Design of strengthening with near-surface-mounted CFRP strips - Strengthening of Concrete Structures with Adhesively Bonded Reinforcement - page 62

Fig. 5.1 Bond strength of externally bonded and near-surface-mounted CFRP strips compared
with ribbed reinforcing bars.(single crack)

It is assumed that the strip is always embedded at the maximum depth of the slot t s - an

approach that lies on the safe side. The depth of the slot in the concrete should be
dimensioned such that the strip can be fully embedded in the slot even allowing for any
unevenness of the surface. According to part 3 of the DAfStb guideline, the largest
permissible slot depth t s is
t s c Δ c dev (5.2)

where Δ c dev is the concrete cover to the existing reinforcement. This is calculated as
follows:
Δ c dev Δ c tool Δ c slot Δ c member (5.3)

Fig. 5.2 Cross-section with near-surface-mounted CFRP strips