Utilization of ceramic waste powder in self-compacting concrete

Self-compacting concrete (SCC) mixtures include high powder content (i.e. 450-600 kg/m³) which is needed to maintain sufficient stability/cohesion of the mixture and hence improving segregation resistance. The use of high cement content to meet the need of high powder is not desirable as it will increase the cost and has other negative effects on concrete properties. The requirement for high powder content in SCC is usually met by using mineral admixtures such as slag, fly ash and/or less reactive filler materials such as limestone powder and granite powder. Ceramic waste powder (CWP) produced during the polishing process of ceramic tiles are dumped in landfills and can cause soil, air and groundwater pollution making a serious environmental problem. CWP is characterized by its fine particles’ size and chemical composition which is mainly SiO2 and Al2O3 (i.e. more than 80%). This makes CWP a very good candidate to be used as filler in SCC. Therefore, the utilization of CWP would achieve sustainable SCC with strong environmental incentives. In this study the utilization of CWP in making SCC is evaluated. The study involves two experimental phases. In the first phase; the main characteristics of the ceramic waste powder (i.e. chemical composition, specific surface area and scanning electron microscope) are examined. In the second phase; the effect of using CWP on fresh concrete properties and mechanical properties of SCC are investigated. It is found that CWP can be used to successfully produce SCC mixtures with improved fresh and hardened concrete properties.