Effect of addition of glass waste on masonry ceramics

Abstract

This work investigated the effect of the addition of glass waste to the manufacture of masonry ceramics. Was conformed cylindrical samples with 27 mm in diameter by 45 mm in height were made from the standard mass of a hard clay ceramic industry and other 3 formulations (5, 10 and 20 %) with glass incorporation, based on studies presented in the literature. The heat treatment was carried out in a muffle at three temperatures (800, 900 and 1000 °C). The technological properties evaluated were: linear drying shrinkage and linear firing shrinkage, water absorption, fire loss and mechanical resistance to compression. It was observed that the drying retraction decreased from 7.9 to 5.9 % with the increase of the glass content added. The addition of glass waste to the ceramic mass did not significantly interfere with the retraction of burning at 800 and 900 °C, but increased significantly at 1000 °C, as well as water absorption was reduced considerably at 1000 °C. The addition of glass waste reduces the resistance to compression of the ceramic pieces by up to 4.4 MPa, but the values found were within the established by norm. The composition with addition of 20 % of sintered glass waste at 900 °C reached a value of 6 MPa, value greater than 1,5 MPa for standard to hollow ceramic block for non-load-bearing. At 1000 °C was observed the occurrence of overfiring, which leads to the appearance of bubbles and deformation. The addition of up to 20 % of glass residue to the ceramic mass for sintered masonry at 900 °C presents values acceptable by the Brazilian standard, of the technological properties evaluated, with the advantage of reducing the tendency to cracks and dimensional variation, besides contributing to the reduction of the use of virgin raw materials and of giving a sustainable destination to a waste.