**7. Ductility ratio**

A better measure of the mechanical property of a rebar, and that of the performance of a concrete flexural element, reinforced with such a bar, would have been the ductility ratio rather than the arbitrarily selected percent elongation.

Assuming that the percent elongation will be at least large enough to ensure that the specified yield strength and the specified ultimate strength of the bar will be achieved, the only other useful information that a percent elongation may provide is a vague understanding that the bar may not break during necessary bending.

That should suggest that vaguely specified percent elongation is an unnecessary specification when separate tests for bending of bars are specified.

In contrast, while tests for yield and ultimate strengths (stresses) will ensure the said strengths (stresses), the information on ductility and the shape of the

load-deformation plot of the bar beyond yield will provide important information on an idea about the bendability of a rebar. And in addition, the ductility ratio, coupled with a plot of the load-elongation curve of the bar will provide a great deal of information about the performance of a flexural element beyond the yield stress level of the rebar, provided that the rebar will have the requisite "engagement" with concrete, and it happens best in the case of PSWC-BARs; Kar [2].
