Experimental Investigation of RC Beams Reinforced with Saudi Steel Rebars under Different Tensile Strain Limits

In Saudi Arabia, although the steel reinforcing bars are manufactured by different processes that produce quite a large difference in yield strength ( ) values, they are being marketed and used as Grade 420 Rebars. It is due to this reason; there is a substantial probability that a beam that is designed to fail in a ductile mode (at reaching to limit state of collapse) may fail in a brittle manner, i.e., without enough warning of impending failure. A study that investigates the effect of on ductility of RC beams, reinforced with steel bars obtained by different processes of manufacturing, is, therefore, necessary. In the present study, the steel bars manufactured by the two Saudi companies, abbreviated as Rj and Sb, were used to reinforce sixteen RC beam specimens designed for different values of tensile strains at failure. The bars of these two companies possess the same specified yield strength (Grade 420) but differ substantially in their actual yield strength values. It was observed that, in general, Sb-steel reinforced beams show a more brittle response than their counterpart Rj-steel reinforced beams. The results of the experiments illustrated that to maintain the desired ductility for Sb-steel reinforced beams, Sb-steel should either be designated as Grade 500 (instead of Grade 420) pmax or limit should be reduced for this steel. One possible proposal for the reduction of limit for Sb-steel could be computing the maximum steel ratio corresponding to a tensile steel strain of 0.0065 (instead of 0.005). Limits for transition- and compression-controlled Sb-steel reinforced RC beam sections can also be modified accordingly