Fire Performance of High-Strength Concrete Structural Members

High-strength concrete (HSC) provides a high level of structural performance, especially in strength and durability, compared to traditional, normal-strength concrete (NSC). Previously employed in bridges, offshore structures and infrastructure projects, HSC has seen increased use in high-rise buildings, especially for columns. The higher compressive strength of HSC allows for the use of smaller-diameter columns, which increases the amount of usable space in a building. In building design, the provision of appropriate fire resistance for structural members is a major requirement. The fire resistance of a structural member is dependent on its geometry, the materials used in its construction, the load intensity and the characteristics of the fire itself. The recent version of CSA Standard CSA-A23.3-M94 (“Design of Concrete Structures”) provides detailed provisions for the design of HSC structural members. However, there are no specific guidelines for evaluating the fire performance of HSC in either this standard or the National Building Code of Canada 1995 (NBC).