This research aims to study the efficiency of flexural strengthening of RC beams with different lengths of CFRP strips by using (NSM) technique. The study is carried out experimentally on (14) concrete beams; the variables considered are (the length
and number of CFRP strips). This is established by dividing the work into two groups: the first one includes (6) beams strengthened by variable carbon fiber strip lengths and one strip, The second group includes (6) beams strengthened by variable carbon fiber strip lengths and two strips, as well as two control beams. The results indicate that carbon fibers have a noticeable effect on increasing the bearing capacity of (NSM) strengthened beams. The results also show that strengthening the beams by CFRP and not along the length of the beam and in one layer does not contribute to increasing beam strength, but when the number of layers increases, an increase in beam strength is noticed at a rate range (40%-72%).
In this research work, an epoxy polymer- Carbon Black composite has been
prepared and characterized regarding the effects of adding carbon black to
epoxy polymer on some structural properties such as polymerization behavior,
cross-linking reaction
time and yield and some properties e. g. glass transition
temperature (Tg), Young modulus (E) and flexural strength (σ).
The cross-linking reaction and glass transition temperature were studied by
Differential Scanning Calorimetry (DSC), and the mechanical tests were done
by Universal Testing Machine.
