High (HPC) and ultrahigh performance concrete (UHPC) is playing a more and more important role in civil engineering. However, when these concrete are subjected to fire, the high temperature might cause spalling, which significantly decrease the mechanical properties of the material, influencing the structural performance. It is important to study the spalling behavior of high and ultrahigh performance concrete.

The results of many experiments and analysis on explosive spalling of HPC and UHPC shows that high pore pressure and low permeability are the key factors of spalling. However, the mechanisms are still under investigation. In consideration of the high cost of experiments and the advantage of numerical simulation, simulations predicting the spalling behavior will be carried out. The influence of several parameters (pore pressure, permeability, pore size) on the simulation of concrete panels will be studied and compared with the experiments result. The results of the numerical calculations in addition to the comparison will permit the development of a simulation strategy for spalling behavior of high and ultrahigh performance concrete.