Repairing and Strengthening Earthquake Damaged RC Beams with Composites

The dominant judgment for earthquake damaged reinforced concrete (RC) structures is to rebuild them with the new ones. Consequently, this paper estimates if there is chance to repair earthquake RC beams and obtain economical contribution to modern day society. Therefore, the totally damaged (damaged in shear under cyclic load) reinforced concrete (RC) beams repaired and strengthened by externally bonded carbon fibre reinforced polymer (CFRP) strips in this study. Four specimens, apart from the reference beam, were separated into two distinct groups. Two experimental beams in the first group primarily tested up to failure then appropriately repaired and strengthened with CFRP strips. Two undamaged specimens from the second group were not repaired but strengthened by the identical strengthening scheme as the first group for comparison. This study studies whether earthquake damaged RC beams that have been repaired and strengthened will validate similar strength and behavior to equally strengthened, undamaged RC beams. Accordingly, a strength correspondence according to strengthened specimens was acquired for the repaired and strengthened specimens. Test results confirmed that repair and strengthening, which were estimated in the experimental program, were effective for the specimens with the cracking patterns considered in the experimental program. 





References:
<p>[1] Swamy RN, Jones R, Charif A. The Effect Of External Plate
Reinforcement On The Strengthening Of Structurally Damaged RC
Beams. The Structural Engineering 1989;67(3):45-
[2] Emmanuelle, D, Chafika, D., François, B, B., Repair and Strengthening
of Reinforced Concrete Beams Using Composite Materials 2nd
International PhD Symposium in Civil Engineering, 1998, pp. 1-8.
[3] Buyukozturk, O., Hearing, B., Failure Behavior of Pre-cracked Concrete
Beams Retrofitted with FRP, Journals of Composites for Construction,
1998, Vol. 2, pp. 138-144.
[4] Shamim, A., Sheikh, A., Derose, D., Mardukhi, J., Retrofitting of
Concrete Structures for Shear and Flexure with Fiber-Reinforced
Polymer,” ACI Structural Journal, 2002, Vol. 99, pp. 451-459.
[5] Jayaprakash, J, Samad, A, A, A., Abbasovich A, A., ,Abang, A, A, A,
Shear Capacity Of Precracked And Non-Precracked Reinforced
Concrete Shear Beams With Externally Bonded Bi-Directional CFRP
Strips,” Journal of Composites for Construction, Article in Press.
[6] Arduini M, Nanni A. Behaviour Of Pre-Cracked RC Beams
Strengthened With Carbon FRP Sheets, Journal of Composites for
Construction, 1997;1(2):14 043.
[7] ACI Committee 318. Building Code Requirements for Structural
Concrete, American Concrete Institute Committee, 2005, 430 pp.
[8] ACI 224.1R-93. Causes, Evaluation, and Repair of Cracks in Concrete
Structures, American Concrete Institute Committee, 1998, 22 pp.
[9] ACI Committee 440. State-of-the-art Report on Fiber Reinforced Plastic
(FRP) Reinforcement for Concrete Structures, American Concrete
Institute Committee, 1996, Detroit, Michigan, 68 pp.
[10] Tanarslan, H, M,. Altin, S,. Ertutar, Y,. The Effects of CFRP Strips for
Improving Shear Capacity of RC Beams, Journal of Reinforced Plastics
and Composites, 2008, Vol. 27, No. 12, 1287-1308
[11] Tanarslan, H, M,. Repairing&Strengthening of Earthquake Damaged
RC Beams with CFRP Strips, An Experimental Investigation, Magazine
of Concrete Research, 2010, No. 5, 365-378</p>