Flexural strengthening of damaged RC T-beams using self-compacting concrete jacketing under different sustaining load

An experimental test is proposed in the present study to investigate the flexural behavior of damaged reinforced concrete (RC) beams strengthened by self-compacting concrete jacketing under different sustaining load. Eight RC T-beams with primary damages are designed and strengthened under different sustaining load. Then, the flexural testing test is employed to investigate the structural behavior of the strengthened beams. The influences of the sustaining load on beam response are clarified. The prediction method for the flexural capacity of the strengthened beams is also discussed. Results shows that the strengthening method proposed in the present study improves effectively the flexural behavior of beams, both in the stiffness after concrete cracking and the flexural capacity of the beams. Especially the flexural capacity, which becomes about twice as great. The interface treatment by surface roughening and rebar planting can provide effective bond strength between the substrate-new concrete. Sustaining load increase slightly the stiffness and the flexural capacity of beams until exceeding a critical value. The critical load was about 30% of the yield moment of beam before strengthening in the present test. The prediction of flexural capacity had high accuracy by the plastic limit analysis method and neglecting the strain-lag effects caused by the sustaining load during the strengthening process.