Application of spent grains to increase porosity in bricks

The dumping of spent grains is going to be more difficult because of the increasing number of cattle. That means new ways of dumping must be developed. The goal of the work was to test the technical properties of bricks produced with spent grains added to increase porosity. The flexural strength of the fired samples remained at 8.5 MPa; the air-dried samples exhibited a small increase in flexural strength. The shrinkage and true density were almost identical, while the raw density, capacity for water absorption and open porosity showed minor differences. In the large-scale experiment no problems were observed during the production. The bricks produced with spent grains possessed a comparable or higher strength, a higher porosity and a reduced density after firing than those from a standard production clay. Because of the lower sintering temperatures the fired clay product was more strongly sintered, exhibiting both greater strength and higher porosity. (C) 2004 Elsevier Ltd. All rights reserved.