Design and Behavior of RC Columns Incorporating High-Strength Materials

摘要

The current New Zealand concrete design standard, NZS 3101:1995, allows the use of higher strength materials than earlier editions. This standard has design provisions for structures with specified concrete compressive cylinder strength f′_c up to 100 MPa (14,500 psi). An exception is that for elements of earthquake resisting structures designed to be ductile, f′_c is limited to 70 MPa (10,200 psi). For all structures, high-strength steel. with a lower characteristic yield strength of up to 500 MPa (72,500 psi) is permitted for longitudinal reinforcement. High-strength steel is also permitted for transverse reinforcement and the maximum value for the steel yield strength allowed in design calculations is 500 MPa (72,500 psi) for shear reinforcement and 800 MPa (116,000 psi) for reinforcement for concrete confinement and lateral restraint of longitudinal bars against buckling. The permitted use of higher strength materials has come about as a result of the availability of such materials and the research conducted into their use in New Zealand and in other countries. This article describes some of that research and highlights the advantage of using high-strength concrete and steel reinforcement in columns.