The effects of organic and inorganic pore-forming agents additives on the building materials

THE EFFECTS OF ORGANIC AND INORGANIC PORE-FORMING AGENTS ADDITIVES ON THE BUILDING MATERIALS Rasim CEYLANTEKİN Ceramics Engineering, Master Thesis, 2002 Supervisor: Assoc. Prof. Dr. İskender IŞIK SUMMARY In this study, after determining the characteristics of calcite-bearing (marl; also known as Southern clay) and clays without calcite (also known as Northern clay) from Baden- Wurttemberg (South Germany) and Essen and Westerwald (North Germany), the effects of organic and inorganic pore-forming agent on the physical-mechanical properties of these clays were investigated. 70ml paper, saw dust, polysterol, 0.6% (by weight) Syn-por and 4% (by weight) perlite were added to both clays and new recipes were prepared by using Syn-por, paper and sintering agent. Firing the brick samples at 960°C and 1000°C, thermo-physical, thermo- mechanical and physico-mechanical properties were investigated. According to chemical analysis done* by XRF method, north clays consists of Si02%68.75, A1203 %18.11, FeaOa %5.72 and south clay consists of Si02 %53.55, A1203 %15.39, CaO %14.29 and Fe203 %6.60 by weight. According to mineralogical analysis done by XRD, quartz, kaolen, illite, albite and microcline are present in both clays. Chlorite, calcite and dolomite were also determined in the south clay. In addition clay sized particles in south and north clays have been determined as 31% and 55% respectively. According to physico-mechanical tests, while paper, sawdust and Syn-por additives increase water absorption and appearing porosity values for both of the clays after firing 960°C and 1000°C, polysterol effects to a little extent and perlite causes a decrease. But except for Syn-por addition, all the additives causes a decrease both in dried and in fired strength while the recipes increase the fired strength values of the clays by about 150%. That's why Syn-por makes homogeneous dispersed and spherical pore morphology. Furthermore according to the thermal analysis, the addition of Syn-por not only decreases the decomposition temperature of calcite but also increases the silicate formation, and suppresses the negative effects of calcite bearing clays caused by the free CaO. Key Words: Brick, Calcite Bearing Clay (Marl), Porosity, Syn-por,