The spherical blast wave generated by the detonation of a heterogeneous explosive charge has been investigated experimentally and numerically. The charge consists of a packed bed of metallic particles saturated with a liquid explosive. When the charge is centrally detonated, the blast wave generated by the explosion differs from that of an ideal homogeneous explosive due to the interaction of the dispersed particles and their combustion with the gaseous flow field. When the blast wave trajectories are plotted in energy-scaled coordinates, the nonideal blast waves for the heterogeneous explosives are displaced relative to the homogeneous case. For the heterogeneous charge, the energy is released in two steps, i.e., first from the detonation of the high explosive and a secondary energy release due to afterburning of the particles with the combustion products or surrounding air. Experimental results are presented for the blast wave pressure and impulse for heterogeneous charges containing spherical magnesium particles and a liquid explosive, with variations in both the particle size and charge diameter.