Suggestion of flexural capacity evaluation and prediction of prestressed CFRP strengthened design

Numerical Investigation of Rc Beams Strengthened With Prestressed CFRP

“…Thus load carrying capacity of the beams with prestressed CFRP has increased. Another research (Woo et al 2008) shows that the bigger increase of the load carrying capacity is obtained with the lower prestress level. Research conducted by Deng and Xiao (2010) showed that prestress level did not influence the increment of load carrying capacity, but influenced the increase of cracking moment and yielding moment.…”

Load-bearing capacity of flexural reinforced concrete members strengthened with fiber-reinforced polymer in fracture stage

“…9,33 Other benefits of prestressing FRP are reduced deflection, controlled cracks, restored prestress losses in a prestressed concrete beam, higher concrete cracking and tensile reinforcement yield loads of strengthened beams, and stress redistribution. 8,[34][35][36][37][38][39][40] For the practical applications in the field, it is easier to prestress FRP sheets/ plates by bonding them to concrete surface (EBR) 27,[35][36][37][38][39][40] in comparison to prestressing FRP rods/strips installed into the grooves on the concrete surface (NSM). 19,22,24 Moreover, it is necessary to access the ends of the beams in order to use the prestressing devices when strengthening by NSM method.…”

“…The experimental results are collected from different scientific publications. 19,20,[22][23][24][25][26][27] A focus is made on the assessment of crack depth of critical normal section and evaluation of FRP strainstress relationship. The stiffness of strengthened flexural RC members is reduced because of the slippage between concrete and FRP.…”

“…Generally, we can classify FRP systems into two categories: externally bonded reinforcement (EBR), when FRP sheets, plates, or strips are bonded to the surface of the concrete; and near-surfacemounted (NSM), when circular or rectangular FRP bars or strips are installed and bonded in the grooves of the concrete surface. [19][20][21][22][23][24][25][26][27][28][29][30] Seven typical failure modes could be distinguished for RC structures strengthened with FRP: 18 (1) flexural failure caused by FRP rupture, (2) flexural failure caused by crushing of compressive concrete, (3) shear failure, (4) separation of concrete cover of tensile reinforcement, (5) interfacial debonding in FRP plate end, (6) interfacial debonding caused by flexural crack in midspan of the beam, and (7) interfacial debonding caused by intermediate flexural shear crack. Failure mode caused by FRP rupture (mode 1) is appreciated, because, in such case, the full strength of FRP would be used.…”

Flexural Behavior of RC Members Using Externally Bonded Aluminum-Glass Fiber Composite Beams

“…To date, many experimental and analytical research projects [8][9][10] have examined FRP sheets or rods for externally strengthening or internally reinforcing materials. The externally [11][12][13][14] or internally bonded method [15], the unbonded mechanically anchored method [16,17], the prestressing method [18][19][20], and the near surface mounted method [21][22][23] have been commonly used to apply FRP to concrete beams. Attari et al [11] reported that the number of layers didn't have significant influence on the flexural stiffness (or strength), but the U-anchorage made the strengthening material and concrete well confined.…”