Effect of grog addition on the properties and microstructure of a red ceramic body for brick production

In the present paper crushed fired brick waste, known as grog, was used in mixtures with clayey body to make typical red ceramics for bricks. The effect of the grog addition up to 20 wt% on the extrusion stage as well as on properties and microstructure of bricks fired at 700 °C was evaluated. The results indicate that the extrusion of the unfired clayey body was not impaired by the grog addition. Additions above 5 wt% decreased the mechanical strength of both the dry body and the fired ceramic pieces. This is associated with the increase in porosity during the firing stage due to the grog behavior.