This paper presents the experimental results of investigations the shear behavior of strengthened
reinforced concrete beams by using glass fiber reinforced polymers (GFRP) rods. The strengthening
system used GFRP rods were done by Near Surface Mounted technique (NSM), NSM technique
contains a groove on the outside surface of the concrete member to adjust the depth to be less than
the cover of the member. After cleaning, the epoxy paste was used to fill half of the groove's depth.
The particular FRP element is then mounted in the groove. Finally, the groove is filled with epoxy
and the too much epoxy is leveled with the outside surface of the concrete. This method enables the
fiber reinforcement polymer FRP materials is covered completely by epoxy. The main objective of
this research is to study the effect of NSM technique on shear resistance for RC beam. The
parameters are considered in this study are effect of the material type used for strengthening (inner
steel stirrups and external glass fiber stirrups), effect of FRP rods inclination on strengthened
beams, shape with different end anchorage of FRP (strips and rods), and the effect of number of the
used FRP rods. This paper involved 13 experimental investigations of half-scale R.C beams. The
experimental program included two specimens strengthened with inner steel stirrups, eight
specimens strengthened with stirrups of Glass Fiber Reinforced Polymer GFRP rods with the shape
of different end anchorage and angle, and two specimens strengthened with externally bonded
GFRP strips. The remaining un-strengthened specimen was assigned as a control one for comparison. The test results included ultimate capacity load, deflection, cracking, and mode of
failure. All beams strengthened with GFRP rods showed an increase in the capacity ranging
between 14% to 85% comparing to the reference beam, and beams strengthened with GFRP strips
showed an increase in the capacity ranging between 7% to 22% comparing to the reference beam. |
