For this study, saturated surface immerged concrete specimens
in water bath can be assumed as an outdoor environment with relatively
high humidity condition. Four concrete specimens were exposed
in air at 23 C for 7 days to introduce dried surface condition,
while four concrete specimens were immersed in a water bath for
7 days to provide fully saturated surface condition. Concrete specimens
exposed in air and partially emerged concrete specimens in
the water bath before applying the sprayed FRP composite,
respectively.
Before applying the sprayed FRP composite, four specimen out
of eight concrete specimens were coated with commercial primer
resin, DNY-200 on unsaturated (WB-US-P and SB-US-P) and saturated
(WB-S-P and SB-S-P) concrete surfaces specimens by using
a roller. After spraying, the four retrofitted concrete specimens
(WB-US-NP, WB-US-P, SB-US-NP and SB-US-P) were cured for
2 weeks at a temperature of 23 C to ensure the desired mechanical
properties of the layer. The other 4 retrofitted concrete specimens
(WB-S-NP, WB-S-P, SB-S-NP and SB-S-P) were partially submerged
in a water bath to provide humidity on concrete surface during
2 weeks.