Database trends and critical review of seismic performance tests on high strength steel reinforced concrete components

The use of High Strength Steel (HSS) reinforcement in concrete construction is emerging rapidly, especially in high performance concrete applications. The ACI 318-19 code has permitted the use of HSS reinforcement Grades 80 (550 MPa) and 100 (690 MPa) in earthquake-resistant concrete components. This change was motivated by recent experimental and analytical research to assess the benefits and drawbacks of using HSS reinforcement in seismic design of concrete. The use of HSS reduces bar congestion and provides more effective confinement to concrete, however, great attention must be paid to its drawbacks. Examples of such drawbacks are lower hysteretic energy, higher bond stresses, lower plasticity spread due to local strain concentrations, and potential for premature confined concrete crushing before full utilization of HSS full capacity. This study reviews past experimental research on cyclic performance of various concrete structural components reinforced with HSS, including columns, beams, beam-column joints, walls, and coupling beams. In addition, a comprehensive database of cyclic tests on HSS reinforced components is established, presented and evaluated. An HSS reinforced flexural section parametric study is performed to aid in interpreting database trends and literature results. The effect of HSS design parameters and cyclic response measures of these components such as load-deformation relationships, strength, curvature and strains, ductility and energy dissipation capacity are discussed and compared to their conventional steel reinforced concrete counterparts based on literature and the database trends observed. The database and the cyclic behavior observations presented may serve as basis for future experimental and analytical studies concerned with characterizing seismic response, modeling and design of HSS reinforced concrete components.

Automated summary

The use of High Strength Steel (HSS) reinforcement in concrete construction has been rapidly increasing, especially in high performance concrete applications. Recent experimental and analytical research has led to the approval of the use of HSS reinforcement Grades 80 and 100 in earthquake-resistant concrete components. While HSS reinforcement offers benefits such as reduced bar congestion and more effective concrete confinement, attention must be paid to drawbacks such as lower hysteretic energy and potential for premature confined concrete crushing. Various concrete structural components reinforced with HSS have been studied, and a comprehensive database of cyclic tests on HSS reinforced components has been established and evaluated to aid in future experimental and analytical studies on seismic response and design of HSS reinforced concrete components.