Example 2: Strengthening a beam with near-surface-mounted CFRP strips - Strengthening of Concrete Structures with Adhesively Bonded Reinforcement - page 72

Fig. 6.4 Shear forces and bending moments

6.2 Internal forces
Figure 6.4 shows the basic bending moment and shear force diagrams for the simply
supported beam. The actual maximum values for the load combinations relevant to the
design are given in Table 6.2.

p ? x 2
2

p
2 ? l ? x

M x

p
2 ? l

V x p ? x

6.3 Determining the prestrain
DAfStb guideline [1, 2] part 1 section 5.1.1 (RV 19) requires that the prestrain be taken
into account in the design. This is determined below using the example of the maximum
moment. As according to the DAfStb guideline a prestrain should be determined with a
quasi-permanent load combination for the serviceability limit state, characteristic
material parameters are used in this section.

Table 6.2 Maximum shear forces and bending moments for the relevant load combinations.

Load combination M max V max V min

— kNm kN kN

Load case 3; ULS 978 489 489

Load case 3; SLS, rare 680 340 340

Load case 2; SLS, quasi-permanent 240 120 120