Dd

Figure 7.26. Comparison of general and simplified methods of prEN 1992-1 proposal -Evaluation of the relative error

7.4.5 Formula proposed for slenderness limit

In order to take into account the influence of the concrete grade on deflections, which is important, especially for low steel ratios, and in order to provide designers with a continuous relationship between the slenderness ratio and the reinforcement ratio, which is especially helpful for slab elements, the following expressions have been proposed.

These formulas are a mathematical approximation to Fig. 7.23. In Fig. 7.27, this approximation is evaluated. Four plots are presented for the four concrete grades considered in section 7.4.3.11. As can be seen the degree of coincidence between the formula and the calculated values of the slenderness limits is very good, and mostly on the safe side.

Concrete Grade C30

0 0

Post a comment