Psyllium Seeds Used as Pore Forming Agent in Clay Bricks

Psyllium seeds were used as a pore forming agent in clay mixtures due to their properties to swell in the presence of water in a similar way with clays. The purpose of the study it was to establish the optimal quantity of psyllium seeds that can be added as pore forming agent in clay bricks to maintain the mechanical properties required. The physical properties of clays and of the psyllium seeds were analyzed, and then psyllium seeds were added in clay matrix in percentages of 5, 10, 15 of volume. The compressive strength and water absorption were determined for each sample. The pore size distributions were measured by using image J software and analyzed microscopically. The texture, the porosity and the fissure/cracks size are directly influenced by the amount of psyllium seeds contained in the clay mixtures. Reducing the pore forming agent to 5%, the tendency of cracking decreases and suggests that the mixture can be used in clay bricks manufacturing.