Abstract

Fire accidents result in a rapid increase of temperature especially in underground structures such as tunnels where temperatures of 1400 °C within 5 min can occur. This leads to severe damage of concrete due to strength loss and explosive fire spalling. The prediction of the process and final extent of explosive spalling is crucial for the designing and retrofitting of structures but accurate models and experimental procedures are still lacking.

In this presentation we will talk about the challenges of fire testing and address the following:

The application of the thermal loading in fire tests is of crucial importance, as the temperature history strongly affects the risk and extent of explosive spalling. The range of material and environmental properties present in real-life situations needs to be captured and considered for the experimental planning of fire tests.

Furthermore, we will discuss results obtained from fires test on different concrete mixtures and try to answer the following questions:

Is it possible to identify key parameters triggering explosive spalling? How does the water content and the permeability influence spalling? How can we proceed to assess the risk and extent of spalling?