This study investigated the influences of the particle size distribution (characterized by the amounts of fines and coarses and by the maximum particle size (1|3 mm)) and the compaction pressure (50|100 MPa) of die-pressed bars on the behavior of the bulk density, cold modulus of rupture (CMOR) and Young’s modulus E during five thermal shocks (TS). Highest densities were obtained for wide particle size distributions with densest packed coarse aggregates, a slight excess of lubricating fines and a high compaction pressure. Highest CMOR and E were obtained for the same parameters with the exception of a maximum particle size of 1 mm inducing lower flaw sizes. Independent on the compaction pressure, lowest CMOR losses during TS were obtained for a wide particle size distribution with a high number of aggregates constituted of medium-sized grains and densest packed coarses. Supposedly, crack deflection and contact shielding toughening occurred. During TS, E behaved differently. Probably, E was low when there were many flaws. During TS, these led to a large process zone and high decrease of E whereas for batches with higher initial E a crack could propagate with less microstructural interactions giving supposedly a smaller process zone and a reduced decrease.