Characterization of Clay brick materials produced with red mud and nut shell wastes for building applications

In this study, clay based brick with micro pores was developed for thermal insulation in the building materials. Turkey produces about 70% of the world hazelnut production. The aim of this thesis is to reduce the thermal conductivity coefficient by adding organic waste (hazelnut shell) into clay mixture to form porosity during firing of clay bricks. Moreover, it is to maintain the similar mechanical properties by adding inorganic waste (red mud) into clay mixture. The development of a highly porous bricks with applicable mechanical strength will contribute to save energy in the building. The physical, mineralogical, microstructural, thermal and mechanical properties of bricks contributing waste were investigated. Clay based brick structures which are produced from ceramic raw materials that have large compositions, can tolerate many waste materials with similar composition. Low water content (about 15% by weight) were applied to the clays used in the mixtures. In this work, dry brick mixtures were prepared by adding (2.5%, 5%, 7.5% and 10% by weight) hazelnut shell and (5%, 10%, 15%, 20% and 30% by weight) red mud to the clay. The mixtures containing brick clay with hazelnut shell and red mud addition were prepared in a mechanical mixer. The mixtures were pressed, dried and then fired to obtain the highly porous durable structure. Highly porous ceramics from the mixtures with up to 10% hazelnut shell and up to 30% red mud addition was successfully produced. Thermal conductivities of the samples decreased from 0.78 W/mK (1.80 g/cm3) to 0.45 W/mK (1.41 g/cm3) with increasing hazelnut shell and red mud addition. The lowest compressive strength of 9.12 MPa was found, it is appropriate for usage. This study is an important study for recycling of waste in the thermal insulating lightweight brick production