Michel KIMUHA KIRUMBA* and Richard VALL RICARDO

This study investigates experimentally the uniaxial stress-strain behavior of reinforcing steel bars under various low strain rates, quasi-static from 0.001 12 s-1 to 0.006 70 s-1. The main objective of these tests was to give an indication of the effect of the low strain rate variation on the uniaxial, monotonic, stress-strain, elongation-strain, section reduction-strain curves of reinforcing steel bars. The results of the tensile tests indicate that the yield strength and the ultimate tensile strength of reinforcing steel bars increase as the strain rate increases; while the elongation and section reduction of reinforcing steel bars do not appear to be substantially affected by the low strain rate variation. It was also observed that the smaller reinforcing steel bars were more affected by low strain rate variation, although sometimes inconsistently, than the relatively bigger ones. Thus, one should be more precautious while testing smaller reinforcing steel bars. Furthermore, a new regression formula is proposed for both yield strength and ultimate tensile strength with an “R squared” of 80%. This formula may be used as a means by which some quick verifications and checking may be done. Télécgarger l'article