Concrete in tension area
There are several options available for the stress-strain diagram of the concrete in the tension area.
The concrete tensile strength can, inter alia, be considered as per CEB-FIP Model Code 90:1993. Until the tensile strength of concrete fctm is reached, the program assumes the distribution for reaching the crack strain of 0.15 ‰ shown in Figure 2.134.
Alternatively, you can use the concrete's stiffening effect in the tension zone (tension stiffening). This procedure is described in the following chapter.
