Two Optimized Comminution Sequence tests have been carried to evaluate the effect of preconditioning induced by bench blasting in two different types of mortar, in a comminution process. The materials were collected from 15 small scale bench blasting tests on originally virgin material. All of them had 3 successively shot rows of 7 holes each and were of dimensions 660×280×210 mm with burden and spacing B×S = 70×95 mm. These tests allow comparing the specific surface created by the applied specific energy consumption required to crush and grind the 25-40 mm fractions of the blast fragmented mortar down to 1 mm size. The results obtained showed a reduction of about 11% and 15% for batch 2013 and batch 2014 respectively in specific energy consumption due to the blast preconditioning of the third row burden relative to the blasted burden of the first row.