Installation - Strengthening Design of Reinforced Concrete with FRP - page 223

Concrete Substrate

Primer
Putty
1 st resin coating

2 nd resin coating FRP Sheet

FIGURE 8.7 Wet lay-up process and layers.

a. Primer and resin putty
Primer is the first coat to be applied to the substrate concrete surface
using a paint roller. The primer is immediately followed by resin
putty that is used to fill in small bug holes on the concrete surface.

b. FRP sheet placement

Before the primer and resin putty are completely allowed to cure, the first
layer of the saturating resin is generously applied to the surface using a
paint roller, as shown in Figure 8.8. Then a sheet of fibers is pressed into
the saturating resin or adhesive with a ribbed aluminum or plastic roller to
prevent air pockets from forming under the fiber sheet.

Consecutive layers of saturating resin or adhesive and of fiber sheets
should be applied before completely curing the existing saturant. ACI
440.2R-08 recommends inter-layer surface preparation by light surface
sanding or using solvent if previous layers are fully cured. The recommen-
dation of the FRP system manufacturer is important.

c. Precured laminate placement

Precured laminates are typically bonded to concrete surfaces
using the manufacturer's recommended adhesive. Adhesive
should be uniformly applied to the bonding surface to main-
tain an even interface. The precured laminates themselves
should be clean and free of dust and should be pressed against

FIGURE 8.8 Applying resin to FRP with a paint roller (left) and clearing the air pockets
with a wooden roller (right).