FLEXURAL BEHAVIOR OF REINFORCED CONCRETE BEAMS STRENGTHENED WITH CARBON-FIBER-REINFORCED POLYMER LAMINATES AT DIFFERENT LEVELS OF SUSTAINING LOAD. DISCUSSION AND CLOSURE

A discussion of a prior paper with the aforementioned title by Y. Shin and C. Lee, published in this journal (Volume 100, Number 2, March-April 2003), is presented. The discusser acknowledges the importance of conducting a large-scale experimental program to further the quality of strengthening reinforced concrete (RC) structures with carbon fiber-reinforced polymer (CFRP) laminates. The paper presents an innovative idea of strengthening at the different levels of sustaining loads. Significance of this work to help structural engineers in strengthening RC elements under sustained load in practice is stressed by the discusser. However, the discusser believes that certain aspects of the paper need to be reexamined, with some key details presented relating to steel reinforcement location from compression edge of the beam, cross section and Young's modulus of CFRP laminates, loading location, compression relationships, and tension steel reinforcement. Closure from the authors is also included.