Age Coefficient Concrete

Will experience a hardening concrete completely after 28 days so that on previous days will have different compressive strength to know can use a conversion table concrete formulas age 3 7 14 21 and 28 days. This value is usually needed when they wanted to set a time dismantling formwork so no need to wait up to 28 days and formwork can be used for other parts of concrete work.

 The compressive strength of concrete before the 28 days were also made by large-scale contractors for the purposes of reporting the quality of the concrete to the project owner that the concrete used in the field has a compressive strength of at least the same as planning.Testing can be done by creating a cylindrical specimen diameter 15 cm with a height of 30 cm, can also use a cube-shaped concrete test specimen size of 15 cm x 15 cm, but the results should be converted into a cylindrical shape with the formula:Fc = 0.83 FckFck is the compressive strength of concrete (MPA) obtained from the results of testing with a cube-shaped test piece 15 cm x 15 cm). The following conversion table concrete for each age

Concrete conversion table

Age of concrete (days)        Comparison of Compressive Strength

3                                  0.46
7                                  0.70
14                                0.88
21                                0.96
28                                1.00

Concrete compressive strength formula:
Fc = FCR - 1.64 s

Fc = compressive strength, with units Mpa
FCR = average compressive strength, in MPa

s = standard deviation