The unit weight of rebars is typically around 7.85 kg/m³. In a reinforced concrete mix with a compressive strength of 60 MPa, the amount of reinforcement steel used is usually between 1-2% of the total volume of concrete. Therefore, the weight of rebars per cubic meter of reinforced concrete at 60 MPa would be approximately 78.5 kg/m³ to 157 kg/m³.
the strength of concrete
42 mpa for pre tension and 35 mpa for post tensioned
Bagged Premixed Concrete will achieve an mpa strength of around 20 mpa and is usually expected to reach this at 28 days. The "Rapid Set" Premix Bagged products are only good for about for about 5 mpa. .
40 MPa
Concrete strengths are customarily denominated in psi(pounds per square inch) in the imperial system and in MPa's(megapascals) in metric. These are units of pressure.
They're talking about compressive strength - the amount of force that can be applied to a defined area of the concrete before it fails. 25 MPa concrete in the states would be 3625 psi concrete - very ordinary stuff; the kind in bags at Home Depot is stronger than that.
MPa (Megapascal) is a unit of pressure, while kg/m^3 (kilograms per cubic meter) is a unit of density. They measure different physical properties and cannot be directly converted from one to the other.
I called bunco today and for duramix concrete, it is $210/ meter delivered with the environmental fee... There is a $15/meter Saturday fee and a small load fee. $70 for every meter under 4 meters. Duramix has admixtures to stop corrosion of rebar and to stop it from turning corrosive and it is strong (32 mpa I believe) This is a basic idea of the cost. It can very massively depending on what you want and need, Where you are located, if you want color it and so on.
Proportions for different grades: Cement : Sand : Gravel 1 : 2 : 5 for grade C15(general purpose concrete) 15 mpa 1 : 2 : 4 for grade C25(strong) 25 mpa 1 : 2 : 3 for grade C30(very strong) 30 mpa Remember the proportion is done in terms of volume. This means the above proportions are correct if using the same measure.
Concrete with compressive strength more than 55 MPa is known as high strength concrete.It is used in the construction of bridges, dams. etc.,High strength concrete is produced by adding normal constituents of concrete with admixtures.
1 MPa = 1 Newton/square milli meter = 106 Pascal