Strength evaluation of a fire damaged concrete slab: combined correlation approach

Strength evaluation of fire damaged concrete is not well studied although fire damaged concrete is encountered in many settings. There are limited studies that investigate the effect of physical properties on the strength of fire damaged concrete. In this paper, a fire damaged concrete slab element is evaluated based on non-destructive (rebound hammer and impact pulse velocity) and destructive (core and porosity) testing. Two correlation models are developed to assess the compressive strength of the slab element. The first model correlates the corrected core compressive strength to rebound number, impact pulse velocity and porosity. The second model correlates the corrected core compressive strength to rebound number and impact pulse velocity. Both correlation models are based on Pearson's statistical approach. The two correlations are compared based on William's modification of the Hotelling test and results indicate that rebound number, impact pulse velocity and porosity combined correlates more significantly to the corrected core compressive strength than rebound number and impact pulse velocity alone.