  During the planetary formation process, mutual collisions among planetesimals
take place, making an impact on their porosity evolution. The outcome of these
collisions depends, among other parameters, on the tensile strength of the
colliding objects. In the first stage of this work, we performed impact
experiments into dust samples, assembled with material analogous to that of the
primitive Solar System, to obtain highly compressed samples that represent the
porosities measured in chondritic meteorites. In the second stage, we obtained
the tensile strengths of the compressed dust samples by the Brazilian Disk
Test. We found a correlation between the tensile strength and the volume
filling factor of the compressed dust samples and obtained the corresponding
critical fragmentation strength in mutual collisions and its dependence on the
volume filling factor. Finally, we give prescriptions for the catastrophic
disruption threshold as a function of the object size, for different values of
the volume filling factor that can be utilized in collisional models.
