Investigation of brick products made with lightweight aggregates

Abstract

In this study, the effect of expanded perlite on the performance of fired clay bricks was investigated. This additive material is in other areas of the construction industry such as lightweight concrete production in use. The reason for its popularity is based on the excellent thermal insulation properties of expanded perlite. In the experiments, different clay masses were prepared by pan mill. The moisture content of the clay masses was set to 25 wt% in each case. The amount of expanded perlite was varied between 2,5-6,5wt%. Cylindrical samples were prepared by a laboratory vacuum extruder and then the dried samples were sintered in a laboratory furnace at 880 °C. Results showed that the density of fired samples decreased from 1855 to 1695 kg/m³ by increasing the amount of perlite. Samples without perlite had an average compressive strength of 32MPa which decreased down to 27MPa with the mixing of perlite. The amount of perlite had no relevant effects on compressive strength. This is out of accordance with the effect of organic pore-forming additives which significantly lower the compressive strength.