On ameliorating the residual strength of reinforced concrete panels subjected to elevated temperature

As retrofitting techniques are seeing widespread implementation in modern concrete infrastructure, a major concern in the construction industry is the residual material properties of retrofitting techniques after exposure to fire. This project presents the performance of these residual properties for a number of retrofitting methods subjected to dynamic loading conditions after fire exposure. Retrofitted and standard control specimens with dimensions of 600 × 600 × 100 mm, were exposed to a standard ISO 834 fire for 3 h or until failure. The specimens were then subjected to a dynamic loading and observations were documented. Using linear variable differential transformers (LVDTs) the displacement that each slab underwent during impact was recorded and tabulated, and used to calculate the residual impact energy absorption. The results demonstrate that ferrocement reinforced with polyethylene mesh best sustains its strength and stiffness after exposure to fire and impact.

► Residual RC strength of retrofitted elements after exposure to fire is the concern.
► Residual strength of various retrofitting techniques were assessed.
► Retrofitted RC slabs were exposed to fire and dynamic loading.
► Displacements during impact were used to assess the residual impact energy absorption.
► Ferrocement reinforced with polyethylene mesh sustains its strength after exposure.