Specimen 3 failed outside the constant moment region and in shear-flexure mode,

probably due to the lack of shear reinforcement in the area under the load point. This

mode was brittle and resulted in the complete collapse of the specimen (see Figs 5-15).

Concrete spelling was not observed prior to the failure of specimen 3 which was sudden

and abrupt.

 Specimen 4 was tested in a three point bending configuration and in that

configuration no constant moment region exists. The specimen experienced, in addition

to the bending moment, shear forces across its length. Specimen 4 failed close to mid-

span primarily in flexure. Some minor concrete spelling of the cover concrete did occur

prior to failure which supports the previous statement of a flexure failure. Concrete

spelling also indicates concrete confinement by the CFRP grid. Specimen 4 although

severely damaged did not collapse (see Figs 5-16). This was partially due to the

confinement provided by the CFRP grid.












 ah.




Figure 5-15. Specimen 3 after testing

 The behavior of specimens 3 and 4, which had CFRP flexural reinforcement

instead of GFRP, had two stages rather than the three stages of the previous specimens.