phoenix has risen dramatically. In the 1920s, it ranged from 89.3 to 92.7 degrees; in the past decade, it sat between 94.7 and 102.7 degrees.
The ground floor with a slab on grade has less temperature rise compared to middle and top floors, and an increase of the supply air temperature causes a decrease in the temperature rise. The temperature rise is not significantly affected by the perimeter zone orientation, the internal heat gain and the window-to-wall ratio. [ 16 ]