In the case of continuous beams/slabs, the approximate determination of the available anchorage length is not included in the software.
The anchorage is achieved by extending the CFRP to the compression zone hence it is necessary to have detailed information of the load distribution in order to estimate the neutral point of the bending moment envelope.
The estimation of the anchorage length in the case of continuous beams and positive bending moments can be done using the following process (Fig. 2-18):
The position where the envelope of the bending moment equals zero (x) at ultimate, must be determined.
After this, a horizontal displacement of the diagram (al) is taken into account, according to the “shift rule” indicated in Eurocode 2.
From this defined section, the designer must provide the maximum anchorage length, lb,max, as follows: