Sawdust and grapes and cherries seeds, thanks to their organic substances content, during their combustion,
bring an energetic support in the bricks firing phase and act as pore forming agent. Usually the
addition of this kind of waste is limited to 10 wt.% in order to reach an equilibrium between positive
(weight and shrinkage decrease and porosity increase) and negative (increase of water absorption and
mechanical resistance decrease) effects. The results show that grapes and cherries seeds, added in a percentage
of 5 wt.% to a brick formulation, have better influence with respect to the sawdust, maintaining
the mechanical properties of the fired brick (950 C), showing modulus of rupture around 21–23 MPa
with a weight reduction of 3–10% (respect to the standard one). Regarding the sugar cane ash, the addition
of 5 wt.% improves the mechanical properties (modulus of rupture around 27 MPa) and no weight
decrease is observed. These results confirmed the role played by this kind of agricultural waste, which
thanks to its high silica content (61 wt.%) is capable to demonstrate a filler and plasticity reducing effect
on the brick bodies. Tests carried out highlighted that the addition of these by-products (5 wt.%) do not
change negatively the main technological properties measured (water absorption, linear shrinkage, flexural
resistance, etc.) and permit to hypothesize their use to obtain bricks with both insulating and higher
mechanical properties using a pore agent forming or silica carrier alternative raw materials, respectively.