Example 1: Strengthening a slab with externally bonded CFRP strips - Strengthening of Concrete Structures with Adhesively Bonded Reinforcement - page 42

Fig. 4.3 Shear forces and bending moments

that the work can be carried out without delay, the design will be based on these sizes.
The strengthening system includes an appropriate adhesive based on epoxy resin.

4.2 Internal forces
Figure 4.3 shows the basic bending moment and shear force diagrams for the simply
supported slab. The actual maximum values for the load combinations relevant to the
design are given in Table 4.3.

p ? x 2
2

p
2 ? l ? x

m x

p
2 ? l p ? x

v x

4.3 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 4.3 Maximum shear forces and bending moments for the relevant load combinations.

Load combination m max v max v min

— kNm/m kN/m kN/m

Load case 3; ULS 39.18 36.44 36.44

Load case 3; SLS, rare 27.74 25.80 25.80

Load case 2; SLS, quasi-permanent 9.25 8.60 8.60