Defining structurally acceptable mechanical properties of high-strength reinforcing steel bars through low-cycle fatigue testing
Low-cycle fatigue tests were performed on high-strength reinforcing bars currently being developed in the United States, to quantify mechanical properties and fatigue life under simulated seismic conditions. Reinforcing bars with yield strengths ranging for about 60ksi to over 100ksi were tested. The high-strength bars with yield strengths exceeding 80ksi were obtained from three manufacturers that produce high-strength bars using the main three manufacturing techniques in use in the United States. Primary variables considered also include chemical composition, geometric deformations, bar grade, clear gripping span, loading protocol, and manufacturing process. The results of monotonic and cyclic tests are presented and comparisons are made based on the variables listed. A previously proposed fatigue model is considered and recalibrated for the new testing data.