Abstract: BFRP tendon reinforced un-bonded full post-tensioned and partially post-tensioned concrete beams were prepared, the differences in the flexural behaviors of the concrete beams was studied with non-pre-stressed bars as references. The influence of reinforcement ratios of non-pre-stressed steel bars on the flexural behavior of un-bonded partially post-tensioned concrete beams was analyzed. It showed that, the cracking resistance, crack widths, and deflections of concrete beams were greatly improved by BFRP tendons, resulting in better serviceability. The ductility of partially post-tensioned concrete beams was better than that of full post-tensioned beams, and the yield loads and ultimate loads was enhanced as the reinforcement ratios of non-pre-stressed steel bars increased, whereas the crack intervals and ultimate crack widths was decreased.

Key words: basalt fiber reinforced plastic bar, unbondedness, full post-tensioned, partially post-tensioned, concrete beam, post-tensioned method, lexural behavior