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The concept of permeability is of importance in determining the flow characteristics of hydrocarbons in oil and gas reservoirs, [4] and of groundwater in aquifers. [5]For a rock to be considered as an exploitable hydrocarbon reservoir without stimulation, its permeability must be greater than approximately 100 md (depending on the nature of the hydrocarbon – gas reservoirs with lower ...
Adding an air entrainment agent during the mixing of fresh concrete induces the formation of tiny air bubbles in the fresh concrete slurry. This creates numerous small air-filled micro-cavities in the hardened concrete serving as empty volume reserve to accommodate the volumetric expansion of ice and delays the moment tensile stress will develop.
Also known as storage pores because of the ability to store water useful to plants. They do not have capillary forces too great so that the water does not become limiting to the plants. The properties of mesopores are highly studied by soil scientists because of their impact on agriculture and irrigation. [3] Size 30–75 μm. [4]
A pervious concrete street in 2005. Pervious concrete (also called porous concrete, permeable concrete, no fines concrete and porous pavement) is a special type of concrete with a high porosity used for concrete flatwork applications that allows water from precipitation and other sources to pass directly through, thereby reducing the runoff from a site and allowing groundwater recharge.
For level ground conditions, the total vertical stress at a point, , on average, is the weight of everything above that point per unit area. The vertical stress beneath a uniform surface layer with density ρ {\displaystyle \rho } , and thickness H {\displaystyle H} is for example:
Concrete has a total embodied energy of 1.69 GJ/tonne, lower per unit mass than most common building materials besides wood. However, concrete structures often have high masses, so this comparison is not always directly relevant to decision making. Additionally, this value is based only on mix proportions of up to 20% fly ash.
Creep and shrinkage of concrete are two physical properties of concrete. The creep of concrete, which originates from the calcium silicate hydrates (C-S-H) in the hardened Portland cement paste (which is the binder of mineral aggregates), is fundamentally different from the creep of metals and polymers.
Permeability (earth sciences), a measure of the ability of a material (such as rocks) to transmit fluids Relative permeability, in multiphase flow in porous media; Permeability (foundry sand), a test of the venting characteristics of a rammed foundry sand; Hydraulic conductivity, the permeability of soil for water