The effect of expanded perlite on fired clay bricks

Abstract

Abstract Nowadays stricter energy regulations are compelling us to further improve the thermal insulation performance of current building materials. In this study we investigated the possibility of improving the thermal insulating performance of fired clay bricks. In our work we used two types of additives: sawdust, which is a general additive, and expanded perlite, which is typically a synthetic additive based on SiO2 and Al2O3. Sawdust and expanded perlite in amounts varying between 3.35-6.5 wt% were mixed into a clay masses to prepare test samples by pan mill. The moisture content of the clay masses was 25 wt%. Samples were prepared using a laboratory vacuum extruder, after which they were dried, and then sintered at 880 °C. The fired specimens were measured for firing shrinkage, water absorption, bulk density, and compressive strength. Furthermore, we determined the thermal conductivity of the specimens. The purpose of our research was to examine the usability of expanded perlite as an additive in brick manufacturing, and also to compare the results with sawdust, one of the most popular additives. In addition, measurements were made using the two additives together.