2.3 Preparation of RC beam specimens
All RC beam specimens were cast using timber formwork and
ready mix concrete designed for Grade 50. The RC beam
specimens were demoulded in the next day after concrete
casting. After demoulding, the RC beam specimens were wet
cured by covering them with wet burlap for 28 days and cured
for another three (3) weeks after installation of the NSM
GFRP rod/s and EB with CFRP sheet/s.
2.5 Strengthening the RC beam specimens
Series II: NSM technique
The groove has square cross-section, size 25 mm,
corresponding to a groove-size-to-bar-diameter ratio equal to 2
to avoid splitting failure of the epoxy cover [9]. For first
series, the length of the groove is 1800 mm and was adopted
for all beams strengthened with NSM technique. The groove
then was cleaned and each groove was filled half way with
epoxy.The GFRP bar was placed in the groove and then was
lightly pressed. The groove was then filled with more paste
and the surface was leveled. Figures 3 (a) to (d) show the
procedure of preparing RC beam specimens strengthened with
NSM GFRP rods.