High strength concrete (HSC) has become a commonly used material over the last decades, in particular in tall buildings where it allows to increase the net marketable area. As it carries loads more efficiently than normal strength concrete (NSC), it is also specified where architectural considerations call for small support elements. The reduction in member size that can be obtained with HSC results in an increase in usable area. Alternatively, for a fixed column size, longer spans can be supported which leads to a reduced number of supports. HSC also provides advantages in terms of durability. These advantages have resulted in the increased use of HSC observed lately in various applications of civil engineering.An important requirement for building structures is the performance under fire situations. Previous research has shown that HSC behaves differently than NSC at elevated temperature (Phan and Carino, 1998). The most notable differences regard the relative loss of compressive strength with temperature and the occurrence of spalling. For these two aspects, the performance of HSC is lower than that of NSC, i.e. HSC experiences higher rates of strength loss with temperature and a higher susceptibility to spalling. In addition, HSC is often used to reduce the size of structural members. However, this reduction may be detrimental to the fire performance as it leads to faster temperature increase in the section core of the members, and in-