Marble-Looking Fired Clay Tiles Produced by Utilizing Local Clay and Glass Cullet

This research is aim at developing marble-looking fired clay tile by utilizing waste glass cullet (CGC) mixed up with local plastic clay, sediment soil, and laterite clay. Boric oxide is also used as sintering aid. The experimental formulation is divided into 3 groups (A, B, and C) with 27 formulas. Test samples are moulded at 100 bar by Uni-axial pressing in dimension 50 x 100 x 7 mm and fried at temperature 850 °C. The initial results show that all formulas can develop marble texture and achieve Thai Industrial Standard TIS 2508-2555. Reducing firing temperature to 800 °C is the further investigation. However, formulas consisting 90% glass cullet are not selected, due to difficulty of molding workpieces. The final results of firing 800 o C show that formula A6 containing 15% Plastic clay, 85% glass cullet, 2% boric oxide has the highest bending strength and lowest water absorption (<1%). Its properties are similar to formula C6 containing 15% laterite soil 85% glass cullet, 2% boric oxide. They can pass Thai Industrial Standard TIS 2508-2555 Floor Tiles BI b . Analyzing microstructure the fired specimens of these formulas by Scanning Electron Microscope has found glassy phases and dense matrix structures. Furthermore, Nepheline, Quartz, Cristobalite, Wollastonite, Devitrite, and Albite are identified by X-Ray Diffractometer. It can be summarized that marble texture surface fired clay tile can be developed by utilizing waste glass and low cost local materials.