The design of structural elements takes into account the characteristic resistance of concrete and steel. The cross-sectional dimensions, material strength and stresses due to applied loads are taken into account in the design of structural elements.
According to BS 5328 Part 1, the following definition is given for characteristic resistance.
The strength value below which 5% of all possible strength measurements of the specified concrete are expected to fall.
The resistance that is 5% of the test results below this value is called the characteristic resistance. In other words, 95% of test results show resistance above the characteristic resistance. Figure 01 presents the probability diagram used to determine concrete strength.
Figure 01 Characteristic strength of concrete
Concrete testing verifies that the concrete has reached its strength during construction. The testing method and sampling procedure are explained in more detail in another article.
