Investigation of the usability of industrial ceramic wastes in geopolymer mortar production

The ceramic industry plays a major role in our country's economy and is going through a period where raw material search and extraction processes are weak in this sector and this may lead to disadvantages in the long term. Our country, which has a say in ceramic production in the world, generates approximately 320 thousand tons of ceramic waste annually. These wastes have negative effects on the environment. This study offers a solution for recycling and re-evaluating ceramic waste. The usability of ceramic wastes in cement-free mortar production is investigated. This approach aims to use ceramic wastes sustainably and reduce their environmental impacts. The study examines how different ceramic wastes (filter-press cake waste, vitrified waste and pottery waste) can be used in cement-free mortars and the effects of this use on physical and microstructural properties. In this study, ceramic wastes were studied in different mass ratios (100/0; 75/25; 50/50; 25/75; 0/100) in the prepared geopolymer mortars and sodium hydroxide and sodium silicate were used as activators. Geopolymers were produced with two different thermal curing periods of 6 and 24 hours at 90°C. The flexural and compressive strength values of the mortars were recorded separately before and after exposure to 400, 600 and 800°C. In addition, crystal phase (XRD) and microstructure analysis (SEM/EDX) were performed on the selected mortars before and after exposure to high temperature. The initial strength values of the geopolymers produced with 24-hour thermal curing were higher, but the 6-hour thermal curing values were determined to be close, which will provide advantages in terms of time and energy consumption. In this study, it is emphasized that using ceramic waste instead of fly ash used in cement-free mortars will reduce costs and provide a solution to the waste problem of ceramic factories. It also aims to combine academic and industrial perspectives by encouraging industry-university cooperation.